is ftl travel possible

• Gameumentary
• Review in 3 Minutes
• Design Delve
• Extra Punctuation
• Zero Punctuation
• Area of Effect
• Escape the Law
• In the Frame
• New Narrative
• Out of Focus
• Slightly Something Else
• Privacy Policy
• Terms of Use
• Affiliate Policy

5 Faster-Than-Light Travel Methods and Their Plausibility

Science tells us that it is impossible for an object to travel at light speed, let alone faster than that. But so many of our favorite science-fiction movies, games, and TV shows rely on faster-than-light travel to craft their interplanetary adventures.

Let’s take a look at five means of FTL found in sci-fi that don’t break the rules of relativity and examine how plausible they are based on the science behind them.

1. Hyperdrive

Popularized by Star Wars and used extensively in fiction, a hyperdrive enables a spaceship to travel at FTL speeds by entering another dimension known as “hyperspace.” The spaceship isn’t actually traveling faster than the speed of light, but rather is making use of hyperspace as a shortcut, and the hyperdrive is the mechanism that shunts the spaceship into and out of this parallel dimension.

Specific coordinates within hyperspace have corresponding coordinates in normal space, but the distance between those two points will be shorter in hyperspace, allowing for a faster journey. Before making a “hyperspace jump,” calculations must be made to find the matching coordinates between hyperspace and normal space in order to know when and where to exit hyperspace at the desired normal space destination.

Is it plausible?

Physicist Bukrhard Heim proposed a theory in 1977 that FTL travel may be possible by using magnetic fields to enter higher-dimensional space. The theory uses a mathematical model that calls upon six or more dimensions in an attempt to resolve incompatibilities between quantum mechanics and general relativity, but Heim’s ideas have not been accepted in mainstream science. Still, the fact that a theoretical physicist devoted a large portion of his life in pursuit of a theory that could lead to a means of space travel lends the concept of hyperspace a little more credibility than if it were simply the fancy of a sci-fi writer.

2. Jump Drive

Seen in such works as Battlestar Galactica , a jump drive allows for instantaneous teleportation between two points. Similar to a hyperdrive, coordinates must be calculated to ensure a safe jump; the longer the desired travel distance, the more complex the calculation. In theory, there is no limit to how far a jump can take a ship, but an incorrect calculation may result in a catastrophic collision with a planet or space debris.

The Dune universe’s FTL, based on the fictional “Holtzman effect,” can also be considered a jump drive.

Master of hard sci-fi Isaac Asimov was the first to suggest the idea of a jump drive in the Foundation series, which lends some credibility to the idea. However, most fiction doesn’t clearly explain the principles of physics that allow for this teleportation, making it impossible to claim a jump drive as plausible. However, if it functions by opening a wormhole…

3. Wormholes

A wormhole, as seen in the Stargate franchise, allows for near-instantaneous travel across vast distances. Wormholes may be naturally-occurring or man-made, but are almost always temporary and serve as tunnels through spacetime.

Imagine our universe as a piece of paper, and an ant walking on that piece of paper as a spaceship. If the ant wants to walk from one end of that piece of paper to the other, the fastest way to do so would be to travel in a straight line. But paper, like space, bends. If you bend the paper into a U shape, the ant’s journey goes largely undisturbed – it still has to traverse the same distance along that line. However, in 3D space, the two ends of the paper are very close to each other now. Cut off a piece of a drinking straw and let the ant use it as a bridge or tunnel between the two ends of the paper, and the journey is suddenly much shorter.

While we have never directly observed any evidence for one, wormholes are theoretically possible. Albert Einstein and his colleague Nathan Rosen first discovered wormholes in 1935 as solutions to equations within Einstein’s general theory of relativity – the math says they can exist.

Since then, other scientists, including Stephen Hawking, have argued that it may be possible to traverse a wormhole, under the right circumstances. The debate surrounding wormholes isn’t about their plausibility, but rather how they may be created and sustained.

4. Slipstream

The concept of slipstream can be found in such works as Star Trek , Doctor Who , and the Halo video game franchise, but there is no widely-agreed upon definition of what slipstream is or how it works beyond it being a means of FTL. We’ll consider the slipstream seen in Gene Roddenberry’s Andromeda , where it is “not the best way to travel faster than light, it’s just the only way,” as per the show’s protagonist.

Slipstream is a form of interdimensional highway in which ships ride a series of slipstream “strings” – the unseen connections between all objects in the universe. These strings are in constant flux and form a tangled mess of intersections and divergent paths. Any time a pilot reaches a fork in the road, he has to guess which is the correct path to take to continue along toward his desired destination. Before the pilot makes that decision, both paths are simultaneously the correct and incorrect route, and it is the act of choosing a path that forces one to be correct and the other to be incorrect – if this made you think of Shrödinger’s cat, that does seem to be the basis for this concept. A computer selects the “correct” path 50% of the time, but due to intuition, a human picks the correct path 99.9% of the time.

There are no mainstream scientific theories that support this idea of slipstream. Reading the “lore” of this means of FTL evokes fantastical interpretations of string theory, quantum entanglement, and other concepts in modern physics, but the ideas are supported only through their internal consistency rather than actual fact, much like a well-explained magic system that allows fictional wizards to cast spells.

5. Warp Drive

Popularized by Star Trek , a warp drive distorts space around a ship while leaving the ship itself inside a “bubble” of normal space. The space in front of the ship is contracted, while the space behind it is expanded, and the ship “rides” the distortion wave at FTL speeds. Technically, it is not the ship that is moving, but rather space itself, which is how we avoid breaking any laws of physics.

Imagine a surfer slowly paddling back to shore. When a wave comes, it will lower the water level in front of him and raise the water level behind him, and he can ride the downward slope all the way to shore. Relative to the wave, the surfer isn’t moving – he’s staying between the crest and the trough, and it is instead the wave that is moving.

Surfing doesn’t quite work like that, but it’s a simplification that we can all visualize. In a similar manner to how a wave will distort water to propel a surfer, a warp drive will distort space to propel a ship.

In 1994, the Alcubierre drive was proposed as a theoretical means of FTL travel and is based on a mathematical solution to equations within Einstein’s general theory of relativity. Just like a warp drive, the Alcubierre drive would contract space in front of a spaceship and expand space behind it.

NASA has been actively researching this technology since 2012 , and the lead researcher even worked with a 3D artist to develop a model of what a warp-capable ship might look like . As far as real-life FTL goes, warp is the current front-runner to becoming reality.

As far as real-life FTL travel goes, the fictional favorites can be found in Star Trek and Stargate : the warp drive, and wormholes. Both are theoretically possible; however, both require further scientific breakthroughs before practical testing can begin. In either case, we need to discover “exotic matter” – hypothetical particles with negative mass – to get these mechanisms to work. “Element zero” from the Mass Effect series, the rare material that is essential to FTL travel in that universe, doesn’t quite fit the description, but the lore is at least scientifically sound in suggesting that some new, rare form of matter is required to make this technological leap.

The good news is that scientists don’t believe this is a matter of if, but rather when. There will be a time in the future when a stately, bald man in uniform will sit back in a command chair and relay the order, “Engage.”

We have completed maintenance on Astronomy.com and action may be required on your account. Learn More

• Login/Register
• Solar System
• Exotic Objects
• Upcoming Events
• Deep-Sky Objects
• Observing Basics
• Telescopes and Equipment
• Astrophotography
• Space Exploration
• Human Spaceflight
• Robotic Spaceflight
• The Magazine

Warp drives: Physicists investigate faster-than-light space travel

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away, or about 25 trillion miles (40 trillion kilometers). The fastest ever spacecraft, the now- in-space Parker Solar Probe will reach a top speed of 450,000 mph. It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earth’s nearest neighboring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimov’s Foundation series , humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characters – like the astronauts in the movies “Interstellar” and “Thor” – use wormholes to travel between solar systems in seconds. Another approach – familiar to “Star Trek” fans – is warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

Compression and expansion

Physicists’ current understanding of spacetime comes from Albert Einstein’s theory of general relativity . General relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime – hefty objects like stars and black holes curve spacetime around them. This curvature is what you feel as gravity and why many spacefaring heroes worry about “getting stuck in” or “falling into” a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? “Star Trek” took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity . So, what does that mean? Imagine the distance between two points is 33 feet (10 meters). If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, let’s say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second. In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from “Star Trek” was in fact theoretically possible.

Proxima Centauri here we come, right? Unfortunately, Alcubierre’s method of compressing spacetime had one problem: it requires negative energy or negative mass.

A negative energy problem

Alcubierre’s warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative mass – a theorized type of matter – or a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierre’s warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe .

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly , to just about the mass of the Sun. A significant improvement, but still far beyond all practical possibilities.

A sci-fi future?

Two recent papers – one by Alexey Bobrick and Gianni Martire and another by Erik Lentz – provide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realized that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of general relativity, and by doing so, he found that a warp drive wouldn’t need to use negative energy. Lentz’s solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I won’t fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard , things are only impossible until they are not.

Space weather forecasting needs an upgrade to protect future Artemis astronauts

William Anders, NASA Astronaut and US Air Force Major General, dies at 90

The People’s Spaceship: NASA, the Shuttle Program, and Public Engagement after Apollo

Why do pictures of Earth taken from the Moon show a black sky with no stars?

Oleg Kononenko reaches a record-setting 1,000 days in space

Boeing starliner launches nasa astronauts on mission to the iss.

What Is Polaris Dawn? The upcoming SpaceX mission, explained

Why Boeing’s Starliner launch is an important milestone for commercial spaceflight

SpaceX adds tourism offering to website

New warp drive research dashes faster than light travel dreams – but reveals stranger possibilities

Associate professor, Australian Catholic University

Disclosure statement

Sam Baron receives funding from the Australian Research Council.

Australian Catholic University provides funding as a member of The Conversation AU.

View all partners

In 1994, physicist Miguel Alcubierre proposed a radical technology that would allow faster than light travel: the warp drive , a hypothetical way to skirt around the universe’s ultimate speed limit by bending the fabric of reality.

It was an intriguing idea – even NASA has been researching it at the Eagleworks laboratory – but Alcubierre’s proposal contained problems that seemed insurmountable. Now, a recent paper by US-based physicists Alexey Bobrick and Gianni Martire has resolved many of those issues and generated a lot of buzz .

But while Bobrick and Martire have managed to substantially demystify warp technology, their work actually suggests that faster-than-light travel will remain out of reach for beings like us, at least for the time being.

There is, however, a silver lining: warp technology may have radical applications beyond space travel.

Across the universe?

The story of warp drives starts with Einstein’s crowning achievement: general relativity. The equations of general relativity capture the way in which spacetime – the very fabric of reality – bends in response to the presence of matter and energy which, in turn, explains how matter and energy move.

General relativity places two constraints on interstellar travel. First, nothing can be accelerated past the speed of light (around 300,000 km per second). Even travelling at this dizzying speed it would still take us four years to arrive at Proxima Centauri, the nearest star to our Sun.

Second, the clock on a spaceship travelling close to the speed of light would slow down relative to a clock on Earth (this is known as time dilation). Assuming a constant state of acceleration, this makes it possible to travel the stars. One can reach a distant star that is 150 lightyears away within one’s lifetime. The catch, however, is that upon one’s return more than 300 years will have passed on Earth.

This is where Alcubierre came in. He argued that the mathematics of general relativity allowed for “warp bubbles” – regions where matter and energy were arranged in such a way as to bend spacetime in front of the bubble and expand it to the rear in a way that allowed a “flat” area inside the bubble to travel faster than light.

Read more: Don't stop me now! Superluminal travel in Einstein's universe

To get a sense of what “flat” means in this context, note that spacetime is sort of like a rubber mat. The mat curves in the presence of matter and energy (think of putting a bowling ball on the mat). Gravity is nothing more than the tendency objects have to roll into the the dents created by things like stars and planets. A flat region is like a part of the mat with nothing on it.

Such a drive would also avoid the uncomfortable consequences of time dilation. One could potentially make a round trip into deep space and still be greeted by one’s nearest and dearest at home.

A spacetime oddity

How does Alcubierre’s device work? Here discussion often relies on analogies, because the maths is so complex.

Imagine a rug with a cup on it. You’re on the rug and you want to get to the cup. You could move across the rug, or tug the rug toward you. The warp drive is like tugging on spacetime to bring your destination closer.

But analogies have their limits: a warp drive doesn’t really drag your destination toward you. It contracts spacetime to make your path shorter. There’s just less rug between you and the cup when you switch the drive on.

Alcubierre’s suggestion, while mathematically rigorous, is difficult to understand at an intuitive level. Bobrick and Martire’s work is set to change all that.

Starship bloopers

Bobrick and Martire show that any warp drive must be a shell of material in a constant state of motion, enclosing a flat region of spacetime. The energy of the shell modifies the properties of the spacetime region inside it.

This might not sound like much of a discovery, but until now it was unclear what warp drives might be, physically speaking. Their work tells us that a warp drive is, somewhat surprisingly, like a car. A car is also a shell of energy (in the form of matter) that encloses a flat region of spacetime. The difference is that getting inside a car does not make you age faster. That, however, is the kind of thing a warp drive might do.

Using their simple description, Bobrick and Martire demonstrate a method for using Einstein’s general relativity equations to find spacetimes that allow for arrangements of matter and energy that would act as warp bubbles. This gives us a mathematical key for finding and classifying warp technologies.

Their work manages to address one of the core problems for warp drives. To make the equations balance, Alcubierre’s device runs on “negative energy” – but we are yet to discover any viable sources of negative energy in the real world.

Worse, the negative energy requirements of Alcubierre’s device are immense. By some estimates, the entire energy in the known universe would be needed (though later work brings the number down a bit).

Bobrick and Martire show a warp drive could be made from positive energy (i.e. “normal” energy) or from a mixture of negative and positive energy. That said, the energy requirements would still be immense.

If Bobrick and Martire are right, then a warp drive is just like any other object in motion. It would be subject to the universal speed limit enforced by general relativity after all, and it would need some kind of conventional propulsion system to make it accelerate.

The news gets worse. Many kinds of warp drive can only modify the spacetime inside in a certain way: by slowing down the clock of the passenger in exactly the way that makes a trip into deep space a problem.

Bobrick and Martire do show that some warp drives could travel faster than light, but only if they are created already travelling at that speed – which is no help for any ordinary human hoping for a bit of interstellar tourism.

The end game

Remember that a warp drive can modify the region of flat spacetime it encloses. It can, in particular, speed up or slow down a clock inside the drive.

Consider what it would mean to have such an object available. Want to put someone with a terminal illness on ice? Stick them in a warp drive and slow their clock down. From their perspective, a few years will pass, while a hundred years will pass on Earth — time enough to find a cure.

Read more: The art and beauty of general relativity

Want to grow your crops overnight? Stick them in a warp drive and speed the clock up. A few days will pass for you, and a few weeks will pass for your seedlings.

There are even more exotic possibilities: by rotating the spacetime inside a drive one may be able to produce a battery capable of holding huge amounts of energy.

Faster-than-light travel remains a distant dream. But warp technology would be revolutionary in its own right.

• Time travel
• General Relativity
• Space travel
• Theoretical physics

Want to write?

Write an article and join a growing community of more than 185,400 academics and researchers from 4,982 institutions.

Register now

• Subscribe to BBC Science Focus Magazine
• Previous Issues
• Future tech
• Everyday science
• Planet Earth
• Newsletters

Faster-than-light travel: Is warp drive really possible?

A NASA scientist recently released a report analysing the feasibility of warp drive as a means of faster-than-light travel. Could this Star Trek technology really be possible?

In the Universe of Star Trek , humanity ventures out into the Galaxy on 5 April 2063 with the first ever journey on a ship capable of faster-than-light travel. The newly-invented ‘warp drive’ not only lets humans explore the cosmos, but attracts the attention of Vulcans and brings about our first contact with an alien species.

It’s been 54 years since we were first introduced to the Enterprise , and many of Star Trek ’s futuristic technologies have since been invented, from handheld communicators to universal translators. Warp drive is the next obvious choice: Voyager 1, which has travelled furthest from Earth of any spacecraft, took nearly 35 years to leave the Solar System. Not exactly handy for interstellar travel.

Luckily for humanity, theoretical physicists have been working on it. In May 2020, NASA scientist Harold “Sonny” White released an internal feasibility report discussing the technology from the point of view of ‘early mission planning’.

Read more about the science of Star Trek:

• ' Star Trek replicator' uses light to create 3D objects in minutes
• Star Trek -inspired aeroplane powered by ‘ionic wind’ takes flight
• Five things from Star Trek that came true

The first scientific theory of warp drive came about in 1994, when theoretical physicist Miguel Alcubierre used Einstein’s theory of General Relativity to develop a framework that would allow faster-than-light travel within the confines of the laws of physics. The key that makes it possible is that, technically, the ship itself doesn’t travel faster than light.

“What warp drive is doing is basically saying that there is no law of physics that says space-time itself can't go faster than the speed of light,” says Dr Erin Macdonald , astrophysicist and science consultant for Star Trek .

“And so the concept of warp drive is to say, all right, let's take our ship, let's build a bubble of space-time around it, and then we'll have that propel us faster than the speed of light,” she says. It’s similar to the idea of a racecar driving onboard a train: someone standing by the tracks would see the car travelling much faster than its top speed.

According to General Relativity, the Universe is a flat sheet of space-time which is warped by any object with mass. “We think of the bowling ball on the trampoline and that bowling ball dips the trampoline down,” says Macdonald, “and that's what mass does to space-time.” This distortion of space-time is what we experience as gravity.

• Subscribe to the Science Focus Podcast on these services: Acast , iTunes , Stitcher , RSS , Overcast

The Alcubierre drive uses the same concept. The ‘bubble’ surrounding the ship is an area of space-time that is compressed in front of the ship and expanded behind it. As with gravity, you could create this distortion using a large amount of mass. Alternatively, thanks to Einstein’s E = mc 2 (energy is equal to mass, times the speed of light squared), you could equally use a huge amount of energy.

Inside the bubble, space-time is completely flat, meaning the space travellers wouldn’t notice any strange, relativistic effects. The result is that the bubble of space-time is hurled across the Universe, with the travellers sitting comfortably inside their ship, speedometer still reading the same number.

Unfortunately, actually creating a warp drive is even harder than it sounds. “You have to have a very, very large amount of energy,” says José Natário , Associate Professor in mathematics at the Instituto Superior Técnico in the University of Lisbon.

“To have the deformation that you need for this kind of thing to work, you'd need much, much more energy than the Sun or the Galaxy,” he says. “But also, it’s negative energy.”

Read more from Erin Macdonald:

• Star Trek Picard premiere: solving plot holes, supernovae and our Sun’s fate
• The science of Picard with Dr Erin Macdonald

Negative energy is not something that we can currently create – certainly not in the quantities needed to power a warp drive. How could energy be negative at all?

One way to think about it is to consider a particle with negative mass. These particles would react to gravity in the exact opposite way to particles of positive mass. Instead of being pulled towards a planet or star, they would be thrown away.

“If we had some sort of component like that where we had a negative mass, whatever is keeping that mass together would be that negative energy,” says Macdonald.

This isn’t a problem that will go away with refining the idea, either: Natário proved mathematically that any form of warp drive will require negative energy.

Joseph Agnew is a graduate student at the University of Alabama in Huntsville whose undergraduate work on warp drive was published in the AIAA journal . He thinks that more research into the fundamentals of physics is the way forward for warp drive.

"Further experimental study of naturally occurring gravitational waves and perhaps a study on trying to generate artificial gravitational waves would really advance the understanding of gravity, and therefore spacetime and all the connected science," Agnew says.

Natário believes there’s an even greater problem with the concept of the Alcubierre drive. Imagine a supersonic aircraft travelling faster than the speed of sound. You don’t hear the aircraft until it has already gone past, because the sound waves can’t keep up. The warp drive experiences the same effect with light waves, meaning there is no way to send a message ahead of you.

“I call it the 'you need one to make one' problem,” says Natário. How do you create the warped space-time geometry around your ship? First, you would need to send a signal ahead of you to ‘tell’ space-time to warp, Natário says. “To make it go faster than light, you need something that would be going faster than light to begin with so that you'd be able to communicate outside the horizon.”

These two problems – combined with the slight issue that the travelers would be bombarded with incredibly high-energy radiation – are the downfall of warp drive, Nátario believes. “The bottom line is, in my opinion, it's completely impossible,” he says.

Read more from Reality Check :

• Why are so many people playing Animal Crossing?
• Peaceful protests: Are non-violent demonstrations an effective way to achieve change?

Agnew is more optimistic. "Many of these theoretical space transportation concepts rely extensively on a thorough understanding of gravity and spacetime, which just isn't the case currently," he says.

"I don't yet see any way we can say, with absolute certainty, that it will 'never happen in a million years'. When in doubt, history dictates it's better to err on the side of cautious, scientific optimism."

Macdonald, too, is hopeful. “I'm an eternal optimist with this because I want to join Starfleet,” she says. “The way I think about it is it's like we never know what's going to come down the pipe with sort of these weird, exotic, fun thought experiments.

“I agree at this stage, right now, it's a fun thought experiment. But that's not to preclude some massive discovery that may happen that we can't predict.”

Visit the BBC's Reality Check website at bit.ly/reality_check_ or follow them on Twitter @BBCRealityCheck

Share this article

Online staff writer, BBC Science Focus

• Terms & Conditions
• Privacy policy
• Cookies policy
• Code of conduct
• Magazine subscriptions
• Manage preferences

Scientists Believe Light Speed Travel Is Possible. Here’s How.

A functioning warp drive would allow humans to reach the far ends of the cosmos in the blink of an eye.

White and his team in LSI’s Houston laboratory were conducting research for the Defense Advanced Research Projects Agency, or DARPA, and had set up these particular experiments to study the energy densities within Casimir cavities, the mysterious spaces between microscopic metal plates in a vacuum. The data plot indicated areas of diminished energy between the plates, which caused them to push toward each other as if trying to fill the void. This is known as negative vacuum energy density, a phenomenon in quantum mechanics called, appropriately enough, the Casimir effect . It’s something that’s helping scientists understand the soupy physics of microscale structures, which some researchers hope can be applied to energy applications that are more practical, such as circuits and electromechanical systems.

But White noticed that the pattern of negative vacuum energy between the plates and around tiny cylindrical columns that they’d inserted in the space looked familiar. It precisely echoed the energy pattern generated by a type of exotic matter that some physicists believe could unlock high-speed interstellar travel. “We then looked, mathematically, at what happens if we placed a one-micron sphere inside of a four-micron cylinder under the same conditions, and found that this kind of structure could generate a little nanoscale warp bubble encapsulating that central region,” White explains.

That’s right—a warp bubble. The essential component of a heretofore fictional warp drive that has for decades been the obsession of physicists, engineers, and sci-fi fans. Warp drive, of course, is the stuff of Star Trek legend, a device enclosed within a spacecraft that gives the mortals aboard the ability to rip around the cosmos at superhuman speed. To the lay sci-fi fan, it’s a “black box”—a convenient, completely made-up workaround to avoid the harsh realities of interstellar travel. However, after decades of speculation, research, and experimentation, scientists believe a warp drive could actually work.

To emphasize: White didn’t actually make a warp bubble. But the data from his study led to an aha moment: For the first time, a buildable warp bubble showed promise of success.

Warp technology’s core science is surprisingly sound. Though the specific mechanics of an actual device haven’t been fully unpacked, the math points toward feasibility. In short, a real-life warp drive would use massive amounts of energy, which can come in the form of mass, to create enough gravitational pull to distort spacetime in a controlled fashion, allowing a ship to speed along inside a self-generated bubble that itself is able to travel at essentially any speed. Warp drives popped up in fiction intermittently for several decades before Star Trek creator Gene Roddenberry plugged one into the USS Enterprise in 1966. But Miguel Alcubierre, PhD, a Mexican theoretical physicist and professed Star Trek enthusiast, gave the idea real-world legs when he released a paper in 1994 speculating that such a drive was mathematically possible. It was the first serious treatment of a warp drive’s feasibility, and it made headlines around the world. His breakthrough inspired more scientists to nudge the theoretical aspects of warp drive toward concrete, practical applications.

“I proposed a ‘geometry’ for space that would allow faster-than-light travel as seen from far away, essentially expanding space behind the object we want to move and contracting it in front,” Alcubierre says. “This forms a ‘bubble’ of distorted space, inside of which an object—a spaceship, say—could reside.”

Physicists tend to speak in relative terms. By injecting the sly qualifier “as seen from far away,” Alcubierre might sound like he’s describing the galactic equivalent of an optical illusion —an effect perhaps similar to driving past a truck going the opposite direction on the highway when you’re both going 60 miles an hour. Sure feels like a buck-twenty, doesn’t it? But the A-to-B speed is real; the warp effect simply shortens the literal distance between two points. You’re not, strictly speaking, moving faster than light. Inside the bubble, all appears relatively normal, and light moves faster than you are, as it should. Outside the bubble, however, you’re haulin’ the mail.

.css-2l0eat{font-family:UnitedSans,UnitedSans-roboto,UnitedSans-local,Helvetica,Arial,Sans-serif;font-size:1.625rem;line-height:1.2;margin:0rem;padding:0.9rem 1rem 1rem;}@media(max-width: 48rem){.css-2l0eat{font-size:1.75rem;line-height:1;}}@media(min-width: 48rem){.css-2l0eat{font-size:1.875rem;line-height:1;}}@media(min-width: 64rem){.css-2l0eat{font-size:2.25rem;line-height:1;}}.css-2l0eat b,.css-2l0eat strong{font-family:inherit;font-weight:bold;}.css-2l0eat em,.css-2l0eat i{font-style:italic;font-family:inherit;} THOUGH THE SPECIFIC MECHANICS OF AN ACTUAL DEVICE HAVEN’T BEEN UNPACKED, THE MATH POINTS TOWARD FEASIBILITY.

Alcubierre’s proposal had solved one of the initial hurdles to achieving warp speeds: The very idea clashes with Einstein’s long-accepted theory of general relativity, which states that nothing can travel faster than the speed of light, but it doesn’t preclude space itself from traveling faster than that. In fact, scientists speculate that the same principles explain the rapid expansion of the universe after the Big Bang .

While concluding that warp speed was indeed possible, Alcubierre also found that it would require an enormous amount of energy to sustain the warp bubble. He theorized that negative energy—the stuff hinted at by White’s experimentation with Casimir cavities—could be a solution. The only problem is that no one has yet proved that negative energy is real. It’s the unobtanium of our spacefaring imaginations, something researchers only believe to exist. In theory, however, this unknown matter may be sufficiently powerful that future warp drive designers could channel it to contract spacetime around it. In conceptual drawings of warp-capable spacecraft , enormous material rings containing this energy source surround a central fuselage. When activated, it warps spacetime around the entire ship. The more intense the warping, the faster the warp travel is achieved.

Of course, it’s not that simple. Physicist José Natário, PhD, a professor at the Instituto Superior Técnico in Lisbon, wrote his own influential paper about the mathematical feasibility of warp drives in 2001. However, he is concerned about practical conundrums, like the amount of energy required. “You need to be able to curve spacetime quite a lot in order to do this,” he says. “We’re talking about something that would be much, much more powerful than the sun.”

Alcubierre is similarly skeptical that his theoretical ideas might ever be used to develop a working warp drive. “In order to have a bubble about 100 meters wide traveling at precisely the speed of light, you would need about 100 times the mass of the planet Jupiter converted into negative energy, which of course sounds absurd,” he says. By that standard, he concludes, a warp drive is very unlikely.

Physicists love a challenge, though. In the 29 years since Alcubierre published his paper, other scientists have wrestled with the implications of the work, providing alternative approaches to generating the energy using more accessible power sources, finding oblique entry points to the problem, and batting ideas back and forth in response to one another’s papers. They use analogies involving trampolines , tablecloths, bowling balls, balloons, conveyor belts, and music to explain the physics.

They even have their own vocabulary. It’s not faster-than-light travel; it’s superluminal travel, thank you. Then there’s nonphysical and physical—a.k.a. the critical distinction between theoretical speculation and something that can actually be engineered. (Pro tip: We’re aiming for physical here, folks.) They do mention Star Trek a lot, but never Star Wars . Even the scruffiest-looking nerf herder knows that the ships in Star Wars use hyperdrive, which consumes fuel, rather than warp drives, which don’t use propulsive technology but instead rely on, well, warping. They’re also vague about details like what passengers would experience, what gravity is like on board since you’re carrying around boatloads of energy, and what would happen if someone, say, jumped out of the ship while warping. (A speculative guess: Nothing good.)

Such research isn’t typically funded by academic institutions or the DARPAs and NASAs of the world, so much of this work occurs in the scientists’ spare time. One such scientist and Star Trek enthusiast is physicist Erik Lentz, PhD. Now a researcher at Pacific Northwest National Laboratory in Richland, Washington, Lentz was doing postdoctoral work at Göttingen University in Germany when, amid the early, isolated days of the pandemic, he mulled the idea of faster-than-light travel. He published a paper in 2021 arguing that warp drives could be generated using positive energy sources instead of the negative energy that Alcubierre’s warp drive seemed to require.

“There are a number of barriers to entry to actually being able to build a warp drive,” Lentz says. “The negative energy was the most obvious, so I tried to break that barrier down.”

He explored a new class of solutions in Einstein’s general relativity while focusing on something called the weak-energy condition, which, he explains, tracks the positivity of energy in spacetime. He hit upon a “soliton solution”—a wave that maintains its shape and moves at a constant velocity—that could both satisfy the energy-level challenge and travel faster than light. Such a warp bubble could travel along using known energy sources, though harnessing those at the levels needed are still far beyond our capabilities. The next step, he notes, may be bringing the energy requirements for a warp drive to within the range of a nuclear fusion reactor.

A fusion-powered device could theoretically travel to and from Proxima Centauri , Earth’s nearest star, in years instead of decades or millennia, and then go faster and faster as power sources improve. Current conventional rocket technology, on the other hand, would take 50,000 years just for a one-way trip—assuming, of course, there was an unlimited fuel supply for those engines.

“IF YOU COLLIDE WITH SOMETHING ON YOUR PATH, IT WOULD ALMOST CERTAINLY BE CATASTROPHIC.”

Like Alcubierre’s original thesis, Lentz’s paper had a seismic impact on the warp drive community, prompting yet another group of scientists to dig into the challenge. Physicist Alexey Bobrick and technology entrepreneur Gianni Martire have been particularly prolific. In 2021, they released a paper theorizing that a class of subliminal warp drives, traveling at just a fraction of light speed, could be developed from current scientific understanding. While that paper essentially argued that it’s perfectly acceptable to walk before you can run, they followed it up with another theory earlier this year that describes how a simulated black hole , created using sound waves and glycerin and tested with a laser beam, could be used to evaluate the levels of gravitational force needed to warp spacetime. The duo coded that breakthrough into a public app that they hope will help more quickly push theoretical ideas to practical ones. Though the team is waiting for the technology to clear a peer review stage before releasing details, the app is essentially a simulator that allows scientists to enter their warp-speed equations to validate whether they’re practical.

“When somebody publishes a warp metric for the first time, people say, ‘Okay, is your metric physical?’” Martire says. The answer to that question—whether the metric has practical potential or is strictly theoretical—is hard to establish given the challenges of testing these hypotheses. That determination could take six to eight months. “Now we can tell you within seconds, and it shows you visually how off you are or how close you are,” he says.

While useful, the app will speed up the preliminary math only for future researchers. Galaxy-sized challenges remain before we ever experience turbocharged interstellar travel. Alcubierre worries in particular about what may happen near the walls of the warp bubble. The distortion of space is so violent there, he notes, that it would destroy anything that gets close. “If you collide with something on your path, it would almost certainly be catastrophic,” he says.

Natário mulls even more practical issues, like steering and stopping. “It’s a bubble of space, that you’re pushing through space,” he says. “So, you’d have to tell space ... to curve in front of your spaceship.” But therein lies the problem: You can’t signal to the space in front of you to behave the way you want it to.

His opinion? Superluminal travel is impossible. “You need these huge deformations that we have no idea how to accomplish,” Natário says. “So yes, there has been a lot of effort toward this and studying these weird solutions, but this is all still completely theoretical, abstract, and very, very, very, very far from getting anywhere near a practical warp drive.” That’s “very” to the power of four, mind you—each crushing blow pushing us exponentially, excruciatingly further and further away from our yearned-for superluminal lives.

Ultimately, the pursuit of viable high-speed interstellar transportation also points to a more pressing terrestrial challenge: how the scientific community tackles ultra-long-term challenges in the first place. Most of the research so far has come from self-starters without direct funding, or by serendipitous discoveries made while exploring often unrelated research, such as Dr. White’s work on Casimir cavities.

Many scientists argue that we’re in a multi-decade period of stagnation in physics research, and warp drive—despite its epic time horizons before initial research leads to galaxy-spanning adventures—is somewhat emblematic of that stagnation. Sabine Hossenfelder, a research fellow at the Frankfurt Institute for Advanced Studies and creator of the YouTube channel Science Without the Gobbledygook , noted in a 2020 blog post that physics research has drifted away from frequent, persistent physical experimentation to exorbitant infusions of cash into relatively few devices. She writes that with fewer experiments, serendipitous discoveries become increasingly unlikely. Without those discoveries, the technological progress needed to keep experiments economically viable never materializes.

When asked whether this applied equally to warp drive, Hossenfelder sees a faint but plausible connection. “Warp drives are an idea that is not going to lead to applications in the next 1,000 years or so,” she says. “So they don’t play a big role in that one way to another. But when it comes to the funding, you see some overlap in the problems.”

So, despite all the advances, the horizon for a warp drive remains achingly remote. That hasn’t fazed the scientists involved, though. A few years ago, while teaching in France, White visited the Strasbourg Cathedral with his wife. While admiring its 466-foot-tall spire, he was struck by the fact that construction began in 1015 but didn’t wrap up until 1439—a span of 424 years. Those who built the basement had no chance of ever seeing the finished product, but they knew they had to do their part to aid future generations. “I don’t have a crystal ball,” White says. “I don’t know what the future holds. But I know what I need to be doing right now.”

Eric Adams is a writer and photographer who focuses on technology, transportation, science, travel, and other subjects for a wide range of outlets, including Wired, The Drive, Gear Patrol, Men's Health, Popular Science, Forbes, and others.

.css-cuqpxl:before{padding-right:0.3125rem;content:'//';display:inline;} Pop Mech Pro .css-xtujxj:before{padding-left:0.3125rem;content:'//';display:inline;}

The CIA’s Plan to Deploy an Army of Super Spies

She Was Pronounced Dead—Then Found Gasping for Air

A B-1B Lancer Was Seen With a New Super Bomb

All About China’s Terrifying New Aircraft Carrier

Navy Fighter Seen Packing Huge, Ship-Fired Missile

Hieroglyphics Unveil Ramses II’s Lost Sarcophagus

This Navy Warship Program Is Kind of a Disaster

Every Single Cell in Your Body Could Be Conscious

How to Live Forever, or Die Trying

The Army & Navy Working Together Defense Missiles

How Russia Copied America’s Deadliest Missile

• June 14, 2024 | Scientists May Have Discovered the First Sign of Autism: An Unusually Large Brain
• June 14, 2024 | Webb Does the “Impossible” – Space Telescope Captures First Glimpse of an Exoplanet’s Interior
• June 14, 2024 | Why Your Migraines Get Worse When It’s Hot Outside
• June 14, 2024 | Sugar-Sensing Proteins: A Potential Breakthrough for Sustainable Biofuel
• June 14, 2024 | A New Dimension of Heat: New Approach for Controlling Thermal Emission Developed

Warp Drives and Negative Energy: Physicists Give Chances of Faster-Than-Light Space Travel a Boost

By Mario Borunda, Oklahoma State University May 16, 2021

Faster than light travel is the only way humans could ever get to other stars in a reasonable amount of time. Credit: NASA

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away, or about 25 trillion miles (40 trillion km). The fastest ever spacecraft, the now-in-space Parker Solar Probe will reach a top speed of 450,000 mph (201 km/s). It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earth’s nearest neighboring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimov’s Foundation series, humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characters – like the astronauts in the movies “Interstellar” and “Thor” – use wormholes to travel between solar systems in seconds. Another approach – familiar to “Star Trek” fans – is warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

This 2-dimensional representation shows the flat, unwarped bubble of spacetime in the center where a warp drive would sit surrounded by compressed spacetime to the right (downward curve) and expanded spacetime to the left (upward curve). Credit: AllenMcC/Wikimedia Commons

Compression and expansion

Physicists’ current understanding of spacetime comes from Albert Einstein’s theory of General Relativity. General Relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime – hefty objects like stars and black holes curve spacetime around them. This curvature is what you feel as gravity and why many spacefaring heroes worry about “getting stuck in” or “falling into” a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? “Star Trek” took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity . So, what does that mean? Imagine the distance between two points is 10 meters (33 feet). If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, let’s say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second. In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from “Star Trek” was in fact theoretically possible.

Proxima Centauri here we come, right? Unfortunately, Alcubierre’s method of compressing spacetime had one problem: it requires negative energy or negative mass.

This 2–dimensional representation shows how positive mass curves spacetime (left side, blue earth) and negative mass curves spacetime in an opposite direction (right side, red earth). Credit: Tokamac/Wikimedia Commons, CC BY-SA

A negative energy problem

Alcubierre’s warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative mass – a theorized type of matter – or a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierre’s warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe .

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly , to just about the mass of the sun. A significant improvement, but still far beyond all practical possibilities.

A sci-fi future?

Two recent papers – one by Alexey Bobrick and Gianni Martire and another by Erik Lentz – provide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realized that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of General Relativity, and by doing so, he found that a warp drive wouldn’t need to use negative energy. Lentz’s solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I won’t fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard , things are only impossible until they are not.

Written by Mario Borunda, Associate Professor of Physics, Oklahoma State University.

Adapted from an article originally published on The Conversation .

More on SciTechDaily

Aging’s Antidote? The Crucial Role of HKDC1 in Keeping Cells Youthful

Meltwater Pulse 1A: Melting Ice Sheets Caused Sea Levels to Rise Up to 18 Meters

Illuminating Life’s Origins: Uncovering the Synthesis of Sugars on Ancient Earth

Unlocking the Mysteries of the Bio/Nano Interface

CRISPR-HOT: New Genetic Tool Can Label Specific Genes and Cells

Simulating the Cosmos: Is a Miniature Universe Possible?

Astronomers May Have Found the Secret Behind Mysterious Location of Massive Stars

The battle of the covid variants: a winning approach, 27 comments on "warp drives and negative energy: physicists give chances of faster-than-light space travel a boost".

Chinese Logicians School and their paradoxes aside for the time being: Even though it’s white, has wings and it’s name is Pegasus, it’s still a horse. It cannot fly and is as dead as the Mythology that spawned it. A dead horse is not a horse. Beat it all you want, it’s a deadhorse. Subtle Logic. Essentials and Essential Quality (Whiteness and Horse-ness) define a beast of a different color. Light is not a speed limit if everything is moving at the speed of light. It is more like a bullet fired off the trailing end of a speeding train. You can’t see it until it hits something… like your retina. The problem begins in the occipital lobe and migrates frontally. From there, it is only a matter of TIME… and the MANIFOLD UNIVERSE of the MIND: IT is all in how one looks at it.

Now… Back to the telescope and a cup of hot chocolate. Here’s looking at you. ☝️

Wow, that’s some deep brown matter, Alex, and I don’t mean the coffee.

Well… We ARE immersed in a wealth of brown matter. Orthodoxy notwithstanding, one can science the heck out of it, but it is a meaningless WASTE of human resources when misdirected: particularly when it is EXPENSIVE. It’s in the GREY MATTER, ultimately, the biases that allow us to poison our “home” planet on the promise of finding another one JUST LIKE IT. Good luck with that: not in a hundred lifetimes, even @ the speed o’ lite. To wit: Whatever we might aim our Lightships at, ISN’T THERE ANYMORE. WARP NINE, MUSTER WARF. MAKE IT SO. LOL What I was suggesting was a paradigm (that word) SHIFT. Ya know, like… maybe stand still, RELATIVELY SPEAKING, while Space moves past us. Forget about TIME for the time being. There is no way “around” it, but maybe there is a way outside of it. Some theorists are pursuing this line of reasoning. I have been “educated” to an insight: The solution is much simpler than our Science can imagine; as vested as it is in misconceptions about this ONE Universe, that belong in the Middle (muddle?) Ages, along with witches, goblins, the homunculus, god, seven days in the week and a paradigm of EXISTENCE hopelessly mired in its obsession with mortality and bodily functions; which is still trying to turn lead into gold, but fails at differentiating SH*T FROM SHINOLA. Call me IDEALISTIC… and I will correct your thinking. REALISTICALLY speaking, Pangloss, I GUESS was correct: We live in the BEST if all possible WORLDS…I have some land in Florida for sale. Real cheap. It only under water twice a day.

It’s not brain surgery.

BTW, I was drinking hot chocolate; a suggestion of a neurosurgeon friend who drinks it during prolonged surgeries (+6 hours). It contains a better form of caffeine than coffee; one that does not rattle the nerves. With the “work” he does, one little tremor and ZIP! there goes your memory of Aunt Tilly, or maybe just the memory of how to tie your own shoelaces…

👽 Keep looking up. ☝️

Why did you take out my comment on Dr. Lee and Synthetic Gravity demonstrated in Huntsville, Alabama in 1998? I realize the program went black, i.e., Beyond Top Secret and thus was scrubbed from the Internet by the year 2000.

Quantum information travels faster than light, so that is what everyone else in the universe exploits to travel to the stars. Quantum Tunneling Vehicles (QTV). They emulate an elementary particle by spinning a strong electric or magnetic field around a superconducting hull to engage a particle spreadsheet function. Altering and renormalizing the spin of the field should cause the universe to re-locate the ersatz particle. It’s a form of quantum teleportation, if you mess with the constancy of the spin field, you can trick the universe into changing it’s location. Electric tunneling vehicles would be oblate spheroids, magnetic tunneling vehicles would be cigar shaped. Classic UFO’s, saucers and cigars. Why don’t we just follow their lead? Or are we stupid cavemen who need rockets to fly through space? Classical physics has a speed limit, the speed of light. If you want to beat it safely, you have to play the quantum game instead. Fortunately, quantum information travels faster than light. Quantum laws govern the conservation laws, which are monitored on every particle in the universe at once. So if I can con the universe into thinking my ship is an elementary particle and that my “particle” belongs somewhere else, I’ll instantly find my “particle” there. The quantum machinery of reality is not subject to the limitations of the classical laws it emulates. The closest stars may be only hours or minutes away to a sophisticated Quantum Tunneling Vehicle. And if you need a lift vehicle that can hit orbit 20 rimes a day with no pollution, or go to Mars in minutes, all we need are room temperature superconductors and a lot of electricity.

You have something there. Generating a strong enough field will effectively create a “bubble” around which Time and Space will flow…at the Speed of light and beyond, as the “vector” of “flight” shortens in response to Space/Time distortion… Only a Theory. But it beats the Wile E. Coyote, strap a rocket to your ass, school of space travel. As in any Scientific theorising, the first SPACE one needs to overcome is the space between one’s ears. It is, after all, the Final Frontier.

Babu G. Ranganathan* (B.A. Bible/Biology)

JUST BECAUSE SCIENCE CAN EXPLAIN how an airplane works doesn’t mean that no one designed or made the airplane. And just because science can explain how life or the universe works doesn’t mean there was no Designer and Maker behind them.

Natural laws may explain how the order in the universe works and operates, but mere undirected natural laws cannot explain the origin of that order. Once you have a complete and living cell then the genetic code and biological machinery exist to direct the formation of more cells from raw materials such as amino acids and other chemicals, but how could life or the cell have naturally originated when no directing code and mechanisms existed in nature? Read my Internet article: HOW FORENSIC SCIENCE REFUTES ATHEISM.

WHAT IS SCIENCE? Science simply is knowledge based on observation. No human observed the universe coming by chance or by design, by creation or by evolution. These are positions of faith. The issue is which faith the scientific evidence best supports.

SCIENCE SHOWS THAT THE UNIVERSE CANNOT BE ETERNAL because it could not have sustained itself eternally due to the law of entropy (increasing and irreversible net energy decay, even in an open system). Even a hypothetical oscillating universe could not continue to oscillate eternally! Einstein’s General Theory of Relativity shows that space, matter, and time all are physical and all had a beginning. Space even produces particles because it’s actually something, not nothing. What about the Higgs boson (the so-called “God Particle”)? The Higgs boson, even if it existed, would not have created mass from nothing, but rather it would have converted energy into mass. Einstein showed that all matter is some form of energy. Even time had a beginning! Time is not eternal.

The law of entropy doesn’t allow the universe to be eternal. If the universe were eternal, everything, including time (which modern science has shown is as physical as mass and space), would have become totally entropied by now and the entire universe would have ended in a uniform heat death a long, long time ago. The fact that this hasn’t happened already is powerful evidence for a beginning to the universe.

Popular atheistic scientist Stephen Hawking admits that the universe had a beginning and came from nothing but he believes that nothing became something by a natural process yet to be discovered. That’s not rational thinking at all, and it also would be making the effect greater than its cause to say that nothing created something. The beginning had to be of supernatural origin because science teaches us from the First Law of Thermodynamics that natural laws and processes do not have the ability to bring something into existence from nothing.

The supernatural origin of the universe cannot be proved by science but science points to a supernatural intelligence and power for the origin and order of the universe. Where did God come from? Obviously, unlike the universe, God’s nature doesn’t require a beginning.

The disorder in the universe can be explained because of chance and random processes, but the order can be explained only because of intelligence and design.

Gravity may explain how the order found in the precise and orderly courses of thousands of billions of stars is maintained, but gravity cannot explain the origin of that order.

Some evolutionary astronomers believe that trillions of stars crashed into each other leaving surviving stars to find precise orderly orbits in space. Not only is this irrational, but if there was such a mass collision of stars then there would be a super mass residue of gas clouds in space to support this hypothesis. The present level of residue of gas clouds in space doesn’t support the magnitude of star deaths required for such a hypothesis. And, as already stated, the origin of stars cannot be explained by the Big Bang because of the reasons mentioned above. It’s one thing to say that stars may decay and die into random gas clouds, but it is totally different to say that gas clouds form into stars.

Even the father of Chaos theory admitted that the “mechanisms” existing in the non-living world allow for only very rudimentary levels of order to arise spontaneously (by chance), but not the kind or level of order we find in the structures of DNA, RNA, and proteins. Yes, individual amino acids have been shown to come into existence by chance but not protein molecules which require that the various amino acids be in a precise sequence just like the letters found in a sentence.

Some things don’t need experiment or scientific proof. In law there is a dictum called prima facie evidence. It means “evidence that speaks for itself.”

An example of a true prima facie would be if you discovered an elaborate sand castle on the beach. You don’t have to experiment to know that it came by design and not by the chance forces of wind and water.

If you discovered a romantic letter or message written in the sand, you don’t have to experiment to know that it was by design and not because a stick randomly carried by wind put it there. You naturally assume that an intelligent and rational being was responsible.

It’s interesting that Carl Sagan would have acknowledged sequential radio signals in space as evidence of intelligent life sending them, but he wouldn’t acknowledge the sequential structure of molecules in DNA (the genetic code) as evidence of an intelligent Cause. Read my popular Internet article, HOW DID MY DNA MAKE ME.

I encourage all to read my popular Internet articles:

NATURAL LIMITS TO EVOLUTION HOW FORENSIC SCIENCE REFUTES ATHEISM

Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION (This site answers many arguments, both old and new, that have been used by evolutionists to support their theory)

Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

*I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

Strong is the wind that blows…

We should continue to search, yet it seems to me more effort is and should be placed on inner planetary travel. Nuclear rocket engines or even better fusion drive with impulses reaching 30,000 mps would open the planets and mining of asteroids. This would reduce travel time and fuel consumption making the inner planets give up their secrets and spread out mankind against catastrophe. I would love to travel to proxima centaury in what’s left of my life, it’s not going to happen. That’s why we have science fiction stories!

Warp drives and negative energy…either reduce mass beyond zero or…maybe a large time difference.. bubble with large time difference like helium vs. air…or tuning a radio to a different frequency than the natural surrounding space?

The way that the Star Trek’s warp dive works is that the Antimatter is stored because it needs a smaller area to contain it in a magnetic field. The Nacelles in the front is what collects the matter. They are called Bussard Collector. It then goes to a Dilithium Chamber where the Dilithium Crystals are. The matter and antimatter enters the chamber and instead of a violent explosion the Dilithium controls the explosion and is converted to warp plasma. The plasma then goes back to the nacelle where the Warp Plasma Coils are and creates the warp bubble and then bends the space in front of the ship.

SpaceTime idea seems like a 2D model. Living on Earth is a kind of gravity well that’s why we need massive energy to escape it pull down. I don’t but the ‘spacetime’ idea. Space is relative emptiness. Time is a measure of movement.

Thus far humans have been thinking of REpulsion methods of travel. Pretty much male thinking. But say you want to go towards a female, you can use ‘push’ but most importantly ‘pull’ method; ie: attraction A combination of pull(attraction) and push(repulsion) would work better.

Think of a plant. How does it grow towards the light? It produces a substance that captures and stores light energy and transfers it to the roots to push further into the soil. So a plant has a pull and push method/mechanism (ATP, is it?)

Now you want to go to another star system. Ok. Aim your light-capture device at the stars center mass. Begin light collection, storage and transfer. Expel light thru rear. This method is like using light as zipline. But what material could capture light energy, store and/or transfer it out causing the spacecraft to pull and push itself towards the destination?

Or maybe a light-attracting device in the bow and a light-repelling device in the stern. Lineup the ship between two stars and go. The bow pulls towards the destined/arrival star while the stern pushes off the source/departing star.

Another way or maybe related is a kind of lightplane that sucks in light and expells it (like an airplane). But what kind of engine & fuel would one need to suckin light, ‘combust it and expell it’?

Another idea is to run a ship on cosmic background radiation.

Think of how long it took ‘god’ to build an organism to build a telescope to see light from a distant star. Evolution got us here in about 4.5B years, right? How can we travel at the speed of imagination? We need light. Go towards the light.

1) Attract light and repel light. Photonic propulsiom? 2) Space is a relatively cold void, what cuts thru a cold void? Hot plasma? Plasma Drive? 3) Combination of engines/methods (all-in-one).

We can build and prepare for when our star goes supernova and surf that in all directions. ~4.5B years.

It makes sense that our star’s life cycle and consciousness would follow ours. At midlife, I am beginning to see what is possible and not for me. Sure I still wish and hope with imaginatiom, but time to get real. It follows that since this star made and sustains us that once its gone, so will we be. Unless perhaps if we link up to another star or to the supermassive giant star in our galactic core. And when that goes supernova we can surf that. When a star goes boom, it spreads its matter out. Its amazing enough that the star maintains a balanced fusion reaction, but that it also explodes or dies out as it loses mass. We don’t have to wait. I’m sure we can imagine something and mame it real. I mean can we even excite a particle to go at light speed? And 6k years is still shorter than waiting 4.5 billion years to be shot out like dead matter. I think we need to capture more energy from our star, concentrate it, build brains (organic & inorganic), swarm brains, augment/unify intelligence and consciousness. Maybe there is a way to recombine light coming from another star with light from our star to build particles/matter at the destined end by scanning ourselves from our end. Yes teleportation via 3D printing matter using light from destined star and energy from our star. In 4.5B years I think we can perfect this. (One issue is it might be less dense at the destined end.)

Imagination is the key; the crazier the better.

We might have to figure out a way to take our Earth mothership with us since we are wholly dependent on her ATM. Say within 4.5B years we would have been able to remake all the matter in the solar system into useful devices, basically remaking our planet & ourselves via 3D quantum plank’s length printing. Basically reshape all matter to our imagined consciousness. Priority is to extract more and more energy from our star then we’ll have more possibilities and if we figure out a hack can multiply virally throughout the galaxy increasing our chances. Seems destined and predetermimed. Energy capture & matter manipulation is key. We need sharper senses: better ‘nanoscopes’, better causal-logic processes, finer manipulation of matter, energy efficiency, more accurate theories & mathmatics…anything & everything; there is no limit to godliness.

how long would you say it would take to successfully and completely create said warp drive?

In truth, it took God one day to create the first human being without evolution. It took six days to create the whole Universe. He made us in his image, but not so that we ARE Gods, but his children. He is the God of creation, thus we should be creative, we will find a way to travel faster than the speed of light many times over.

In 2013, A group of us (named C-PLUSS) definitively proved that this proposed method for “warp drive” does not work the way that they say it works. The localised tidal-forces on space-time would be too much to bear. It can cause irreparable damage to local space-time. I have copies of our notes, our conclusions, and our recommendations for an alternative methodology to create a “warp drive”. C-PLUSS stands for the Committee to Propose Legitimate Ultra-luminal Speed Systems. I can be reached at [email protected] .

Leave a comment Cancel reply

Email address is optional. If provided, your email will not be published or shared.

Save my name, email, and website in this browser for the next time I comment.

• The Magazine
• Stay Curious
• The Sciences
• Environment
• Planet Earth

How Humans Could Go Interstellar, Without Warp Drive

Faster-than-light (ftl) travel is possible..

The field equations of Einstein’s General Relativity theory say that faster-than-light (FTL) travel is possible, so a handful of researchers are working to see whether a  Star Trek -style warp drive, or perhaps a kind of  artificial wormhole , could be created through our technology.

But even if shown feasible tomorrow, it’s possible that designs for an FTL system could be as far ahead of a functional starship as Leonardo da Vinci’s 16th century drawings of flying machines were ahead of the Wright Flyer of 1903. But this need not be a showstopper against human interstellar flight in the next century or two. Short of FTL travel, there are technologies in the works that could enable human expeditions to planets orbiting some of the nearest stars.

Picking the Target

Certainly, feasibility of such missions will depend on geopolitical-economic factors. But it also will depend on the distance to nearest Earth-like exoplanet. Located roughly 4.37 light years away, Alpha Centauri is the Sun’s closest neighbor; thus science fiction, including  Star Trek , has envisioned it as humanity’s first interstellar destination.

In 2012, a planet was  identified  orbiting closely around Alpha Centauri B, one of three stars comprising the Alpha Centauri system. Three years later, astronomers were unable to find that same planet, but if it exists it would be too hot for life anyway. What we really want to know is whether planets exist further out from the two main stars, or whether their much smaller, dimmer companion star, Proxima Centauri, located just 4.24 light years from Earth, has planets of its own.

Very soon, these questions will be answered by the  James Webb Space Telescope (JWST) that NASA will be launching into space in 2018, and by other instruments that will follow, instruments capable of more than merely detecting a planet’s presence. They will also be able to read the chemical composition of planetary atmospheres.

Imagine this: If there’s an Earth-like planet around Alpha Centauri or another nearby star system, astronomers will know about it within a decade or two — certainly long before we can build a ship like the  Enterprise .

Maybe we could consider flying under the speed of light.

Propulsion 

It is not widely known, but the US government spent real money, tested hardware and employed some of the best minds in late 1950s and early 60s to develop an idea called  nuclear pulse propulsion .

Known as  Project Orion , the work was classified because the principle was that your engine shoots a series of “nuclear pulse units” — atomic bombs of roughly Hiroshima/Nagasaki power — out the back. Each unit explodes and the shockwave delivers concussive force to an immense, steel pusher plate, which is connected to the most immense shock absorber system that you could imagine.

The researchers calculated that the ship could reach five percent the speed of light (0.05  c ), resulting in roughly a 90-year travel time to Alpha Centauri. The Nuclear Test Ban Treaty of 1963, which forbade nuclear explosions in the atmosphere, and the Outer Space Treaty of 1967, which forbade nuclear explosive devices in space, effectively ended  Orion .

In his epic TV series Cosmos, Carl Sagan noted such an engine would be an excellent way to dispose of humanity’s nuclear bombs, but that it would have to be activated far from Earth. But back when  Orion  was being funded, amazingly, the plan was to use the nuclear pulse engine even for launching the vessel, in one massive piece, from the surface of Earth. Suffice it to say it does not seem likely that we’ll every build a nuclear pulse ship, but it’s something that we already have the technology to build.

A Cleaner System

But what about a less explosive, cleaner propulsion system that could achieve the same end? The British Interplanetary Society took on this goal in the 1970s with Project Daedalus . Named for the inventor from Greek mythology who built wings to escape the island of Crete, the design was based on projected development of inertial confinement fusion (ICF), one of two main strategies for generating nuclear fusion energy on Earth.

The other strategy is magnetic confinement fusion (MCF), and similar to ICF, designs exist for  adapting MCF to space propulsion . Like  Orion , a  Daedalus  craft would have to be rather large. But using deuterium and helium-3 (obtained from the lunar surface, or from Jupiter’s atmosphere) as fuel,  Daedalus  craft could reach 0.12  c , cutting travel time to Alpha Centauri to something like 40 years.

There are other ingenious ideas, such as the  Bussard ramjet  that could approach the speed of light, but the size of the engines and technological gaps that we must fill become so large that they may not seem easier than warp drive. So let’s limit our discussion to capabilities up to the neighborhood of the 0.12  c  of  Daedalus  as we consider what form a human interstellar voyage might take

The Generation Starship

It has been said that if you want to go fast, go alone, but if you want to go far, go together. This proverb characterizes the strategy of building an interstellar ship so large that you don’t worry so much about the travel time.

Effectively, the ship is a space colony. It contains a large population — current estimates are that a minimum of tens of thousands of colonists are needed for a  healthy gene pool — and all that is needed for people to live comfortably, but it follows a trajectory out of the solar system. Ideas for an interstellar ark taking millennia to reach a destination date back to the fathers of the Space Age — Russia’s Konstantin Tsiolkovsky and America’s Robert Goddard— — the idea really set sail with mid 20th century science fiction writers.

In a two-part novel series written in 1941, Robert A. Heinlein wrote of a vessel that took so long to reach its destination that the people aboard had forgotten they were on a ship. Instead, they believed the large craft to be their natural world.

Sending colonists on a voyage lasting centuries or millennia raises social questions, such as whether it is ethical to commit unborn generations to live out their lives in transit between planets.

10,000 years is a rather long time and means a large number of generations to commit to the interstellar void. But if we’re talking 40 or even 90 years, that’s probably more palatable to many more people. Still, it raises questions as to who would volunteer for such an expedition.

But what about people with shorter attention spans and what if we have no will to build enormous, moving colonies?  

Here’s another science fiction strategy: sending cryopreserved human embryos, or gametes (ova and sperm) into deep space. Upon reaching the destination star system, the embryos would be developed. This would require an artificial uterus, which we don’t have yet, but like fusion, here we’re also talking in terms of a matter of decades.

At some point in this century,  motherless birth  could become a technological reality. Theoretically, we’ll be able to send cryopreserved embryos through space, for centuries if needed due to propulsion limitations, and set them to develop into full-term infants on the new planet.

Then, all you need are robot nannies to raise and educate the infant colonists. And if there’s one area of technological progress that people are supremely confident will keep advancing at warp speed, it’s robots and artificial intelligence.

The egg ship concept is loaded with ethical questions, which can be hashed out in the comments section.

Suspended Animation

As technically ambitious as it may sound, medical science is making incremental progress toward a safe form of human hibernation.

Currently, it’s routine to lower a patient’s body temperature intentionally by a few degrees, thereby inducing a mild hypothermic coma, following cardiac arrest. This enables the brain to recover after oxygen has been cut off, whereas remaining at normal body temperature results in what’s called reperfusion injury.

Not routine yet, but now under clinical trials, trauma surgeons are cooling patients down to just above freezing temperature in cases of severe blood loss. This is true  suspended animation . It’s done just for two hours, or possibly three, stalling death so that injuries can be repaired and blood replaced, but the person is basically hibernating during that time.

With incremental progress, the procedure may eventually be extended to time frames of many hours, and eventually days or weeks to treat other conditions. Perhaps, in time, we’ll put people to sleep long enough, and with enough supervision by computers, to slumber away for an entire interstellar voyage the way you now doze off for a transoceanic flight.

• space exploration
• human spaceflight
• spaceflight

Already a subscriber?

Register or Log In

Keep reading for as low as $1.99!

Sign up for our weekly science updates.

Save up to 40% off the cover price when you subscribe to Discover magazine.

Warp Drive May Be More Feasible Than Thought, Scientists Say

HOUSTON — A warp drive to achieve faster-than-light travel — a concept popularized in television's Star Trek — may not be as unrealistic as once thought, scientists say.

A warp drive would manipulate space-time itself to move a starship, taking advantage of a loophole in the laws of physics that prevent anything from moving faster than light . A concept for a real-life warp drive was suggested in 1994 by Mexican physicist Miguel Alcubierre; however, subsequent calculations found that such a device would require prohibitive amounts of energy.

Now physicists say that adjustments can be made to the proposed warp drive that would enable it to run on significantly less energy, potentially bringing the idea back from the realm of science fiction into science.

"There is hope," Harold "Sonny" White of NASA's Johnson Space Center said here Friday (Sept. 14) at the 100 Year Starship Symposium , a meeting to discuss the challenges of interstellar spaceflight.

Warping space-time

An Alcubierre warp drive would involve a football-shape spacecraft attached to a large ring encircling it. This ring, potentially made of exotic matter, would cause space-time to warp around the starship, creating a region of contracted space in front of it and expanded space behind. [ Star Trek's Warp Drive: Are We There Yet? | Video ]

Meanwhile, the starship itself would stay inside a bubble of flat space-time that wasn't being warped at all.

Get the Space.com Newsletter

Breaking space news, the latest updates on rocket launches, skywatching events and more!

"Everything within space is restricted by the speed of light," explained Richard Obousy, president of Icarus Interstellar, a non-profit group of scientists and engineers devoted to pursuing interstellar spaceflight. "But the really cool thing is space-time, the fabric of space, is not limited by the speed of light."

With this concept, the spacecraft would be able to achieve an effective speed of about 10 times the speed of light, all without breaking the cosmic speed limit.

The only problem is, previous studies estimated the warp drive would require a minimum amount of energy about equal to the mass-energy of the planet Jupiter.

But recently White calculated what would happen if the shape of the ring encircling the spacecraft was adjusted into more of a rounded donut, as opposed to a flat ring. He found in that case, the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA launched in 1977.

Furthermore, if the intensity of the space warps can be oscillated over time, the energy required is reduced even more, White found.

"The findings I presented today change it from impractical to plausible and worth further investigation," White told SPACE.com. "The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab."

Laboratory tests

White and his colleagues have begun experimenting with a mini version of the warp drive in their laboratory.

They set up what they call the White-Juday Warp Field Interferometer at the Johnson Space Center, essentially creating a laser interferometer that instigates micro versions of space-time warps.

"We're trying to see if we can generate a very tiny instance of this in a tabletop experiment, to try to perturb space-time by one part in 10 million," White said.

He called the project a "humble experiment" compared to what would be needed for a real warp drive, but said it represents a promising first step.

And other scientists stressed that even outlandish-sounding ideas, such as the warp drive, need to be considered if humanity is serious about traveling to other stars.

"If we're ever going to become a true spacefaring civilization, we're going to have to think outside the box a little bit, we're going to have to be a little bit audacious," Obousy said.

You can follow SPACE.com assistant managing editor Clara Moskowitz on Twitter @ClaraMoskowitz .   Follow SPACE.com on Twitter  @Spacedotcom . We're also on Facebook  &  Google+ .

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected].

Clara Moskowitz is a science and space writer who joined the Space.com team in 2008 and served as Assistant Managing Editor from 2011 to 2013. Clara has a bachelor's degree in astronomy and physics from Wesleyan University, and a graduate certificate in science writing from the University of California, Santa Cruz. She covers everything from astronomy to human spaceflight and once aced a NASTAR suborbital spaceflight training program for space missions. Clara is currently Associate Editor of Scientific American. To see her latest project is, follow Clara on Twitter.

Holy Stone HS900 Sirius drone review

Autel EVO Max 4T drone review

Could nearby stars have habitable exoplanets? NASA's Chandra X-ray Observatory hopes to find out

Most Popular

• 2 This Week In Space podcast: Episode 115 — Our Friendly Mr. Sun
• 3 Space weather forecasting needs an upgrade to protect future Artemis astronauts
• 4 How the world-famous Griffith Observatory became a huge Hollywood star
• 5 How are galaxies destroyed?

[Physics FAQ] - [Copyright]

By Philip Gibbs, 1997, 1998.

It might be thought that special relativity provides a short negative answer to this question.  In actual fact, there are many trivial ways in which things can be going faster than light (FTL) in a sense, and there may be other more genuine possibilities.  On the other hand, there are also good reasons to believe that real FTL travel and communication will always be unachievable.  This article is not a full answer to the question (which no doubt will continue to be discussed in the newsgroups for the foreseeable future), but it does cover some of the more common points that are repeatedly made.

It is sometimes objected that "they said no-one would ever go faster than sound and they were wrong.  Now they say no-one will ever go faster than light..."   Actually it is probably not true that anybody said it was impossible to go faster than sound.  It was known that rifle bullets go faster than sound long before an aircraft did.  The truth is that some engineers once said that controlled flight faster than sound might be impossible, and they were wrong about that.  FTL travel is a very different matter.  It was inevitable that someone would one day succeed in flying faster than sound, once technology got around the problems.  It is not inevitable that one day technology will enable us to go faster than light.  Relativity has a lot to say about this.  If FTL travel or FTL communication were possible, then causality would probably be violated and some very strange situations would arise.

First we will cover the trivial ways in which things can go FTL.  These points are mentioned not because they are interesting, but because they come up time and time again when FTL is being discussed, and so they are necessary to deal with.  Then we will think about what we mean by non-trivial FTL travel/communication and examine some of the arguments against it.  Finally, we will look at some of the more serious proposals for real FTL.  Many of these things are discussed in more detail elsewhere in the FAQ and hyper-links are provided.  The sections are numbered so that they can be referred to individually.

Trivial FTL Travel

1. cherenkov effect.

One way to go faster than light is to make the light slow down!  Light in vacuum travels at a speed c which is a universal constant (see the FAQ entry Is the speed of light constant? ), but in a dense medium such as water or glass, light slows down to c/n where n is the refractive index of the medium (1.0003 for air, 1.4 for water).  It is certainly possible for particles to travel through air or water faster than light travels in that medium, and Cherenkov radiation is produced as a result.  See the FAQ entry Is there an equivalent of the sonic boom for light? .

When we discuss moving faster than light, we are really talking about exceeding the speed of light in vacuum c (299,792,458 m/s).  The Cherenkov effect is thus not considered to be a real example of FTL travel.

2. Third-Party Observers

If a rocket A is travelling away from me at 0.6c in a westerly direction, and another B is travelling away from me at 0.6c in an easterly direction, then the total distance between A and B as seen in my frame of reference is increasing at 1.2c .  An apparent relative speed greater than c can be observed by a third person in this way.

But this is not what is normally meant by relative speeds.  The true speed of rocket A relative to rocket B is the speed at which an observer in rocket B observes his distance from A to be increasing.  The two speeds must be added using the relativistic formula for addition of velocities.  (See the FAQ entry How do You Add Velocities in Special Relativity? )  In this case the relative speed is actually about 0.88c , so this is not an example of FTL travel.

3. Shadows and Light Spots

Think about how fast a shadow can move.  If you project the shadow of your finger using a nearby lamp onto a distant wall and then wag your finger, the shadow will move much faster than your finger.  If your finger moves parallel to the wall, the shadow's speed will be multiplied by a factor D/d where d is the distance from the lamp to your finger, and D is the distance from the lamp to the wall.  The speed can even be much faster than this if the wall is at an angle to your finger's motion.  If the wall is very far away, the movement of the shadow will be delayed because of the time it takes light to get there, but the shadow's speed is still increased by the same ratio.  The speed of a shadow is therefore not restricted to be less than the speed of light.

This behaviour of a shadow is all about the arrival of successive "pieces of light" (photons, if you will) at a screen.  It is really no different to the faster-than-light speed of a spot on the Moon's surface caused by a laser that has been aimed at that surface and is being waved around on Earth.  Given that the distance to the Moon is 385,000 km, try working out the speed of that spot if you wave the laser at a gentle speed.  You might also like to think about a water wave arriving obliquely at a long straight beach.  How fast can the point at which the wave is breaking travel along the beach?

This sort of thing turns up in Nature; for example, the beam of light from a pulsar can sweep across a dust cloud.  A bright explosion emits an expanding spherical shell of light or other radiation.  When this shell intersects a surface, it creates a circle of light which expands faster than light.  A natural example of this has been observed when an electromagnetic pulse from a lightning flash hits an upper layer of the atmosphere.

These are all examples of "things" that seem to be moving faster than light.  In reality, no object or signal is moving faster that light here.  For a more prosaic example, imagine squirting water from a garden hose at a fence, and moving your aim from one end of the fence to the other.  The intersection point of water stream and fence moves quickly, but of course no thing or signal is really moving along the fence.  A succession of water molecules strikes the fence, but their speed of travel has nothing to do with how quickly you move the hose.  It is a kind of optical illusion for us to think that the wet spot advancing along the fence is a moving object or signal.  The ban in relativity against faster-than-light travel actually concerns the speed of signals (which includes material objects and waves): in a vacuum, no signal is allowed to move faster than light moves in its vicinity.  Neither a moving shadow, nor a laser spot, nor a wet spot on a fence, constitute a signal that is being sent from the initial position of those spots to the final position.  Since these moving spots don't constitute a signal, they are all allowed to move faster than light.  This is not really what we mean by faster-than-light travel, although it shows how difficult it is to define what we really do mean by faster-than-light travel.  See also the FAQ The Superluminal Scissors .

4. Rigid Bodies

If you have a long rigid stick and you hit one end, wouldn't the other end have to move immediately?  Would this not provide a means of FTL communication?

Well, it would if there were such things as perfectly rigid bodies.  In practice the effect of hitting one end of the stick propagates along it at the speed of sound in the material; this speed depends on the stick's elasticity and density.  Relativity places an absolute limit on material rigidity in such a way that the speed of sound in the material will not be greater than c .

The same principle applies if you hold a long string or rod vertically in a gravitational field and let go of the top end.  The point at which you let go will start to move immediately, but the lower end cannot move until the effect has propagated down the length.  That speed of propagation depends on the nature of the material and the strength of the gravitational field.

It is difficult to formulate a general theory of elastic materials in relativity, but the general principle can be illustrated with newtonian mechanics.  The equation for longitudinal motion in an ideal elastic body can be derived from Hooke's law.  In terms of the mass per unit length p and Young's modulus of elasticity Y , the longitudinal displacement X satisfies a wave equation (see for example Goldstein's "Classical Mechanics"):

Plane wave solutions travel at the speed of sound s where s 2 = Y/p .  This wave equation does not allow any causal effect to propagate faster than s .  Relativity therefore imposes a limit on elasticity: Y < pc 2 .  In practice, no known material comes anywhere near this limit.  Note that even if the speed of sound is near c , the matter does not necessarily move at relativistic speeds.  But how can we know that no material can possibly exceed this limit?  The answer is that all materials are made of particles whose interaction are governed by the standard model of particle physics, and no influence faster than light can propagate in that model (see the section on Quantum Field Theory below).

So although there is no such thing as a rigid body, there is such a thing as rigid body motion; but this is another example in the same category as the shadows and light spots described above which do not give FTL communication.  (See also the FAQ articles The Superluminal Scissors and The Rigid Rotating Disk in Relativity ).

5. Phase, Group, and Signal Velocities

Look at this wave equation:

This has solutions of the form:

These solutions are sine waves propagating with a speed

But this is faster than light, so is this the equation for a tachyon field?  (See the paragraph on tachyons below ).  No, it is the usual relativistic equation for an ordinary particle with mass!

Superluminal speeds such as this present no problem once we recognise three types of speed associated with wave motion: phase velocity , group velocity , and signal velocity .  Phase velocity is the velocity of waves that have well-defined wavelengths, and it often varies as a function of this wavelength.  We can combine ("superpose") waves of different wavelengths to build a wave packet , a blob of some specified extent over which the wave disturbance is not small.  This packet does not have a well-defined wavelength, and because it usually spreads out as it travels, it doesn't have a well-defined velocity either; but it does have representative velocity, and this is called its group velocity, which will usually be less than c .  Each of the packet's constituent wave trains travels with its own individual phase velocity, which in some instances will be greater than c .  But it is only possible to send information with such a wave packet at the group velocity (the velocity of the blob), so the phase velocity is yet another example of a speed faster than light that cannot carry a message.

In some situations, we can build a fairly exotic wave packet whose group velocity is greater than c .  Does this then constitute an example of information being sent at a speed faster than light?  It turns out that for these packets, information does not travel at the group velocity; instead, it travels at the signal velocity , which has to do with the time of arrival of the initial rise of the wave front as it reaches its destination.  You might not now be surprised to learn that the signal velocity turns out always to be less than c .

6. Superluminal Galaxies

If something is coming towards you at nearly the speed of light and you measure its apparent speed without taking into account the diminishing time it takes light to reach you from the object, you can get an answer that is faster than light.  This is an optical illusion, and is not due to the object's moving at FTL.  See the FAQ Apparent Superluminal Velocity of Galaxies .

7. Relativistic Rocket

A controller based on Earth is monitoring a space ship moving away at a speed 0.8c .  According to the theory of relativity, he will observe a time dilation that slows the ship's clocks by a factor of 5/3, even after he has taken into account the Doppler shift of signals coming from the space ship.  If he works out the distance moved by the ship divided by the time elapsed as measured by the onboard clocks, he will get an answer of 4/3 c .  He infers from this that the ship's occupants determine themselves to be traversing the distances between stars at speeds greater than the speed of light when measured with their clocks.  From the point of view of the occupants their clocks undergo no slowing; rather, they maintain that it is the distance between the stars which has contracted by a factor of 5/3.  So they also agree that they are covering the known distances between stars at 4/3 c .

This is a real effect which in principle could be used by space travellers to cover very large distances in their lifetimes.  If they accelerate at a constant acceleration equal to the acceleration due to gravity on Earth, they would not only have a perfect artificial gravity on their ship, but would also be able to cross the galaxy in only about 12 years of their own "proper time": that is, they would age 12 years during the journey.  See the FAQ What are the Equations for the Relativistic Rocket?

Nevertheless, this is not true FTL travel.  The effective speed calculated used the distance in one reference frame and the time in another.  This is no way to calculate a speed.  Only the occupants of the ship benefit from this effective speed.  The controller will not measure them to be travelling large distances in his own lifetime.

8. Speed of Gravity

Some people have argued that the speed of gravity in a gravitationally bound system is much greater than c or even infinite.  In fact, gravitational effects and gravitational waves travel at the speed of light c .  See the articles Does Gravity Travel at the Speed of Light? and What is Gravitational Radiation? for the explanation.

9. EPR Paradox

In 1935 Einstein, Podolsky, and Rosen published a thought experiment that seemed to produce a paradox in quantum mechanics, as well as demonstrating that it was incomplete.  Their argument used the fact that there can be an apparent instantaneous interaction in the measurement of two separated particles that have been prepared in a certain "entangled" manner.  Einstein called it "spooky action at a distance".  It has been shown by Eberhard that no information can be passed using this effect; so there is no FTL communication, but the paradox is still very controversial.  See the FAQ article The EPR Paradox and Bell's Inequality for more details.

10. Virtual Photons

In quantum field theory forces are mediated by "virtual particles".  The Heisenberg Uncertainty Principle allows these virtual particles to move faster than light.  But virtual particles are not called "virtual" for nothing.  They are only part of a convenient mathematical notation, and once again, no real FTL travel or communication is possible.  See the FAQ Virtual Particles .

11. Quantum Tunnelling

Quantum Tunnelling is the quantum mechanical effect that permits a particle to pass through a barrier when it does not have enough energy to do so classically.  You can do a calculation of the time it takes a particle to tunnel through such a barrier.  The answer you get can come out less than the time it takes light to cover the distance at speed c .  Does this provide a means of FTL communication? Ref: T. E. Hartman, J. Appl. Phys. 33 , 3427 (1962).

The answer must surely be "No!"—otherwise our understanding of QED is very suspect.  Yet a group of physicists have performed experiments that seem to suggest that FTL communication by quantum tunneling is possible.  They claim to have transmitted Mozart's 40th Symphony through a barrier 11.4cm wide at a speed of 4.7 c .  Their interpretation is, of course, very controversial.  Most physicists say this is a quantum effect where no information can actually be passed at FTL speeds.  If the effect is real it is difficult to see why it should not be possible to transmit signals into the past by placing the apparatus in a fast-moving frame of reference. Refs: W. Heitmann and G. Nimtz, Phys. Lett. A196 , 154 (1994); A. Enders and G. Nimtz, Phys. Rev. E48 , 632 (1993).

Terence Tao has pointed out that apparent FTL transmission of an audio signal over such a short distance is not very impressive.  The signal takes less than 0.4 ns to travel the 11.4 cm at light speed, but it is quite easy to anticipate an audio signal ahead of time by up to 1000 ns simply by extrapolating the signal waveform.  Although this is not what is being done in the above experiments, it does illustrate that the experimenters will need to use a much higher frequency random signal, or transmit over much larger distances, if they are to demonstrate FTL information transfer convincingly.

The likely conclusion is that there is no real FTL communication taking place, and that the effect is another manifestation of the Heisenberg Uncertainty Principle.

12. Casimir Effect

The Casimir Effect describes the fact that a very small but measurable force exists between two uncharged conducting plates when they are very close together.  It is due to the existence of vacuum energy (see the FAQ article on the Casimir Effect ).  A surprising calculation by Scharnhorst suggests that photons travelling across the gap between the plates in the Casimir Effect must go faster than c by a very very small amount (at best 1 part in 10 24 for a 1 nanometre gap.) It has been suggested that in certain cosmological situations, such as in the vicinity of cosmic strings if they exist, the effect could be much more pronounced.  Even so, further theoretical investigations have shown that, once again, there is no possibility of FTL communication using this effect. Refs: K. Scharnhorst, Physics Letters B236 , 354 (1990) S. Ben-Menahem, Physics Letters B250 , 133 (1990) Andrew Gould (Princeton, Inst. Advanced Study). IASSNS-AST-90-25 Barton & Scharnhorst, J. Phys. A26 , 2037 (1993).

13. Expansion of the Universe

According to Hubble's Law, two galaxies that are a distance D apart are moving away from each other at a speed HD , where H is Hubble's constant.  So this interpretation of Hubble's Law implies that two galaxies separated by a distance greater than c/H must be moving away from each other faster than light.  Actually, the modern viewpoint describes this situation differently: general relativity takes the galaxies as being at rest relative to one another, while the space between them is expanding.  In that sense, the galaxies are not moving away from each other faster than light; they are not moving away from each other at all!  This change of viewpoint is not arbitrary; rather, it's in accord with the different but very fruitful view of the universe that general relativity provides.  So the distance between two objects can be increasing faster than light because of the expansion of the universe, but this does not mean, in fact, that their relative speed is faster than light.

As was mentioned above, in special relativity it is possible for two objects to be moving apart by speeds up to twice the speed of light as measured by an observer in a third frame of reference.  In general relativity even this limit can be surpassed, but it will not then be possible to observe both objects at the same time.  Again, this is not real faster-than-light travel; it will not help anyone to travel across the galaxy faster than light.  All that is happening is that the distance between two objects is increasing faster when taken in some cosmological reference frame.

14. The Moon revolves round my head faster than light!

Stand up in a clear space and spin round.  It is not too difficult to turn at one revolution each two seconds.  Suppose the Moon is on the horizon.  How fast is it spinning round your head?  It is about 385,000 km away, so the answer is 1.21 million km/s, which is more than four times the speed of light!  It might sound ridiculous to say that the Moon is going round your head when really it is you who is turning, but according to general relativity all co-ordinate systems are equally valid, including rotating ones.  So isn't the Moon going faster than light?

What it comes down to is the fact that velocities in different places cannot be compared directly in general relativity.  Notice that the Moon is not overtaking any light in its own locality.  The speed of the Moon can only be compared to the speeds of other objects in its own locality.  Indeed, the concept of speed is not a very useful one in general relativity, and this makes it difficult to define what "faster than light" means.  Even the statement that "the speed of light is constant" is open to interpretation in general relativity.  Einstein himself, on page 76 of his book "Relativity: the Special and the General Theory", wrote that the statement cannot claim unlimited validity.  When there is no absolute definition of time and distance it is not so clear how speeds should be determined.

Nevertheless, the modern interpretation is that the speed of light is constant in general relativity and this statement is a tautology given that standard units of distance and time are tied together using the speed of light.  The Moon is given to be moving slower than light because it remains within the "future light cone" propagating from its position at any instant.

Relativity Arguments Against FTL Travel

15. what does "faster than light" mean.

The cases given so far only demonstrate how difficult it is to pin down exactly what we mean by FTL travel or communication.  If we do not include things such as moving shadows, then what exactly do we mean by FTL?

In relativity there is no such thing as absolute velocity, only relative velocity; but there is a clear distinction between "world lines" that are "timelike", "lightlike", and "spacelike".  By "world line" we mean a curve traced out in the four dimensions of space-time.  Such a curve is the set of all events that make up the history of a particle.  If a world line is spacelike then it describes something moving faster than light.  So there is a clear meaning of what is meant by a "faster-than-light" speed which does not depend on the existence of third-party observers.

But what do we mean by an "object" if we don't want to include shadows?  We could define an object to be anything that carries energy, charge, spin, or information; or perhaps just that it must be made of atoms, but there are technical problems in each case.  In general relativity energy cannot be localised, so we had better avoid using energy in our definition.  Charge and spin can be localised, but not every object need have charge or spin.  Using the concept of information is better but tricky to define, and sending information faster than light is really just FTL communication—not FTL travel.  Another difficulty is knowing whether an object seen at A is the same as the one that was earlier seen at B when we claim that it has travelled across the gap faster than light.  Could it not be a duplicate?  It could even be argued that FTL communication makes FTL travel possible, because you can send the blueprint for an object FTL as advance information, and then reconstruct the object—although not everyone would accept such teleportation as FTL travel.

The problems of specifying just what we mean by FTL are more difficult in general relativity.  A valid form of FTL travel may mean distorting space-time (e.g. making a worm hole) to get from A to B without going on a spacelike curve locally.  There is a distinction between going faster than light locally and getting from A to B faster than light globally .  When a gravitational lens bends the light coming from a distant galaxy asymmetrically, the light coming round the galaxy on one side reaches us later than light that left at the same time and went round the other side.  We must avoid a definition of FTL travel that says a particle going from A to B gets there before light that has made the same journey along a lightlike geodesic.  This makes it very difficult, perhaps impossible, to define global FTL travel unambiguously.

If you were expecting me to finish this section with a precise definition of what is meant by FTL travel and FTL communication, I am afraid I must disappoint you!  The above difficulties are insurmountable.  Nonetheless, you will probably recognise the real thing when confronted with it now that I have given some examples of what would not be FTL travel.

16. The Infinite-Energy Argument

When Einstein wrote down his postulates for special relativity, he did not include the statement that you cannot travel faster than light.  There is a misconception that it is possible to derive it as a consequence of the postulates he did give.  Incidentally, it was Henri Poincare who said "Perhaps we must construct a new mechanics [...] in which the speed of light would become an impassable limit."  That was in an address to the International Congress of Arts and Science in 1904—before Einstein announced special relativity in 1905.

It is a consequence of relativity that the energy of a particle of rest mass m moving with speed v is given by

As the speed approaches the speed of light, the particle's energy approaches infinity.  Hence it should be impossible to accelerate an object with rest mass to the speed of light; also, particles with zero rest mass must always move at exactly the speed of light, since otherwise they would have no energy.  This is sometimes called the "light speed barrier", but it is very different from the "sound speed barrier".  As an aircraft approaches the speed of sound it starts to feel pressure waves which indicate that it is moving close to the speed of sound, and before the existence and effects of these waves were well understood, they destroyed several aircraft in the mid 20th century; hence the old name of sound "barrier".  In fact, with more thrust and the right aerodynamics, an aircraft can certainly pass through the sound barrier.

The situation is different for light.  As the light speed barrier is approached (in a perfect vacuum) there are no such waves according to relativity (destructive or otherwise).  Moving at 0.999 c is just like standing still with everything rushing past you at −0.999 c .  Particles are routinely pushed to these speeds and beyond in accelerators, so the theory is well established.  Trying to attain the speed of light in this way is a matter of chasing something that is forever just out of your reach.

This explains why it is not possible to exceed the speed of light by ordinary mechanical means.  But it does not in itself rule out FTL travel.  It is really just one way in which things cannot be made to go faster than light, rather than a proof that there is no way to do so.  Particles are known to decay instantly into other particles which fly off at high speed.  It is not necessary to think in terms of the particles' having been accelerated, so how could we say that they could not go faster than light?  What about the possibility of particles that might always have been moving faster than light, and which might be used to send information if they can be detected without ever slowing down to less than the speed of light?  Even if such "tachyons" don't exist (and we don't believe that they do exist), there may be ways of moving matter from A to B faster than light is able to travel from A to B by the usual route, but without anything having to go at a FTL speed locally.  See the paragraph on tachyons below .

17. Quantum Field Theory

Except for gravity, all physical phenomena are observed to comply with the "Standard Model" of particle physics.  The Standard Model is a relativistic quantum field theory which incorporates the nuclear and electromagnetic forces as well as all the observed particles.  In this theory, any pair of operators corresponding to physical observables at space-time events separated by a spacelike interval "commute" (i.e. their order can be reversed).  In principle, this implies that effects cannot propagate faster than light in the standard model, and it can be regarded as the quantum field theory equivalent of the infinite energy argument.

But no completely rigorous proofs of anything exist in the quantum field theory of the Standard Model, since no one has yet succeeded in showing that the theory is completely self consistent; and in fact, most likely it is not!  In any case, there is no guarantee that there are not other undiscovered particles and forces that disobey the no-FTL rule.  Nor is there any generalisation that takes gravity and general relativity into account.  Many physicists working on quantum gravity doubt that such simplistic expressions of causality and locality will be generalised.  All told, there is no guarantee that light speed will be meaningful as a speed limit in a more complete theory that might arise in the future.

18. Grandfather Paradox

A better argument against FTL travel is the Grandfather Paradox.  In special relativity, a particle moving FTL in one frame of reference will be travelling back in time in another.  FTL travel or communication should therefore also give the possibility of travelling back in time or sending messages into the past.  If such time travel is possible, you would be able to go back in time and change the course of history by killing your own grandfather.  This is a very strong argument against FTL travel, but it leaves open the perhaps-unlikely possibility that we may be able to make limited journeys at FTL speed that did not allow us to come back.  Or it may be that time travel is possible and causality breaks down in some consistent fashion when FTL travel is achieved.  That is not very likely either, but if we are discussing FTL then we had better keep an open mind.

Conversely, if we could travel back in time we might also claim the ability to travel FTL, because we can go back in time and then travel at a slow speed to arrive somewhere before light got there by the usual route.  See the FAQ article on Time Travel for more on this subject.

Open Possibilities for FTL Travel

In this last section I give a few of the speculative but serious suggestions for possible faster-than-light travel.  These are not the kinds of thing usually included in the FAQ because they raise more questions than answers.  They are included merely to make the point that serious research is being done in this direction.  Only a brief introduction to each topic is given; more information can be found all over the Internet (and should, like almost everything on the Internet, be taken with a huge grain of salt!).

19. Tachyons

Tachyons are hypothetical particles that travel faster than light locally.  Their mass must take on imaginary values (i.e. to do with the square root of −1) to be able to do so, but they have real-valued energy and momentum.  Sometimes people imagine that such FTL particles would be impossible to detect, but there is no reason to think so.  Shadows and spotlights suffice to show that there is no logic in this suggestion, because they can certainly go FTL and still be seen.

No tachyons have definitely been found and most physicists doubt their existence.  There has been a claim that experiments to measure neutrino mass in tritium beta decay indicated that the neutrinos were tachyonic. ; while this is very doubtful, it is not entirely ruled out.  Tachyon theories have problems because, apart from the possibility of causality violations, they destabilise the vacuum.  It may be possible to get around such difficulties—but then we would not be able to use tachyons for the kind of FTL communication that we would like.

The truth is that most physicists consider tachyons to be a sign of pathological behaviour in field theories, and the interest in them among the wider public stems mostly from the fact that they are used so often in science fiction.  See the FAQ article on Tachyons .

20. Worm Holes

A famous proposition for global FTL travel is to use "worm holes".  Worm holes are shortcuts through space-time from one place in the universe to another which would permit you to go from one end to the other in a shorter time than it would take light passing by the usual route.  Worm holes are a feature of classical general relativity, but to create them you have to change the topology of space-time.  That might be possible within a theory of quantum gravity.

To keep a worm hole open, regions of negative energy would be needed.  Misner and Thorne have suggested using the Casimir Effect on a grand scale to generate the negative energy, while Visser has proposed a solution involving cosmic strings.  These are very speculative ideas which may simply not be possible.  Exotic matter with negative energy may not exist in the form required.

Thorne has found that if worm holes can be created, then they can be used to construct closed timelike loops in space-time which would imply the possibility of time travel.  It has been suggested that the "multiverse" interpretation of quantum mechanics (many universes co-existing) gets you out of trouble by allowing time to evolve differently if you succeed in going back to a previous time.  But multiverses are entirely out of keeping with the Ockham's Razor approach to doing science, and constitute more of a popular interpretation of quantum mechanics than a serious physical theory.  Hawking says that worm holes would simply be unstable and therefore unusable.  The subject remains a fertile area for thought experiments that help clarify what is and what is not possible according to known and suggested laws of physics. Refs: W. G. Morris and K. S. Thorne, American Journal of Physics 56 , 395–412 (1988) W. G. Morris, K. S. Thorne, and U. Yurtsever, Phys. Rev. Letters 61 , 1446–9 (1988) Matt Visser, Physical Review D39 , 3182–4 (1989) See also "Black Holes and Time Warps", Kip Thorne, Norton & co. (1994) For an explanation of the multiverse see "The Fabric of Reality" David Deutsch, Penguin Press.

21. Warp Drives

A "warp drive" such as used in the Star Trek science fiction series would be a mechanism for warping space-time in such a way that an object could move faster than light.  Miguel Alcubierre made himself famous by working out a space-time geometry which describes such a warp drive.  The warp in space-time makes it possible for an object to go FTL while remaining on a timelike curve.  The main catch is the same one that may stop us making large worm holes.  To make such a warp, you would need exotic matter with negative energy density.  Even if such exotic matter can exist, it is not clear how it could be deployed to make the warp drive work. Ref.   M. Alcubierre, Classical and Quantum Gravity, 11 , L73–L77, (1994). Ref.   S. Finazzi, S. Liberati, C. Barcel�, Semiclassical instability of dynamical warp drives at arxiv.org.

• To begin with, it is rather difficult to define exactly what is really meant by FTL travel and FTL communication.  Many things such as shadows can go FTL, but not in a useful way that can carry information.
• There are several serious possibilities for real FTL which have been proposed in the scientific literature, but these always come with technical difficulties.
• The Heisenberg Uncertainty Principle tends to stop the use of apparent FTL quantum effects for sending information or matter.
• In general relativity there are potential means of FTL travel, but they may be impossible to make work.  It is thought highly unlikely that engineers will be building space ships with FTL drives in the foreseeable future, if ever, but it is curious that theoretical physics as we presently understand it seems to leave the door open to the possibility.
• FTL travel of the sort science fiction writers would like is almost certainly impossible.  For physicists the interesting question is "why is it impossible and what can we learn from that?"

share this!

March 9, 2021

Breaking the warp barrier for faster-than-light travel

by University of Göttingen

If travel to distant stars within an individual's lifetime is going to be possible, a means of faster-than-light propulsion will have to be found. To date, even recent research about superluminal (faster-than-light) transport based on Einstein's theory of general relativity would require vast amounts of hypothetical particles and states of matter that have 'exotic' physical properties such as negative energy density. This type of matter either cannot currently be found or cannot be manufactured in viable quantities. In contrast, new research carried out at the University of Göttingen gets around this problem by constructing a new class of hyper-fast 'solitons' using sources with only positive energies that can enable travel at any speed. This reignites debate about the possibility of faster-than-light travel based on conventional physics. The research is published in the journal Classical and Quantum Gravity .

The author of the paper, Dr. Erik Lentz, analyzed existing research and discovered gaps in previous 'warp drive' studies. Lentz noticed that there existed yet-to-be explored configurations of space-time curvature organized into 'solitons' that have the potential to solve the puzzle while being physically viable. A soliton—in this context also informally referred to as a 'warp bubble'—is a compact wave that maintains its shape and moves at constant velocity. Lentz derived the Einstein equations for unexplored soliton configurations (where the space-time metric's shift vector components obey a hyperbolic relation), finding that the altered space-time geometries could be formed in a way that worked even with conventional energy sources. In essence, the new method uses the very structure of space and time arranged in a soliton to provide a solution to faster-than-light travel , which—unlike other research—would only need sources with positive energy densities. No exotic negative energy densities needed.

If sufficient energy could be generated, the equations used in this research would allow space travel to Proxima Centauri, our nearest star, and back to Earth in years instead of decades or millennia. That means an individual could travel there and back within their lifetime. In comparison, the current rocket technology would take more than 50,000 years for a one-way journey. In addition, the solitons (warp bubbles) were configured to contain a region with minimal tidal forces such that the passing of time inside the soliton matches the time outside: an ideal environment for a spacecraft. This means there would not be the complications of the so-called 'twin paradox' whereby one twin traveling near the speed of light would age much more slowly than the other twin who stayed on Earth: in fact, according to the recent equations both twins would be the same age when reunited.

"This work has moved the problem of faster-than-light travel one step away from theoretical research in fundamental physics and closer to engineering. The next step is to figure out how to bring down the astronomical amount of energy needed to within the range of today's technologies, such as a large modern nuclear fission power plant. Then we can talk about building the first prototypes," says Lentz.

Currently, the amount of energy required for this new type of space propulsion drive is still immense. Lentz explains, "The energy required for this drive traveling at light speed encompassing a spacecraft of 100 meters in radius is on the order of hundreds of times of the mass of the planet Jupiter. The energy savings would need to be drastic, of approximately 30 orders of magnitude to be in range of modern nuclear fission reactors." He goes on to say: "Fortunately, several energy-saving mechanisms have been proposed in earlier research that can potentially lower the energy required by nearly 60 orders of magnitude." Lentz is currently in the early-stages of determining if these methods can be modified, or if new mechanisms are needed to bring the energy required down to what is currently possible.

Provided by University of Göttingen

Explore further

Feedback to editors

Saturday Citations: Bacterial warfare, a self-programming language model, passive cooling in the big city

11 hours ago

Some CRISPR screens may be missing cancer drug targets

17 hours ago

Novel photocatalyst enables efficient ester reduction with blue light

20 hours ago

Physicists confirm quantum entanglement persists between top quarks, the heaviest known fundamental particles

Jun 14, 2024

25 years of massive fusion energy experiment data open on the 'cloud' and available to everyone

Quantum entangled photons react to Earth's spin

Q&A: Barrier islands and dunes protect coastlines, but how are environmental changes affecting them and adjacent land?

A new weapon in the battle against antibiotic resistance: Temperature

Sharks have depleted functional diversity compared to the last 66 million years, study finds

Quebec lake meteorite impact yields rare rocks and evidence of extreme heat

Relevant physicsforums posts, do entanglement networks encode a unique, local historical record.

6 hours ago

Transferring information faster than the speed of light

15 hours ago

Field Operator for Edge States

21 hours ago

On partial trace in quantum theory

Can energy be stored in a single particle indefinitely, can humans really create the quantum computer they expected.

More from Quantum Physics

Related Stories

A potential model for a real physical warp drive

Mar 4, 2021

Don't stop me now! Superluminal travel in Einstein's universe

Nov 27, 2015

There's no way to measure the speed of light in a single direction

Jan 11, 2021

Colliding solitons in optical microresonators to reveal important fundamental physics

Apr 24, 2020

High Altitude Water Cherenkov observatory tests speed of light

Mar 31, 2020

The trouble with rockets

Jan 5, 2018

Recommended for you

Exploring the origin of polaron formation in halide perovskites

Researchers tune Casimir force using magnetic fields

Jun 13, 2024

Liquid crystal source of photon pairs opens path to new generation of quantum sources

New theory describes how waves carry information from surroundings

Jun 12, 2024

Let us know if there is a problem with our content

Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form . For general feedback, use the public comments section below (please adhere to guidelines ).

Please select the most appropriate category to facilitate processing of your request

Thank you for taking time to provide your feedback to the editors.

Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.

E-mail the story

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Newsletter sign up

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.

More information Privacy policy

Donate and enjoy an ad-free experience

We keep our content available to everyone. Consider supporting Science X's mission by getting a premium account.

E-mail newsletter

What is the future of travel?

All aboard! After the pandemic upended life and leisure as we know it, travel is roaring back. The industry is set to make a full recovery by the end of 2024, after losing 75 percent of its value in 2020. Much of this has been so-called “revenge travel,” or people embarking on international or bucket list trips that were delayed by the pandemic. But domestic travel is recovering quickly too and is set to represent 70 percent of travel spending by 2030.

Get to know and directly engage with senior McKinsey experts on travel and tourism

Margaux Constantin is a partner in McKinsey’s Dubai office, Matteo Pacca is a senior partner in the Paris office, and Vik Krishnan is a senior partner in the Bay Area office.

We’ve done a deep dive into the latest travel trends and how industry players can adjust accordingly in The state of travel and hospitality 2024 report. Check out the highlights below, as well as McKinsey’s insights on AI in travel, mass tourism, and much more.

Learn more about McKinsey’s Travel, Logistics, and Infrastructure Practice .

Who are today’s travelers, and what do they want?

In February and March 2024, McKinsey surveyed  5,000 people in China, Germany, the United Arab Emirates (UAE), the United Kingdom, and the United States who had taken at least one leisure trip in the past two years. Here are six highlights from the results of that survey:

• Travel is a top priority, especially for younger generations. Sixty-six percent of travelers we surveyed said they are more interested in travel now than before the COVID-19 pandemic. And millennials and Gen Zers  are traveling more and spending a higher share of their income on travel than their older counterparts.
• Younger travelers are keen to travel abroad. Gen Zers and millennials who responded to our survey are planning nearly an equal number of international and domestic trips in 2024. Older generations are planning to take twice as many domestic trips.
• Baby boomers are willing to spend if they see value. Baby boomers still account for 20 percent of overall travel spending. They are willing to spend on comforts such as nonstop flights. On the other hand, they are more willing to forego experiences to save money while traveling, unlike Gen Zers who will cut all other expense categories before they trim experiences.
• Travel is a collective story, with destinations as the backdrop. Travelers both want to hear other travelers’ stories and share their own. Ninety-two percent of younger travelers were inspired by social media in some shape or form for their last trip.
• What travelers want depends on where they’re from. Sixty-nine percent of Chinese respondents said they plan to visit a famous sight on their next trip, versus the 20 percent of European and North American travelers who said the same. Respondents living in the UAE also favor iconic destinations, as well as shopping and outdoor activities.

Learn more about McKinsey’s  Travel, Logistics, and Infrastructure Practice .

What are the top three travel industry trends today?

Travel is back, but traveler flows are shifting. McKinsey has isolated three major themes for industry stakeholders to consider as they look ahead.

• The bulk of travel spending is close to home. Seventy-five percent of travel spend is domestic. The United States is currently the world’s largest domestic travel market, but China is set to overtake it in the coming years. Stakeholders should make sure they capture the full potential of domestic travelers before turning their attention abroad.
• New markets such as India, Southeast Asia, and Eastern Europe are growing sources of outbound tourism. Indians’ travel spending is expected to grow 9 percent per year between now and 2030; annual growth projections for Southeast Asians and Eastern Europeans are both around 7 percent.
• Unexpected destinations are finding new ways to lure travelers and establish themselves alongside enduring favorites. Rwanda, for example, has capitalized on sustainable tourism by limiting gorilla trekking permits and directing revenue toward conservation.

Introducing McKinsey Explainers : Direct answers to complex questions

For a more in-depth look at these trends, check out McKinsey’s State of travel and hospitality 2024   report .

How will AI change how people travel?

In the 1950s, the introduction of the jet engine dramatically reduced travel times, changing the way people traveled forever. Now AI is upending the industry  in a similarly fundamental way. Industry players down to individual travelers are using advances in generative AI (gen AI) , machine learning , and deep learning  to reimagine what it means to plan, book, and experience travel. “It’s quite clear,” says McKinsey partner Vik Krishnan , “that gen AI significantly eases  the process of travel discovery.”

For travel companies, the task now is to rethink how they interact with customers, develop products and services, and manage operations in the age of AI. According to estimates by McKinsey Digital, companies that holistically address digital and analytics opportunities have the potential to see an earnings improvement of up to 25 percent .

McKinsey and Skift Research interviewed executives from 17 companies across five types of travel business. Here are three key findings on how travel companies can reckon with emerging technologies, drawn from the resulting report The promise of travel in the age of AI :

• Segmentation. Companies can use AI to create hyperspecific customer segments to guide how they interact with and serve customers. Segmentation can be based on a single macro characteristic (such as business versus leisure), or it can be so specific as to relate to just one customer.
• Surprise and delight. In the travel context, gen AI could take the form of digital assistants that interact with customers throughout their journeys, providing personalized trip itineraries and tailored recommendations and helping to resolve unexpected disruptions.
• Equipping workers better. AI tools can free up frontline workers’ time, allowing them to focus more on personal customer interactions. These tools can also shorten the training time for new hires and quickly upskill  the existing workforce.

AI is important, yes. But, according to Ella Alkalay Schreiber, general manager (GM) of fintech at Hopper, “The actual challenge is to understand the data, ask the right questions, read prediction versus actual, and do this in a timely manner. The actual challenge is the human thinking, the common sense .”

How is mass tourism changing travel?

More people are traveling than ever before. The most visited destinations are experiencing more concentrated flows of tourists ; 80 percent of travelers visit just 10 percent of the world’s tourist destinations. Mass tourism can encumber infrastructure, frustrate locals, and even harm the attractions that visitors came to see in the first place.

Tourism stakeholders can collectively look for better ways to handle visitor flows before they become overwhelming. Destinations should remain alert to early warning signs about high tourism concentration and work to maximize the benefits of tourism, while minimizing its negative impacts.

For one thing, destinations should understand their carrying capacity of tourists—that means the specific number of visitors a destination can accommodate before harm is caused to its physical, economic, or sociocultural environment. Shutting down tourism once the carrying capacity is reached isn’t always possible—or advisable. Rather, destinations should focus on increasing carrying capacity to enable more growth.

Next, destinations should assess their readiness to handle mass tourism and choose funding sources and mechanisms that can address its impacts. Implementing permitting systems for individual attractions can help manage capacity and mitigate harm. Proceeds from tourism can be reinvested into local communities to ensure that residents are not solely responsible for repairing the wear and tear caused by visitors.

After risks and funding sources have been identified, destinations can prepare for growing tourist volumes in the following ways:

• Build and equip a tourism-ready workforce to deliver positive tourism experiences.
• Use data (gathered from governments, businesses, social media platforms, and other sources) to manage visitor flows.
• Be deliberate about which tourist segments to attract (business travelers, sports fans, party groups, et cetera), and tailor offerings and communications accordingly.
• Distribute visitor footfall across different areas, nudging tourists to visit less-trafficked locations, and during different times, promoting off-season travel.
• Be prepared for sudden, unexpected fluctuations triggered by viral social media and cultural trends.
• Preserve cultural and natural heritage. Engage locals, especially indigenous people, to find the balance between preservation and tourism.

How can the travel sector accelerate the net-zero transition?

Global warming is getting worse, and the travel sector contributes up to 11 percent of total carbon emissions. Many consumers are aware that travel is part of the problem, but they’re reticent to give up their trips: travel activity is expected to soar by 85 percent  from 2016 to 2030. Instead, they’re increasing pressure on companies in the travel sector to achieve net zero . It’s a tall order: the range of decarbonization technologies in the market is limited, and what’s available is expensive.

But decarbonization doesn’t have to be a loss-leading proposition. Here are four steps  travel companies can take toward decarbonization that can potentially create value:

• Identify and sequence decarbonization initiatives. Awareness of decarbonization levers is one thing; implementation is quite another. One useful tool to help develop an implementation plan is the marginal abatement cost curve pathway framework, which provides a cost-benefit analysis of individual decarbonization levers and phasing plans.
• Partner to accelerate decarbonization of business travel. Many organizations will reduce their business travel, which accounts for 30 percent of all travel spend. This represents an opportunity for travel companies to partner with corporate clients on decarbonization. Travel companies can support their partners in achieving their decarbonization goals by nudging corporate users to make more sustainable choices, while making reservations and providing data to help partners track their emissions.
• Close the ‘say–do’ gap among leisure travelers. One McKinsey survey indicates that 40 percent of travelers globally say they are willing to pay at least 2 percent more for carbon-neutral flights. But Skift’s latest consumer survey reveals that only 14 percent  of travelers said they actually paid more for sustainable travel options. Travel companies can help close this gap by making sustainable options more visible during booking and using behavioral science to encourage travelers to make sustainable purchases.
• Build new sustainable travel options for the future. The travel sector can proactively pioneer sustainable new products and services. Green business building will require companies to create special initiatives, led by teams empowered to experiment without the pressure of being immediately profitable.

What’s the future of air travel?

Air travel is becoming more seasonal, as leisure travel’s increasing share of the market creates more pronounced summer peaks. Airlines have responded by shifting their schedules to operate more routes at greater frequency during peak periods. But airlines have run into turbulence when adjusting to the new reality. Meeting summer demand means buying more aircraft and hiring more crew; come winter, these resources go unutilized, which lowers productivity . But when airlines don’t run more flights in the summer, they leave a lot of money on the table.

How can airlines respond to seasonality? Here are three approaches :

• Mitigate winter weakness by employing conventional pricing and revenue management techniques, as well as creative pricing approaches (including, for example, monitoring and quickly seizing on sudden travel demand spikes, such as those created by a period of unexpectedly sunny weather).
• Adapt to seasonality by moving crew training sessions to off-peak periods, encouraging employee holiday taking during trough months, and offering workers seasonal contracts. Airlines can also explore outsourcing of crew, aircraft, maintenance, and even insurance.
• Leverage summer strengths, ensuring that commercial contracts reflect summer’s higher margins.

How is the luxury travel space evolving?

Quickly. Luxury travelers are not who you might expect: many are under the age of 60 and not necessarily from Europe or the United States. Perhaps even more surprisingly, they are not all millionaires: 35 percent of luxury-travel spending is by travelers with net worths between $100,000 and $1 million. Members of this group are known as aspirational luxury travelers, and they have their own set of preferences. They might be willing to spend big on one aspect of their trip—a special meal or a single flight upgrade—but not on every travel component. They prefer visibly branded luxury and pay close attention to loyalty program points and benefits .

The luxury-hospitality space is projected to grow faster than any other segment, at 6 percent per year  through 2025. And competition for luxury hotels is intensifying too: customers now have the option of renting luxurious villas with staff, or booking nonluxury hotels with luxury accoutrements such as rainfall showerheads and mattress toppers.

Another critical evolution is that the modern consumer, in the luxury space and elsewhere, values experiences over tangible things (exhibit).

Luxury properties may see more return from investing in a culture of excellence—powered by staff who anticipate customer needs, exceed expectations, create cherished memories, and make it all feel seamless—than in marble floors and gold-plated bath fixtures. Here are a few ways luxury properties can foster a culture of excellence :

• Leaders should assume the role of chief culture officer. GMs of luxury properties should lead by example, to help nurture a healthy and happy staff culture, and listen and respond to staff concerns.
• Hire for personalities, not resumes. “You can teach someone how to set a table,” said one GM we interviewed, “but you can’t teach a positive disposition.”
• Celebrate and reward employees. Best-in-class service is about treating customers with generosity and care. Leaders in the service sector can model this behavior by treating employees similarly.
• Create a truly distinctive customer experience . McKinsey research has shown that the top factor influencing customer loyalty in the lodging sector is “an experience worth paying more for”—not the product. Train staff to focus on tiny details as well as major needs to deliver true personalization.

What’s the latest in travel loyalty programs?

Loyalty programs are big business . They’ve evolved past being simply ways to boost sales or strengthen customer relationships; now, for many travel companies, they are profit centers in their own right. One major development was that travel companies realized they could sell loyalty points in bulk to corporate partners, who in turn offered the points to their customers as rewards. In 2019, United’s MileagePlus loyalty program sold $3.8 billion worth of miles to third parties, which accounted for 12 percent of the airline’s total revenue for that year. In 2022, American Airlines’ loyalty program brought in $3.1 billion in revenue, and Marriott’s brought in $2.7 billion.

But as this transition has happened, travel players have shifted focus away from the original purpose of these programs. Travel companies are seeing these loyalty programs primarily as revenue generators, rather than ways to improve customer experiences . As a result, loyalty program members have become increasingly disloyal. Recent loyalty surveys conducted by McKinsey revealed a steep decline in the likelihood that a customer would recommend airline, hotel, and cruise line loyalty programs to a friend. The same surveys also found that airline loyalty programs are driving fewer customer behavior changes than they used to.

So how can travel brands win customers’ loyalty back? Here are three steps to consider:

• Put experience at the core of loyalty programs. According to our 2023 McKinsey Travel Loyalty Survey , American respondents said they feel more loyal to Amazon than to the top six travel players combined, despite the absence of any traditional loyalty program. One of the reasons for Amazon’s success may be the frictionless experience it provides customers. Companies should strive to design loyalty programs around experiential benefits that make travelers feel special and seamlessly integrate customer experiences between desktop, mobile, and physical locations.
• Use data to offer personalization  to members. Travel brands have had access to customer data for a long time. But many have yet to deploy it for maximum value. Companies can use personalization to tailor both experiences and offers for loyalty members; our research has shown that 78 percent  of consumers are more likely to make a repeat purchase when offered a personalized experience.
• Rethink partnerships. Traditionally, travel companies have partnered with banks to offer cobranded credit cards. But many credit card brands now offer their own, self-branded travel rewards ecosystems. These types of partnerships may have diminishing returns in the future. When rethinking partnerships, travel brands should seek to build richer connections with customers, while boosting engagement. Uber’s partnership with Marriott, for example, gives users the option to link the brands’ loyalty programs, tapping into two large customer bases and providing more convenient travel experiences.

In a changing travel ecosystem, travel brands will need to ask themselves some hard questions if they want to earn back their customers’ loyalty.

Learn more about McKinsey’s Travel, Logistics, and Infrastructure Practice . And check out travel-related job opportunities if you’re interested in working at McKinsey.

Articles referenced include:

• “ Updating perceptions about today’s luxury traveler ,” May 29, 2024, Caroline Tufft , Margaux Constantin , Matteo Pacca , and Ryan Mann
• “ Now boarding: Faces, places, and trends shaping tourism in 2024 ,” May 29, 2024, Caroline Tufft , Margaux Constantin , Matteo Pacca , and Ryan Mann
• “ Destination readiness: Preparing for the tourist flows of tomorrow ,” May 29, 2024, Caroline Tufft , Margaux Constantin , Matteo Pacca , and Ryan Mann
• “ How the world’s best hotels deliver exceptional customer experience ,” March 18, 2024, Ryan Mann , Ellen Scully, Matthew Straus, and Jillian Tellez Holub
• “ How airlines can handle busier summers—and comparatively quiet winters ,” January 8, 2024, Jaap Bouwer, Ludwig Hausmann , Nina Lind , Christophe Verstreken, and Stavros Xanthopoulos
• “ Travel invented loyalty as we know it. Now it’s time for reinvention. ,” November 15, 2023, Lidiya Chapple, Clay Cowan, Ellen Scully, and Jillian Tellez Holub
• “ What AI means for travel—now and in the future ,” November 2, 2023, Alex Cosmas  and Vik Krishnan
• “ The promise of travel in the age of AI ,” September 27, 2023, Susann Almasi, Alex Cosmas , Sam Cowan, and Ben Ellencweig
• “ The future of tourism: Bridging the labor gap enhancing customer experience ,” August 1, 2023, Urs Binggeli, Zi Chen, Steffen Köpke, and Jackey Yu
• “ Hotels in the 2030s: Perspectives from Accor’s C-suite ,” July 27, 2023, Aurélia Bettati
• “ Tourism in the metaverse: Can travel go virtual? ,” May 4, 2023, Margaux Constantin , Giuseppe Genovese, Kashiff Munawar, and Rebecca Stone
• “ Three innovations to solve hotel staffing shortages ,” April 3, 2023, Ryan Mann , Esteban Ramirez, and Matthew Straus
• “ Accelerating the transition to net-zero travel ,” September 20, 2022, Danielle Bozarth , Olivier Cheret, Vik Krishnan , Mackenzie Murphy, and Jules Seeley
• “ The six secrets of profitable airlines ,” June 28, 2022, Jaap Bouwer, Alex Dichter , Vik Krishnan , and Steve Saxon
• “ How to ‘ACE’ hospitality recruitment ,” June 23, 2022, Margaux Constantin , Steffen Köpke, and Joost Krämer
• “ Opportunities for industry leaders as new travelers take to the skies ,” April 5, 2022, Mishal Ahmad, Frederik Franz, Tomas Nauclér, and Daniel Riefer
• “ Rebooting customer experience to bring back the magic of travel ,” September 21, 2021, Vik Krishnan , Kevin Neher, Maurice Obeid , Ellen Scully, and Jules Seeley

Want to know more about the future of travel?

Related articles.

The promise of travel in the age of AI

Travel Disruptors: Bringing fintech to travel booking