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

Wormhole Passage

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. 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?

Alcubierre

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.

One Sided Spacetime Curvatures

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.

Originally published on The Conversation.

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

  1. 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. ☝️

  2. Mintas Lanxor | May 17, 2021 at 9:26 am | Reply

    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. ☝️

  3. Lance L. Landon | May 17, 2021 at 10:59 am | Reply

    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.

  4. Arnold J. Barzydlo | May 17, 2021 at 4:46 pm | Reply

    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.

  5. Babu G. Ranganathan | May 18, 2021 at 8:46 am | Reply

    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.

  6. Albert Barnett | May 18, 2021 at 12:54 pm | Reply

    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!

  7. 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?

  8. 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.

  9. Marin Tomuța | June 12, 2021 at 4:28 pm | Reply

    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.

  10. Marin Tomuța | June 12, 2021 at 4:32 pm | Reply

    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.

    • Marin Tomuța | June 12, 2021 at 4:34 pm | Reply

      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?)

      • Marin Tomuța | June 12, 2021 at 4:44 pm | Reply

        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?

      • Marin Tomuța | June 12, 2021 at 4:52 pm | Reply

        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.

        • Marin Tomuța | June 12, 2021 at 5:04 pm | Reply

          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’?

  11. Marin Tomuța | June 12, 2021 at 5:06 pm | Reply

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

  12. Marin Tomuța | June 12, 2021 at 5:09 pm | Reply

    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.

  13. Marin Tomuța | June 12, 2021 at 5:28 pm | Reply

    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).

  14. Marin Tomuța | June 12, 2021 at 5:30 pm | Reply

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

    • Marin Tomuța | June 12, 2021 at 5:47 pm | Reply

      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.)

  15. Marin Tomuța | June 12, 2021 at 5:49 pm | Reply

    Imagination is the key; the crazier the better.

  16. Marin Tomuța | June 12, 2021 at 6:12 pm | Reply

    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.

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