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Is It Possible To Build a Warp Drive? (popularmechanics.com) 166

appedology.pk quotes Popular Mechanics: Warp drive is one of the many futuristic ideas proposed in Star Trek, allowing for faster-than-light travel across the galaxy. Einstein's Theory of Relativity prevents anything from moving faster than light. In 1994, a theoretical physicist proposed a workaround: creating a bubble within space-time that would twist distances, allowing anything within the bubble to travel long distances. Many think it makes theoretical sense, but is practically unworkable. An undergrad at the University of Alabama wants to restart the conversation, and he's focused on how much energy such a bubble would need...

"Mathematically, if you fulfill all the energy requirements, they can't prove that it doesn't work," he recently said at a standing-room only talk on the subject.... "People used to say, 'You're dealing in something that would be great, but it takes the mass of the entire universe to do it,'" Agnew said. "Now, we're down to where it is still an immense amount of energy and exotic matter is still a problem, but if we had that energy, we could do it."

After five to eight years of theoretical work, Agnew said, "it's been reduced by many, many orders of magnitude."

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Is It Possible To Build a Warp Drive?

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  • by Akardam ( 186995 ) on Sunday October 06, 2019 @11:38AM (#59275506)

    ... eventually. Probably. Who knows. But us human beans are pretty good at doing something if we put our minds to it (for long enough).

    In the mean time, it's great that the theoretical work is ongoing. No, I mean it. If the theory and resultant engineering come together in my lifetime, I'll become very interested. Until then, I'll derive occasional small pleasure by hearing about the latest theory work.

    • My take on "inmy lifetime" is, well im 45, and so if i sort out my dumb neglect part of my health (ie exercise, eat better and quit the vapes) and dont get ambushed by the big C or a random heart whoops, I've got another 40 years left on me, knock on wood. I figure I'll live long enough to see humanity perhaps do some interesting stuff on mars, but me almost certainly not leaving the planet.

      So... what I'd really like out of science is to hurry up and solve this ageing shit, so I vcan throw another hundred o

      • Re: (Score:3, Insightful)

        Comment removed based on user account deletion
        • I flailed around for about 30 seconds earlier trying to get up off a bean bag.

          In my 50's here - I'd probably have to change my forwarding address to the bean bag.

      • by gweihir ( 88907 )

        It is rather unlikely we will get to Mars in this time. If all the psychopathic morons stop pouring so much money into weapons, wars and getting rich, we may have a permanent Moon-base and the climate fixed in that time, but I do not have high hopes either way.

  • Mathematically, if you fulfill all the energy requirements, they can't prove that it doesn't work,

    Now, all they need to do is prove the theory is valid.

    • Re:in theory... (Score:4, Insightful)

      by careysub ( 976506 ) on Sunday October 06, 2019 @12:11PM (#59275590)

      Mathematically, if you fulfill all the energy requirements, they can't prove that it doesn't work,

      Now, all they need to do is prove the theory is valid.

      Bingo! This is the fundamental problem with the Alcubierre drive and similar. No contradiction with General Relativity has been shown, but is also has not been shown that the theory is physically meaningful. No means of testing it have been proposed.

      This paper consists of determining how much "energy", actually how much exotic matter of a type not known to exist, would be required to create a warp "pocket". Sort of like using tachyons for communication. They don't contradict GR but we also have no reason to believe they exist.

      Restarting the conversation should really address showing that the theory is valid, and whether the required exotic matter is real, not debating "how much energy it would take". Without a valid theory this is just arguing about angels dancing on the head of a pin.

      • ...but is also has not been shown that the theory is physically meaningful.

        Actually I would argue that it has been shown that it is NOT physically meaningful because it relies on a type of matter that has not only never been seen but is also not needed to explain any current observation. We know the Standard Model is incomplete but none of the extensions to it add exotic matter with negative mass to explain phenomena that the SM cannot account for.

        Indeed the existence of such matter would likely create significant problems not least because it would potentially let you create

      • by sjames ( 1099 )

        How much energy it would take has a lot of bearing on the question "can we ever test this?". If it's more energy than there is in the universe, we can drop it because there can be no test. If it's MANY orders of magnitude less than that, then perhaps.

      • by HiThere ( 15173 )

        I've never encountered a decent explanation of what it would be like. What it's characteristics would be. What it would be like to be a passenger.

        I think we can be rather certain that it wouldn't be much like the Star Trek version, but that doesn't help much.

    • But science never proves theories valid. It only disproves them.
      • Re:in theory... (Score:4, Interesting)

        by RazorSharp ( 1418697 ) on Sunday October 06, 2019 @12:50PM (#59275718)

        But science never proves theories valid. It only disproves them.

        While a strict adherence to Popper's falsification model would assume this is true, in practice we do the type of induction Popper and other philosophers find to be problematic all the time. However, I agree with your point on a pedantic level—science doesn't prove anything—but we do allow science to guide our assumptions about reality despite the problem of induction.

        So I think the OP has a valid point that just isn't carefully worded: "We would need to demonstrate that we have sufficient evidence for believing in the theory first" would be more appropriate.

        What's interesting is that the quote the OP takes from the article demonstrates an interesting problem with the falsification model: "they can't prove that it doesn't work" isn't a strong argument to suggest that it does work. This argument from ignorance is a common fallacy most often associated with deists and supernaturalists. Despite philosophical problems with positivist notions of truth, we still have to apply some sort of induction when determining which (non-falsified) theories to accept or reject, hence the OP's point that we need some type of evidence (albeit "proof" is impossible) to suggest that the theory is true.

      • Re:in theory... (Score:4, Insightful)

        by Immerman ( 2627577 ) on Sunday October 06, 2019 @03:52PM (#59276312)

        You're right, it can't prove that a theory is perfect - but it does routinely prove that theories are accurate enough to be useful.

        For example - the fact that a transistor operates as intended doesn't prove that Quantum Mechanics is perfectly accurate - but it does prove that QM is valid enough to allow transistors to operate. Which in turn proves that QM is more accurate, at least in some domains, than Newtonian physics - which offers no explanation for how such a device could operate.

        Science is an endeavor that explains the functioning of the universe through successive approximation - absolute truth has no place there, as the keepers of absolute (self-contained) mathematical truth have proven.

    • by hey! ( 33014 )

      I should think validity is the easy part. Proving that the idea is *true* -- i.e., that it corresponds to reality -- is probably the hard part.

      "Validity" usually refers to consistency, both internal and with the generally accepted rules of drawing inferences. A valid logical argument can't have its conclusion negated without negating one or more of its premises. A valid statistical inference connects a hypothesis to specific data to within a certain degree of uncertainty. But neither guarantees a conclus

  • by shoor ( 33382 ) on Sunday October 06, 2019 @11:51AM (#59275542)

    In old fashioned physics there's the conservation of momentum, which mostly gets ignored in science fiction, but it means the center of mass of a closed system cannot change. If you fire off a rocket to alpha-centauri, by the time it gets there enough mass from rocket exhaust will have moved in the other direction that the center of mass of the rocket and the exhaust will be at the place where the rocket started. (It could be, for example, some of the exhaust falls to a planet or star and transfers momentum to it, nudging it away from alpha-centauri.) I think there is a symmetry imposed on the universe as a whole, that its center of mass-energy cannot changed. Maybe that's covered in Noether's Theorem (which I admit I've never been able to follow the math for, but it gets highly praised in physics you-tube videos.) Anyway, that would mean you'd have to warp something off in the opposite direction for your drive to work.

    • In old fashioned physics there's the conservation of momentum

      Momentum implies movement through space. So-called warp drives warp space around you so that the object itself never actually moves through space at all. Hence the object remains at rest the entire time so momentum is conserved.

      • I thought warp drives warped space so that you could effectively travel at FTL by traveling slower than light, and that the thing you're describing is called a space fold drive?

        • Well zero velocity is less than the speed of light so it is consistent with your definition! Since you cannot measure your speed relative to space you actual velocity is irrelevant since it will just be relative to some nearby object. A space-fold drive suggests that you fold two points in space together, cross over and then unfold them. You do not pass through the intervening space and such a drive is, so far as we know, complete fantasy.
    • by fermion ( 181285 )
      A rocket works, in part, that momentum is conserved. Simplistically, if you start with zero momentum, then you must continue to have zero momentum so if you start at rest, and push particles out the rocket in one direction, the rocket will move in the other to conserve momentum. The momentum is speed and mass, so tiny particles going very fast can push a rocket a bit.

      What this means is that, maybe, as mentioned in the TV show Stargate, if you enter something like a warp field of wormhole, your momentum

      • > We know that those fears were wrong, but they were not without basis.

        Actually, they *were* without basis, pure fear of the unknown by ignorant people. Nobody had any testable hypothesis explaining why people would suddenly die at high speeds, and well-tested Newtonian mechanics clearly showed that speed was irrelevant to any known influence on the human body.

        Now, there's nothing wrong with a bit of fear of the unknown - when doing something that's never been done before there's always a chance you'll

    • by ceoyoyo ( 59147 )

      Physical laws that behave the same everywhere in space implies the conservation of momentum via Noether's law. Uniformity in time implies the conservation of energy. When you start messing with space time, you pretty much have to break both of those. Energy is not conserved in our universe, for example, because it is expanding.

      Put another way, the universe isn't really a closed system, although it seems that way on a small enough scale. Until you go creating warp bubbles, that is.

    • >that would mean you'd have to warp something off in the opposite direction for your drive to work.
      Actually, no - warp drives sidestep conservation of momentum right along with lightspeed limitations.

      Conservation of momentum applies to objects moving through space - with a warp drive your ship remains motionless within a bubble of space that is itself moving through the geometric manipulation of the surrounding space-time. Since your ship never accelerates with respect to the surrounding space-time, con

  • by nasch ( 598556 ) on Sunday October 06, 2019 @11:53AM (#59275550)

    OK, but you can reduce "more energy than exists in the entire observable universe" by many many orders of magnitude and it could still be far too much energy. If you need the energy output of an entire galaxy to make it work, it may as well be impossible. Not that people should stop investigating it, I mean why not?

    • by ShanghaiBill ( 739463 ) on Sunday October 06, 2019 @12:20PM (#59275618)

      If you need the energy output of an entire galaxy to make it work, it may as well be impossible.

      Sure, the mass of a whole galaxy is impractical, but if we could get it down to just a couple solar masses then we can start running tourist excursions to Betelgeuse.

      • Nah, for this to really work, we have to reduce the required energy until it is the same as a fresh cup of really hot tea.

    • you can reduce "more energy than exists in the entire observable universe" by many many orders of magnitude

      Energy is not the problem. You need negative mass exotic matter. None of that has ever been observed anywhere in the universe so the amount you need exceeds the amount we know exists by infinite orders of magnitude.

      • It's been argued the type of negative energy density in the Casimir effect could be used instead of exotic matter.
  • by Ungrounded Lightning ( 62228 ) on Sunday October 06, 2019 @11:57AM (#59275562) Journal

    Relativity (even special) says that if you can send objects faster than light (in a practical sense: Objects with payloads in the human/computer scale, experiencing forward time or reverting to sublight speed after a while, able to interact with their environment well enough to see out - either during or after the trip - and blink a flashlight, or use a radio) it's pretty simple to use them to send a signal backward in time. This brings up issues of breaking causality.

    That's not to say that the universe doesn't include ways to do just that. But if it does things could get very weird.

    "Temporal shipping company: When it absolutely HAS to be there yesterday."

    • "Temporal shipping company: When it absolutely HAS to be there yesterday."

      How else do you plan on mailing Terminators?

    • The problem with these warp drives is that nothing moves through space, it is space that moves. As such you have to radically deform space-time so your space-time metric is nowhere near flat. As such I suspect that this would resolve the causality problems which rely on objects moving through space-time, not deforming space-time itself!
    • Relativity (even special) says that if you can send objects faster than light (in a practical sense: Objects with payloads in the human/computer scale, experiencing forward time or reverting to sublight speed after a while, able to interact with their environment well enough to see out - either during or after the trip - and blink a flashlight, or use a radio) it's pretty simple to use them to send a signal backward in time. This brings up issues of breaking causality.

      Nope. The information reaches you at C, you interpret it, then you send it on behind you at C again, and your message will reach your destination AFTER the information reaches where you're sending your signal.

      You can't change what happened, either. If you go FTL, that still doesn't actually take you into the past. If you get a message, it was already sent. No matter how fast you go, you can't possibly get to the place it came from faster than instantaneously. Causality remains safe.

      The only threat to causal

  • by Immerman ( 2627577 ) on Sunday October 06, 2019 @12:01PM (#59275572)

    >"Now, we're down to where it is still an immense amount of energy and exotic matter is still a problem, but if we had that energy, we could do it."

    Correction: If we had that energy and the necessary kind of exotic matter actually exists, then we could do it.

    And of course, if the Relativity remains valid under the extreme conditions required, but we have to start somewhere.

    There's been some incredible advances in reducing the theoretical energy required for a warp drive, usually by many, many orders of magnitude at a time. I do harbor a hope that so long as smart people keep tossing the idea around, we may eventually get the energy down to something we might actually be able to try in the lab at least and the spin-off technologies alone would be worth the chase, even if we never manage to actually make a ship that passengers could survive.

    It's catching the right kind of exotic matter unicorns that seems likely to be the big problem.

    • If you have enough energy you can make the exotic matter.
      • If you have enough energy you can make the exotic matter.

        Uh, no. We aren't even sure if it can exist, let alone how to make it.

    • by gweihir ( 88907 )

      >"Now, we're down to where it is still an immense amount of energy and exotic matter is still a problem, but if we had that energy, we could do it."

      Correction: If we had that energy and the necessary kind of exotic matter actually exists, then we could do it.

      Ooops. Essentially this is "If we had magic, we would have magic!".

      The mind boggles how soft some apparently intelligent people can be in the head.

      • In fairness, when wrestling with a puzzle whose most basic test implementation may not be built until long after your death here's no sense trying to tackle everything at once. Maybe the necessary exotic matter is discovered to exist. Maybe someone else comes up with a trick that eliminates the need for it. If we keep pecking away at the problem from different angles we may eventually get something that will work - and every advancement in one domain tends to offer a loosening of constraints in others.

        I

  • Re: (Score:2, Insightful)

    Comment removed based on user account deletion
  • I would be thrilled if we found some way to ascend from a gravity well without explosive chemical reactions.

    Batteries with energy densities (in terms of both volume and mass) far greater than existing chemical batteries would be great and possibly even save the planet (for now.)

    Zero-emission fusion energy sources? Always feasible 20 years from now but so far found only in sci-fi.

    Highly reliable fact sources on the web? Awww.. going to far like that's never gonna happen.

    • We can do this now using an orbital ring. The technology exists, we have the manufactuing ability and capacity, and it's affordable. No carbon nanotubes or other exotic materials required.
      • >we have the manufacturing ability and capacity

        To produce the raw materials and components? Perhaps. To construct them into an orbital structure that dwarfs all previous feats of human engineering...? Not so much. Not quite yet anyway. We have theory on how we could do it, but zero proven orbital manufacturing and construction expertise on that scale. Once we begin to master asteroid mining at production levels, maybe then we can talk.

        • Comment removed based on user account deletion
          • Thank you! I've been trying to remember that name all day.

            It's certainly an interesting idea, but has its own engineering challenges that in many ways are far greater - for starters it'd be by far the longest maglev rail system ever created, and any failure of any section could potentially destroy much of the system within seconds. An orbital ring is at least just bits of "string" and counterweight linked together - like a beanstalk or skyhook it has no large-scale moving parts to fail, which I suspect wi

  • Granted if you established a condition on one side of and object where space shrank, and another on the opposite side where space expanded (along with appropriate wierdness beside it so you don't have to do this sideways "to infinity and beyond!", you would have an object which, when viewed from beyond the space warping goofiness would appear to travel faster than light.

    But that brings up the question of how fast the limited-range space-shrinking effect propagates into undisturbed space - or how long it too

  • Someone explain to this clown about proving negatives. Another non story about an idiot.

    • Don’t be so narrow-minded. His line of thinking is perfect for getting a few hundred million dollars as a Silicon Valley startup. If he can talk smoothly enough, he might make it all the way to an IPO.

  • ... or perish.

  • by Eloking ( 877834 ) on Sunday October 06, 2019 @12:37PM (#59275668)

    If we compress the universe life to a year, human existed for an hours and the industrial age lasted less than a second.

    If we aren't alone...oh wait, no if we aren't the only 'intelligent' being in the universe, chances are they existed days/months earlier than us.

    So my theory is that if warp drive is possible, chances are we would have being visited a long, long time ago by different Aliens species (and not in the 'we are so advanced that we can travel galaxies but can handle a safe landing at area51).

    And I don't believe we're alone.

    • You're assuming that warp drive is the only possible way to travel FTL. That's not a safe assumption.

    • Perhaps we are the result of that long-ago visit by an alien species, becoming marooned on this rock!

    • My theory is that aliens have been here, and concluded that there's no intelligent life on this planet.

  • If we find ways to manipulate things at the quantum level, it opens up the possibility of manipulating space-time directly.

    • Yes!
      Because changing quantum states of an electron or an atom even, folds space around it!!

      I'm happy my iPhone did not create a wormhole yet.

  • Is It Possible To Build a Warp Drive?

    Sure. A *working* Warp Drive on the other hand ...

  • Someone was trying to make a warp drive work and that's what created Big Bang.

  • by jythie ( 914043 )
    This whole thing started as thought experiment, people sitting down and trying to calculate the consequences if something impossible was possible, but after bad reporting and hype it has really taken on a life of its own, with people kinda skipping over the whole 'impossible premise' part.
  • At the Large Hadron Collider.
    But yesterday it broke down.
    They are gonna have to bring in a quantum mechanic.

  • I heard there was no such thing as 'faster than light'. If you have zero mass (like light) you will arrive instantaneously (in your terms). For any other observer, there seems to have been a 'speed', based on a constant 'c', which is as immutable as 'pi'. Check back for warp drive when you have found a circle that does not respect pi.
    • by Greyfox ( 87712 ) on Sunday October 06, 2019 @02:40PM (#59276138) Homepage Journal
      The warp drive gets around this pretty much by sitting still and moving space around it. More or less. We know you can warp space-time because gravity observably does that now, so the idea is that we just figure out the mechanism to do that and build a machine to do it better. The problem is, for any of the math to not require all the mass in the universe to be converted to energy, you need some sort of matter that has a negative mass. If you poke at the math some more, apparently you can get it down to around the point where you need to convert the entirety of Jupiter to energy to create your warp field without the negative mass matter. That's still more energy than we can generate, but the math apparently says that it could work. I suspect that even if possible, it'll be centuries before we get to the point where we can pull it off, and we have a lot more pressing problems to solve in the meantime if we're not going to kill ourselves off before we get there.
    • A sphere does not respect pi, because you can get from one point to another in a straight line.

  • ... it cannot be formatted.

  • I am not a physicist, so if one reads this please answer.
    So, the question is how space-time curvature propagate from a massive body? I suppose the propagation happens at the speed of light.

    So, if a massive body moves the space-time curvature must move with it. However, since the propagation happens at the speed of light I suppose some kind of bow shock must happen in front of the body. A bow-shock of space-time curvature.

    This means if a spaceship travels FTL, it will outrun its own space-time curvature caus

    • by crgrace ( 220738 ) on Sunday October 06, 2019 @03:51PM (#59276308)

      What you say is in essence true. It is like a space-time boom, analogous to a sonic boom in an airplane.

      There are cases of massive objects traveling faster than light and this is actually used in some experiments. Remember when people say "the speed of light" they usually mean "the speed of light in a vacuum". That is c. When traveling in a medium, though, the speed of light is slower.

      In a medium where the speed of light is less than c (for example in water) certain reactions or collisions cause electrons or neutrons to travel faster than light in that medium. Then you really do get an "optical boom".

      This optical boom is called Cherenkov Radiation and is the reason that water moderated nuclear fission reactors shine blue. They are throwing off neutrons and some of them have so much energy they are going faster than light can go in water.

  • Non-repulsive field-effect vehicle on Navy sensors / pilots' eyes-on:

    https://youtu.be/CnIG-i2WCfg [youtu.be]

  • Exotic matter (basically negative energy density matter) is not *known* to be impossible, but its quite likely it *is* impossible. There is no evidence that it does exist and it allows one to construct all sorts of pathological space-time geometries. (Note the Casimir effect allows the creation of a very slightly negative density relative to free space in a very localized region, but in a way that doesn't seem to allow conditions that noticeably affect gravitational fields (eg the field of the atoms of the

  • A physics professor of mine stated once that we already know time travel is impossible, because if it was possible we'd have already had someone come back and visit us from the future. Of course that more proves that mankind never invents it rather than it being "impossible", but you get the jist.

    Similarly, the vast expanse of space virtually ensures that many other alien civilizations exist. We don't have any measure by which to currently judge their frequency, but even if there's only say, 1 in every 10

  • First, "we" (humanity) thought that Sound was the fastest thing.
    Then we found Light, and declared that to be fastest.
    Perhaps there's something faster than light that we simply haven't been able to perceive, or record yet?

    Basing our "fastest" on things we can perceive is a classic scientific principle, sure. It's also a bit flawed.

"Protozoa are small, and bacteria are small, but viruses are smaller than the both put together."

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