First the Math and Physics and Then the Warp Drive

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“First, you get the money, then you get the power, and then you get the women.” Tony Montana Scarface.

For Warp drive. First, we get the math, then we get the physics and then we get the warp drive.

We do not have all of the math and the physics but there has been progress on getting a better mathematical understanding of the physics of warping space and understanding how to possibly create warp drives.

There has been progress made on the math and physics of the warping space. In 1994, Miguel Alcubierre found a way to make them work in General Relativity. It is called the Alcubierre Drive. The idea was you contract space-time in front of you and expand it behind you, which moves you forward. There were still huge problems and it has barely moved from hand waving concept to mathematical hand waving. The amount of energy needed was like converting the mass of Jupiter into negative energy and concepts did not actually describe acceleration.

There have been experiments and efforts to try to make warping space into engineerable problems. However, new work mathematically defines mechanism for acceleration.

Problems with Alcubierre Drive: it requires negative energy (which we have never made and do not know for sure if it exists). Second, it requires a huge amount of that. Third, the energy is not conserved. Instead, what you actually do when you write down the Alcubierre space-time, is that you just assume you have something that accelerates it beyond the speed of light barrier. That it’s beyond the barrier is why you need negative energies. And that it accelerates is why you need to feed energy into the system. Please check the info below the video for a technical comment about just what I mean by “energy conservation” here.

The new paper is titled “Introducing Physical Warp Drives” and was written by Alexey Bobrick and Gianni Martire.

Bobrick and Martire describe the geometry of a general warp-drive space time. The warp-drive geometry is basically a bubble. It has an inside region, which they call the “passenger area”. In the passenger area, space-time is flat, so there are no gravitational forces. Then the warp drive has a wall of some sort of material that surrounds the passenger area. And then it has an outside region. This outside region has the gravitational field of the warp-drive itself, but the gravitational field falls off and in the far distance one has normal, flat space-time. This is important so you can embed this solution into our actual universe.

What makes this fairly general construction a warp drive is that the passage of time inside of the passenger area can be different from that outside of it. That’s what you need if you have normal objects, like your warp drive passengers, and want to move them faster than the speed of light. You cannot break the speed of light barrier for the passengers themselves relative to space-time. So instead, you keep them moving normally in the bubble, but then you move the bubble itself superluminally.

The relevant question is then, what does the wall of the passenger area have to be made of? Is this a physically possible distribution of mass and energy? Bobrick and Martire explain that if you want superluminal motion, you need negative energy densities. If you want acceleration, you need to feed energy and momentum into the system. And the only reason the Alcubierre Drive moves faster than the speed of light is that one simply assumed it does.

The new paper advances toward understanding how to improve the math. There are still gaps to getting the first warping of space.

The writers have previously summarized the mathematics of warping space and math and physics of warp drives.

SOURCES – backreaction – Sabine Hossenfelder
Written By Brian Wang, Nextbigfuture.com

100 thoughts on “First the Math and Physics and Then the Warp Drive”

  1. Gluons and relativistic inertial mass.
    The gluon provides the binding energy for quarks to form protons and neutrons. It is this binding energy, as described by m =e/c^2, that is responsible for the preponderance of inertial mass of nucleons, or about 99% in hadrons and baryons. It is thought that an anti gluon would not result in antimatter but produce relativistic negative inertial mass resulting positive space-time curvature and gravitational repulsion rather than attraction. There are profound causality issues introduced by this interpretation and clarification awaits a testable theory of quantum gravity. It is interesting to consider this eventuality in the context of both quantum foam and dark energy and of anomalous cosmological expansion. The implications for Alcubierre warp drive are also worth thinking about.

  2. The physics is the big problem. The math appears to be sound, at least so far no one has found any errors. The Alcubierre metric depends on the ability to warp space time in both positive and negative curvatures. Ordinary matter/energy curves space negatively but positive curvature, which would result in gravitational repulsion rather than attraction is quite another thing. That would require matter with negative mass and most physicists doubt that exists or even that it can exist. There are some clues, however, that suggest otherwise. Dark energy, if it’s real, implies that gravitational repulsion is real and one interpretation of the behavior of quantum foam, also if it exists, suggests the presence of complementary pairs of particles of positive and negative matter (not to be confused with matter and antimatter). At this point these things are pure conjecture but further study may reveal otherwise. It has been suggested by others (including me) that if this interpretation of quantum foam is correct it may be possible to separate the positive and negative components before they self annihilate thus providing sources of both positive and negative space time curvature. As far as a time scale is concerned these things are probably a long way in the future.

  4. I think the answer will be via biological & physiological adaptations, by changes to the human genome. Don’t know what the timeframe is, but it seems the most likely solution to a very difficult problem.

  5. Sorry it took a while for me to respond. I had teleported via wormhole 9880.67B to hang with friends on Themyscira for a few years. I learned among other things, that "Father Christmas" is just a myth. It obviously should be Mrs Betty Christmas (married it seems).

  8. Yes, energy has mass, so adding kinetic energy to an object gives it more mass. That’s “relativistic mass”, though that term isn’t used much these days.

    But again, that is positive mass, and it only curves space in a way that has positive energy. So it isn’t giving the negative energy that an Alcubierre drive would need.

  9. You can never prove whether you are in a simulation, or not. Because no matter what property you decide to look for, it could have been programmed into a simulation. Or it could have been part of the laws of nature in a non-simulated universe.

    I think Brett Bellmore was just giving an analogy, where separate things look random when you look at each individually, but non-random when looked at together. Which is also true of entangled particles.

  10. And I'm pretty sure that you will not be allowed to head towards Earth at super speeds. Once it becomes common they'll probably have something to shoot you down once you violate the exclusion zones.
    (Guided warp speed torpedoes, such as nobody in Star Wars ever thought of.)

  11. I'm pretty sure Marcus means, can we use a warp drive to get to a useful for space travel type sub-luminal speed. Like 0.9C or something.

  12. While absence of evidence is indeed evidence of absence, it often is not very strong evidence.
    It all depends on what proportion of the total possibility space you have explored.

    Look through 0.01% of the possible options? Not finding any evidence is not strong evidence of anything much. Look through 93% and you are starting to make a pretty strong case.

    When it comes to SETI, we really don't have strong grasp on how much of the solution space we have explored. Because we're pretty sure that any actual technological civilisation is probably going to be way, way ahead of us, to the point that we might not be able to see anything we would recognise as evidence. Just like a Homo Erectus could find a rusted out V8 engine block in the sand and never dream it was proof of the existence of other people.

  13. Many amusement parks already have a ride called something like "The gravitron" which is basically a big hollow cylinder that spins fast enough to pin the humans inside to the walls.

    https://en.wikipedia.org/wiki/Gravitron

    So you just have one of those in your moon/Mars/Pluto colony. It doesn't even have to be as fast as the ride because you only want to replicate Earth gravity, not 2 or 3 g which is what you need to be exciting.

    Now this isn't big enough to live in, but it is big enough to sleep in, and maybe have a gym. (Boring machine gym, no snatches allowed)

    The theory is that maybe 8 hours of 1g per day would be enough to keep a human healthy. THough, as BB points out, we have exactly zero experimental evidence.

  15. Many theories initally proposed e.g. earth is round get rejected until proven. Having said that, I take exception to the last sentence – in what universe does Minowski make more sense? Most scientists & science educators agree that space-time is counter-intuitive. It may end up being the correct theory but for now, whilst I'm willing to entertain higher order dimensions, they are just that – entertainment. I hope I'm around in the next 50 years b/c I predict there will be massive changes to all fields of science. In a betting contest b/w 3D space vs 4D-space-time (or if string theorist what to get involved even higher dimensions) – my money is on 3D space eventually winning.

  16. Actually, when you walk at a normal pace you are actually moving at a sub luminal speed. In other words, sub luminal speed that is any velocity less than the speed of light (186,000 miles per second). And thus you don't need a warp drive to do that.

    In terms of space travel, sub luminal speeds will get you where you need to go, but at the cost of very long transit times. For example, the New Horizon space probe was launched from Earth in 2006, travelled at about 52,000 mph, and finally reached Pluto in 2015.

  17. The ship isn't a big issue, as you can see from the Polynesian island hopping, which was done with very small boats. The real issue is the need for life support, and since we're using industrial technology, a complete, closed industrial ecology.

    The life support could be as simple as a genetically engineered plant, but you need that replicator, even if, as on Earth, it has human components.

  18. Eh, you can design a distribution of mass under your feet which would produce the same gravitational gradient as the centrifuge. The real difference is when you turn your head and experience Coriolis 'force'.

    That doesn't mean acceleration isn't indistinguishable from gravity in a closed box, it just means that rotation is distinguishable. But still an adequate biological substitute, if you build a large enough centrifuge.

  19. Well, I did mean theoretically indistinguishable from a biological standpoint. Obviously not from an engineering standpoint; It takes a lot less mass to generate substantial amounts of centrifugal force, but centrifuges require better bearings than planets.

    It's a continual theme of mine that we really, desperately, need to do some partial gravity research, ideally in LEO, to determine the biological effects of acceleration between 0 and 1 g. This should obviously come prior to committing to Mars, as Musk has done. If we find 1/3rd g isn't enough for long term health, we're probably better off colonizing airless bodies, because it's easier to build centrifuges there. But if Martian gravity IS enough to maintain health on Mars, (Even if it means no return trips.) it's easier to colonize the planet.

    A lunar centrifuge would be relatively easy to build, because of the lack of an atmosphere. Just a big, round habitat on magnetic bearings. The Moon doesn't rotate fast enough for precession to be an issue. Free flying O'Neill colonies could float near asteroids. But even then the acceleration tolerance studies would be needed for design purposes.

  21. I looked at those links, but they weren't very helpful. So I googled Mr. Sorli. From what I can see his "spacetime has no time dimension" theory – while interesting – is not accepted by the scientific community. Perhaps some day it will be proven to be true, however having read some of Mr. Sorli's theory, I think Minowski makes much more sense.

  22. Good question. Permanent colony wise, I can't think of any. All the new world settlements that survived were group efforts (Pilgrims, Jamestown, Columbus, Cortez conquest on Mexico). And even that wasn't a guarantee. Scotland financed a settlement in Panama which was destroyed by disease and supposedly bankrupted their treasury.

    I expect space will be the same model, just with better tech. Unless Brett's replicators become possible.

  23. Agreed that in space it does, but that wont help on the surface of Mars (unless there's some way to build a colony inside a huge centrifuge!). I realize Mars is .32g of earth grav, but I still think that's too low for permanent human settlement. I realize I have no evidence to back that up, except to say that it's hard to see how a life form that evolved at 1g is not going to have serious health issues in a .32g environment over the span of a normal human life. One year in the space station, admittedly its zero g, has serious effects. On Mars were talking low grav for 75 years. Intuitively, one would expect serious if not fatal effects.

    Of course, 5 years from now Elon Musk will move to Mars, then proceed to live there healthily for the rest of his life, and I will have been completely wrong.

    Chris68

  24. Hi JS, you have me a bit confused. How would centrifugal gravity replace the moon or Mars' surface gravity. In space aboard a station or a ship, sure thing it could. But on the surface, how so? What I'm trying to get at above is that no one has ever lived in a low grav environment. Sure, it's been done on the space station for year long periods, but no one knows what will happen to a human that lives on the moon permanently. Same for Mars. Given that we know that zero grav has detrimental effects on the human body, what effects will low grav have over the life span of a normal human? I realize we wont know that until we try, but I would surmise that it could kill us.

    Chris68

  25. agreed. however, the food chain of:
    pure math -> applied math -> theoretical physics -> experiment-based physics -> engineer -> technician is very trickle-down and that both significant advances and incremental movements in knowledge and technique come disproportionately 'from above' rather than from within the lateral direction or below (but increasingly from sympathetic and distant fields). That being said much 'pie in the sky' concepts tend to 'stay up there' and provide nothing but drains on grant money, tenure fill, NASA funding, trust-fund playtime, and pre-retirement 'running out the clock'.

  26. Your conjecture re: my beliefs is incorrect.
    I note that some people prefer to believe in fictitious negative energy, imaginary fields and multi-dimensional space.
    Just b/c a mathematical model fits observed data does not validate that model – I can fit almost anything to a polynomial!
    I concur with Dr Pat & amend slightly – do NOT drink & shoot!

  28. But can you use the fact that there is correlation between entangled particles to prove that the universe is indeed a simulation? Just wondering

  29. If you could warp space to have negative energy, then you’d have solved the biggest problem in building Alcubierre drives. And if you could build one that goes FTL, then you could build a time machine.

    But negative energy isn’t the same as time travel. It’s just one of the building blocks that you need to do time travel.

    BTW, the time travel isn’t “negative time”. It’s just a closed loop, where information goes around the loop and comes back to the start before it left. That’s called a Closed Timelike Curve.

  31. I think the idea is that nothing material would move at high velocity. Once the warp bubble collapses, the ship and dust shouldn't have particularly high velocity.

    As to small debris encountered during flight – I guess it'd be shunted around the curved space bubble, though maybe accelerated somewhat by what I presume would be like a very-quickly-passing intense gravitational field?

  32. It's interesting to speculate on the comparative paces of development – autonomous robots versus human expansion into space.

    Of late it's looking like we could have fairly independent robots (with some remote human oversight) by the time we might start to do serious lunar or asteroid mining (say 2035).

    Here's hoping Starship soon works as advertised and we finally begin to see a visibly accelerating pace of human space operations – lest we end up turning space completely over to the robots out of an over-abundance of caution.

    BTW – I like the idea of an orbital shipyard, but suspect it'd be in Earth orbit – why send crew all the way to lunar orbit? Also there's the protection of Earth's magnetic field.

  33. We're in the process of moving past the age of government exploration (Queen Isabella) and into the phase where "public/private" consortiums (Dutch and British East India Corporations) begin to do so – though really still just extensions of government.

    Lunar ice mining seems likely to be done by government-supported corporations, less focused on immediate profits and more on enhancing and securing governments' power in space.

    Eventually providing fuel for Mars missions and beyond will continue to be a big stated objective. (Using lunar fuel in LEO to reduce the cost of flying to the moon to mine ice to make fuel to fly back to LEO is a bit too obviously circular.) TBD, of course, whether Biden will continue to support 'back to the moon to mine it' – but even if he doesn't, I suspect other nations will.

  35. It’s true that your length is different according to different frames of reference. But that’s unrelated to space time itself being curved. Curved space time is what explains gravity, and gravitational waves, and the Alcubierre drive.

  36. There is energy inherent in curved space time. For example, a lump of matter curves the space time around it, which is curved in a way that you get a positive number when you calculate the energy of that curvature. Antimatter also creates a curvature with positive energy. Even photons (which are their own antiparticle) curve it that same way.

    Alcubierre requires space time to curve in a different way, which makes the calculated energy negative. This is how space would curve near a lump of a substance that has negative mass. No one really knows what “negative mass” would even mean. Certainly, nothing currently known to science would have negative mass. So such a hypothetical substance is called “exotic matter”.

    It looks like you need it to create an Alcubierre drive. And you also need it to create a traversable wormhole. But currently, there’s no particular reason to think such a substance can exist.

  37. Ah, thanks! I wascunser the impression that the VEM concept was facilitating the warping of space, so perhaps that's where my confusion came from. I'll have to go back and read it again.

  39. What is negative energy? Is energy relative, so that an energy of 1J is -1J relative to an energy of 2J? Do masses moving in opposite directions have negative kinetic energy wrt each other? Waves of equal energy but opposite phase cancel out – is that an example of negative energy? I doubt any of these are what is meant… but then what does it mean for energy to be negative?

  40. Using that logic there absolutely must be dragons in unexplored regions of the maps, and elves in the deep forests, and if you want your shoes repaired just leave them out at night along with little cups of milk. If you don't have suitable cups, write a letter to Father Christmas.

  41. When an object (with mass) is in motion, its measured length shrinks in the direction of its motion. If the object reaches the speed of light, its measured length shrinks to nothing

  43. Do we have any historical analogies where it wasn't possible to survive without having a big , capital intensive, technological package with you? The only examples I can think of is the oceanic exploration, where you needed a functional ship. A human without a ship, or even a non-functional ship, was sharkfood.
    Hence, I guess, the way most space SF is ship based, and comes across as a retelling of the Odyssey at one end through to Horatio Hornblower at the other end, rather than looking like a western, or Arthurian, or Lord of the Rings, or any other story type.

  44. They're theoretically indistinguishable.

    For a point mass.

    For a physical body with non-zero height, the vertical force varies differently depending on whether it is dependent on the inverse square of the distance from a point below your feet (mG/r^2), or linear inverse with respect to distance from a point above your head. (v^2/r).

    In practice you make both systems have a large enough r that this should be biologically indetectable.

  45. Unless there's something really blatant we've missed about physics, there's no question at all that centrifugal gravity can replace real gravity. They're theoretically indistinguishable.

  46. That depends on whether or not centrifugal gravity can truly replace real gravity. Also, making the cost of accessing space affordable to anyone but the wealthy. If those two criteria are met then the same type of people who have colonized every frontier on earth will migrate to space as well. I think you're correct, 200-400 years is about right. Like I said though, gotta start somewhere.

  48. The real reason for the Fermi paradox is that your internet connection gets really laggy in between the stars. And who wants that?

  49. Yeah, he believes it's plausible. I don't, it's "pulling yourself up by your bootstraps" territory. Just another Dean drive.

    He dumps energy into a mass, thus increasing it's mass, (E=MC2) and pushes it one way. Then he sucks energy out of it, reducing its mass, and pushes it back the other way. Thus producing a slight imbalance of forces.

    But the only reason it looks on paper like an unbalanced force, is that he's not accounting for the force necessary to move the energy itself around. Once you take THAT into account, the thrust goes away.

    It's a sad example of hope overcoming physics competency.

  50. Won't be old west, barring small scale Von Neuman replicators. The old west was possible because you could live off the land with a reasonably small set of tools. The infrastructure and skill set to 'live off the land' in space is much greater.

    Group efforts, that I could see. A group could be large enough for the necessary skill set and infrastructure.

  51. not convinced that exploration/ expansion will be old-west style settlement (or even gloms of workers or religious/ cultish group 'missions'). With labor and operations mostly AI-driven (in the sense of a great deal of autonomous decisions/ adaptability), I would guess that most of space-focussed out-growth will be (in order of accomplishment with number of humans (mostly techs) at open): moon-orbit node/lab(2), moon lab/mine(5+), earth-orbit hotel(20+), asteroid mine(0), moon base(20+), mars-orbit lab(0), mars mine(0), asteroid base(1?), moon-orbit shipyard/habitation(50+), mars base(Elon+5 – on his 64th), moon habitation(100+), asteroidal orbit base (2?); after 2040: cislunar infrastructure (300+), 5 – 10+ full-time asteroid habitat/ mines(5+)….
    assume most tours at less than 21 days; 1 in 10, more than 6 months….my 2c.
    First family: Moon 2050.
    taking bets…..

  52. meh. i suppose some people prefer to believe that the universe is a series of billiard balls — and anything more nuanced is time wasted that could otherwise be spent drinking and shooting stuff (which isn't to say i don't like drinking and shooting stuff).

  53. Well. TNG was sometimes preachy and sub-servient to current 'causes' but was fundamentally a show of optimism and aspiration – unlike all other genres (except YA and kids shows) and even most of that-time (or our time) speculative entertainment. I, for one, don't believe that anything more enviro-/woke-rogue (short of Archie Bunker-type/ FOX-ish sitcoms) could have made it to cable tv. If you listen to some of the writers/ producers talking about the show – they pushed back against Gene's intentions a lot. We have MR. Roddenbury's stubborn (there's a better future out there – and by extension, better people to inhabit it) attitude to thank.

  54. Perhaps.
    But I would like to think that an entity, and by extension its species and civilization (even contrary to my own previous comment-but not really); would retain some kind of ambition for undertaking 'firsts', have a limited physical presence preference, wish to undertake an individualistic experience (in the sense of collecting 'time' in a life) through a series (even if time is not linear) of events that specializes it vs. its member organisms, and otherwise wish to follow a path of discovery beyond whatever the intergalactic version of Netflix can show them of what is entertaining 'out there'. The difference between a sentient species and intelligent one (mostly) is purpose. So, it will certainly be nice to be able to spectate universally, but I still believe that exploration/ existence is more than just looking 'through the glass'.
    IMHO: The intention of the Fermi – to understand if 'far-flung' species can indeed be aware of each other – is more a function of the species wish to make itself known (since the technology level at the time would make such control/ intent easy), than the other series of 'lottery' chances of existence that that nonsense string of factors (charitably called an equation) would have us believe (i believe the hyper-techno species out there are sufficient to have influence overlap, so potential=1). Its a nice mathematical navel-gaze, but that such complexity could be confined to such factors is non-sensical beyond even 'arbitrary'.

  55. Many people want FTL, star gates, farcasters, etc. Lots of those same folks want to believe in what could be called the "Star Trek" galaxy model – a galaxy full of hundreds of space travel capable, sentient species.

    The reality is that no evidence exists to support any of that. Yes, I know I'm the buzz kill, Grinch Who Stole Christmas, when I say this, but so far it appears we humans are the only sentient species in the galaxy, perhaps even the universe. Even a sentient species that evolved as little as a few hundred thousand years before us, and without the aid of FTL, would have colonized our galaxy by now using sub light speed ships. That they aren't out there is indicative that they don't exist. That doesn't mean we won't travel to the stars, but most likely humanity will spend thousands of centuries spreading across the galaxy.

  56. There must be a viable theory of traveling to distant places in a blink of an eye. Otherwise the universe is truly a lonely place. Maybe it's waiting for the right visitors to show us the "how". Maybe our concept of matter (physical spaceships) needs to be re-thought. Maybe hitchhiking across galaxies is metaphysical. And if someone does prove a theory, how would we know it happened?

  58. Not completely as such. They did use it once to emphasize that they were only using high warp because it was an emergency.

    As I understand it, this came close enough to the end of the series that they were no longer sweating continuity, just wrapping things up.

  59. It's the negative energy requirement that's the challenge. The Alcubierre Drive requires negative energy to generate a warp bubble. The VEM appears to be another type of zero propellant propulsion. I didn't see the connection between that and generating a warp bubble.

  60. If the universe were a simulation, quantum entanglement would be particles being assigned the same random number generator.

    But it's still a random number, so not useful for transmitting information FTL.

  61. I agree, but I think the time frame to get to the Expanse is likely much longer than a few hundred years. Colonizing the solar system involves overcoming some serious obstacles, such as making it profitable and the long term health effects of low grav on the human body. No one is going to move their family to the moon or Mars permanently if the low grav kills them.

  62. What fix? That was never in any episode or any other canon I know of. They didn't fix anything. The writers probably just realized that the concept was a bad idea in terms of the show and the series, and so they've just completely ignored it ever since.

  63. Where did you get that idea? I think perhaps you may be confusing the concept of time dilation, which actually does occur at high velocities, with the concept of bending spacetime.

  64. The mathematical model known as spacetime was originated in 1908 in a paper written by Hermann Minkowski, who was once one of the math professors of a young Einstein in Zürich, Switzerland. The model fuses the three dimensions of space and the one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why different observers perceive differently where and when events occur.  Gravity actually bends spacetime. It can also be dilated at high velocities. I suggest you google the term "spacetime" and read up on it.

  65. If you look at the farthest galaxies we can detect, and measure their redshift, you'll find that they're receding from us at close to the speed of light. For example, the farthest one yet detected, GN-z11, is receding at 98% of c. With a bit of math, you may conclude that the farthest galaxies on opposite sides from us are receding from each other faster than the speed of light (and are, in fact, outside of each other's observable universe). This is normal, because, the galaxies aren't moving that fast relative to space. Rather, the space between them is expanding. The point is, we do observe such phenomena (but AFAIK, none of what we observe is in any way useful for constructing a warp drive).

  66. No such physical entity as "space-time". There are objects and empty space & it takes time (defined as: numerical order of events or motion) for objects to travel from one location to another.
    As such bending or any other physical manipulation of "space-time" is mathematical gibberish!

  68. You’re probably thinking of quantum cryptography (or “quantum key distribution”). That’s not faster than light. And it doesnt use entanglement. 

    It’s intended to be more secure than other types of cryptography. Though there are actually reasons to prefer traditional crypto.

  69. When you're traveling near light speed the space in front of you is already contracting and the space behind you is expanding relative to you, this whole warp drive just sounds like something to explain what it looks like from a reference frame of traveling near FTL and not about how it's achieved.

  71. Doesn't this invalidate the quantum entanglement communication experiments conducted from space that have already occurred? Or are those not the same kind of thing? I don't understand enough about it. xD

  73. Which is of course one of the proposed solutions to the Fermi paradox.
    That there is only a very short time, if any, between a species become technically advanced enough to start any interstellar exploration, and when they reach the point of not even needing to do it any more.
    Much faster to just replicate the entire universe in data form and explore it virtually, which gets rid of all that tedious travel time.
    Which is good, because by then you're starting to crank up your own brain's clock speed, so that even if you CAN travel at 0.9C, it is still (subjectively) many centuries because your brain is overclocked by a few orders of magnitude. And accelerating.
    Eventually even interplanetary distances are too far, subjectively, and everyone takes the form of multiple software agents operating in a planet converted to solid computonium.
    Meanwhile those species that haven't quite solved the P=NP problem just yet are wondering where everyone else is, and maybe, just maybe, encountering a few lost orphan equivalents of Pioneer probes.

  74. I bet we're closer than we think we are. It's probably something nature does every day that we see with our own eyes, and don't realize it's happening. Wouldn't surprise me a bit. We miss so much that takes place right in front of us.

    SWD/QED-Ne appears to have already made progress on this. Their paper has already been peer reviewed (I think; unless I'm insane [which I am, shhh]). I can't make heads or tales of the physics, so anyone skeptical feel free to enlighten me if you've read it. I'm aware of issues people bring up, such as not being able to test in a vacuum, yet. But I don't know quite how this would affect their experiments. They've made a ton more progress since that publication.

    I believe the paper is called "The Artificial Inducement of a Local Space Warp Bubble Using a VEM Drive".

  77. Yes, it’s “true” time travel for information. Where you receive a message from yourself before you send it. So you could see tomorrow’s lottery numbers.

    You can even use it (under some models of Novikov consistency) to basically force extremely unlikely things to happen. So it could find the cure for cancer. Or invent a better time machine.

    Of course, you could also use it to see what you’ll do tomorrow, then try to do the opposite. What will stop you? It’s paradoxes such as that that cause some physicists to speculate time travel is impossible. Which would imply FTL communication is impossible. But maybe someday we’ll see how to do it.

  78. Interesting. Though, i would only call it a 'true' time machine if you could see yourself doing something from 'before'. Otherwise, I assume, its just varying 'frames of reference'.

  79. I agree. It’s sad that entanglement doesn’t let us build a real ansible.

    And FTL communication would be even more cool than it sounds. Because, if you could do it, then it becomes extremely easy to build a time machine. And that introduces all sorts of interesting possibilities.

  80. Frustrating. based on that explanation, it's remarkable that *even* mainstream media could ever use 'teleportation' anywhere in a description of such an experiment – how is it any different from 2 scientists doing two 'classical' experiments in 2 separate locations and having the exact same result based on 1 communicating their process to the other. Where is the 'link'? What does it even mean that A and B are entangled if there is no 'relationship' that can be quantified? Anyway, i'll just continue to call it my 'ansible'.

  81. I think if you need negative energy to make a warp drive then antimatter is one piece of the puzzle. Recently breakthroughs in generating antimatter have increased its yield 20 fold. Maybe annihilating space in front of the craft by using antimatter would create the warp. It may take less effort than one would think and by annihilating what's in front of you the craft wont be subject to particle violation while warping. Fun to think of…

  83. Suppose there are 4 particles, A,B,C,D, with A and B entangled, and C and D are not entangled with anything. You have A and C. I have B and D.

    My D particle is in some quantum state, and we want your particle C to be in that state. To achieve that, I can do a procedure that causes B and D to interact and be measured, in such a way that it destroys both the entanglement and the state of D.

    Then I send you an email (slower than light), telling you the result of my measurement. You can then do a procedure that interacts A and C, where the exact procedure depends on the result that I emailed to you.

    At this point, C now has the quantum state that D originally had. And the state of D is destroyed. And neither of us knows exactly what that state is.

    That’s called “quantum teleportation”. It doesn’t help us transfer anything faster than the speed of light. Because you can’t do your part of it until you receive my email. And the email is limited to traveling at the speed of light, or slower.

    My last paragraph was about the Alcubierre drive. It has nothing to do with quantum teleportation. It has nothing to do with entanglement. It’s purely something from General Relativity, not quantum mechanics. It’s a way to send both matter and information somewhere faster than light. But it requires us to use a hypothetical thing (negative energy) that doesn’t exist, as far as we know.

  84. I'm not seeing how the last sentence(3) follows from(2) in all cases: "…(1)It allows me to send you a quantum state. (2)But one step in the process is that I have to send you some ordinary information by ordinary, slower-than-light means, such as radio waves or an email. (3) So it can’t be used to send information faster than light. …" Why (2)? Isn't (1) enough? I am assuming that we have already populated the immediate universe around us with libraries of information (node satellites) and the mechanisms to access and fabricate (by light sails at 0.1 to 0.2c in the previous century). We need only to 'signal', at FTL, the libraries to build the 'object' – not actually send anything original and unique. I assume the quantum state 'signal' sent can be read and interpreted as a single piece of the instructions. Or am I misunderstanding – and that quantum teleportation is simply signal(unpredictable) and receiver(unusable) without any other point?

  85. They probably worked around that with a fix on the warp engines, that later became standard tech.

    They mostly did the "warp tech damages subspace" as an analogy of pollution and environmental impact of technology, and it was as cumbersome as its real life counterparts and it was most likely worked around with more tech development.

  86. Quantum entanglement doesn’t allow FTL communication. It’s a common misconception that if you and I each have a particle, and they’re entangled, then we can transfer information faster than light. But it’s not true. 

    There’s a theorem in quantum mechanics that says this is impossible. If you and I each measure our particle alone, then we each get random results. No communication.

    Instead, EPR and Bell’s Theorem says that if we later get together and compare answers, then we’ll see the “random” results were actually correlated, as if the particles were communicating with each other faster than light as they made up the random results that we saw when we measured them. But the theorem says there’s no way you and I can use that to communicate information.

    There’s also something called “quantum teleportation”, which is definitely NOT teleportation. It allows me to send you a quantum state. But one step in the process is that I have to send you some ordinary information by ordinary, slower-than-light means, such as radio waves or an email. So it can’t be used to send information faster than light.

    Of course, an Alcubere drive actually could send information faster than light. But it requires negative energy, which doesn’t exist, as far as we know. So it’s just a form of science fiction, unless the universe is different from what we know. Maybe someday we’ll find it is. But we’re no closer to having negative energy today than we were 26 years ago.

  87. of course, by that time we will most likely have ultimate, instant, and simultaneous access to any universal experience we want anywhere using an array of sensing apparatus that would make having a 'casing' at all, ridiculous, assuming that something has been there first that we can interact with/ access. Ho – hum – the monotony of being a future omni-potent/-scient species.

  88. of course, the likelihood of us each having a monogamous relationship with a single, unbacked-up body over decades or even years, by then, is so small that it is most likely we are simply transferring our conscientiousness – and therefore just data — around anywhere we want to inhabit – in a 'casing' that would be most suitable for the environment we are 'travelling' to.

  89. of course, the likelihood of having universal replicators by that time means that everything is everywhere anyway and nothing needs to be moved around past the first time — except, I suppose, for those silly 'one-off' biological entities that define themselves as the sum of their lifelong experiences – ho hum.

  90. of course, that de-romanticizes the naval ship/ fleet thematic that has monopolized space travel/ space opera/ scifi literature and entertainment for the last 150 years. Moving about in a vessel – so Verne/ Wells/ Clarke/ Astor(?).

  92. agreed. but was hoping that the arc would have some impact on storylines going forward so that travel had some consequences – i mean for tv, not us, of course 😉

  93. For FTL, I envision a huge array of quantum entanglement teleportation nodes that allow the information transfer and re-creation of the object, when undertaken in multiple steps, over distances that would make after-first contact space travel less of a bottleneck.

  95. brings to mind famous TNG episode:
    "…Force of Nature" (S07, E09) In this episode, a pair of sibling scientists show that warp drive propulsion is harming the very fabric of space…" eh. eh. could happen.

  96. Im certain a mix of quantized inertia with frame dragging provides the keys to true understanding of warping space. If they continue with this “negative” energy thought process, you won’t get anywhere. Einstein didn’t like QM cause he knew it was missing something. 
    QI provides a link to so much, and can explain things with easier concepts imo

  97. Zeno's arrow. Math maps unto reality but is not reality… and asymptotic relationships (such as in Zeno's arrow) don't necessarily correlate to reality.

    Or, if we do accept the confines of the relativity conventions, If some areas of space, by some natural process, are already moving/expanding faster than the speed of light (which we should be able to detect through secondary effects, e.g. some equivalent of Cherenkov radiation but in the not-entirely-a-vacuum-of-space), then maybe we can find a way to 'skyhook' ourselves into it.

    I don't know how, but relativity is a physics machine with many levers to play with.

  98. This would be a wonderful step for humanity. First though, we need to start manufacturing things in space. I wouldn't like to see the results of activating this thing near the Earth's crust.

  99. Maybe someday:

    "Woodward’s MEGA drive is different. Instead of propellant, it relies on electricity, which in space would come from solar panels or a nuclear reactor. His insight was to use a stack of piezoelectric crystals and some controversial—but he believes plausible—physics to generate thrust. The stack of crystals, which store tiny amounts of energy, vibrates tens of thousands of times per second when zapped with electric current. Some of the vibrational frequencies harmonize as they roll through the device, and when the oscillations sync up in just the right way, the small drive lurches forward."

    See:

    https://www.wired.com/story/mach-effect-thrusters-interstellar-travel/

  100. Its easy to get worked up about FTL starships but using a warp drive to move around the solar system at a few hundred km/s would be transformational.

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