Warp Drives May Come With a Killer Downside

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Planning a little space travel to see some friends on Kepler 22b? Thinking of trying out your newly-installed FTL3000 Alcubierre Warp Drive to get you there in no time? Better not make it a surprise visit — your arrival may end up disintegrating anyone there when you show up.

“Warp” technology and faster-than-light (FTL) space travel has been a staple of science fiction for decades. The distances in space are just so vast and planetary systems — even within a single galaxy — are spaced so far apart, such a concept is needed to make casual human exploration feasible (and fit within the comforts of people’s imagination as well… nobody wants to think about Kirk and Spock bravely going to some alien planet while everyone they’ve ever known dies of old age!)

While many factors involving FTL travel are purely theoretical — and may remain in the realm of imagination for a very long time, if not ever — there are some concepts that play well with currently-accepted physics.

Warp field according to the Alcubierre drive. (AllenMcC.)

The Alcubierre warp drive is one of those concepts.

Proposed by Mexican theoretical physicist Miguel Alcubierre in 1994, the drive would propel a ship at superluminal speeds by creating a bubble of negative energy around it, expanding space (and time) behind the ship while compressing space in front of it. In much the same way that a surfer rides a wave, the bubble of space containing the ship and its passengers would be pushed at velocities not limited to the speed of light toward a destination.

Of course, when the ship reaches its destination it has to stop. And that’s when all hell breaks loose.

Researchers from the University of Sydney have done some advanced crunching of numbers regarding the effects of FTL space travel via Alcubierre drive, taking into consideration the many types of cosmic particles that would be encountered along the way. Space is not just an empty void between point A and point B… rather, it’s full of particles that have mass (as well as some that do not.) What the research team — led by Brendan McMonigal, Geraint Lewis, and Philip O’Byrne — has found is that these particles can get “swept up” into the warp bubble and focused into regions before and behind the ship, as well as within the warp bubble itself.

When the Alcubierre-driven ship decelerates from superluminal speed, the particles its bubble has gathered are released in energetic outbursts. In the case of forward-facing particles the outburst can be very energetic — enough to destroy anyone at the destination directly in front of the ship.

“Any people at the destination,” the team’s paper concludes, “would be gamma ray and high energy particle blasted into oblivion due to the extreme blueshifts for [forward] region particles.”

In other words, don’t expect much of a welcome party.

Another thing the team found is that the amount of energy released is dependent on the length of the superluminal journey, but there is potentially no limit on its intensity.

“Interestingly, the energy burst released upon arriving at the destination does not have an upper limit,” McMonigal told Universe Today in an email. “You can just keep on traveling for longer and longer distances to increase the energy that will be released as much as you like, one of the odd effects of General Relativity. Unfortunately, even for very short journeys the energy released is so large that you would completely obliterate anything in front of you.”

So how to avoid disintegrating your port of call? It may be as simple as just aiming your vessel a bit off to the side… or, it may not. The research only focused on the planar space in front of and behind the warp bubble; deadly postwarp particle beams could end up blown in all directions!

Luckily for Vulcans, Tatooinians and any acquaintances on Kepler 22b, the Alcubierre warp drive is still very much theoretical. While the mechanics work with Einstein’s General Theory of Relativity, the creation of negative energy densities is an as-of-yet unknown technology — and may be impossible.

Which could be a very good thing for us, should someone out there be planning a surprise visit our way!

 

Read more about Alcubierre warp drives here, and you can download the full University of Sydney team’s research paper here.

Thanks to Brendan McMonigal and Geraint Lewis for the extra information!

Main image © Paramount Pictures and CBS Studios. All rights reserved.

 

114 Replies to “Warp Drives May Come With a Killer Downside”

    1. you might want to try rerouting the EPS conduits first. Also modulating the phase inducers might help.

      1. Subroutine. (drink a shot) Deflector dish. (drink a shot)
        …and you’re blotto.

      2. my name is Zefram Cochrane and you are all wrong. I`ve already given the plans for the first Warp Ship to NASA , but as they usualy work, i guess the first flight will take place in 2063. Don`t ask me where i get the plans from, a spaceship came from future gave them to me, but this is secret.

  1. looks like we had better find a way to convert the energy inside the bubble that is either usable, or find a way to neutralize it.

  2. “Nothing can travel through space faster than the speed of light but space can do whatever the heck it wants.” http://youtu.be/Myd2OyH21Eg Give a theoretical physicist a condom and a dream and he’ll give you a warp drive.

  3. Maybe then they could create some kind of energy sink for this, and ensure that all of these ships stop at regular intervals. Unfortunately, thousands of years into the future this could be the ultimate suicide bomb. The “suicide” part may not even be true if it is just a robotic drone programmed to stop somewhere far away.

  4. By the way, the last sentence in the paper, for anyone who read it.

    ” While in one way journeys particles travelling towards the origin are potentially dangerously blueshifted, their supposed distance from the origin would render them too sparse to be of major concern by the time they reached the origin.”

  5. If we could create a manageable black hole, it could provide gravity for the ship, suck in those particles, and evaporate the energy to recharge the ship’s batteries 🙂

    1. Does not compute. Error is conflict of values. Evaporate the energy… energy does the vaporizing not the other way around… you mean pile it up into a type of gun or magnetic field generator… I hope.

      1. What I really meant, I think, is to use the Hawking radiation to power the ship.

  6. As-of-yet is not a proper phrase. It makes no sense, yet people continue to use it. With that said, I think we’re getting way ahead of ourselves when discussing the ramifications of a theoretical mode of travel. One that is, as of now, still considered impossible.

    1. “As of yet” may be redundant, in that “as-of-yet unknown technology” means exactly the same thing as “yet unknown technology.” It might be poor grammar, as the adverb “yet” appears to be used as a noun — probably the modifier “yet” was applied because the entire phrase is used as an adjective. That doesn’t really make it nonsense, though.

      Discussing the ramifications of a theory is getting ahead of ourselves? What else is a theory for? (Sorry, for what else do we use a theory?)

      Also, the idea of a new kind of particle accelerator is interesting outside the travel aspects.

  7. These spacetime solutions are pathological. The energy released here appears to be due to the negative energy condition on the “exotic field” which is the source of the spacetime curvature. A couple of years ago it was found the Alcubierre warp drive results in a huge burst of Hawking-like radiation which demolishes the spacetime configuration. This type of research is important, for by figuring out the failure points of solutions we can identify the source of chronology protection and the censorship of singularities.

    LC

    1. Cronology protection?

      Is there any hint that this warp bubbles could be used to travel back in time?

      1. Of course, how else are you going to bring whales to the future… um… present. I guess that part’s relative.

      2. Warp drives violate the weak energy condition, with the WEC being T^{00} >= 0, and if the universe violates this then not only are warp drives possible, but wormholes and a host of other things. Wormholes and Kransnov tubes can be converted into time machines.

        LC

    2. Yes, if there’s anything that makes my day, it’s identifying the censorship of singularities! I’m going right out now to start a flash mob to promote the freedom of open singularities!

      1. You might have better luck at, and a better outcome with, calling up Cthulhu from the deep. If you are familiar with complex variables you know that paths which enclose a singular point or pole can have a branch cut. The branch cut connects an infinite stack of complex planes. A naked spacetime singularity would do something similar, and you would become lost in an infinite arrays of spacetimes. The inner timelike region of a Kerr or Reissner-Nordstrom black hole metric would do something similar if you encountered the singularity inside there. This assumes you can cross the inner horizon and the blueshift divergence there. You would find yourself lost in a cosmological version of the Bill Murray movie “Groundhog Day.” A naked singularity would confront our entire universe with that sort of horror.

        LC

      2. Cosmic censorship?What about this?

        Destroying a near-extremal Kerr-Newman black hole
        http://arxiv.org/abs/1105.3950

        It is about plunging a test particle into a rapidly spinning Kerr black hole. Since black holes form if and only if a very dense object (like a collapsing stellar core) follows the inequality:

        M^2 ? a^2+ Q^2 ; a =J/M;

        M is mass, J angular momentum and Q is electric charge.

        When the above is an equality, we have an extremal black hole. The idea of destroying a near extremal or extremal black hole is to plunge a test particle with the right charge and momentum to make the hole violate the above inequality.

        For the case in question, a Kerr black hole is destroyed plunging into it a test particle that is fast enough and go in the right angle to increase the angular momentum of the black hole enough to break the inequality. Since the hole only barely follows the inequality, this fast particle could be very small in comparison with the hole to make this happen. Then, the two event horizonts disappear and the central singularity is exposed.

        It was known that an exactly extremal black hole cannot be destroyed in this way but a nearly extremal one can as the paper explains(the math is the article above).

        The article show the example of “rapidly rotating black holes in quasars and radio galaxies . These black holes are very massive, having typically M ? 10^8M?, and can attain an angular momentum such that a/M ?0.9 . A test body with mass comparable to the moon mass, ? ? 4 × 10?8M?, will certainly be able to reach the horizon if thrown from infinity with angular momentum L/M^2 = 10^?5 (…) any test body thrown from infinity with angular momentum L/M^2 = 10^?5 and energy E such that Emin < E < Emax will produce a naked singularity (produced destroying the black hole)"

        What do you think?

      3. I will comment on this in greater depth later today or tomorrow. Time is a bit constrained for a long discussion right now. However in looking at this paper I think there is a serious problem. If a Kerr black hole is some increment of angular momentum away from extremal condition, you can’t easily apply that amount of angular momentum and get it to extremality. When you perturb a black hole it produces gravity waves. If you try to hurl a mass at high velocity at a near extremal black hole you will produce lots of gravity waves that carry off most of that angular momentum.

        Reaching extremal condition is analogous, or really the same, as trying to reach absolute zero temperature. This violates the third law of thermodynamics. I will break this out in greater detail later. However, to reach absolute zero you need to approach a situation with zero entropy, but the emission of gravity waves prevents that. The horizon area will not reach the extremal case with zero temperature.

        This does get into the issue of quantum bits for BPS and extremal quantum black holes. BPS black holes have tri-partite entanglements of states and extremal black holes have 4-fold or GHZ entanglements. The interrelationship between these is a rather abstract topic involving Lie group theory.

        LC

      4. This is to follow up on the Kerr metric and angular momentum. The two event horizons in the Kerr black hole with angular momentum J and mass m are,

        r_{+/-} = (G/c^2)(m +/- sqrt{m^2 – (Jc/Gm)^2}.

        with the the metric

        ds^2 = -[(r_+^2 – r_-^2)(r – r_+)/r_+^2]dt^2 + 1/[(r_+^2 – r_-^2)(r – r_+)/r_+^2]dr^2 + …

        This more or less works for the RN black hole with a charge. One just replaces Jc/Gm with a charge in naturalized units. The horizon r_+ is the outer horizon which separates the exterior world with a timelike metric from an interior region with a spacelike metric. The inner horizon r_- interior to the black hole separates the spacelike region from a further timelike region which contains a ring singularity. The surface r_- is physically itself a singularity, for if the black hole is formed by inward flowing geodesics they all meet at this surface with infinite blueshifted frequencies. The interior timelike region may be mathematical artifact of the exact solution for the “eternal black hole.” The surface gravity on a sphere of radius r is

        ? = (GM/r)(r_+ – r_-)/2r_+

        where the gravity on the surface of the event horizon is found by setting r = r_+. For r_- = 0 this recovers the Schwarzschild black hole. The temperature for this black hole is

        T = ?/4?

        which for r _- = 0 recovers T = 1/8?m. Hence for the extremal black hole the temperature is zero.

        Black holes obey thermodynamics, where the area of the event horizon is proportional to the entropy. The extremal black hole is then a zero temperature state, which is not reached by any adiabatic process. Such a process would for black holes the spinning up of a black hole by shooting small masses at it with some angular momentum relative to its center.

        LC

      5. In the formula above ? is zero for extremal black holes because for them r_- = r_+ and so the term (r_+ – r_-) vanishes.

        But the paper was not about extremal black holes but about NEAR-extremal black holes. The paper began with the impossibility to destroy an extremal black hole. Then it showed that however, it should be possible to destroy a black hole that is almost(but not quite) extremal. A small and rapid object should be enough to destroy the hole and “undress” the singularity.

      6. The problem is that this is a thermodynamic process, which the authors of this paper seem to be ignoring. Reaching the extremal condition is a black hole thermodynamic process of reaching absolute zero. The extremal black hole is not a naked singularity, for the r_+ = r_- region does not propagate classical information to the outside world. If you are able to spin the black hole up further then you do have the naked singularity. The extremal gravity is zero and for the naked singularity it is repulsive.

        I am avoiding getting into BPS black holes, extremal black holes and quantum gravity. In quantum gravity, the BPS black hole is compared to a timelike path with ds^2 > 0. This is defined on the moduli space of the solution. The extremal black hole is the null case with ds^2 = 0, and the naked singularity is ds^2 0 condition on the BPS moduli can be transformed into a ds^2 < 0 case on the moduli for a naked singularity is within a quantum fluctuation, with an uncertainty in energy ?E?t = ?/2, where the fluctuation in the energy changes the ADM mass (or there is an uncertainty in its value) so it ranges into the case of a naked singularity. Yet in order to communicate real information into and out of the singularity requires one have some hidden variable process in quantum mechanics. This is an other big “no-no.”

        LC

      7. But what loophole in the paper analysis can save the near-extremal black hole from destruction?

        The paper shows how we go from a near extremal black hole to a naked singularity, and if I understand it well, WITHOUT BECOMING AN EXTREMAL BLACK HOLE in the middle of the process (your totally valid objection assumes that).

        So we start with a near-extremal Kerr black hole, then that little moon crosses the horizon (tidal effects are negligible because this black hole is a supermassive monster) and falls toward the center.

        We now have a dynamic situation were the moon is falling towards the singularity. What the destruction of a black hole would look like I have no idea. Maybe the attraction between the singularity and the moon becomes repulsion and the moon is violently ejected, restoring the black hole horizon and you are right, but this is just guessing.

        A computer simulation could be the only way to have an idea of what can happen.

      8. The problem is that trying to get a naked singularity, even by trying to leap frog across the null condition for the extremal black hole, is that it is like trying to get a temperature colder than absolute zero. The extremal condition, or the closest one can get to is is analogous to a Bose-Einstein condensate. What prevents things from going to a lower energy state (colder) is that the eigenstates of the universe are bounded below with some absolute minimum. If that does not exist then things go a bit awry.

        F. Dyson pondered what would happen in QED if a charge were imaginary valued. Opposite charges would repel and by QED electron positron pairs would come gushing out of the vacuum. In a sense something similar happens. In fact the naked singularity is repulsive and would produce a huge amount of radiation in a violent event far in excess of any supernova.

        LC

      9. We can have a black hole with a small “delta” departure from extremality:

        delta^2= M^2 ? a^2 > 0, delta/M? 1.

        Then the paper showed that any test particles that:

        1) Have energy E, electric charge e, and orbital angular momentum L that are small enough for the test particle approximation to be valid:

        E/M ? 1, L/aM ? 1, and e/Q ? 1,

        2) Follow the condition:

        Emin < E < Emax

        Where

        • Emin is the minimum energy necessary to assure the particle does in effect plunge into the black hole

        • Emax is the maximum energy E allowed for having a black hole and not a naked singularity: the total mass (mass hole +mass particle) ^2 bigger than total angular momentum (ang. Momentum hole + ang. Momentum particle)^2

        (M+E)^2 ? (a+ L/M)^2

        3) An angular momentum (with respect to the hole center) that follow:

        L/(M^2) ? delta

        Will produce a naked singularity.

        The paper then showed an example. The example was a supermassive black hole with M ? 108M?. This will give an outer horizon of r_+?10^8 km.

        The parameter delta was taken ?10^-5. This can happen valid for a lunar mass(?4*10^-8 M?) with angular momentum that follows L/M^2 ? 10^-5 trown from infinity. In this case, if that moon also has an energy bigger than Emin ? 10^3M?. and follow E/M < Emax/M = 10?5(1 – 10^?5)/2, that moon will destroy the hole.

    3. The renormalized stress-energy tensor at the leading edge of the warp bubble has been shown to become exponentially unstable over time, rendering it unstable.

      See http://arxiv.org/abs/0904.0141v2

      And in reference to the above article, the prospect of being blasted by gamma radiation from superluminal space travellers, decelerating carelessly, supports Stephen Hawking’s aversion to making our presence known 🙂

      1. This is the paper I was thinking of last night, when I was a bit too tired to research it up and get the authors, when I mentioned the demolition of this spacetime configuration by Hawking type of radiation. The central region is separated from the exotic material by the particle horizon of this spacetime. This is similar to a Rindler wedge. The observer in the central region is not causally connected to the exotic matter, so the warp bubble can’t be controlled. Further, the horizon emits a thermal bath of radiation which grows enormously.

        These types of spacetimes are interesting in order to understand how quantum gravity gives rise to classical spacetimes which are not pathological. By some means quantum gravity probably removes these spacetimes as physically real.

        LC

  8. Since warp occurs in sub-space… I don’t see what the problem is here.

  9. So what you need is some sort of superluminal diode to prevent the energy spike in the same way a conventional diode keeps an energy spike caused by the field collapse when a switch is thrown from damaging the switch itself. Then a sort of capacitor to store the energy so that it could be used to power the next hyperspace jump. There, see, simple.

    1. true, everybody knows that it is forbidden to use warp engines near planetary sistems. First get some distance with the impulse engines, THAN use warp. It`s just commonsense.

  10. How about a way to convert any “particles” into plasma and then expel them while driving to keep the energy load down? Small, short-burst warps could be induced along the way to expand the space-time between the ship and any accumulated particles.

  11. Next on Sci-fi warfare: Warp missiles that once arrive to the target planet liberate enough radiation to burn the upper atmosphere of it!

    Scary!

  12. A simple navigational rule requiring warp vessels to drop out of warp a safe distance from a star system and then proceed using sub-light propulsion would easily solve this problem. It also eliminates the risk of driving a vessel into a planet, asteroid, or moon at while still at warp, which would be quite a disaster for the crew of the ship one would think.

  13. Since it is all theoretical, perhaps the build-up is negated by the particles being deflected to the side off the forward part of the bubble like water off of the prow of a boat. Then there would be no noticeable build-up. Did they do calculations to that effect or just as if the front of the bubble is scooping everything up like the bucket on a front-end loader?

  14. Wow. I’m as remote of an astronomer as anyone can be. Specially amongst all you guys. And I somehow got sucked into reading this story. And I must say… wow! That was quite fascinating! O.o Never could have thought something like warp speed could ever be considered possible. Much less the destructive effects of it! But very fascinating!

  15. We are so small minded. Talking about space time and bending it… think about the bubbles of energy surrounding everything within the Galaxy! The force that makes each creator spaced from another, and holds clouds of debris near the edge of gravity. The real atmospheres of Suns (extend well beyond the planets) A sun makes so much energy… interacting with other stars with planets. We can’t just cut through it. We have to ride it.
    Space travel was never meant to be sped up. But think of how quickly an electron jumps from one shell to the next by absorbing energy… [A vessel should be able to flash from one galaxy to the next. or even one universe to the next. That would be a “multidimensional” trip.]
    The Sun should be able to do this if it could be realigned against the will of the universe. It sits where it is and moves as it does through space because of the Galaxy’s sphere of influence that all within it is subjected to. A space ship ought to only need a small orb at it’s center. One you can spin and orient at will. The orb needs to be extremely dense material.
    And you need to collect enough solar energy concentrated upon this orb. (So the orb needs to be designed to absorb that energy into increasingly denser material)
    If you had a large saucer, you could mount lenses to collect and condense into “pipes” that channel it together like an LED array. This makes the ship shallow. Very big diameter, not very tall. As few impediments on the energy as possible means straight path.

    This vessel cannot land on planets or even be built on one.
    It is powered like a planet’s core, only, you can manipulate it to move the ship around using the Sun and the planets’ influences. Simple repulsion and attraction.
    If you figure out how to tune it’s emission you could potentially target planets and attract your ship towards them. Propel towards the next star system by shutting down the drive just before entering it’s sphere. Spinning of dense energetic material is very important to gravity generation. Pressure can compensate for density.
    Think about how much pressure the Earth’s mantle being pulled inwards by gravity-creates on the core. This would make plasma states likely. The sun constantly bombarding half of the Earth with energy. Starting cold, it would probably take millions of years to heat to it’s current state. But having started hot, the Sun likely slows Earth-core-entropy greatly. The question is, will the sun explode before entropy cools the Earth too much that the Ocean cycles die slowly disintegrating a complex system called Life? Are we even monitoring conditions at the bottom of the Pacific and Atlantic Oceans?

    The simple truth is: We are short lived for space travel. Our “Gods” lived for thousands of years. Maybe even more. We would have to really raise our children right, and get ethics under control… to really sustain life for the trip that takes generations. Stasis is viable too. The real magic comes when you start imagining the source of existence. The thing that all matter is connected with and how it is capable of reintegrating your consciousness on a grand scale, with a collective of sorts that sits far beyond the reaches of this tiny universe.
    To the real “God” of all, we are infinitesimal specks of nothing comparable to dust within the atoms making the bacteria in his Gut.
    We’re supposed to be in the image and likeness, yet we can’t recognize the trillions of individual lives we are responsible for tending to daily and being in touch with. We take it for granted and are wrought with sin. God is connected with that of which God is made. Accessible to any who would align their self with the source where all knowledge may be found. Repent!

    1. I think it would be easier to hack into the programming code of the Universe and just modify your present location. Just make sure it has the right temperature and pressure, unless you could mod yourself?? Or call Keanu Reeves.. Just don’t rely on God, who’s too busy playing galaxy-pinball somewhere far away.

      1. Search for RAM values of *location* associated with *your name*?

        If I’m in the system anyway… set value “Nafin” HP 9999

    2. Thanks. You and I are somehow connected by a similar way of thinking about “our” existence.

  16. Saying thanks will not just be sufficient, for the phenomenal clarity in your writing.
    I will directly grab your rss feed to stay informed of any updates. Admirable work
    and much success in your business dealings!

  17. science fiction is a reaction, in many cases, to the realization of the fact that we are earthbound and will die earthbound. the imagination reels and attempts to find a way. the best sci-fi hews to plausibility, as opposed to fantasy. there is no literary device that will destroy dramatic tension as well as a time machine. (just go back and fix it and where are the visitors from the future?)

    we will only visit the stars in our imaginations and learn of them from incident photons upon our instruments.

    however, through some alchemy, a keyboard can generate vast amounts of cash.

    1. Fully agree. Space travel is not within the current realm of possibility. Assuming we even had the technology in present day to start the exploration, it would take hundreds, even thousands of years to perfect it as the unknowns are far too great for our measly human minds to comprehend.

      A lot of space travelers would die, and shortly thereafter, it would basically be a Banzai mission just to retrieve very minimal amounts of information on each trek.

      Unfortunate, but reality. Plus, I don’t know that the space aliens would care too much for a Walmart in deep space. We’d just end up spending more time trying to figure out ways to monetize the Universe than to actually explore it. Then we’d end up finding oil on another planet and would immediately have to declare war on it and invade the crap out of it. Thus, destroying it anyways, so what’s the point?

      Humans today are just not mentally ready for space travel. Our priorities are also our restrictions.

  18. Everyone knows that real super-luminal space drives cannot be used in the vicinity of a gravity well. This is well settled “hard” sci-fi.

    And now, not so sci-fi.

    From http://www.jerrypournelle.com

    Metamaterial-based model of the Alcubierre warp drive

    Igor I. Smolyaninov (Submitted on 28 Sep 2010)

    Abstract: Electromagnetic metamaterials are capable of emulating many exotic space-time geometries, such as black holes, rotating cosmic strings, and the big bang singularity. Here we present a metamaterial-based model of the Alcubierre warp drive, and study its limitations due to available range of material parameters. It appears that the material parameter range introduces strong limitations on the achievable “warp speed”, so that ordinary magnetoelectric materials cannot be used. On the other hand, newly developed “perfect” magnetoelectric metamaterials are capable of emulating the physics of warp drive gradually accelerating up to 1/4c.

    http://arxiv.org/abs/1009.5663

    1. Hold on a minute, emulating a black hole does not mean that it IS a balck hole.
      It is only emulating a property that is equivalent of a black hole. 99.999% of that material does not act at all like a black hole.

      1. In the case of building a device like an optical cloak based on black holes, where you are only interested in exploiting a few specific exotic properties, it doesn’t matter if you emulate a black hole perfectly as long as you get the relevant parts right. It’s even possible that you could reduce or eliminate the the drawbacks of the Alcubierre warp drive with nothing more than better materials research.

      2. As far as I know — from the paper mentioned above –, there is (still) no way to make physically relevant conclusions from this metamaterial approach to what happens around a real black hole. For me this would mean, that they did *not* get the relevant parts right. I’m afraid, it’s a dead-end street.

      3. I comment on this above. The analysis is done from a particular frame where the body starts off at zero velocity. By doing this the analysis does not appear to take into account the covariant transformation of the embedding spacetime.

        LC

      4. Your explanation is great, but I can’t see how it addresses my point that “there is (still) no way to make physically relevant conclusions” from theory to reality. For this we would need (at least) experimental observations.

        For example the theory of relativity is supported by a lot of observations nowadays, and from the outset there have already been serious and promising suggestions for experiments. In the case of the metamaterial approach I don’t see anything like this — not even suggestions — in the paper mentioned above or anywhere else. For clarity let me emphasize: something allowing physically relevant conclusions from theory to reality.

        May be, I don’t recognize it. Do you know something about the point I made? Is there more than research in a cloud of formulae?

      5. This metamaterial approach is really a sort of phenomenological “gadget.” It amounts to using one form of physics to model another form of physics. The results are curious, for it implies a limiting velocity. I think a more complete analysis would show that the limiting velocity is the speed of light. If the Alcubierre warp drive could be derived that obeys the Hawking-Penrose energy conditions, maybe violating this for some local or false vacua and obeying the condition globally, with a warp velocity v < c, then this spacetime configuration is plausible.

        LC

      6. Thank you for your answer, but, except for your first two statements, to which I completely agree, we talk about different things, I think 😉

      7. I will have to read the paper again. As I recall the model is set within a certain “frame,” which is the frame of the material. The limiting velocity is v = c/4, but this is within the frame of the accelerated object with v = 0 at the start. An observer on another frame with velocity u observes this object accelerate to

        V = (v + u)/(1 + vu/c^2)

        If this observer watches the object reach terminal velocity in its initial frame v = c/4 from a frame moving at xc, x < 1,

        V = (x + 1/4)c/(1 +x/4).

        From a frame moving near the speed of light the Alcubierre warp drive can only approach the speed of light.

        There is then something odd about this, for we can suppose from a starting frame that the object accelerates to near c/4. We then reset the problem according to an observer moving with u = c/4 and do the velocity addition formula

        V = .5c/(1.125) = .444c,

        Then iterate this process by repeating again to find the Alcubierre WD accelerates to a velocity asymptoting to the speed of light.

        LC

    2. I remember reading this paper. There are similar papers which use optical metamaterials to emulate black holes, and some people are using Josephson junctions. This is though not the real thing as such. This solid state-optics analogue fall short of being spacetime physics, but is maybe a bit more than a CGI computer simulation.

      LC

  19. Today’s wild thought: Perhaps GRB’s (Gamma-Ray Bursts) – incredibly energetic outbursts now ascribed to extreme stellar phenomenon – are actually Alcubierre drive ships actually dropping out of warp?

    Perhaps GRB’s are indeed proof of SETI?

  20. you could just hop around multiple times to keep the energy level low…

  21. He, Carbon Copies!
    All you have to do is to learn how to fold Space, no hyper speed needed, just point in the right direction, move slowly ahead and shhht, arrive!
    Nothing to it.

    1. That’s basically how an Alcubierre drive works. You can’t travel faster than light, but if you fold space ahead and behind you you get pulled along on the wave, whilst still travelling at sub-light speed.

      1. Alcubierre’s method requires you travel from point A to point B. What MOZ is recommending is to make points A and B the same point, and travel to it/them. Saves a whole lot of time, though it would probably require the same amount of energy. 😀

      2. Would it though? If you’re standing at point A, and point B is 1,000,000 miles away, getting from point A to point B would require a considerable amount of energy. However, as you stated, if you can bend that distance making point A and point B the same point, you would be arriving at point B no later than you left point A.

        Unless you’re referring to the energy needed to bend space in the first place. In which I have no logical explanation on the energy needed for that.

  22. there are some concepts that play well with currently-accepted physics.

    Not unless you mean “won’t work according to currently-accepted physics.” The general problem with an Alcubierre ‘drive’ is that it isn’t an actual drive. And this paper validates that in spades.

    – If you take the overall spacetime solution and forget for a moment how it is created, if it is created as a ftl bubble it will go ftl. The problem is then how to populate it with mass traveling ftl.

    – If you start with matter generated bubble, say with exotic matter, and forget for a moment how that is created, you have no drive to take it to ftl. This paper shows that all matter, used in a reaction drive say, leaves the bubble at less than ftl velocity and compounds to the problem. According to this paper you have to keep boosting the old fashioned way.

    The paper also shows how the ‘drive’ will act as a large brake. It will be much easier to accelerate only the ship, instead of using up energy to generate a field and accelerate encountered mass as you go.

    Maybe we should rename it “the Alcubierre deflector shield”. Not a very efficient shield at that, mind.

    1. In supporting what Torbjörn Larsson says, I would to add, that, from all I read about Alcubierre’s concept, it *is* purely theoretical. I like to say, it’s research in the formular cloud, and only there. There are no experiments, not even serious suggestions for experiments (correct me someone, please, if there are serious suggestions in the meantime; I would be interested). For me “currently accepted physics” needs much more than what has been achieved regarding Alcubierre’s concept.

  23. Isn’t there still the problem of turning off the warp drive, and then having the compressed space time in front of the ship expand to knock you back to where you started? So you killed your friends for NOTHING!

  24. Actually if you follow these shows warp drive is not used within the heliosphere as it would destroy the ship. Ion drives are used used within a system.

  25. Good thing we have NASA on the job, so that we need never worry about having “warp drive” propulsion technology. Or any other similar advanced technology, for that matter.

    Whew! Thanks, NASA!

  26. i would guess that the blast would only have to -graze- the atmosphere of a planet to do damage to a planet.

  27. That’s why you drop out of warp before destination and do the rest of the trip with the Impulse Drive.

  28. Sounds pretty easy to weaponize. Who needs lasers when you can simply play a game of bumper cars on a galactic scale and vaporize the car you “hit”. Double-impact: first your enemy’s Unmanned Space Vehicle drops out of warp and zaps you, then a few seconds later it rams you at sub-warp-but-asteroid-strike-like speed. 🙁

  29. Sounds pretty easy to weaponize. Who needs lasers when you can simply play a game of bumper cars on a galactic scale and vaporize the car you “hit”. Double-impact: first your enemy’s Unmanned Space Vehicle drops out of warp and zaps you, then a few seconds later it rams you at sub-warp-but-asteroid-strike-like speed. 🙁

  30. We cannot go to Mars, or the moon again. Instead we must first make sure everyone here gets free TV and sneakers, a new car, cheese and an goobermint education and free contraceptives so they will know how to vote. Then, maybe…in about the year 3568 or so the lib hacks might consider doing something to actually benefit the folks who pay the tab. China will be there long before us.

  31. You can also just stop your trip at several waypoints in deep space, discharging the energy before it builds up.

  32. You can also just stop your trip at several waypoints in deep space, discharging the energy before it builds up.

  33. Talk about thinking in a box. Since little or nothing is actually known about this theory, particles may not be swept into the warp bubble. They may be actually be repelled. Speculation about warp physics using the current page of currently-accepted physics is actually only an exercise in negative thinking. Of course warp drive won’t work with current physics. The next step, the next page has to be found and learned before this is even closer to happening.

  34. Eh, they had gone through all that trouble only to ignore most obvious solution.

    For each superluminal second you drop to subluminal speed for a microsecond and voilla- problem solved!

  35. ha very interesting and i am glad i am not the only crazy one..lol mine is called the atomic spaceship able to travel three times the speed of light, slight similar to this the possibility but i am using one equation that’s been around for 100 years and it was created by the none other than Einstein the world famous E=MC2 for according to the book i am writing called sittos science within the equation lies the very clues that travelling faster than speed of light is possible eve though it was created to prove the contrary yet with my own equations i believe that a spaceship is possible to be build and reach beyond the speed of light, if you people willing to share what you have come up with i am willing to share all drawings of the spaceship and equations and possible know how… interested?/ email me: [email protected] imean why be in competition i don’t mind sharing the glory..

  36. Maybe sunspots are the result of ships politely aiming this reentry energy towards the sun.

  37. The “Star Trek” warp drives have something called “Bussard collectors” which are supposed to collect particles while the ship travels. The particles are used to power the ship. In 1965 it was total gibberish, and who knows who “Bussard” was, but it’s a convenient “out” for the Trekkies!

  38. Besides making a nasty weapon one would have to come out of FTL much further away an on a blind side to avoid irradiating inhabited planets.

    Since it is still on paper as in hypothetical. (A theory is proven, this hasn’t been) then we can work on what to do with the excess energy. Well it would be a nice idea to put it into a capacitor to use again or find a way of releasing it in another lower frequency like light.

    And if this is the only way that works if we can’t create wormholes to use it would be dangerous to use them for exploration if we reach a system then blast it with dangerous doses of radiation. An imagine coming back to Terra? But we can rest for the moment. And we have far more dangerous things happening on our own planet from our previous 300+ years of irresponsibility.

  39. A) Deflector dishes knock particles out of the path of Trek ships

    B) Bussar Collectors sweep up interstellar hydrogen for fuel supplimentation (the deflector allows these through its field)

    C) Even without both A & B, the ship and the warp field are not ‘stopping’ instantly by dropping the warp field, they need to decelerate or you also risk injury / death for the crew (whether by splattering them across the bulkheads, or structural failure(s)). Wouldn’t this also have the effect of decelerating the particles that got swept up in your ‘wake’?

  40. meh. Slip-stream technology then. That’s what Star Wars Hyperspace is anyway….another dimension that mirrors the gravity points in their “real” galaxy.

    Create a dimensional portal device that allows the ship to slide into the dimensional space, proceed with the journey, then slide out once you arrive.

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