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New study simulates gravitational waves from failing warp drive

2024-07-2915:23130192www.aei.mpg.de

Warp drives are staples of science fiction, and in principle could propel spaceships faster than the speed of light. However, there are many problems with constructing them in practice, such as the…

Warp drives are staples of science fiction, and in principle could propel spaceships faster than the speed of light. However, there are many problems with constructing them in practice, such as the requirement for an exotic type of matter with negative energy. Nevertheless, physicists have been exploring the theoretical possibility of warp drives for decades, and a new study published in the Open Journal of Astrophysics takes things a step further – simulating the gravitational waves such a drive might emit if it broke down.

The evolution in time of the real part of the Weyl scalar Ψ4 for the case of v = 0.1. This quantity provides a measure of the spacetime curvature and, in the far region, can be identified with the gravitational wave content of the spacetime. In the last two panels, we see a burst of gravitational-wave radiation leaving the collapsed remnant of the warp bubble.

Paper abstract

Despite originating in science fiction, warp drives have a concrete description in general relativity, with Alcubierre first proposing a spacetime metric that supported faster-than-light travel. Whilst there are numerous practical barriers to their implementation in real life, including a requirement for negative energy, computationally, one can simulate their evolution in time given an equation of state describing the matter. In this work, we study the signatures arising from a warp drive ‘containment failure’, assuming a stiff equation of state for the fluid. We compute the emitted gravitational-wave signal and track the energy fluxes of the fluid. Apart from its rather speculative application to the search for extraterrestrial life in gravitational-wave detector data, this work is interesting as a study of the dynamical evolution and stability of spacetimes that violate the null energy condition. Our work highlights the importance of exploring strange new spacetimes, to (boldly) simulate what no one has seen before.


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Comments

  • By vessenes 2024-07-2918:453 reply

    I love, so much, the idea that we might get a sort of galactic-scale AAA roadside warning service “Uh-oh, 2 billion years ago somebody’s warp drive went wonky in Sector ZZ9 Plural Z Beta” before we can easily move around our own Solar System. Humans would be like the old guy in a neighborhood listening to the police scanner, essentially.

    • By m463 2024-07-301:481 reply

      the trick is to say:

      Looks like your ship has a mechanical problem <click for more...>

      and collect click information about their civilization before they get any information about their warp drive

      • By pimlottc 2024-07-312:53

        Too bad the Arecibo Telescope collapsed:

        “We've Been Trying To Reach You About Your Starship’s Extended Warranty…”

    • By dreamcompiler 2024-07-3021:141 reply

      Or like the Vulcans, who were constantly listening for warp signatures and thus discovered the humanoids of Earth after Zefram Cochrane invented the warp drive.

      https://en.m.wikipedia.org/wiki/Zefram_Cochrane

      • By vessenes 2024-07-3111:56

        Ahh the non-dark-forest angle on finding aliens! So hopeful!

    • By floren 2024-07-2919:402 reply

      This was done computationally, no gravitational waves actually came into existence.

      • By jkingsman 2024-07-2920:101 reply

        I think the commenter's point was that a model for detecting events caused by advanced tech before we even get our space exploration training wheels off would be a funny irony.

        • By Already__Taken 2024-07-306:541 reply

          kinda the premise of Stargate where most aliens copied other aliens advanced tech. So actually anyone who could build it from scratch was kinda rare.

          • By thaumasiotes 2024-07-306:591 reply

            > kinda the premise of Stargate where most aliens copied other aliens advanced tech

            This is how all technology has always worked.

            • By noduerme 2024-07-308:142 reply

              Pyramids, writing, and agriculture with irrigation developed independently in at least two completely separate places on Earth within just the last 3000 years.

              • By pkaeding 2024-07-3015:40

                Developed independently? Or were both visited by aliens sharing the ideas?

              • By thaumasiotes 2024-07-309:092 reply

                And, as a percentage of cultures using pyramids, writing, and agriculture, that would be...?

                • By noduerme 2024-07-3013:291 reply

                  This is survival bias. As of 1000 years ago, the answer was an entire hemisphere. So as long as barriers like oceans or space between stars slow the propagation of technology, technology will develop on its own.

                  • By thaumasiotes 2024-07-3014:02

                    > As of 1000 years ago, the answer was an entire hemisphere.

                    You honestly believe that there was just one culture across the entire geographical and historical extent of the Americas, despite not believing the same thing about the Old World?

                • By dumpsterdiver 2024-07-309:272 reply

                  Irrelevant.

                  • By thaumasiotes 2024-07-309:571 reply

                    I think you mean "zero". Why would you expect technology to work any differently between planets?

                    • By dumpsterdiver 2024-07-3017:041 reply

                      No, I mean irrelevant, as is your newest argument. The functional capabilities of technology between planets is irrelevant to the observation that disparate groups develop similar levels of technology independently.

                      • By thaumasiotes 2024-07-313:041 reply

                        > The functional capabilities of technology between planets is irrelevant to the observation that disparate groups develop similar levels of technology independently.

                        That "observation" is false.

                        • By noduerme 2024-08-027:43

                          No, it's not. The observation that agriculture developed independently along the Tigris/Euphrates, the Yangtzee, the Indus, Sub-Saharan Africa, Mesoamerica, Peru, and several other places is indisputable and proven by the human-influenced domestication of local plants over thousands of years and the lack of any evidence of communication between those cultures when domestication began. If you're simply trying to make the case that no culture which develops a technology matters besides whichever culture ended up most dominant, it's an absurd point because all of them influenced each other bilaterally (that means both ways) when they came into contact. Corn and tomatoes were domesticated in Mesoamerica and wheat was domesticated from a grass in Mesopotamia. All are now worldwide staples. Without agriculture having developed independently in numerous places and NOT being wiped out by other technologies, one or the other of those would not exist. Have you had a Kung Pao chicken satined with corn flour? Or a corn tortilla around steak? Or spaghetti with marinara sauce? None of those combinations was possible a mere 524 years ago.

                  • By exe34 2024-07-309:57

                    precisely

      • By quotemstr 2024-07-2920:1510 reply

        The absence of such detections is yet another unsettling input to the Fermi paradox.

        • By 7thaccount 2024-07-2920:381 reply

          I saw something recently that one explanation is that we're in a cosmic void. Sure the milky way is big, but we're still exposed to a fraction of the worlds that a non-void area would be.

          Of course there are 80,000 other explanations that are also fascinating. A wonderful subject.

          • By IsTom 2024-07-3010:544 reply

            For me what makes most sense is that we're relatively early in cosmic history. You need enough heavy (and diverse!) elements to be able to support life/civilization and you won't get that from early stars.

            • By jajko 2024-07-3011:442 reply

              Most probably yes, I mean we only have few generation of stars actually producing heavy elements enough to see what we see ie on Earth, not just some hydrogen & helium ball.

              Also most probably there isnt any way to travel back in time, since we would most probably be eliminated at the seed to not compete for resources or avoid aggression. For all wonderful things mankind did and does, we are still deeply flawed and highly emotional primitive beings, and we may kill ourselves due to this.

              • By BriggyDwiggs42 2024-07-3022:07

                On cosmic scales of time, theres no reason to assume spacefaring humans would remotely resemble us in any recognizable way. Imo especially their minds, they’d almost certainly have augmented and modified their thinking drastically.

              • By JoeAltmaier 2024-07-3011:48

                The real tragedy, we're taking so many others with us.

            • By wongarsu 2024-07-3014:521 reply

              And earth has been around for 1/3rd of the current age of the universe. As far as things go it's pretty old.

              Add to that that we probably aren't as "normal" as we initially believed. A solar system with small rocky planets on the inside and big gas giants on the outside seems to be the exception and was very important for earth's development. Then there's the above mentioned "void" we are in, and probably other things we don't realize yet.

              There's a really good case that we are among the earliest spacefaring civilizations

              • By Teever 2024-07-317:031 reply

                > A solar system with small rocky planets on the inside and big gas giants on the outside seems to be the exception

                Is this actually the case?

                • By defrost 2024-07-317:12

                  They haven't cited a source or their reasoning, I would guess they mean "seems to be an exception by observation"

                  Emphasis on "observation".

                  Currently we infer planets that orbit stars that are extremely distant by starlight dipping in intensity .. this is a method that works better with larger planets and that skews the results of observing distant planets.

                  We have observed some small rocky earth like planets IIRC but these are rare, observations perhaps due more to luck in looking than frequency of existence.

                  This is the crux of the problem; does the distribution of planets we observe match the distribution of planets that exist?

            • By Modified3019 2024-08-014:19

              I hadn’t considered that angle of things before. It also brings up the opposite idea, I wonder if the over abundance of heavy elements in an old universe could reduce the likeliness of life being able to form due to the toxicity or higher levels of background radiation.

            • By shepardrtc 2024-07-3018:301 reply

              Well don't forget that Earth had it's reset button smashed 66 million years ago. Let's say another world started out at the same as we did but never encountered such a cataclysm. Even if they took an additional 65 million years to develop, they'd still be a million years older than us.

              • By quotemstr 2024-07-3019:05

                The KT boundary is hardly a "reset button smashed". Yes, it was a mass extinction event, but these things happen. The products of billions of years of evolution survived, even if megafauna had a setback. Evolution spent billions of years figuring out basic things like the genetic code, sexual reproduction, and mitochondria. All these technologies survived the KT boundary. Complex multicellular life emerged only about 560 million years ago (after single-celled life had been around for billions of years). The implication is that the early innovations in life (ribosomes, etc.) were "harder" than later ones involving eyes, brains, and so on.

                A "reset button" would be more like the impact that created the moon: ramming a Mars-sized body into Earth turns Earth into a magma ocean. Nothing survives that. By comparison, the KT boundary asteroid is small potatoes.

        • By pfdietz 2024-07-3010:14

          Unsettling? It's highly comforting.

          What would be horribly unsettling is detection of ET intelligence, as it would imply either interstellar travel is impossibly difficult or that the Great Filter is in our future.

        • By mr_mitm 2024-07-2920:423 reply

          Or warp drives are simply impossible or at least ultra unfeasible. Nothing unsettling about that thought.

          • By Loughla 2024-07-301:246 reply

            It is unsettling though. Because it places a limit on what has so far been essentially limitless success as a species.

            Without travel beyond our solar system, we won't last forever.

            And that's kind of sad for me.

            • By ben_w 2024-07-305:561 reply

              We don't need a warp drive to get to the next star, it would just make it faster.

              • By wongarsu 2024-07-3015:03

                Exactly. If we set our minds to it and dedicated enough resources we could likely reach the next star within the century: 40 years travel time at 0.1c with something like nuclear pulse propulsion, and we could probably get the remaining technical challenges for achieving that out of the way in 30 years.

            • By dTal 2024-07-301:482 reply

              We won't last forever anyway. Nothing does.

              • By rkagerer 2024-07-304:303 reply

                If I was a really advanced civilization and the universe was nearing its end, I'd embark on a project of unparalleled scale that might wind up resembling a big bang with a spark of panspermia-precursor seasoned in.

                • By worstspotgain 2024-07-3011:13

                  Indeed, we know so little about the nature of things that it's really a bit premature to hold our current understanding as the final word over what will happen.

                  For one thing, a large fraction of possibilities involves simulations. In a simulation with successful traits, some constants and elementary particles might turn out to have been misunderstood later on...

                • By mab122 2024-07-309:10

                • By luxpir 2024-07-306:321 reply

                  Goosebumps thinking of how many universes could have played out before this one. Or alongside it.

            • By tshaddox 2024-07-303:57

              Doesn’t seem like a limit to me, other than a limit on speed (and of course there will be limits on speed).

            • By baq 2024-07-309:43

              In a physically constrained system all exponential growth becomes at best a sigmoid sooner or later... it's only sad if you let it make you feel this way.

            • By SanderNL 2024-07-307:54

              It’s sad to not last forever? That’s an interesting thought. I understand, don’t get me wrong, but it’s completely unnatural in so many ways.

            • By pfdietz 2024-07-3010:16

              We don't need FTL to colonize beyond the solar system, not at all.

          • By rkagerer 2024-07-304:22

            Not unsettling, but a little bit melancholy.

          • By quotemstr 2024-07-2920:501 reply

            Superluminal travel being infeasible probably limits our species to our own solar system.

            • By evilduck 2024-07-305:271 reply

              You don't need anything near light speed for single human lifetimes to navigate beyond the solar system but it will be a one way trip mostly devoid of communication. We can seed the galaxy but can't watch it bloom.

              • By JumpCrisscross 2024-07-306:591 reply

                > but it will be a one way trip mostly devoid of communication

                Which describes our species' travels until only a few thousand years ago.

                • By evilduck 2024-07-3113:44

                  Absolutely. We want FTL in stories because it allows us to tell a sequential narrative across vast galactic distances. We want FTL in science and mathematics because humans as a species don't like hard limits to what is allowed. We want FTL in our life because few people are willing to cut all ties to their family, friends, and society to wander off into the void without hope of ever returning or being heard from again. But... some people are okay with that finality of their decision to push limits and that's how islands over the horizon get discovered and settled.

        • By mystified5016 2024-07-3022:22

          We haven't actually looked for them yet. The frequency of the theoretical gravitational waves is also beyond what our current detectors can reasonably pick up.

          IIRC, a warp bubble a few km in diameter moving at <0.3c produces gravitational waves at a frequency just beyond what we can currently detect. Superluminal warp bubbles haven't been simulated, apparently that's beyond the computational resources available to this team.

          Don't expect a real detection any time soon. We'll need another generation or two of development on our detectors and to actually simulate a more realistic (small and superluminal) warp field.

          Personally, I think we'll find something once we build detectors good enough. I'm a firm believer that purely based on statistics there has to be someone else out there. I also choose to believe that superluminal travel is possible because the universe would be a much less interesting place otherwise.

        • By marshray 2024-07-2920:201 reply

          On the bright side, maybe it is evidence against Dark Forest theory?

          • By shepardrtc 2024-07-3021:27

            The Dark Forest theory is fear-mongering anyway. If there's a civilization out there that wants to conquer others, it just has to send a probe to every star out there. Sufficiently advanced automation would allow this to happen without much work on their part. In theory, WE could do that right now, though very clumsily and with many failures. 3D printing, AI, harvesting materials off asteroids. Not outside of possibility, just hard at our level of tech. Now imagine the boogeyman of the Dark Forest theory - they would obviously have a greater level of tech if they're so dangerous, and it would be much easier.

        • By more_corn 2024-08-0121:44

          Warp drives are probably a pretty terrible way to move around since they require exotic things like negative energy that probably don’t exist, and quantities of power that would destroy the destination solar system. If anyone out there is crossing interstellar distances they’re probably doing it a different way. Have you tried wormholes? Those are pretty promising. Let’s simulate one of those collapsing.

        • By downrightmike 2024-07-2921:112 reply

          If you're spending at least a quadrillion dollars to build a warp drive, you better make sure it doesn't fail or fails safe. We may never see a failure, even if we make it depending on where it is.

          • By K0balt 2024-07-3014:45

            No worries, it will be built by Boeing.

          • By exe34 2024-07-3010:00

            if they have accountants, CEOs and shareholders, they'll cut corners.

        • By thegrim33 2024-07-3016:07

          We have no gravitational wave detectors with the sensitivity at the needed frequencies to be able to detect such events.

        • By hoseja 2024-07-3010:32

          Or the ETs know about signal hygiene. Hell, careless warp drive signatures are even a plot point in Three Body Problem.

        • By SoftTalker 2024-07-2920:221 reply

          Why unsettling?

  • By oulu2006 2024-07-2918:42

    I love the summary:

    "we study the signatures arising from a warp drive ‘containment failure’, ...."

    "Our work highlights the importance of exploring strange new spacetimes, to (boldly) simulate what no one has seen before."

    Have just been re-watching StarTrek Voyager.

  • By Tomte 2024-07-2918:57

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