New study simulates gravitational waves from failing warp drive | Hacker News Reader

New study simulates gravitational waves from failing warp drive

aei.mpg.de

130 pointsnabla9192 comments

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.

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

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.

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.

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

This is how all technology has always worked.

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

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

Irrelevant.

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

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.

> 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.

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.

precisely

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.

> 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?

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

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

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

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.

Why unsettling?

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

You don't need FTL travel to expand into our light cone at this point in the evolution of the universe.

That makes absence of FTL detections comforting, not unsettling.

Does it? https://en.wikipedia.org/wiki/Quiet_and_loud_aliens Probably about neutral.

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.

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.

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.

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

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.

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

> 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?

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?

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.

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.

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.

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

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

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.

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

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

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.

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.

We won't last forever anyway. Nothing does.

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.

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

Goosebumps just with ours already: https://m.youtube.com/watch?v=uD4izuDMUQA

May I... https://en.wikipedia.org/wiki/The_Last_Question

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...

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

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

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.

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.

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.

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

Not unsettling, but a little bit melancholy.

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.

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

No worries, it will be built by Boeing.

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.

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

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

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.

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.

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

Too bad the Arecibo Telescope collapsed:

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

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

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

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.

PBS Spacetime: https://youtu.be/8hvzF5oQe1g?si=dU7YRdomARPQzDtd

A positive would mean two amazing news at once: that there are aliens travelling in deep space and that they do so using faster-than-light spaceships.

Only one of those. Warp fields are useful if they can be made, but probably won't allow for FTL.

Right. Because FTL, no matter its form, breaks causality.

And causality is known to be axiomatic because?

Because it seems to hold empirically quite stubbornly.

Not really at the quantum level, at least not in the form that is typically understood as causality. There are all kinds of ways that you can interfere with probability and when you do, the “no taksie-backsies” rule goes out the window. You can prove this to yourself with a flashlight and 3 diffraction gratings.

Only if you don't think MWI is accurate...

That’s where probability manipulation really gets interesting.

My preferred conjecture is that all things exist, at all times, in all places, but only a fraction of all of those infinite-dimensional probability vectors will produce the act of your observation, so those are all of the vector-spaces that you can detect. We can’t observe, for example, a probability vector-space where water boils at 15c/1bar, or where e=3 because we would never have existed to observe within that environment. Perhaps other things exist and observe those places, but not carbon based biological life as we know it.

I think that the Casimir effect and especially Casimir pressure in constrained geometries, Zero point energy, the uncertainty principle and other observable phenomena point towards the possibility of a continuum of multiple overlapping observable probability fields, but obviously that could be just a convenient hand wavy explanation.

In the bandwidth of overlapping probability fields flavour of MWI there is no branching or creation of new realities, merely extant vector spaces drifting in and out of observability based on probabilistic functions. Vector spaces within observability tend to be similar, and the overall aggregate sum is what we perceive as a unified observation.

As we make changes that manipulate this probability space, new probabilities dominate our perception. The apple was very unlikely to be seen on the table until we moved it there, making it then extremely probable to be observed in that position.

There are some very interesting ramifications that appear to be observable phenomena if this line of thought is drawn out to its extrema. It’s one of my favourite possible models.

Perhaps one day I or someone else will figure out how to experimentally test the idea, but so far it seems to be unfalsifiable (which obviously doesn’t mean that it is more correct, just that it’s hard to test, like the simulation conjecture and many others)

I should have also made it clear that the probability vector-spaces that become unobservable include those where you got hit by a bus, and all of the coherent/adjacent spaces to that event. So the bandwidth of perceivable “universes” keeps shrinking to lesser infinities as you go through life.

In addition, the perceivable vector spaces where you can talk to your friend also includes only those where she also got missed by the bus, and to a lesser extent all those who are connected and perceivable through communications… the act of communication being a constraint to the infinities of perceivable vectors where the communication would be possible, making us much more constrained as a society than we would have been when distant people had little or no contact.

There are a lot of interesting implications of this conjecture that may go some distance in explaining subjective human experience.

Um, sorry, how does that experiment prove anything quantum? It's explained entirely by Malus' law of I = I0 * cos^2(alpha) which has an entirely classical, simple wave-theoretical explanation (even if Malus himself was an emissionist and derived his law by introducing transversal asymmetry in the light corpuscles).

Malus’s law does indeed describe the amplitudes of the resulting light, but it does not say “why”, only how. In the same way that Newtonian physics assumes gravity but fails to explain its existence.

For more in depth look at this there is a 1995 paper by K Wódkiewicz contrasting the corpuscular formula with the quantum explanation IIRC.

Obviously, despite its explanatory power, we know that QM is incomplete so YMMV, but I’ll take QM over light corpuscles, until something better comes along.

> I’ll take QM over light corpuscles

Having light corpuscles that have poles and can experience fits of easy transmission/reflection is not much mathematically different from having photons with spins and wave phases, to be fair.

And Malus' original justification of his law straightforwardly carries over to the photons.

Yeah, it was a pretty good theory, given what was known at that time.

For one thing it can create paradoxes, like your future you deciding they didn’t like where they ended up and stopping yourself from setting out on a journey in the first place.

This is true if and only if we live in a universe with a time continuum that is not branching (i.e. a line). Instead, if we live in a time continuum that can branch (which will result in a directed acyclic graph) the act of traveling faster than light simply creates a new branch in which you go to the past and in that branch your past self never traveled.

This relates to the different interpretation of quantum mechanics. The one that has paradoxes is the Copenhagen interpretation and the one with the branching is the many-worlds interpretation.

There is also the pilot wave interpretation, but I am unsure how to map the example you proposed to that one.

Branching in MWI happens when quantum systems become entangled, not when time travellers arrive. I don't think MWI is going to save you here

I thought branches happened when a wavefunction 'collapsed' -- i.e. for every possible value of the wavefunction, you get a branch with a unique answer for 'value of the wavefunction'?

The wavefunction decoheres; it doesn't collapse. Collapse is a function of collapse theories like Copenhagen, but has never been observed in reality.

That said, decoherence doesn't branch time in the sort of absolute manner you might be thinking of. "How many timelines exist" is a question similar to "how long is a coastline"; it depends on how closely you're looking. At the smallest scales, 'timelines' interfere and mingle in a way that distinct universes really shouldn't. It's only once decoherence has gone well out of control that they can be said to be truly separate, and even then the interference never goes to zero, only approximately zero.

Its the Small Scale Mandela Effect for physicists!

it breaks the sacred timeline

If we exist in a block universe, then all time-travel effects are "already" baked in. Just because something's path through the block isn't always "forward" doesn't mean it can change its path, or anything else's.

In a growing block universe, I think time travel would be impossible, but I also think that the growing block universe theory is cope.

If causality isn't then what do you mean by 'because'?

This is a nitpick. The warp drive concept doesn't allow for FTL travel, but it could allow for you to get from point a to point b faster than light could.

This breaks causality.

The idea behind a warp drive is that it utilises expansion of space, which is not subject to speed of light restrictions. The universe has already expanded faster than light without breaking causality.

The causality violation examples I've seen in relativity all involved going back to where you started. No return trips, which includes the cosmic horizon, no causality violation.

One question I've got though: does relativity (1) remove the need for universal frame of reference, or (2) preclude the possibility of a universal frame of reference?

Because if it's the former, then (I think) FTL doesn't need to also be a time machine?

> No return trips, which includes the cosmic horizon, no causality violation.

The drawback is that if a warp drive going from A to B leaves expanded space in its wake, a return trip will take longer than light would take to make a round trip. At the same time, an observer on B looking in the direction of the ship will see a shift to blue until the ship arrives, and, then, would see a marked shift to red when observing A.

Nothing in specific would stop you going around the Krasnikov tube, however?

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

Causality is not robust, and you can prove it to yourself with three sheets of light polarizing gratings. When we figure out how to put probability hooks on things other than photons, it’s going to get rowdy.

I should have said perfectly robust. It is rather robust in normal parlance.

Afaik, if we introduce a special frame of reference (e.g. the cosmic microwave background frame) and this special reference frame is the only frame in which FTL is permitted, FTL does not violate causality

See https://physics.stackexchange.com/questions/203708/can-ftl-c...

That's a fascinating thread. Thanks for the link.

Put another way, travelling FTL in and of itself does not mean you're travelling backwards in time. But the geometry of the universe provides a barrier between STL and FTL, yet no barrier between forwards and backwards in time except inasmuch as you need to first rotate from STL to FTL before you can rotate from forwards to backwards-

So if you invent such a barrier, then sure, FTL is fine. It's just that there's geometrically nowhere to attach that barrier, except if you make use of the CMB.

The CMB is not a reference frame - everyone sees their own CMB.

Would they allow a reactionless drive?

There is "ftl" then there is "reactionless" then there is "doing better than the rocket equation"

We will take any of it.

Three, because also that their warp drives fail. :D

Or it’s just them hitting the brakes hard.

I’m suddenly terrified advanced species capable of FTL travel would have Starfleet levels of shoddy engineering. A Kardashev type 3 is always one idiot away from destroying the universe.

You have 2 things that have not been discovered/invented yet and you go and simulate how one fails

Here is the paper: https://arxiv.org/abs/2406.02466v2

I firmly believe we just need to build extremely sensitive gravitational wave detectors to pick up these "warp" traces. That'd validate the Fermi equations. How sensitive do they need to be? 3,000km long detectors floating in space might do the job.

Every single second spent 'studying' warp bubbles is a second wasted. A dollar misspent. A CPU cycle squandered.

"How do you move the warp bubble?"

uh... uh... uh... uhhhhhhhhhhhhhhhhhhh... this paper's title is sexy and will get me published!

Even string theory is better than this nonsense.

What interesting research are you currently pursuing? Would love to read the papers!

15 years ago I played a small, insignificant but still important, role in saving Hubble: https://ntrs.nasa.gov/api/citations/20080023344/downloads/20...

Now I design sensors that go on things designed to kill Russian soldiers in Ukraine.

I am very confident that what I have done has been a tangible net benefit to humanity and is not the modern-day equivalent of spending time and money on the study of Orgone Energy.

So you were helping kill people who you've never met but bashing on the dudes studying warp drives? Not even saying you're a bad person but stones and glass houses man

>So you were helping kill people

Not were, am.

My sensors are also good at quantifying sea level changes, measuring shore erosion, determining plant foliage density and water content, and can find ancient buried ruins given the right conditions so it's a win-win for all of humanity!

How is it a win/win unless you value human life of russian people at 0? Would you say that to the face of the victims of your work? Do the russians you help kill not have families and partners? Are they any more at fault than the average american was for Iraq?

I would value their lives as negative. Lots of people have lives of negative impact, like Thomas Midgely Jr or the Russian people carrying out genocide in Ukraine.

Thanks for sharing (I really meant the "I like reading interesting papers" request).

In an odd coincidence, that means you're the second person I met this month who helped save Hubble.

You make the bubble after you are already moving in the direction you want to go. The bubble will keep moving. What else would it do? Out of all the questions, this is not a hard one…

That answer has always bugged me.

In relativity, observers only agree on motion at exactly c, so the idea that a warp drive speeds up normal motion… feels like a contradiction.

But then, I know I can't fully grok the relatively simple maths of SR, let alone GR.

Precisely!

You get it!

If you have to spend the entire combined annual energy output of all of humanity getting up to speed, why convert the equivalent of 1% of the mass of the sun into energy to create and maintain a warp bubble?

Which raises the spooky question is it the ship causing the bubble (space-time) to move, or vice versa? Typically space-time tells objects how to move, not the reverse. It would be disconcerting to discover FTL but find that the journey was fated from the beginning.

They're simulating imaginary things?

The latest research in this field says it's physically (not just mathematically) possible - negative energy is no longer a requirement.

Do you have any pointers?

https://www.space.com/warp-drive-possibilities-positive-ener...

https://arxiv.org/pdf/2405.02709

https://github.com/NerdsWithAttitudes/WarpFactory

I'm impressed that they've removed the requirement for negative energy, but it's not quite ready to hand the drawings to your local machine shop to build one. It requires matter packed to an energy density on the order of 10^39 joules per cubic meter.

According to [1], oil has a (chemical) energy density of 4.5x10^10 joules per cubic meter, purified uranium produces 1.5x10^15 J/m^3 in a fission reactor, and that same uranium in pure mass-to-energy conversion produces on the order of 10^21 J/m^3. Uranium has a density of 19x10^3 kg/m^3, and the nucleus of an atom or neutron star has a density on the order of 4x10^17...if you can build the entire ship out of pure neutrons, you're still coming up short by a factor of ~100.

All that does suggest that it seems reasonable we'd be able to observe gravity waves from a long distance if a machine like that ever experienced a loss of compression.

[1]: https://drexel.edu/~/media/Files/greatworks/pdf_sum10/WK8_La...

> and the nucleus of an atom or neutron star has a density on the order of 4x10^17...if you can build the entire ship out of pure neutrons, you're still coming up short by a factor of ~100

Would you be getting into black hole territiry at that density?

> not just mathematically

Let's be clear here. Alcubierre's original "warp drive" idea was for super-luminal speeds (faster than light) and required "exotic matter" (negative energy).

This new one is for sub-luminal speeds (slower than light). It does not require "exotic matter", but it's hardly a "warp drive"

> it's hardly a "warp drive"

Why not? From my understanding, to the ship’s occupants, they’d be travelling (EDIT: subjectively) super-luminally. In one lifetime they could go more than 100 ly.

That doesn't match any definition of super-luminal that I have ever seen. Super-luminal means faster than light, period.

> doesn't match any definition of super-luminal that I have ever seen

I didn’t say it’s physically super-luminal. The undefined term is “warp drive.”

Given the ship’s occupants would subjectively travel super-luminally, it would seem to tick the boxes for warp. If it worked, you or I could travel to the other side of the galaxy. Hundreds of thousands of years would have elapsed outside the bubble. But we’d be alive.

Typically we think of "speed" as observed from outside the moving [object], but I guess "typically" it doesn't matter.

I think it's an interesting point and you're not wrong to say it ticks at least one of boxes. It just doesn't match the concept that people have in mind, so an otherwise interesting discussion ends up rat-holing on semantics.

> Typically we think of "speed" as observed from outside the moving

Is it? We don’t colloquially consider the Earth’s rotation or revolution.

This isn’t a Star Trek warp drive. But dismissing it as “hardly a warp drive” seems categorically wrong.

Sub luminal speeds are in an entirely different category than super luminal speeds. It's hard to overstate how different it is, so the original objection is completely appropriate. You can argue about the wording, but what's the point in that? Everyone with half a brain agrees on the facts.

I don't recall having considered this point before, though granted I will call half a brain a good day.

> We don’t colloquially consider the Earth’s rotation or revolution.

Wasn't this choice of reference frame the basis for that whole drama with Galileo, or am I misunderstanding?

We discovered a couple of centuries later that there's more than one reference frame, you can choose, and the choice matters. It's been a pretty interesting development!

I don’t think it’s a “warp drive”.

It’s a “warp stasis” bubble or field: you’ve effectively suspended (or considerably slowed) the people inside to preserve them for the future — stasis.

I think you’re running into objections because while it is warp technology, it’s not a drive in that it’s not providing atypical propulsion (ie, Star Trek warp drives, Star Wars hyperspace drives, Babylon 5 subspace jump drives, etc).

You’re correct that we’re trying to define “warp drive”, but each of “warp” and “drive” are used independently — and your usage of “warp drive” doesn’t respect their independent usage. That you have a 1:1000 slowdown in perceived time to real time as your example suggests at some level you recognize this isn’t a drive.

I think warp stasis is a super cool technology all on its own, though.

> it’s not a drive in that it’s not providing atypical propulsion (ie, Star Trek warp drives,

AIUI in Star Trek, Cochrane's "space warp generator" and descendants are essentially the Alcubierre design: I don't seem to understand that the warp bubble provides any propulsion by itself (although grav waves could be surfed)

Instead AIUI actual movement is created by a secondary mechanism, which I'm unclear about from a cursory search. Maybe impulse engines? Or maybe those are inefficient/incompatible with warp and it's using a secondary system that comes as a (intentional by design) byproduct of nacelles, like a ramjet engine airplane essentially has two propulsion systems since requires forward speed so you gotta have regular engines.

In Star Trek it's the warp bubble doing all the work, impulse engines are sub-FTL.

> subjectively travel super-luminally

It’s not really subjectively super-luminal either. The travellers could look behind them and see light catching up with them. A signal that left at the same time they left would be to their destination first. Relative to them, light always travels at light speed.

What is subjective is not light, but time.

Being able to move space around a ship, and being able to move space around a ship faster than the speed of light seem to require orders of magnitude different energies. being in a 'warp bubble' doesn't mean that bubble is traveling at super luminal speeds.

> being able to move space around a ship faster than the speed of light seem to require orders of magnitude different energies

They require different kinds of energies. Specifically, the latter requires negative energy, something we have no evidence exists.

> being in a 'warp bubble' doesn't mean that bubble is traveling at super luminal speeds

Nobody claimed as much. The physically-possible warp bubble lets you slow down time. So a 100,000-year journey would feel, to the ship’s occupants (and its structure and computers, et cetera), like possibly months.

(You also get the capability to transport people and things forward in time without degradation. Or, I believe, to speed up time inside e.g. a production or computational environment.)

> The physically-possible warp bubble lets you slow down time.

that... seems odd to me. without substantial changes in velocity - how does a warp bubble (that's sub-luminal - so relativistic velocities) alter the fabric of space-time so fantastically? It's not moving fast: so where does the time dilation come from?!

> not moving fast: so where does the time dilation come from?!

I think it’s from shifting momentum?? The paper is far beyond me [1]. But as I understood it, you’re directly modifying space-time with energy instead of using acceleration as a go-between.

[1] https://arxiv.org/html/2405.02709v1

The mass distribution in the metric can do that; IIRC this was chosen in order to not have time dilation, so I think someone's getting confused (and maybe that someone is me?)

The main appeal of FTL is I think the ability to return to where you came from. If 1000 years pass before your return, it would only be superficially the same place. That being said I would think that the defining feature of a warp drive would be that it uses warped spacetime for motion rather than propellant.

> main appeal of FTL is I think the ability to return to where you came from

If that’s your metric this isn’t the warp drive for you. That hardly means it isn’t a warp drive. The lifetime-lightyear travel boundary for possible experiences would be breached.

Can a normal drive even do that?

You can travel arbitrary distances in one lifetime, even with just constant 1g acceleration. It's just that aeons will pass for the outside observers.

That happens with literally any means of travel. Normal rockets do exactly that.

You could have said that about the Nice model until we found it explained a lot of the early solar system formation and unified a lot of disparate working theories.

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

They are imaginary just until their first detection.

> simulating imaginary things?

Doesn’t this describe the lead up to any theoretical breakthrough?

By definition. That's what simulation means. ;)

> That's what simulation means

Not really. Utah teapots are simulations of known objects [1]. Flight simulators of known phenomenon.

This is closer to Einstein or Schwarzschild’s theorising.

[1] https://en.m.wikipedia.org/wiki/Utah_teapot

Utah teapot is not real (it cannot hurt you). Despite being based on actual physical things, no Utah teapot will ever hold tea.

A simulation cannot be real. Results obtained from a real object are measurements.

The simulation is an imaginary thing. It is simulating something that is not imaginary.

If I’m simulating a bug, it doesn’t make the bug imaginary. The simulation is immaterial. (I wouldn’t quite call it imaginary. Computers don’t imagine.) But I am simulating a real thing. If, on the other hand, I simulate a bug the size of Paris, I am simulating something imaginary.

All simulations are immaterial. But the things they are simulating can be real or imagined.

I understand, completely agree, and plan to continue digging myself into this pedantic hole anyway thank you very much.

Interesting that a difference of scale alone determined the nature of a thing! More interesting, perhaps, are the number of factors that aren't considered!

Would a simulation of a Peruvian ant on the Tibetan Plateau be real or imagined? What about a simulation of an ant after 20 years of climate change? How about an ant in space or experiencing the Big Bang?

On the other hand, is a simulation of a black hole real or imaginary? What about simulations of the history of the universe involving dark matter and dark energy?

I appreciate a sibling comment's (thanks marshray) suggestion that there exists a spectrum of theoreticalness. Theoreticity?

> the simulation in this paper is theoretical to a much larger degree than that of the teapot.

> If, on the other hand, I simulate a bug the size of Paris, I am simulating something imaginary.

Are you really sure about that?

The original Utah Teapot is definitely real and can hold tea :)

I could certainly use some tea now to wash away the taste of the foot I just pulled from my mouth.

However, as an enjoyer of pedantic semantics, is the real Utah Teapot the physical pot or the model?

I've personally seen the physical teapot in the Computer History Museum.

We routinely make detailed simulations of how such a physical teapot interacts with visible wavelengths of light, specifically for the purpose of comparing them with reality. From this we know that we do in fact have the ability to simulate this aspect of reality to a high degree of precision.

The ability to detect gravitational waves is just recently coming on-line, and we have no example of an actual warp drive to measure, so the simulation in this paper is theoretical to a much larger degree than that of the teapot.

What parent is trying to say is that they are about as similar as the map and the territory

Or you may have heard as it as all models are wrong

Things don't have to be real for them to hurt you.

I'm hurt that you'd imply that.

https://knowyourmeme.com/memes/skull-cow-isnt-real-it-cant-h...

They do that all the time.

This is how a lot of science works. You guess that something exists and works a certain way, you build a model, then you see what measurable things that model predicts.

Gravitational waves themselves were "imaginary" for a century or more (depending on who you credit) until they were directly measured in 2015.

isn't that like 99% of modern mathematics?

There is zero evidence for aliens, still people believe in them. And millions and millions are wasted in the search. Just because neon green elephants are and seam possible, doesn't mean there are any. In fact, there are none, except we create them.

The universe is so fast. Why are you so certain that life only evolved on our planet?

When you say “there are none” it seems you are making a more unbelievable statement than the people who say aliens exist.

TBF the comment says that there's no evidence, not that there are none. And indeed, the belief in extraterrestial aliens is much, much bigger than its theoretical underpinnings warrant.

Indeed, especially as 85% of atheists in the US believe in aliens. With zero evidence, no signs, nothing.

The parent comment literally said:

“In fact, there are none, except we create them.”

I was saying that the claim that life in this universe only evolved on our planet is more extraordinary than the claim that life evolved elsewhere.

So the parent comment’s claim that “there are none” would be a belief that is actually bigger than the belief that there are.

It's the biggest and most important question we can answer.

The amount of tax dollars to SETI vs. amount given in bank bailouts in various crises is orders of magnitudes different, setting aside historic and scientific importance.

Would you be fine with the government spending millions of tax dollars in the search for god?

if its a scientific research why not? Governments should spend the money they squander in vote grabbing welfare instead in Researchs of various kind, even crazy ones for points of GDP

2 trillion galaxies in the observable universe, each with 100s of billions of stars on average. How weird would it be if life only arose once out of all those chances?

We don't know.

There are 21 sextillions grains of sand on earth. One of them MUST be the shape of my face. This is not science, this is religion.

A more accurate analogy would be that without looking at very much sand, you already possess one grain of sand in the exact shape of your face. This spikes your curiosity and you ask: What are the chances of finding another?

I do think these are two different arguments.

1. Aliens can exist because we exist

2. Aliens do exist because of probabilities

Mine was about 2

I think it would be orders of magnitude more astounding if aliens didn't exist than if they did, just given the sheer odds of life only happening once in the observable universe. That's all I'm saying.

Holy straw-man.

Funny, no-one said straw-man when I had these discussion in philosophy studies at university. Looks like there are different people on HN than those studying philosophy. Learned something!

There probably is one though right? depending on how you define similarity

You can't know, that's the thing with having a sample of n=1 (Earth). You can't deduce anything.

There are no evidence for any alien civilizations. If they existed, you'd expect them to have a great impact on the space around them, just like we had a great impact on our planet. Destroying stars to get the hydrogen, building megastructures, shaping galaxies... Yet, we see nothing unnatural in our neighborood.

I can't know what? That there are ~200 sextillion stars in the known universe? I'm not saying I know there's life out there, just that it would be pretty amazing if something only happened once in 200 sextillion opportunities.

It's very possible intelligent life destroys itself fairly quickly after becoming industrialized. It's also possible that the technical challenges of doing something at a galaxy scale where we could see it from millions of light years away are insurmountable.

I meant you can't know wether it's weird or not, n=1.

Personally, I believe life is extremely rare. The more I learn about geology and biology, the more I think Earth and the Solar System are very special, and life appearing spontaneously is nothing short of a miracle.

Now, my crackpot theory: I believe that if there are aliens civilizations out there, they are so far from us that the light from their achievements has not reached us. And if it had, then they would be here already, because they travel at roughly the speed of light in every directions. They would have colonized Earth, which would have prevented us from appearing. Thus why we can't see any aliens in the night sky.

I think life is extremely rare too. But 200 sextillion is a big number.

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