The idea of traveling faster than the speed of light (FTL) has been a popular idea long before [Alcubierre] came up with the first plausible theoretical underpinnings for such a technology. Yet even if such an FTL drive is possible, it may be hundreds of years before humanity manages to develop its first prototype. This does however not prevent us from for looking for possible FTL drive signatures in the spacetime around us. Such a concept was recently proposed by [Katy Clough] and colleagues in a recent article (Arxiv preprint).
For a friendly but detailed explanation the PBS Space Time video (embedded below) on the paper comes highly recommended. The gotcha with detecting an FTL warp drive is that it is undetectable until it collapses in some fashion. By simulating what this collapse might look like, the researchers were able to speculate about the properties to look for. These include gravitational waves, which would not be detectable by an existing gravitational wave detector like LIGO, but we might be able to build one that can.
Ultimately we’d be acting on conjecture on what a warp bubble would look like and how it would behave when it collapses so we might just as well mistake something far less intelligent for Vulcans passing through our solar system. It might also be our first sign of extraterrestrial life, possibly ogling some primitive civilization on a Class M planet until it’s ready for First Contact.
Well, now I wonder if there’s some interstellar signpost somewhere:
“Entering a no-wake zone. Sub-light beyond this point.”
If there is, I guarantee there will be gravity wave wake boarder yahoos ignoring it.
That would be a fun Douglas Adams-esque solution to the Fermi paradox. We’re in some galactic federation’s school zone and the FTL cops are very ticket-happy
I think Robin Williams as Mork from Ork once said he got a speed of light ticket in a speed of sound zone. When asked by the policeman if he saw the police car lights he said he didn’t even hear the siren. (Think about it) Nanoo Nanoo.
The USN says “You May Be Right”
Some warp bubbles to go with our previous soap bubbles.
IIRC the paper indicates that we do not currently have the technology to detect such a phenomenon.
Sooo … description of a highly speculative event to be detected by non-existent technology.
Some days I feel like the academic community is just thumbing its collective noses as us … “look what we get paid to do!!”
in all seriousness, it can be a great gig, getting paid to do something you love
That doesn’t make it particularly noble …
I would argue that a person dedicating themselves to fundamental research for not all that much pay, that might not yield real-world results in their lifetime (or even flat out fail), but could payoff a thousand-fold for future generations is quite noble indeed; especially when that person is utilising skills that could make them serious money in a business environment.
As an aside, I read that many people don’t want to verify other people’s work as there is no glory in it, but that’s how science works and progresses: these people who do are unsung heros in my book.
I am slamming the agree button and all that’s happening is the appearance of these words.
You’d think so until you met actual academics, wouldn’t you? It’s a shame
Yes, because we know that every profession is only composed of the paragons of virtue for that field. All doctors put their patients’ lives first, all police officers put the law first, and all politicians put their constituency first.
The nobility of a field is aspirational, not actualized. If you judge a profession by all the people in it, they all suck.
Exactly…..the fanboi’s who seem to keep citing Alcubierre should do more research. All Alcubierre did is rehash old NASA theoretical papers. Let’s throw in a “what-if”, and *maybe*, just maybe we might be onto something (never mind the fact it’s all make believe, pull-this-ASSumption-out-of-my-butt type thinking).
He does not merit the attention. In the same boat as physicist Lisa Randall.
Not to say it won’t happen, just that anyone – anyone, can propose imaginary conditions to curve fit whatever equation they come up with. Derivatives traders do it all the time (and lose money most of the time doing it).
“All Alcubierre did is rehash old NASA theoretical papers.”
What in the hell are you talking about? I mean, you’re right that the “just… pretend it might happen” is silly, but what in the heck are you saying Alcubierre rehashed? There are a grand total of 4 references in the paper, and they’re all basically intros to general relativity. So you’re basically accusing him of plagiarism (taking ideas without citing it).
Alcubierre’s paper was about finding a different metric that allowed for faster-than-light travel *without* changing its connectivity. It absolutely was a novel idea. You’re welcome to dismiss its value (from a *math* standpoint it’s totally valuable), but if you claim it’s just “[rehashing] old NASA theoretical papers,” you better back it up.
Marketing at a cybersecurity software company sounds easier, and probably pays better
It’s not really about the “technology,” it’s about how GR “responds”. I don’t think people realize just how poorly understood general relativity’s behavior as a theory is. There’s a lot of value to trying to find ways that it breaks *way* before black holes and ultra high energies.
It’s entirely possible that before they did this, the effect could’ve literally been topologically unstable, which would’ve been interesting.
If everything thought like that, we’d still be banging rocks together for fire
Demonstrably false.
What date do you think the first ‘university’ was opened?
What was taught there? (Religious dogma/private languages and warfare/civil engineering as applied to war.) The only part of that remotely useful was the glorified ditch digging.
No. The problem is humans pushing efficiency too far.
On the one hand you have for profit “publications” that don’t care about content. The exist to publish what they get paid to.
On another hand you have an academic environment where your job depends on getting published on a quota. The term is “publish or perish”. The content SHOULD be good, but if your paycheck requires 2 white papers a year, but your work only creates 1 paper every few years, you have to find a way.(Real science can take a long time)
Neither of those things have a goal that makes sense, because they are too hyper specialized.
One goal is to make money, not publish reasonable papers.
The other one is to be “prestigious” by having staff that publishes the same or more as a “top” school. And again, the numbers matter more than the content.
Would you blame a clerk for a policy that was enacted by some executive, to raise share prices for investors? Hopefully not.
This is the same kind of situation. All the academics I work with hate the system.
They do enjoy having regular employment though.
You want to be annoyed at someone?
Be annoyed at these shitty publishers, and the publish or perish culture administration is requiring.
“You want to be annoyed at someone?
Be annoyed at these shitty publishers, and the publish or perish culture administration is requiring.”
100% wrong. The paper itself and the publishers are totally fine. Your criticisms on that point are completely off-base, which is easy to verify because you say “you have for profit “publications”” when you haven’t even clicked on the article link to realize it’s in *The Open Journal of Astrophysics* which if you click on their “About” page says:
“Papers can be submitted for publication free of charge, are refereed free of charge and are published (online only) free of charge.”
So yeah, we can pitch literally all of your comments there out the water. The “oh, this was just a throwaway paper” comments don’t hold water either, because the technical details *alone* are worth it. We already know that *not all* solutions like this are NEC-violating, and some become NEC-violating only at v>=c. So it kinda seems like the NEC is somehow related to causality in some way, but also that it’s “not good enough,” which makes total sense because it was basically pulled out of thin air. So trying to understand exactly *how* the NEC is “protecting” things and what’s “not good enough” about it is 100% valid science. (And a part of this is mentioned *in the paper*, to be clear!)
There are some things to be annoyed at, definitely. Primarily the media coverage, but I also have a *strong* negative opinion about Applied Physics who wrote a separate paper (not this one!) and made *terrible* comments to media outlets regarding the importance of stuff like this.
But this paper’s mostly just a fun paper and pointing out what we can do simulation-wise and what could be improved. Nothing wrong with that.
In science the finding that we are limited by the technology of our times is always a acceptable result. Extra points for exploring what technology would actually be needed and what technology trees would have to be explored further to finally be able to achieve the goal.
The academic community sits at the bottom of a well. They believe their echo chamber existence and tiny portion of sky is the whole of reality; everything outside is irrelevant.
The amount of gate keeping and ego massaging that goes on in even smaller universities is depressing enough to drive a person into irrevocable substance abuse. Good luck if you don’t tow the line and tell the dean or their pet associate prof’s what they want to hear. Being unofficially punished for “wrong think” is a very real thing in academia.
Never mind the endless push to publish papers as fast as possible regardless of the quality or absurdly small sample sizes used for their “ground breaking” studies.
The American university system exists to perpetuate itself through grants, fees, and patents. If beneficial science happens its a byproduct, not the end goal.
” it may be hundreds of years before humanity manages”
judging be the speed humanity is altering its own lifeboat, one can only reasonably think this is very very unlikely to happen.
I’m going with ice age termination events and nothing we can do about it but adapt living style and locations.
1 degree C change in average temp equals about 150km latitude.
Soyjak “we need to talk about climate change” versus Gigachad “let’s nuke India four thousand times and colonize the moon”
“…in all seriousness, it can be a great gig, getting paid to do something you love.”
I don’t disagree, though with things of this nature, it’s always fair to ask, “paid with who’s money” and what isn’t being addressed because said monies were spent here.
It’s in the paper. It’s a grant about testing the limits of GR. Not going to be a lot, and it’s not *actually* about the direct topic. When you’ve got theories like GR and QFT, it’s literally impossible to know what their “true” range of validity is because there can’t be any experiments on it: so trying to understand how weird geometries behave helps.
They aren’t really framed like this, though, and the PR often gets away with itself. For instance, there was a solution found a while ago that *doesn’t* violate energy conditions (not the sublight one, the soliton one) – for me that was interesting because it says that the standard energy conditions in GR (which are basically just made up because it seemed reasonable) aren’t enough to enforce physicality, which is really interesting.
Got to let your academics do their research if you want them to hang about to do quality teaching: source, I have worked for academics in 3 different Russell Group unis, and academics drink beer too…
It’s not just about “making them happy” either, stuff like this often makes a good project for a grad student or a really capable undergrad. In some cases all that’s really needed resource-wise is just compute time.
I agree.
Either way, doing away with “basic” research would be the death of a prestige uni.
The purpose of a university is research.
The teaching is just so the research can continue in the next generation.
That said. Tenure == Nice comfy chair.
Also: It must be noted that most of the staff at most universities are useless well before tenure.
The numbers are much better in hard science.
But note ‘science’ outnumbers science.
Grew up on a university campus.
I think you mean faculty, not staff.
And the “teaching is totally unimportant” is very much an outdated idea. It’s a *ton* easier to be a teaching focused faculty given the ease of public outreach these days.
Why? Because there are more grants for it! The purpose of a university is *funding*, not research or teaching.
Hmmmmm detecting a technology we can’t do anything about except watch. Queue ominous music
You mean like the Indians seeing the sails or European boats on the horizon?
Most of the universe falls into the category “stuff we can’t do anything about except watch”
Watch… and learn!
It’s a cute paper, but it makes a ton of assumptions about how the “broken physics” part works, which it acknowledges. So it’s more of a math toolbox for studying gravitational wave production from exotic theories than something actually practical.
This isn’t a knock on it, it’s required: warp drives literally don’t physically work (none of them, not even the sublight ones, have a solution which goes from static to moving to static with known stress-energy, and even if they *did* that still doesn’t mean they work because you *necessarily* have to have energy densities that go beyond where they’re valid).
For the “FTL” ones, since the stress-energy required is impossible, you have to choose how it reacts, and the effect of that choice is (of course) left as a future topic to study.
Or, you know, they’re driven by invisible ether faeries 12 miles long.
Because that’s an equally reasonable assertion.
No, it isn’t. Not unless you actually write down how the invisible ether faeries work. The paper makes an assumption as to how the “warp material” actually behaves on collapse, which means they *are* writing down how their invisible ether faeries work. They might not exist, but it’s a theoretical paper – do you have *any idea* how many ideas people work out that never end up being real, but the math inside ends up being reused somewhere else for something *totally unrelated*?
Understanding exactly how GR goes “outside the bounds” of existing physics is super-important not just from an “aLiEnS!!” standpoint, but also because *we already know the universe goes outside the bounds of known physics*. Understanding what happens when GR goes “segmentation fault” gives you more tools in the toolbox to understand stuff like quantum gravity, dark energy, inflation, etc.
Fine job fighting the corner of intellectual reasoning :-)
If everyone accepted received wisdom as *fact* we would still be in the dark ages, hats off to those who poke holes in reality with maths, they are the cause of scientific advance here, although it can obviously be the other way around…
Experimentation and observation is also needed, but sometimes it helps to know what one is looking for, no?
My area of expertise :-D
…Philosophy done correctly reduces back to biology.
The Aether fae are real, those guys in the 1800s were totally onto something!
Frack ending of sentences with prepositions.
There’s oil in them thar prepositions
Plausible – if you have a source of negative mass?
No, that’s a *terrible* “caveat” that people often bring up when talking about warp drives/wormholes/god knows what else. It’s not “negative mass.” It’s magic fairy dust. It’s the equations literally telling you that can’t happen with stuff you know about, and so magically inventing something that *allows* it to happen is entirely circular logic.
The problem with general relativity is that we only know how to include *really* basic stress-energy terms, and even those only at energy densities such that the “gravity” part doesn’t matter. For instance, general relativity *says* you should be able to create a black hole with just an electromagnetic field (a “kugelblitz”). But that’s crap, because by the time you *get* to those energy densities it doesn’t act like Maxwell’s equations anymore – you’re way, way into quantum electrodynamics.
In fact, there are “energy conditions” that get applied to general relativity so that the stress-energy tensor involved is in some way “sane.” Because we have *no idea* what the stress-energy tensor for, say, a neutron star is, so you come up with some ‘sane’ limits to understand it.
Note that those “sane” limits aren’t even enough! See the above kugelblitz example, for instance. It’s perfectly fine from an energy condition standpoint, it’s just that the electromagnetic field that actually exists doesn’t work like that.
The “negative mass” stuff *throws even those sanity conditions out*, which means you’re totally into circular logic territory. You write down a metric, the equations tell you “no, that can’t work” and you say “but… what if it did?”
“magically inventing something that *allows* it to happen”
Like dark mater?
Nope.
Dark matter isn’t a “thing”: it’s a placeholder name for an observation that there’s more matter-like gravity that can be accounted for. It’s not an idea that a theorist has (like, say, supersymmetry) which may or may not exist. Whatever’s *causing* the myriad observations we call “dark matter” absolutely exists. It’s observed.
The only reason it seems like a “magic invention” is that over time we’ve ruled out practically every already observed thing. It absolutely could’ve been totally boring things (neutrinos would’ve worked!) we just ruled them out.
Assuming there’s a thing you don’t have and working out what it would look like so you can search for it or build it is a perfectly valid strategy in problem solving. That said, we will probably never have the exotic wutzits and the cubic cosmic fuck-ton of energy required to set up an Alcubierre metric
This isn’t about problem solving. It’s about finding solutions in GR that can exist.
If you throw out the energy conditions, GR literally doesn’t mean anything. It’s just topology at that point. The energy conditions are what make it physics
And the basic energy conditions aren’t even enough to generate realizable solutions!
That’s precisely how imaginary numbers were brought about and they have proven to be of incredible usefulness to some of us.
No. Imaginary numbers are understood to be impossible. They are basically tricks and shortcuts to get equations to work. When talking about physical phenomenon, imaginary phenomenon are just another way of saying “then a miracle happens.” It’s hand waving and very very different from theoretical phenomenon. The ether and phlogistan were theories that were subject to proofs. Proofs demonstrated they do not exist. Negative mass is like saying “then we apply arglebar to stabilize the framistan”. It’s made up purely to make the theories look they could work but exists in no widely recognized set of theoretical phenomenon. It’s up there with Tachyons.
Hi just to be clear. I’m saying imaginary numbers are definitely “fake” or “handwaving” or whatever. You seem hung up on that. I’m just saying they are very useful.
Whether something is made up or whatever is kind of irrelevant if the results, however you care to define them, are useful.
.
And for the record as a man of medicine and natural philosophy myself, all the made up crap from medicine was useful in that it promoted and furthered future medical study. Certainly we have stuff going on now that we will later look upon as insane. From our tower of progress.
“Negative mass” isn’t something that’s created to solve a problem. It isn’t a thing, period: there are no ‘negative mass’ equations of state, no ‘negative mass’ dynamics, nothing. It’s just a term that people cooked up for when the you get a stress-energy tensor that violates the (extremely basic) bounds that people thought were reasonable for when you start playing with situations outside of known physics.
It’s like a “NaN” in floating point math, or a segmentation fault. Once you’re there, talking about the dynamics of the situation doesn’t make sense because you’re *already in a situation where GR is incomplete.*
That’s why with this paper they’re talking about *collapse* – they just assume the metric magically becomes “real” and the magic stuff “decays away”, and look at what happens to the matter/spacetime.
The *math* and the dynamics of what’s in the paper are absolutely useful from a theory standpoint, but saying “we just need to solve the problem of negative mass” is like saying “we just need to find the Fountain of Youth” or “we just need to build a perpetual motion machine.” Negative mass isn’t a “problem” to be solved, it’s literally telling you that you need entirely new physics. And yeah, obviously, there’s plenty of physics we don’t *know* but if you find it, you’re not going to use this math to describe it.
Yes! Because it’s math, not physics!
I’ll give you a better example: the Dirac delta function was created by Dirac and he basically just said “I’m gonna use this, you guys figure it out” and it took mathematicians decades to do it.
Those are tools introduced to solve a problem. Ignoring the energy conditions or pretending we’ll find magic material is *changing the problem*.
Metrics like these (wormholes, Alcubierre warp drives) are super-useful *theoretically* because they give you non-intuitive ways *within GR* to break what you *think* of as intuitive physics. So you can apply it to *other* places where you’ve already *got* non-intuitive physics already.
Hence the reason why people look into wormholes for entanglement topology or warp metrics for dark energy situations.
But saying “negative mass” is silly. You need entirely new physics, full stop.
I’m reading recently that gravitational waves, particularly higher frequencies, can be inferred from monitoring the behavior of networks or arrays of neutron star pulsars. At higher sensitivities than instruments like LIGO. So we might have the technology to do this detection if pulsar monitoring ramps up.
As well as having scientists working out ways to see if extra terrestials are approaching, perhaps we should have anthropologists working out ways we could handle ‘First Contact’.
Considering how well that worked for the indigenous population of the Americas and Australia, perhaps we should have our military on the job too…
If they can cross star systems, I am reasonably sure they could throw a pretty big brick at us too…
Let’s hope they’re nice, eh? Or, as a Humanist, may I suggest aiming to be the sort of species aliens wouldn’t feel compelled to throw big rocks at?
That’s only possible after we find out where they live and can find a big rock near their home.
Existing is more than enough reason to be eliminated.
If life elsewhere follows Terran patterns, anything that you can detect is a mortal threat until proven otherwise.
Go read dark forest theory.
But who knows, we might encounter a species so far advanced that we couldn’t possibly threaten them, while ALSO somehow entertaining them. In that case we get to be locked in a zoo and have our advancement stopped.
Yeah but what if the aliens are psychotic ten thousand-year-lifespan vampiric lizards that respect a little edge and ambition, not Bob Ross
Well, in that case, we’re kind of fucked if the find us.
They will know how to say “Hi.” to us, either in perfect English (hey it is the lingua franca like it or not) or with a 10 mile wide asteroid. Either way if they can cross interstellar distance they can do a little scouting.
Please don’t let those commies talk to the aliens first, they’ll kill us all!
If you want to know if aliens are traveling faster than light just listen for the alien physicists screaming “THAT’S IMPOSSIBLE!!!!”
What utter nonsense to be in a Hackaday article…
A paper about an imaginary method, to detect an imaginary drive, that works on imaginary physics.
You might as well publish an article about “Starfleet Academy doesn’t want you to know this one quick trick to align the dilithium crystals in your warp core 3% faster.”
It doesn’t need to be all hard hitting science.
But it DOES need to be non-fiction.
Building a much more sensitive gravitational wave detector is fine and it would have plenty of interesting uses. This is just the one that sounds cool for the publicity release
(Alien wife to husband)….Slow down ! You’re rolling gravity waves…. those weird beings on that third planet might see us…kids….lock the doors !
What a truly awful set of comments.
We’ve got the dozen comments who didn’t even read the summary, nevermind the paper.
The dozen comments who don’t understand the paper and think it claims something it doesn’t.
The dozen comments who are raging that someone anywhere might possibly be paid to think about abstract things rather than being a good wage slave.
And two dozen comments pointing out how the above three groups are incorrect.
At least there’s four comments making an ok and on-topic joke.
Just use AI to highlight anomalies..