WHY DO YOU ALWAYS ASSUME IT IS NOT RAMA followup question: Would there be any gravitational wave signature from an Alcubierre drive, and if so, what would the limits of its detection be considering the sensitivity of LIGO as it stands? (see what I did there? you keep the joke going, but you also force the straight man to keep the joke going while assenting to his request)Edit: Please ask questions?
furiously taking notes on comedy throughout this thread. Beginning to suspect that subject uses my disdain of his RAMA theory to bait me into science... It's not completely impossible, that we know of, yet? But if you were using one, you wouldn't want it to radiate waves, as that'd be a loss of energy from your generator. It's likely that it'd still be somewhat lossy, especially during the process of turning it on or off. If you were to actually achieve faster-than-light travel, that should create a sort of space-time shock wave, which, just like in the atmosphere, would take the form of a conic. That should be the loudest signature. And oof, the limits of detection on an Alcubierre warp drive? If cosmology is the wild west of physics, this is like /b/ in 2006, since we basically have no idea how Alcubierre could work. The only thing I can say fo sho is that it had better be close, maybe only a few galaxies away? I've no idea.Alcubierre warp drive
Recognizing that this is the said same working hypothesis of a supposition of a theory, it occurs to me that the "waves" you get out of a jet engine aren't 100% thrust and that there's fierce amounts of acoustic loss, thermal loss and thrust out of alignment with the vector of motion so I presumed that no matter how theoretically perfect your warp ring might be, the mere act of creating a warp ring would likely cause effects to spill over in directions beyond your control. And while I fully understand that I'm effectively asking you to speculate about the thermal efficiency of a perpetual motion machine, presume our hypothetical Alcubierre drive is gonna spill something. What's the most likely thing it's gonna spill? How would we detect it? Because it is always
Ye, the jet engine analog is max apropos. My take is that in addition to some relatively exotic particles, you might even radiate/produce miniature black holes, not dissimilar to what the LHC is believed to produce. Just like how the LHC works, it's a question of large energy densities, which an Alcub- ...which RAMA would bend spacetime with. It'd probably spawn vortices of space-time disturbances, too. Thing is that if lots of RAMAs are RAMAing around at variable distances, it just looks like noise in the LIGO data. At least for now. And that's a pretty nuts idea, looking for Alcubierre signatures in LIGO data, but someone is probably at least secretly doing it. Eventually, statistics could out the signals from background noise, it just might take another few decades or centuries, or it might take LISA. It's exciting to be alive in this new era of gravitational wave cosmology. Also, remember, if you managed to go faster than light, you'd have to go back in time, at least relative to the frames of reference you started and/or stopped in. This presents some serious causality issues, and may be strictly forbidden, but exactly how is a curious thought experiment. Hollywood version: imagine warp driving to target solar system, but when you got there, it was only in the protoplaentary accretion disk stage. That'd kinda suck.
Maybe not just miniature black holes. I'm trying to work out what would happen to the light emitted towards the front of the Alcubierre bubble from the inside, and there's a possibility it'd get stuck there for the entire duration of FTL flight. Those are mere doodles as far as GR maths goes, but maybe you could end up with a kugelblitz in front of your ship after—or during!—a long enough flight.
Imagine pointing your starship at your friend's star system, pressing "go", and then accidentally enveloping them inside a black hole when you decelerated upon arrival. Bummer. I'd never heard of kugelblitz! That was great. I've thought about the absurd amount of exclusively bosonic energy density that would be required to make a space-time singularity, but I didn't know there was a name for it :).
I thought you wrote grant proposals. Remove 'accidentally', change 'friend' to 'enemy' and get yourself some of that DoD/DoE money.Imagine pointing your starship at your friend's star system, pressing "go", and then accidentally enveloping them inside a black hole when you decelerated upon arrival. Bummer.
Hhahahaha, this was fantastic! My branch of funding now only selects less than ~10% of proposals, and it's getting worse, so I really appreciate you throwin' me a bone here, bruh. :)
like I am I mean really this is kind of a running joke to poke around with the fun shit associated with relativity and its discontents. I can give you a real one to show you how noped out I am: Presume a motor of unlimited, massless fuel such as the archetypal Bussard ramjet. Presume a steady acceleration of 1g to midpoint, at which point you will switch to 1g of steady deceleration. Presume all special relativity holds. How much experienced time will have elapsed for non-passengers to the goal, Alpha Centauri? How much experienced time will have elapsed for passengers? I'm pretty sure that's a barely quadratic problem yet my consultant on that script said "c'mon you have an engineering degree, I'm not helping you any more until you run the calcs" and I was all "yeah but I'm not writing screenplays because I enjoy story problems."
I need to correct myself and point out that the values I got were wrong. Formulae: t' = (c / g) * asinh(gt/c) - time measured by ship's crew Numerical values: g = 9.81 m/s² x = 4.3 ly = 4.07E16 m Time from the perspective of people on Earth (t): 1.63E8 seconds = 5.18 years. Time from the perspective of people on the ship (t'): 7.27E7 seconds = 2.31 years. Derivation was OK, had four other people check it for me and can show the work. It's not a new result anyway. Regardless, sorry for the mistake. am_Unition, ButterflyEffect, nil - you also shared that post, so I'm shouting out just in case it has any relevance for you guys. t = sqrt(x²/c² + 2x/g) - time measured on Earth c = 3.00E8 m/s
I’m in the kleinbl00 bucket of “studied engineering but fuck that”. I sometimes, kind of work as an engineer but it’s mostly stats and more simplistic math based. No derivations here woo-hoo. Am always interested in what the smart folks like you and am_Unition get to saying about math, though!
Pedantry above and beyond the call. The fact that this was worrying in the back of your head like a loose tooth says a lot about your character. The fact that you decided to drag your friends down with you says a lot about the people you hang out with.
Did you do it like: d(t' = t/𝛾), with 𝛾(t), after substituting v=9.8*t into 𝛾(v), and then integrate both sides, solving for the upper limit of the t' integral? Unprimed is Earth's frame, for posterity. Also, "approaching shitfaced at 1 g": not sure if claiming to be drunk or ugly... :| Edit: no but if you really hate yourself, do d(𝛾*t' = t), with 𝛾(t), and then do algebra for days. It reminds me of some homework shit once with deriving a particularly simplistic expression algebraically for a Rankine-Hugoniot shock jump condition expression.
Drunk. Probably still are. Definitely had too much, but flatmate finally got his M.Eng after years of bullshit, so at least it seemed like a good occasion. I have a math major and loved courses like real analysis, so obviously started drinking and deriving from Lorentz transform. For kb's case I got: t' = (c/g) asinh(gt/c) x - distance from stationary frame's perspective. Mea maxima culpa if I fucked it up along the way, but it looks reasonable to me.but if you really hate yourself, do d(𝛾*t' = t), with 𝛾(t), and then do algebra for days.
t = sqrt(x²/c² + 2x/g)
Looks good to me. I might come back with pictures of my chickenscratch, but yeah, I can see how some geometric substitution in the integral leads to a sinh function. Perhaps somewhat ironic is that the asinh function is sometimes pronounced "a cinch", a.k.a. American slang for something considered easy. But some would say "arc shine". As for "inverse hyperbolic tangent", it's just that no one wants to take the time to say an 8 syllable thing. The fact that pronunciation runs the gamut is proof that we've needed to standardize communication since science got off the ground. It's just dumb luck that I'm born into the English-speaking contingent of the world. But meanwhile, you know at least two languages thoroughly, and your brain is all the more ductile for it. Long term benefit! But yeah, I do genuinely feel kinda guilty for just having been born in the U.S., for what seems like an ever-increasing number of reasons, when I consider it. For now, at the very least, enjoy that booze. Kill off the weak brain cells. You'll make more, no worries.
FutureNeg: bebe, U pretty on the surface (Earth's), but at the 2 g's we gotta get to Titan at, that's just U 2 shitfaced 4 me, srry~