A sort of toy solution for an arrangement of spacetime valid in general relativity allows faster than light travel but requires all sorts of things which are varying levels of probably impossible / this doesn’t exist.
Some experimentalists playing around with the Casimir effect (very real) which has to do with very close together things being pushed together while in a vacuum due to quantum effects of a vacuum found something in a simulation that looks quite like the toy solution that allows faster than light travel, involving things a few millionths of a meter across.
They figure you could actually build this contraption which is essentially just a little ball in a little tube and test its effects on electrons to confirm that they really can create tiny warp fields and study them… or they could have just made mistakes or found a way to invalidate some physics.
It doesnt seem like there’s a lot you could do with a micro scale warp field as the effect it relies on really depends on scale, but it is an interesting possibility.
Like most cases of “huh, that’s weird” it’s probably nothing, but it might be something, definitely worth the research funding to build the little device, but hold off on your vacation plans to Alpha Centauri.
I wonder if we could discover new physics/applications or build a warp drive just by brute-forcing/mass experimentation or simulation.
What if our universe is simulation by an "alien" species who wants to achieve FTL travel but are out of ideas on how to do it; but, they can run obscenely massive simulations. And the simulation stops as soon as someone inside the universe achieves FTL travel.
Aside from the general crankery of this musing, you realize that us being able to discover FTL travel would depend on the underlying physics being simulated deeply and accurately enough in the first place, and probably with some headroom?
It doesn’t matter if the simulation is kind of sketchy. Because we can find holes in it, and exploit those to move around. To us simple simulated beings, we achieved FTL and we can conquer the simulated universe. The aliens on the next level, probably will find out that the simulation broke. Or a dilemma, maybe we can’t find FTL, because the simulation was already patched from previous iterations.
If a civilization is capable of simulating universes, most likely it know if FTL is actually possible or not in their own universe.
But it could also be that even the original universe has too many free/independent parameters and the original civilization is as scientifically agnostic as us if FTL is actually technologically possible, so they could say "we thought of everything we could and still cannot prove or disprove FTL, let's create a totally different species and let them have a go, maybe they come up with radically different ideas, but it's better not to create them in our own Universe or they might be smarter than us and turn against us, let's sandbox them in their own simulated universe".
They could probably use "A.I." like AlphaGo to try and build structures within their own universe limitations that create Alcubierre drives, but it could also be that that also failed and after searching for aeons, they just raised their tentacles and said "that's it, we're stuck, the only thing left is to try the simulated universe approach".
Even if the FTL aspect turns out to be impossible, I think it's still an interesting hypothetical alternative to chemical and electric thrusters. More realistically I'd bet it's even further off than terrestrial/lunar mass drivers to solve the payload problem but it's an interesting thought nonetheless.
To your point, even if the theoretical drive is feasible but limited to sub C speeds, a drive that requires zero propulsion mass and where the contents of the bubble don't feel any acceleration would be absolutely huuuuuge for manned space flight.
yeah 100%. I do wonder about the energy requirements though because intuitively they don't totally make sense. I still don't understand why it couldn't be used as an infinite energy generator. Is it really just that the ship would move without gaining any momentum since it's the space around it moving instead of the ship itself?
An Alcubierre drive is a theorized device for faster-than-light travel that kind of doesn't technically violate any known physical laws. Instead of accelerating a ship beyond the speed of light (which we think should take infinite energy), it instead manipulates spacetime itself (contracting the spacetime in front of the ship and expanding the spacetime behind the ship) in order to achieve apparent faster-than-light travel. But just because it can be theorized doesn't mean that such a drive is possible to build, particularly with regard to the requirement for negative energy density. This paper appears to suggest that one candidate for providing negative energy density might be achievable.
