Warp Drive, now WITHOUT negative mass/energy!

[SirKazum]

Some astrophysicist at Göttingen University (https://www.uni-goettingen.de/en/3240.html?id=6192), Germany, came up with a warp drive design that, unlike previous designs, works without "exotic matter" i.e. matter that has negative mass / energy density, which, well, isn't known to exist and there is no particular reason to believe it should. This time around, though, the "soliton" (warp bubble) is made only with regular ol' positive-density energy. About as much as the mass of Jupiter, so there's still a long way to go cutting that down before you can begin to think of practical applications. Of course, as with all previous warp drive work, all this is 100% theoretical, and even if you could somehow conjure up the required energy, it's not like anyone knows how to make a warp drive in practice, just what shape the bubble needs to have if it's going to work.

Anyone else here seen this? All I have to go on is the press release and basic layman knowledge, so I'd love to hear from others whether this makes sense.

[erikun]

This sounds like a refinement on the Alcubierre drive (https://en.wikipedia.org/wiki/Alcubierre_drive), shrinking the distance in front while lengthening the distance behind, while maintaining a "bubble" of relative space for the ship to reside. It could be that this was part of the existing research they studied, or maybe the solution just happened to end up looking similar in the end.

[georgie_leech]

This sounds like a refinement on the Alcubierre drive (https://en.wikipedia.org/wiki/Alcubierre_drive), shrinking the distance in front while lengthening the distance behind, while maintaining a "bubble" of relative space for the ship to reside. It could be that this was part of the existing research they studied, or maybe the solution just happened to end up looking similar in the end.

Er, wouldn't that run into a notable issue wherein your bubble can only travel at sub-light speeds? Unless I'm missing something, most excitement for something like a warp drive would be interstellar distances, which... well, seem like would still be an issue if you've got to cart around a bubble of space with you.

[Fyraltari]

Er, wouldn't that run into a notable issue wherein your bubble can only travel at sub-light speeds? Unless I'm missing something, most excitement for something like a warp drive would be interstellar distances, which... well, seem like would still be an issue if you've got to cart around a bubble of space with you.

Space can expand (and contract) faster than the speed of light in a vacuum, as it did during the Big Bang, for example. The Alcubierre drive is basically a cheat, by contracting and expanding space in front and behind your ship, you can go from point A to B in as little time as if you moved faster than light without your ship actually doing so.

[georgie_leech]

Space can expand (and contract) faster than the speed of light in a vacuum, as it did during the Big Bang, for example. The Alcubierre drive is basically a cheat, by contracting and expanding space in front and behind your ship, you can go from point A to B in as little time as if you moved faster than light without your ship actually doing so.

Right, and in this hypothetical engine being discussed said warping is contained within a bubble that averages out to 0 warping to get around needing negative mass. So within said bubble, you can take advantage of said warping. Like I said though, unless I'm missing something, said bubble would default to the usual rules of propagation: updating the universe at the speed of light. So even if you moved the source of said bubble, the "edge" (for lack of a better term) would move at the speed of light at a maximum, putting an effective limit on the distance you could move within said field before you're back to travelling through the universe with Lightspeed as a maximum.

It would certainly still be amazing for getting things up to the speed of light; Relativity is a pain otherwise. But it would still take this hypothetical engine 4.3 years to get to Alpha Centauri, say, unless the bubble somehow already contained them.

[Radar]

Right, and in this hypothetical engine being discussed said warping is contained within a bubble that averages out to 0 warping to get around needing negative mass. So within said bubble, you can take advantage of said warping. Like I said though, unless I'm missing something, said bubble would default to the usual rules of propagation: updating the universe at the speed of light. So even if you moved the source of said bubble, the "edge" (for lack of a better term) would move at the speed of light at a maximum, putting an effective limit on the distance you could move within said field before you're back to travelling through the universe with Lightspeed as a maximum.

It would certainly still be amazing for getting things up to the speed of light; Relativity is a pain otherwise. But it would still take this hypothetical engine 4.3 years to get to Alpha Centauri, say, unless the bubble somehow already contained them.
I do not think that is the problem here. I did not have much to do with general relativity, but the idea of a warp bubble is not new and the general consensus is that such an isolated fragment of space can travel arbitrarily fast.

Also on the subject, the energy requirements most likely can be diminished very significantly as the publication itself mentions some techniques used for previous warp bubble proposals that can result in some crazy savings beyond what is needed to make the solution viable. There is no telling, if those tricks can be applied directly or will need to be modified, but I am quite optimistic. It still does not answer the question of how exactly one would be able to generate the bubble, but it does make it a reasonable thing to try.

edit: I will not live to see this, but I do have some little hope that some day space will be the final frontier (https://www.youtube.com/watch?v=S6R3MiAv9ac).

[halfeye]

edit: I will not live to see this, but I do have some little hope that some day space will be the final frontier (https://www.youtube.com/watch?v=S6R3MiAv9ac).

I do want us to explore space, but space is not itself a frontier, it's a place a frontier can travel through, and it's almost endless, so that frontier can keep on going for a very long time indeed.

[Yora]

Kyle Hill did a calculation that the energy requirement to create a warp field around a 100m long ship with this equation requires the energy output of a hundred trillion death star lasers.

But hey, at least it's a positive amount of energy.