6 ms·
Large theoretical difficulties, too! To the best of my knowledge, nobody has ever been able to write down a complete mathematical description where an Alcubierr
by Steuard 13y ago
Large theoretical difficulties, too! To the best of my knowledge, nobody has ever been able to write down a complete mathematical description where an Alcubierre bubble "turns on" or "turns off": instead, the math always seems to describe a scenario where the warp bubble exists (and is inaccessible from the outside) into the infinite past and infinite future. Also, all versions of Alcubierre's model that I am familiar with require forms of matter and energy with properties completely different from anything ever observed (and different from most mainstream ideas for possible new types of matter and energy as well): namely, they require violations of various "energy conditions". http://en.wikipedia.org/wiki/Energy_condition http://en.wikipedia.org/wiki/Energy_condition
The vast practical difficulties are in addition to the enormous theoretical challenges. I would absolutely love it if something like the Alcubierre drive could be made real, but there are multiple steps between here and there that would each deserve a Nobel prize. If I were White, I'd be talking about how I'd solved all of those problems (or any of them!) before jumping straight to trying to generate a warp bubble in the lab.
- EthanHeilman 13y ago>If I were White, I'd be talking about how I'd solved all of those problems (or any of them!) before jumping straight to trying to generate a warp bubble in the lab. Why not try to generate a bubble, if it works great, otherwise try formalize it in greater detail. If warp bubbles are possible than it may be that they are already being created through random chance at the micro-level in the natural world.
- VLM 13y ago"Why not try to generate a bubble," Missing the part from the paragraph about having no idea how to generate that condition, although if it existed in the past it would presumably be "sorta stable" in fact it would never be able to shut off as presently understood. A good analogy would be trying to talk to the original Lada Ada about silicon based computers without the folks of that era knowing enough solid state physics to contemplate whats going on in a simple transistor. "So if you could magically understand how to create a transistor, which won't happen for a century, then logically it follows that such and such array of those magic devices would make a great full adder circuit to add binary numbers"
- deleted 13y ago[deleted]
- tekacs 13y agocf. Shor's algorithm in that: this could at least be useful busywork/speculative preparation?
- Someone 13y agoSo what? Half of number theory (I don't know enough of it to say whether that _is_ an exaggeration) does right that: "If the generalized Riemann hypothesis is true, ..."
- VLM 13y agoIts a more fundamental problem. Like "Wouldn't it be cool to be able to multiply. At least for reasonable small integers, if you could add, which you can't at this time, then you could multiply simply by repeated addition. But, of course, you can't add, so ...".
- DennisP 13y agoI just meant that the basic idea doesn't violate general relativity. Your link mentions that negative energy density has been observed at very small scale as a result of the Casimir effect. It's difficult to see how that could be scaled up, but I suspect that's what White is using here.