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<blockquote data-quote="freyar" data-source="post: 6678305" data-attributes="member: 40227">Yes, this is the way the &quot;warp drive spacetime&quot; discovered by Miguel Alcubierre works (along with an expansion of space behind the ship).&nbsp; In fact, the shop doesn't have to move at all --- the bending of space does everything!&nbsp; But don't get your hopes up: the exotic matter necessary is has much more unusual properties than, for example, dark matter (which is in most models like normal matter in many respects).&nbsp; Specifically, it needs negative energy density.&nbsp; That is possible, but most hypothetical forms of exotic matter with negative energy density end up causing mathematical inconsistencies in physics.&nbsp; From a quick literature search today, I'm not finding anything more specific than that for the case of the warp drive spacetime.Also, to give you something from a true authority on the subject, I saw a talk by Professor Alcubierre a couple of months ago.&nbsp; On his slides, he wrote &quot;please, please, please don't believe the hype&quot; about NASA's Eagleworks lab's work on warp drive.&nbsp; In short, he doesn't find that work terribly promising.That's a little more complicated, and I haven't seen anything analyzing this directly in the literature.&nbsp; But here are my thoughts on it.&nbsp; Generally, objects are ok with being in expanding or contracting space, as long as the expansion or contraction is gentle enough.&nbsp; For example, our universe is expanding, but galaxies are able to remain as coherent objects.&nbsp; On the other hand, one paper I did find argues that the &quot;warp bubble&quot; (contracting region) has to be really very thin.&nbsp; In that case, an object passing through the bubble would be contracted (and perhaps stretched) different amounts in different places.&nbsp; That can certainly destroy the poor object, most likely by crushing part of it.&nbsp; Slightly more technically, I'd expect the victim to feel strong tidal forces that stretch or crunch it because there's a different gravitational action on different parts of the object.&nbsp; In a much less extreme form, the gravitational pull of the moon is more on the close side of the earth than the far side, which causes tides in the oceans.&nbsp; Another example of tidal forces that's come up on EN World before is near the event horizon of a black hole --- essentially your feet want to move toward the black hole so much faster than your head does that you stretch out like spaghetti.&nbsp; But for large enough black holes, the stretching of space is actually gentle enough to leave you alive until you're well inside the event horizon.</blockquote>

[QUOTE="freyar, post: 6678305, member: 40227"] Yes, this is the way the "warp drive spacetime" discovered by Miguel Alcubierre works (along with an expansion of space behind the ship). In fact, the shop doesn't have to move at all --- the bending of space does everything! But don't get your hopes up: the exotic matter necessary is has much more unusual properties than, for example, dark matter (which is in most models like normal matter in many respects). Specifically, it needs negative energy density. That is possible, but most hypothetical forms of exotic matter with negative energy density end up causing mathematical inconsistencies in physics. From a quick literature search today, I'm not finding anything more specific than that for the case of the warp drive spacetime. Also, to give you something from a true authority on the subject, I saw a talk by Professor Alcubierre a couple of months ago. On his slides, he wrote "please, please, please don't believe the hype" about NASA's Eagleworks lab's work on warp drive. In short, he doesn't find that work terribly promising. That's a little more complicated, and I haven't seen anything analyzing this directly in the literature. But here are my thoughts on it. Generally, objects are ok with being in expanding or contracting space, as long as the expansion or contraction is gentle enough. For example, our universe is expanding, but galaxies are able to remain as coherent objects. On the other hand, one paper I did find argues that the "warp bubble" (contracting region) has to be really very thin. In that case, an object passing through the bubble would be contracted (and perhaps stretched) different amounts in different places. That can certainly destroy the poor object, most likely by crushing part of it. Slightly more technically, I'd expect the victim to feel strong tidal forces that stretch or crunch it because there's a different gravitational action on different parts of the object. In a much less extreme form, the gravitational pull of the moon is more on the close side of the earth than the far side, which causes tides in the oceans. Another example of tidal forces that's come up on EN World before is near the event horizon of a black hole --- essentially your feet want to move toward the black hole so much faster than your head does that you stretch out like spaghetti. But for large enough black holes, the stretching of space is actually gentle enough to leave you alive until you're well inside the event horizon. [/QUOTE]

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