- #1
MattRob
- 211
- 29
So, this has really stirred my interest. To be clear, I'm not citing these as sources, simply linking for discussion;
An article on the subject,
And the abstract.
Talking about this elsewhere I seem to find no shortage of objections. But to me it seems fundamentally pretty sound.
One thing in particular has me asking, though;
One of the objections is that it could violate causality by allowing for even apparent FTL travel. I'm not so sure.
Special Relativity shows us how FTL = time travel, true, but that's only in the context of flat spacetime. The thing is, though, with this "warp drive," although you achieve apparent FTL, it comes off to me as a way to expand your light cone, not break out of it.
But that's the thing - can you expand your light cone and reach areas that were previously inaccessible? It seems to be a big claim, but it just seems to be a natural result of inflationary cosmology.
As I understand it, Inflationary Cosmology states that the universe didn't start off expanding, but in the earliest moments its rate of expansion rapidly shot up, then came down to a more reasonable level, until large volumes of empty space caused it to increase again.
If the universe expands at rate [itex]H[/itex] per distance [itex]D[/itex], then your cosmic horizon will simply be
[itex] D_{Horizon} = \frac{C}{H} [/itex]
If [itex]H[/itex] decreases, then, the distance [itex]D_{Horizon}[/itex] will increase, thus your "light cone," with the expanding universe taken into account, will include regions of spacetime that were previously inaccessible to it. That is, your light cone now includes regions of spacetime you would have had to exceed [itex]c[/itex] in order to reach at an earlier point in time.
So, isn't it possible, then, in the context of GR, to expand a light cone to include previously inaccessible regions of space, thus, spacetime?
An article on the subject,
And the abstract.
Talking about this elsewhere I seem to find no shortage of objections. But to me it seems fundamentally pretty sound.
One thing in particular has me asking, though;
One of the objections is that it could violate causality by allowing for even apparent FTL travel. I'm not so sure.
Special Relativity shows us how FTL = time travel, true, but that's only in the context of flat spacetime. The thing is, though, with this "warp drive," although you achieve apparent FTL, it comes off to me as a way to expand your light cone, not break out of it.
But that's the thing - can you expand your light cone and reach areas that were previously inaccessible? It seems to be a big claim, but it just seems to be a natural result of inflationary cosmology.
As I understand it, Inflationary Cosmology states that the universe didn't start off expanding, but in the earliest moments its rate of expansion rapidly shot up, then came down to a more reasonable level, until large volumes of empty space caused it to increase again.
If the universe expands at rate [itex]H[/itex] per distance [itex]D[/itex], then your cosmic horizon will simply be
[itex] D_{Horizon} = \frac{C}{H} [/itex]
If [itex]H[/itex] decreases, then, the distance [itex]D_{Horizon}[/itex] will increase, thus your "light cone," with the expanding universe taken into account, will include regions of spacetime that were previously inaccessible to it. That is, your light cone now includes regions of spacetime you would have had to exceed [itex]c[/itex] in order to reach at an earlier point in time.
So, isn't it possible, then, in the context of GR, to expand a light cone to include previously inaccessible regions of space, thus, spacetime?