Questions tagged [warp-drives]
warp drives are generic conceptual space travel mechanisms that try to work around physical limits in the speed of propagation of light imposed by special relativity. Usually they resort to speculative science (exotic matter), or phenomena that are not yet well understood or is hard to make validation experiments (non-eternal rotating black holes)
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How is Alcubierre's warp drive propeled forward?
What is the exact mechanism of the warp drive that propels it forward? I know that it creates negative pressure behind it and a positive pressure in front of it but how does this actually propels it ...
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Would the effective speed of an Alcubierre drive be limited by the propagation speed of gravity?
The idea of a warp drive is to "expand space behind the ship and contract it in front"- in this way reaching a target destination faster than one could conventionally. However, the actual ...
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How does the "York time" measure the expansion of space; why is it equal to the divergence of the comoving observer's four velocity for warp drive?
The mysterious York time, θ is important in warp drive topic. It is plotted on the famous diagrams and is considered the measure of the mechanism that "drives" the warp drive bubble at ...
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Will this hypothetical circular singularity FTL travel warp drive work? [closed]
Not a physicist, but just wanted to know if this would work in theory:
Since nothing can practically travel faster than the speed of light (for now until proven otherwise), the only way for ...
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Do certain quasi-particles really have negative mass?
Do phonons for example really have negative mass or does it just seem like they have negative mass? Could one use the negative mass of certain quasi particles to meet the negative energy requirements ...
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Are there any Alcubierre Style metrics for sub-luminal speed warp drives?
In most literature I have found, research into the Alcubierre Metric, and Warp Drives seems to be highly focused on the plausibility of superluminal travel.
Today I was thinking to myself that maybe ...
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Killing Vectors in The Alcubierre Metric
According to this article about the Alcubierre metric, the metric can be transformed in a way that results in "spherical symmetry" about the x-axis. I have to assume they meant to say ...
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Why does the Alcubierre drive need a negative energy ring specifically?
Now, maybe this is a result of my poor understanding of spacetime, but a theoretical warp bubble contracts space in front, and expands it in the back. Positive energy always contracts, so I get the ...
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Is the kind of physics proposed for "warp drive" related to the way that space really is expanding?
As I understand, some parts of Universe really are moving faster than light -- is this expansion something we think we can create artificially?
And if we can do this artificially, could it be done a ...
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Volume Elements Inside The Warp Bubble
I'm trying to understand how to calculate proper spacelike volumes of metric tensors that have off-diagonal terms. Right now I'm considering a slower-than-light Alcubierre metric:
$ds^2=(v^2f^2-1)dt^2-...
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Violations of the Achronal averaged null energy condition
Many energy conditions have been shown to be violated in the past in semiclassical gravity, for instance when considering Klein-Gordon quantum scalar fields. Victims include the WEC (Weak Energy ...
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Proper spacelike distance in Alcubierre manifold
How do I find the proper spacelike $x$-coordinate on a constant $t$ hypersurface in the two dimensional Alcubierre manifold? The metric is given by
$$\mathrm{d}s^2=(v^2f^2-1)\mathrm{d}t^2-2vf\mathrm{d}...
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Would there be predictable observable signatures to Alcubierre-like “warp” drive usage?
Recognizing that any Alcubierre drive system requires exotic negative energy density matter that, as far as we can tell, does not exist, if somebody managed to find such stuff in the quantities ...
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Is observing (superluminal) velocity independent of choice of coordinates for asymptotically flat spacetimes?
Alcubierre's warped metric in ($1+1$)D is typically given in the form of:
$$ds^2 = -dt^2 + [dx-v(t)f(r) dt]^2 \ \ .$$
Then it is nicely discussed how manipulating:
$$-dt^2 + [dx-v(t) f(r) \ dt]^2=0$$
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Calculating proper volume in the Alcubierre spacetime
I'm trying to calculate the proper volume of a portion of the alcubierre spacetime to see how it compares to the euclidean volume element. As I understand it, the proper volume element in cartesian ...
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