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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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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Could Dark matter manipulation meet the negative energy requirements for an Alcubierre drive?
The biggest issue with the Alcubierre drive is that in order for it to expand the space behind the spacecraft, it would require negative mass with repulsive gravity. No such negative mass is known to ...
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Why would FTL travel break causality, as oppose to the relative time reconciling as in the Twin Paradox? [duplicate]
I have heard that if faster than light travel were ever made possible, such as by an Alcubierre drive, the user would be taken backwards in time, violating causality.
This is odd to me, as it already ...
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Why does an Alcubierre drive, travelling FTL, violate causality, if the universe expanding FTL doesn't?
An Alcubierre drive seems to be plausible as a means to travel faster than light, because
it doesn't move the object itself, but the space around it.
it's said that matter and information can't move ...
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Einstein propulsion system
Will an extended body(cylinder) with asymmetric energy distribution across its H axis experience free-fall(geodesic)acceleration in free space(outside of any influences) in vacuum because of the time ...
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Is it possible to make something similar to Alcubierre's drive but in gas/liquid instead of spacetime?
Is it possible to use something similar to the Alcubierre's drive for traveling in the water or air? How could it be done?
Is it possible to make water flow around bubble keeping it non-disturbed ...
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Could Gott's Cosmic String Time Machine hypothetically be used as a poor man's Alcubierre drive?
I have read much speculation about Gott's theoretical use of cosmic strings for time travel, but if the colliding cosmic strings accelerated the spacecraft faster than light, as Gott theorizes, could ...
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How was this warp bubble generated?
The Debrief just reported that DARPA just "accidentally" created the world's first warp bubble. The actual paper is available here.
My layman understanding is that warp drives were so far ...
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"Swimming" in flat spacetime
Is it possible for a machine with a velocity of zero to translate its position in a perfectly flat region of spacetime? This is possible in curved spacetime https://groups.csail.mit.edu/mac/users/...
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How warp drive could be faster than light? [closed]
If the speed of gravity is as fast as the speed of light then there is no way a warp drive could curve the fabric of spacetime faster than the speed of light. Then how does a warp drive actually make ...
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How to make a warp bubble moving?
In answer to this question it is stated that:
In summary, warp drives move because they already move, or else they need to propel, and their movement is not related to spacetime expansion or ...
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When can information escape from a black hole through a warp bubble-like spacetime?
It is well known that nothing can escape a black hole, including gravitational radiation. Many questions have been asked here about this topic, such as:
Can gravitational waves escape a black hole?
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Shift Vector in Warp Equation
In the Alcubierre metric, why is there a beta with subscript multiplied by a beta with superscript? I know beta with subscript is the shift vector, but what is the difference between the two?
$$\text ...
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How would a warp bubble interact with an atmosphere? [closed]
What would happen if a warp drive entered the Earth atmosphere?
IIRC some scientists have created mathematical models that have shown that warp bubbles that don't exceed the speed of light may be ...
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Escaping from inside the event horizon [duplicate]
This is a hypothetical question. An Alcubierre Warp Drive can theoretically go any speed because space is moving and the ship is not. Could a ship equipped with this drive escape from inside an ...
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What exactly is the motion in Warp drive?
I know that there exists something like the Alcubierre warp bubble, and there are many threads here about it, but unfortunately the answers didn't help me to understand what the basic principle is...
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Does this research paper prove that warp drives are impossible?
Does this preprint prove that warp drives are impossible?
J. Santiago, S. Schuster and M. Visser, "Generic warp drives violate the null energy condition"
It states that the NEC (Null Energy ...
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Energy distorting space
We know that mass distort space and time. Can energy do the same? How much heat will it take to create an observable effect? can we make a warp drive on that principle? By heating one end of a space ...
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Warp drive small scale experiments "proof of concept" [duplicate]
Possible small scale warp drive experiments, or small scale experiments with quantum mechanics to model space-time warping? Why is it so difficult to engineer a small scale warp drive even though ...
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Erik Lentz's faster-than-light soliton
It's well known that, in relativity, if you can go faster than light, you can go backwards in time and create a paradox.
Also, attempts to create "warp-drive" space-times in which something ...
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Analogy for Lentz soliton
Analogy for Alcubeirre Warp Drive:
Every explanation of warp drive in layman terms has this sentence in it:
"The Warp Drive will contract space in thier front and expand space behind."
(I ...
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Testing space-time warp on a smaller scale, "Breaking the Warp Barrier: Hyper-Fast Solitons in Einstein-Maxwell-Plasma Theory" [duplicate]
So according to this paper it creates a warp drive without the need of negative energy to operate which many think does not exist in reality.
So my question is what would you do to experimentally ...
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The center of energy of a closed system maintains constant velocity in the vacuum of space. How can a warp drive overcome this rule?
In the following paper Introducing Physical Warp Drives by Alexey Bobrick, Gianni Martire
they state
5.2. Constructing warp drives: Warp drives, being inertially moving shells of normal or exotic ...
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Will an Alcubierre Drive arrive before a beam of light, if sent between two stationary observers?
First, I'm not a physicist, just an engineer, and my first language is not English, so forgive any strange wording.
I have a simple thought experiment about Alcubierre Drives: Imagine two stationary ...
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Compressing the Earth to a 20-meter-wide sphere would only subtract one hour of time? (General relativity)
The Internet has exploded with news that the Applied Physics Institute of New York published a paper claiming that superluminal speeds can be achieved using a type of Alcubierre Drive, but without the ...
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Could LIGO detect an Alcubierre drive being used within 10 light-years of the Solar system? [closed]
Maybe this question is too speculative... But is it possible that LIGO would detect the ramp-up and ramp-down of an Alcubierre drive being used within 10 light-years of the Solar system? Also, if the ...
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Warp drive causality issue, and a possible error in a paper?
Take a look at this paper on "Warp Drives and Causality:" https://doi.org/10.1103/PhysRevD.53.7365
The author attempts to argue that the Alcubierre Drive spacetime could exhibit Closed ...
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In an Alcuibierre like warp drive, what is the velocity of the object after the warp trip?
Presume a ship is traveling in an Alcubierre-like warp bubble. For concreteness, let us say that it began in a geostationary orbit (that term is used to indicate that the ship is in fact orbiting ...
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Late time behaviour of the Alcubierrie warp drive metric
The Alcubeierrie Warp Drive metric looks like $$ds^2 = -dt^2+(dx-Xdt)^2+dy^2+dz^2$$ where $X = v_s(t)f(r_s)$ and $r_s = [(x-x_s(t))^2+y^2+z^2]^{1/2}$. Now, $f(r_s) \approx 1 \quad 0 < r < R$ ...
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Geodesics in an Alcubierrie Warp Drive metric
The geodesics in an Alcubierrie Warp Drive metric are given by
$$\dot{t} = 1 \quad \dot{x} = X\dot{t} \quad y, z = \text{constant}$$ where $X = \dot{x}_s(t) f(r_s)$. Here $f(r_s)$ is a shape function ...
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Is this solution for interstellar travel viable?
I have in mind a way to enable FTL travel. Is this way viable?
In the paper:
"Weighing the vacuum with the Archimedes experiment"
we can see the dependency of the gravitational repulsion ...
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Frame dragging Warp drive [closed]
Is it possible to use frame dragging to make a warp drive?
For example: a space ship with "frame dragging generators" that constructively interfere between them to let space be dragged in ...
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Dark energy as negative matter for Alcubierre drive
Can dark energy be used for the Alcubierre drive as a substitute for negative mass? After all, to make the Alcubierre drive work, it is necessary to expand the universe behind it, and that is what ...
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The Explosive Force of the Braking Alcubierre Drive - What would this look like? [closed]
The Alcubierre Drive and faster than light travel more generally may be locked away in the realm of fiction forever. That might be depressing to some people but I think their impossibility is really ...
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Alcubierre drive: what is the nature of exotic matter? [closed]
In connection with Alcubierre drive we often hear about necessity of an exotic matter in order to produce a negative energy density. I suspect that such matter has no place in standard particle model.
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What would a Natario Warp Drive look like, outside & inside the warp bubble?
Within a Natario Warp Metric, all mass in front of the ship is pushed outwards by it's negative energy density, this means no light would interact with the front of the ship at all. And since the ...
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In regards to the hypothetical Alcubierre Drive (hear me out), are energy costs consumed immediately, or during transit?
I am aware the Alcubierre Drive is highly hypothetical and likely cannot exist. However, there are significant quantities of research material into Warp Drives of many types, and presumably the answer ...
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Approach for calculating Alcubierre energy function?
NOTE: I know that the Alcubierre drive is on shaky ground and I'm not asking about its practicality or physical feasibility. I'm also not looking for answers like, "It's sci-fi so you can just make it ...
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What would be the energy requirements for non FTL warp drive? [closed]
I have a question about Alcubierre Drive, or other Warp Drive concepts.
I have read a lot about FTL warp drive and the massive energy requirements to perform a jump, varying from bigger than the ...
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Since gravitational waves travel at the speed of light how are Alcubierre warp drives possible?
There are clearly some very large technical challenges to overcome before actually making one but most writers seem to think Alcubierre warp drives are possible in principle.
They work by propagating ...
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How would an Alcubierre warp bubble be affected by external gravitational fields (e.g. black holes)?
Consider a spaceship inside an Alcubierre warp bubble traveling in a straight trajectory. As it travels, it passes near a black hole (for the sake of argument, we'll say it's near the event horizon of ...
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