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 ...

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How does “warp drive” not violate Special Relativity causality constraints?

I'm talking about this nonsense: http://www.washingtonpost.com/news/post-nation/wp/2014/06/11/this-is-the-amazing-design-for-nasas-star-trek-style-space-ship-the-ixs-enterprise/ Now, I'm aware that ...
10
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1answer
365 views

Would warp bubbles emit gravitational Cerenkov radiation in general relativity?

Inspired by the gravtiomagnetic analogy, I would expect that just as a charged tachyon would emit normal (electromagetic) Cerenkov radiation, any mass-carrying warp drive would emit gravitational ...
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2answers
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warp drive with gravitational waves in the nonlinear regime

gravitational waves are strictly transversal (in the linear regime at least), also their amplitudes are tiny even for cosmic scale events like supernovas or binary black holes (at least far away, ...
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Alcubierre Drive - Clarification on relativistic effects

On the Wikipedia article on the Alcubierre drive, it says: Since the ship is not moving within this bubble, but carried along as the region itself moves, conventional relativistic effects such as ...
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223 views

Is every spacetime metric physically realizable?

Is every spacetime metric physically realizable? I know that given any spacetime metric, you could work out a stress-energy tensor for each position that would result in that metric. However, I also ...
7
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669 views

Getting back out of an Alcubierre warp bubble

Does the theory on paper provide a way for hypothetical travelers to get back out of the bubble that has gotten them close to their distant destination by compressing all the space in front of them ...
7
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2answers
167 views

What's going on along the “sides” of an Alcubierre warp bubble?

The models/depictions I've seen of warp bubbles show space compressed ahead of the bubble and expanded behind, so that the space inside the bubble moves with respect to the space outside. If that is ...
7
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1answer
423 views

Alcubierre warp bubble effect on gravity and space

I read the question Faster-than-light communication using Alcubierre warp drive metric around a single qubit?, and these questions came to mind: What kind of impact would an Alcubierre warp bubble ...
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Why Can We Observe Space Curvature / Warping At All?

I don't understand why we are able to see and measure curvature / warping of space at all. Space as I understand it determines distances between objects, so if space were "compressed" or warped, ...
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Doesn't Warp theory violate causality?

I have heard many physicists (ex:- Michio Kaku) saying "Warp speed" from Star Trek doesn't violate any known physical laws. But doesn't it violate causality? Say, we make warp drive possible and ...
6
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482 views

“Warp-drive” thought experiment

Why wouldn't this "warp-drive" work? Assuming we can build a flywheel that can survive near light speed and have an onboard power storage or beamed energy that can spin it up to that speed and back ...
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Harold White's work on the Alcubierre warp drive

I've read a bit on Harold White's recent work. (A paper on Nasa's site) I haven't been able to find any comments by people claiming to know anything about the physics involved. Is this really serious? ...
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1answer
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How could we travel to the nearest supermassive Black hole?

I have just watched a trailer for the upcoming movie Interstellar and started to wonder about some physics involved. In the end of the trailer, they are obviously plunging into a Black hole hoping to ...
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3answers
867 views

Could a ship equipped with Alcubierre drive theoretically escape from a black hole?

Could a ship equipped with Alcubierre drive theoretically escape from a black hole? Also, could it reach parts of the universe that are receding faster than the speed of light from us?
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1answer
102 views

If there is no speed limit on space-time compression, why do gravitational waves travel at light-speed?

From what I've read about spacetime and general relativity it seems there is no limit on how quickly space-time can be compressed or expanded. Why then gravitational waves are limited to light speed? ...
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Does a mass gain inertia against movement in all directions as it approaches the speed of light?

If a mass moves along the x axis at near the speed of light, does it take as much energy to additionally accelerate the mass along the y axis as it does to accelerate it along the x axis by the same ...
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2answers
213 views

Speed of light and warp drives in general relativity

Velocities can be a tricky thing in general relativity. A cool concept seemly consistent with the Einstein field equations) is an Alcubierre drive, described by the Alcubierre metric. However, I ...
3
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2answers
219 views

Alcubierre drive and inertia.

What is the inertia or velocity of a vehicle upon exiting or shutting down an Alcubierre bubble? Would the vehicle maintain the velocity it had in the bubble? I'm not sure I asked the question in a ...
3
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1answer
254 views

How much Energy to create a 'warp field' according to White?

An Alcubierre Drive is a hypothetical device that can move a place someplace else faster than the speed of light without violating known laws of physics. This paper provides some equations as to the ...
3
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2answers
156 views

Why is an Alcubierre drive shaped like it is

When I look up the Alcubierre drive I keep seeing that the drive powering the bubble is shaped like a circle - is this necessary for the creating of the "warp bubble" that travels forward? Does the ...
3
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1answer
132 views

Can an underdensity in space act as a negative matter density powering a warp drive?

Consider a homogeneous isotropic universe filled with a perfect fluid with density $\rho$ and pressure $P = \rho/w$. E.g. for $w=-1$ we get a universe equivalent to one with "vacuum energy" or with ...
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48 views

Looking out from the inside of an Alcubierre bubble

Disregarding the difficulties in achieving a warp "bubble" as per Alcubierre's theoretical warp drive, as far as I understand it the geometry of the spacetime that arises is mathematically sound. ...
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390 views

Could dark energy be heat? Could dark matter be stuff that is not seen because of its refraction limits?

Heat has to go somewhere. Would the light and heat of the stars in the universe amount up to being dark matter ...and dark energy ... Dark matter would just be small pieces of stuff. Dark energy ...
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1answer
143 views

How can I understand $\mathrm ds^2 = -c\,\mathrm dt^2 + [\mathrm dx-v_s(t)f(r_s)\mathrm dt]^2 +\mathrm dy^2 +\mathrm dz^2 $ in the simplest way?

How can I understand this equation $$\mathrm ds^2 = -c\,\mathrm dt^2 + [\mathrm dx-v_s(t)f(r_s)\mathrm dt]^2 +\mathrm dy^2 +\mathrm dz^2 $$ in the simplest way? I am a 13 year old boy who is totally ...
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1answer
61 views

Does Alcubierre drive allow time travel? [closed]

In Alcubierre drive, one can travel apparently faster than the speed of light by "compressing" space in front in the direction of travel. So let's say we have a stationary observer at point A, and an ...
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1answer
3k views

Exotic Matter — What is it?

I have a conceptual understanding of some theoretical physics concepts, so without getting into the math, what is exotic matter? I have read some articles that say it is anything not normal, while ...
2
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1answer
94 views

Space Warps & Frame Invariance

The Alcubierre Warp Drive in Higher Dimensional Spacetime (H. G. White & E. W. Davis), among other sources, proposes that the x-axis symmetry paradox for Alcubierre-style warp drives can be ...
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0answers
172 views

How do we derive force/acceleration vectors from Einstein's field equations?

I'm new here and I don't have any formal experience in physics beyond A-level. I've been exploring an idea for a space sim game someone else is developing in which propulsion of a spacecraft is ...
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2answers
303 views

The Alcubierre drive and closed timelike curves

Under what conditions would it be possible to create closed timelike curves, assuming an Alcubierre drive could exist? Would it be possible to have the latter without the former? See here for ...
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2answers
433 views

Relationship between Alcubierre drive space-time evolution and speed of gravity

The top rated answer to this question about the Alcubierre drive asserts, "spacetime can dynamically evolve in a way which apparently violates special relativity," but according to the Wikipedia ...
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139 views

Exotic matter out of a “squeezed” vacuum?

In the light of the current warp field experiments by NASA I found this paper: http://arxiv.org/pdf/1005.5682v1.pdf Could this actually lead to the creation of exotic matter or at least strengthen ...
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1answer
178 views

How does the Alcubierre drive warp space in the vicinity of it's destination?

I don't understand how this could work. So lets say the drive is set to go 30,000,000 meters in a straight line to get to a distant planet. Now lets say the ship size is 20 meters. Now let's make ...
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1answer
88 views

What happens when some asteroid comes in the way of warp drive?

Recently Harold white, NASA scientist shared his knowledge and the things he is working on. That is Warp drive for interstellar navigation. This spaceship compresses the space in front of it and ...
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1answer
171 views

What would be the resulting effect of two ships passing near each other while using a Alcubierre drive

So, I don't have any formal background in physics or space. but I read about the Alcubierre drive, and now I'm curious. If two ships passed one another, what sort of interference would be generated? ...
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1answer
235 views

Does the Alcubierre drive use negative energy to compress space infront of it?

The contraction in most images looks like a gravity well. Is it that you use negative energy to BOTH contract and expand space or positive and negative to contract (positive energy) and then expand ...
1
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1answer
247 views

Alcubierre Drive

I am a layman. I am aware that the Alcubierre Drive has not yet been proven to be possible, but there is something about the concept itself that I am confused about. If there is no movement within the ...
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1answer
35 views

Function to model deformed spacetime in 2D visualization of an Alcubierre drive

In the Wikipedia article on Alcubierre drive there is a top image. It is 2D visualization of an Alcubierre drive, showing the opposing regions of expanding and contracting space-time that displace the ...
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2answers
140 views

Einstein field equations and SEM tensor + Alcubierre

I wonder how I can find, using the Einstein field equations, the SEM tensor in a region of space with a function $k(x,y,x)$ that describes the curvature of space in that region at a moment (so it is ...
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1answer
109 views

How does a world line of an Alcubierre drive look like?

In my recent question ”Speed of light and warp drives in general relativity” I asked exactly how an Alcubierre drive worked and exactly what "FTL travel" meant. One of the comments I got stated that: ...
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1answer
106 views

Interaction of external light or matter and an Alcubierre warp bubble

For a hypothetical vehicle traveling in an Alcubierre bubble at faster-than-light (FTL) velocities, what would happen when the leading edge of the bubble encounters incident particles or photons? ...
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1answer
47 views

Could an Alcubierre Drive modify a gravitational field? [closed]

I'm a high school student, so I have no clue if warping spacetime has any effect on gravitational fields, but the two seemed to be linked based on what I've watched and read. And if a warp drive is ...
1
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1answer
309 views

Quantum Thrusters and Warp Drives [duplicate]

Any reservations about the potential of this (given in the link below/title above)? Does it seem like a helpless attempt or something which might have the potential of developing into something real? ...
0
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1answer
58 views

Do Gravitational Waves disprove superluminal Alcubierre drive?

I am not a physicist. But... does the rate at which gravitational waves travel set an upper limit to the "speed" of a ship propelled with Alcubierre drive? Or does it present a relativistic trick ...
0
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2answers
301 views

Why does the alcubierre drive get roasted by hawking radiation?

I read that an alcubierre drive would get destroyed by hawking radiation inside the warp bubble. Where does this hawking radiation come from? And why does it only happen to objects inside the bubble? ...
0
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1answer
88 views

How does someone move space?

I've heard that we've known components of the universe appear to be flying apart faster than $c$, and that this can happen because the space containing these materials are also moving apart. How does ...
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1answer
193 views

How Would an Alcubierre Drive “ride” a Wave of Spacetime?

The colloquial explanation is that the spacetime in front of a ship contracts and the spacetime behind expands. I see how one could think that this would bring you closer, but I don't see that it ...
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1answer
62 views

What are negative and positive energies? [closed]

So I have a few questions related to the negative and positive energy topic. 1)What do we mean by negative and positive energies in physics? 2)I have seen in a minute physics video that we need ...
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1answer
55 views

What is the difference between the expansion of space and the Alcubierre drive?

The Alcubierre drive violates causality. As far as I know the expansion of space does not. The usual explanation for why space is allowed to go FTL is that the matter doesn't move. The Alcubierre ...
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1answer
425 views

Why does the Alcubierre drive require negative energy?

The Alcubierre drive is an idea for a faster-than-light spaceship. It works by contracting space-time in front of the ship, and expanding it behind the ship. Physicists say that this requires the use ...
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0answers
210 views

The effect of multiple Alcubierre rings

In all of the descriptions and visualizations I've ever seen of the Alcubierre drive but one, it takes the form of a single ring or toroid surrounding a spherical volume of flat space. The exception ...