Is a warp drive real?

According to Einstein's theories of relativity a warp drive is possible. However, the technical aspects haven't quite been worked out yet.
Actually, the idea is called an Alcubierre drive, after the theoretical physicist Miguel Alcubierre. He published a paper on the concept in 1994, but it's based on the idea of creating a configurable energy-density field lower than that of vacuum (negative mass). He based this on a solution of Einstein's field equations in general relativity, but the mathematical solution ends up requiring exotic matter that has negative mass. Some have suggested a negative mass of  - 10^64 kg, which exceeds the mass of the observable universe. Others suggest that by changing the geometry of the exotic matter could reduce the requirement to - 700 kg and changing the warp bubble to a torus. One such possible exotic matter would be tachyonic matter. Tachyons are theoretical quantum particles that travel faster than light.

The idea of warp drive is to put the ship into a warp bubble carried on a wave that would expand space in back and compress it in front of the ship. The ship in a bubble would be like a surfer riding on the wave that would move faster than light. Essentially, the ship would arrive before the light would in normal space. The crew of the ship would be in free fall and feel nothing, but the bubble would be under extreme tidal forces at the edges during acceleration, and the particles that the bubble has gathered would be released explosively when the ship drops out of warp. This sounds like a good weapon. The other main problem is that the crew couldn't control or guide the ship while it's in warp. At least that's what some theorists believe. The only way we'll know for sure is when they build a prototype.

I've looked at the math and it appears to be valid, but it does result in an energy density metric tensor that's negative, which means that a warp drive requires exotic matter if you go with the Einstein equations.

For those who care, this is the general relativity equation that describes foliation of space-like hypersurfaces: ds^2 = - (α^2 - βi β^i) dt^2 + 2βi dx^2 dt^2 + ϒij dx^i dx^j

The ^ symbol means to the power of
i and j are subscripts
α is interval of proper time between nearby hypersurfaces.
βi   is a vector that relates the spatial coordinate systems on different hypersurfaces.
ϒij  is a positive definite metric on each of the hypersurfaces.

Alcubierre's version of this is:
ds^2 = (vs(t)^2 f(rs(t))^2 - 1) dt^2 - 2vs(t) f(rs(t)) dxdt + dx^2 + dy^2 +dz^2
f is used to mean a function and s is a subscript.
The result is a form of the metric that looks like this:
- c^4/8πG times vs^2(y^2 + z^2)/4g^2 rs^2 times (df/crs)^2

This is the energy density needed to make this thing go faster than light and its negative, meaning that some form of exotic matter is required.

They made it look easy in Star Trek, but in reality it's unclear how you could use matter-antimatter reaction to create exotic material. Someone must believe that this is possible because NASA is experimenting with the idea of a warp drive. How they're trying to create a warp bubble is unknown at this point. Some experiments have been done using an interferometer to detect if warped space is even possible on a microscopic level. A research team consisting of Harold White and Dr. Richard Judas did experiments like this and produced positive results with an EmDrive (Radio Frequency resonant cavity thruster). An EmDrive is a very advanced type of electromagnetic thruster engine. It uses no reaction mass and emits no directional radiation. This is so advanced it violates current scientific theories. Supposedly, this electromagnetic propulsion drive defies the law of conservation of momentum. The reasoning is that it's using a quantum vacuum, which is the lowest quantum state, and this is behaving like ion propulsion. This idea is controversial because the thought is that a quantum vacuum cannot be ionized so there's no propulsion from such a system. Yet, tests all in China and Europe indicate that it works.

According to Wikipedia the EmDrive uses a magnetron to produce microwaves, which are directed into a metallic, fully enclosed conically high Q resonant cavity. A directional thrust is produced by this method. The only thing that's needed is electrical power to run the magnetron (high-powered vacuum tube that generates microwaves).

Essentially, what the warp drive experiment involved is measuring the change in velocity of laser light through the EmDrive resonance chamber while the system was at maximum power, indicating that a micro-warp bubble was created. This indicates that exotic matter isn't required for warp propulsion.

How far this research has progressed is not known, but it indicates that NASA is serious about creating a warp drive propulsion system for spacecraft. That is exciting and shows promise for travel to other star systems across the Milky Way galaxy.

Thanks for reading.