It has been recognized since Einstein came up with his special theory of relativity, that an object with mass cannot accelerate to speed faster than that of light, and maybe even before that. However, there have been ideas that challenge this universal speed limit.
The Long Stick Method
Imagine if you had an extremely long stick. Pushing it across the sky would get the other end to travel move faster than light could get to the other end. Right? Unfortunately, wrong. Like all objects, the stick is minimally ductile. Whenever an object is moved, the rest of it moves according to its distance from the point of force, and the speed of sound. This means that the far end, even if we had a completely rigid material, would only receive the “push” after it travelled down the stick at the speed of sound.
The Opposite Directions Method
What if one spaceship traveled 75% of the speed of light in one direction, and another at 75% of the speed of light in the other. Wouldn’t they be traveling at 1.5% of the speed of light relative to each other. The answer is once again, no. The Theory of Relativity was all about this, how space and time distort while the universal speed limit remains constant. Basically, time would slow down for them, making it impossible to do as such.
The Spinning Disc Method
This is one of the most thought through methods that doesn’t work. Basically you spin a disk at 10,000 rpm with extendable carbon nanotubes that can extend a breathtaking 285 km.
If you took the time to do the math (you probably didn’t), theoretically, this would break the speed of light. However, it isn’t possible to do in practice. Since only the ends would be traveling faster than the speed of light, the photons that bind things with the electromagnetic force wouldn’t be able to hold the arms together. In order to go faster than light, you’ll need to get the whole object to travel at the same speed.
The Wormhole Method
Imagine space is actually two dimensional. If bent it like paper, the inhabitants wouldn’t be able know that their reality was distorted. Now imagine if we touched two locations and punched a hole through it. Going through the whole would get you from point A to point B in a lot less time than if you traveled by conventional means. Although your velocity wouldn’t actually exceed that of light, you would be able to get somewhere faster than a particle of light could.
This is very similar to the wormhole method. Even more, this is actually happening right now. If you placed two objects greater than 1.34 x 1010 light years from each other, they would naturally travel away from each other faster than light. Why? Space is expanding, and cosmologists have no idea why:
Since the speed of light doesn’t stop space itself from moving however it wants, any objects outside of the hubble sphere (radius of 1.34 x 1010 light years, see above) are moving faster than light compared to us. This still isn’t technically a method of faster than light travel, since it is space that is doing all the work.
Quantum Entangled Particle Method
This isn’t really a way to travel faster than light, but it can send a message twice as fast as a photon (actually were going to prove that wrong). Here’s the premise, every particle has a spin, although it may not actually be spinning. There is up spin and down spin. A particle in a quantum state is both, and therefore in a superposition, until measured. If a certain quantum entangled particle is measured and is found to have up spin, its entangled partner will have down spin. So, if two human colonies in the future, who are light years away need to communicate, they can just measure their particles and use morse to send messages.
Critics against this say that when two quantum entangled particles are made, they decide who’s going to be up and who will be down if measured, so they were never in a superposition in the first place. Bell’s Theorem refutes this, proving that quantum mechanics do apply.
Tachyons and Neutrinos
Alas, something that may actually work and is legit. There are these two particles that may travel faster than light. Tachyons are theoretical, but neutrinos exist. Both could theoretically travel faster than light, but we don’t know for sure. They are ghostly particles anyway, so they wouldn’t be very useful, but faster than light communication being possible is AWESOME!