Faster than Light Travel Question

[masonroese]

Assuming a spacecraft had a propulsion system and sufficient fuel, what stops it from reaching the speed of light and beyond if a constant force is always being exerted on it?

And in the event that it can go beyond the speed of light, will time distortion take place, and the crew on board the ship will live for thousands of years?

 

[Whateverworks]

Two things. According to Einstein no object with mass can reach the speed of light. The elementary particle photon which is responsible for the electromagnetic spectrum moves at the speed of light and have no mass. Researchers might have disproved Einstein's hypothesis but that has not been confirmed! (Check the hadron collider in CERN for more info) Time will get distorted and depends on which rate of velocity you're moving. If you were in a space shuttle moving near c your clock will tick slower than the clock will tick on Earth. I think you might can put it like this, but I am not sure:
Sufficient high velocity = Time will go by slower.

//WeW

 

[ghwellsjr]

Here's my answer to someone else's similar question:

With low velocities, the formula for calculating the velocity, v, after an acceleration, a, for a time, t, is:
$$v = a t$$
So this says you could apply any acceleration for a long enough time and get v to exceed c. Or if you had a high enough acceleration, for a shorter time, it says you could get v to exceed c.

But this formula is only an approximation where the velocities end up being very small compared to c.

The correct formula is:
$$v = \frac{a t}{\sqrt{1+(a t/c)^2}}$$

If you look carefully at this formula you will see that when $$a t$$ is very small, the formula approximates to:
$$v < \frac{a t}{\sqrt{1}}$$
$$v < a t$$
This is similar to the original formula.

But when $$a t$$ is very large, the formula approximates to:
$$v < \frac{a t}{\sqrt{(a t/c)^2}}$$
$$v < \frac{a t}{(a t/c)}$$
$$v < \frac{1}{(1/c)}$$
$$v < c$$
So in reality, no matter how much you accelerate, or how long you accelerate, you can never reach c.

 

[FlexGunship]

Assuming a spacecraft had a propulsion system and sufficient fuel, what stops it from reaching the speed of light and beyond if a constant force is always being exerted on it?

The answer that seems to satisfy most people is this:

As your velocity approaches the speed of light the proportional amount of energy required to accelerate further gets higher. The speed of light is the speed at which it an infinite amount of energy is required to accelerate any further. (Strictly speaking, its an asymptotic approach.)

So, the problem is really in your question:

Assuming a spacecraft had a propulsion system and sufficient fuel, what stops it from reaching the speed of light and beyond if a constant force is always being exerted on it?

There's not enough fuel in the universe to get there. You would just get closer and closer and closer until you had exhausted all the matter and energy in the universe.

"Assuming you had a perfect sphere, what prevents it from being a cube?"