Question

You are in a spaceship traveling at a speed of 0.8310000000000001 c relative to Earth, where c is the speed of light. You wish to increase your speed by a factor of x. No matter how much energy you have, x will always be less than what value?

Answer 1

If you are in a spaceship travelling at a speed of 0.8310000000000001c realative to earth,

And we know that the speed of light is c which is nearly equal to 300000000 m/s.

If you wants to increase your speed by a factor of x, and you have no idea about how much energy you have.

Till now there is nothing that can travel faster than the speed of light .

If you increase your speed by a factor of 1.20336943, your spaceship travel with the speed of light realative to earth,but that is not possible , your spaceship speed can't be equal to the speed of light. Till now there is nothing that can travel faster or equal to hre speed of light if you talking about spaceship.

So, x i.e. the factor by which you increase your spaceship speed is always less than 1.20336943.