- One explanation tell that as matter move faster and faster it becomes heavier and heavier and to accelerate it by speed of light it will take infinite amount of energy.
- Another way to explain this is with the help of 4th dimension. As all we know space can be represented by 3 axis; X, Y and Z and when you traveling from point A to point B the distance between them can be figure out A and B coordinates.
Einstein suggested another dimension, a 4th dimension for time and with the help of some complicated mathematics(Which I was not able to understand) he proved following relationship
So as per this relationship if somehow you can manage to travel faster than light in space time will start moving backward( Wow I have just figure out way to build time machine only part left is to build a rocket which can move faster than light)
So even when you are not traveling in space( or even on earth) you are always traveling at speed of light in 4th dimension.
Don't worry if you think your inter-galactic travel is going to take millions of year for your holiday vacation to our closest galaxy (say M31) scientists have good news for you. Faster inter-galactic travel can be achieved with wormholes