3 ms·

You can't travel as fast as you want because it will take ever larger amounts of energy to accelerate each fraction of a percent closer to the speed of light. Y

• Cybiote 10y ago
  Maybe I need to clarify? A certain amount of energy must be expended to reach a particular velocity. For a relativistically relevant velocity, kinetic energy is given as: mass * c^2 * (1/sqrt (1 - v^2/c^2) - 1); it's clear that v will never reach c. For an example of how things can escalate: an object massing 1 kiloton traveling at 90% the speed of light has 4x the kinetic energy as the same mass at 65% (for context, a 1kton object at 0.65c has ~50x the energy as was used in 2013). From 90% -> 99% it's a ~5x increase. And from 99% -> 99.9% it's 3.5x. So just a 0.9% increase in speed has almost as much impact on energy as the 25% increase at a lower velocity.