Faster Than Light?

Abstract

The major problem with travel to distant parts of the universe is that we are restricted to speeds less than that of light. We can get around this by using time tunnels, assuming that they are possible. For now let’s ignore time tunnels and consider other possibilities. We know that the time dilation of special relativity allows us to travel at “effective speeds’’ well in excess of the speed of light. The reason for this is that an observer on Earth notices that time passes very slowly on a clock in a spaceship that is traveling at a speed very close to that of light relative to the Earth. The astronauts in the spaceship don’t notice this slowing; to them time appears to pass normally. But if we use the slowed-down time seen by Earth observers to calculate the “effective speed” of the spaceship, we obtain numbers well in excess of the speed of light (usually called c).