What Is The Fourth Dimension?

Time is usually ascribed the title, fourth dimension. But this is a dimension that's intangible. Our modern day concept of time is derived from the disciplines of astronomy and physics, but the true nature of time is a mystery.

Most people perceive time as linear and constant. Certainly, all our clocks measure time as though it is invariable and proceeds at a uniform speed.

While this does us happily here on Earth, scientists such as Albert Einstein assert that time is relative to light speed and the eyes of the beholder. He was the first to devise the concept of space time that is not only variable but also non-linear and likely to be bent in the same way as light by gravitational forces.

Experiments to put Einstein's theory of relativity to the test have demonstrated that as the velocity of an object approaches the speed of light, its mass increases exponentially, its length reduces and time slows down. This explains why the crew of a space ship flying at 99 per cent of light speed for one year would find that on their return home, seven years had elapsed here on Earth.