   Overview

The special theory of relativity (special relativity) was published by Albert Einstein in 1905. The contents of this theory challenged many of the established truths of physics. In it Einstein stated two postulates or facts about the Universe and from these all its implications can be derived.

Firstly Einstein stated that the laws of physics are the same in all inertial frames, i.e. one which is moving with constant velocity and is undergoing no acceleration. The result of this is that one cannot tell the difference between inertial frames and thus there is no view point of the universe which is the correct one.

Second, Einstein stated that the speed of light is constant regardless of the relative velocity between the observer and the emitter. Before special relativity scientists believed that if an emitter was moving relative to an observer then the speed which you would observe the light to be moving would be the speed of light plus the relative velocity of the emitter to the observer. Einstein stated that this was wrong and that, regardless of the velocity between emitter and observer, the measured speed of light would be always be the same value (which we know to be approx. 300,000,000 ms-1.)

These two postulates have big impacts on time; something which was, until Einstein came along, believed to be constant.

Affects of Special Relativity on Time

This section looks at the following:

1. Time dilation, What is it?

2. If time dilates what is the real time?

3. So time changes, why should I care?

If the questions in the list intrigue you click here to find out more.

Time Dilation Derivation: Interactive Tutorial

Do you think you have what it takes to make a world changing discovery?

Can you use do basic algebra, use Pythagorus' theorem and know your basic speed, distance, time triangle?

If the answer to the above is yes click here to test yourself and try and prove that time really does slow down?

Time Dilation Derivation: Complete Solution

Examples and uses of Time Dilation

Have you ever wanted to:

1. Win the Lottery?

2. See the technological advances of the future?

3. Witness our first contact with extra-terrestrials?