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# Special Relativity Basics

The theory of Special Relativity, first proposed over a century ago and made popular by scientists such as Einstein, Poincaré and Lorentz, ushered a new paradigm in science and changed the way we viewed the properties of our universe.

This theory holds as its foremost principal that the speed of light is a constant at all points of observation. In other words if I were to stand at some distance and point a flashlight at you and you were able to measure the speed of its light, that speed would have a constant value, regardless of whether I was standing still, moving towards or away from you.

This runs contrary to conventional wisdom which holds that velocities are additive and the observer should see the light move faster or slower depending on what direction its source is moving. Special Relativity (SR) counters this by suggesting that the observer has a different ‘time frame’ relative to the source and this would cause him to view the light always at the same speed.

For example, suppose that as I pointed the flashlight at you, you were moving away from me at half the speed of light. In order for you to observe that light at the same speed, your sense of time must be half that of mine, i.e. your wrist watch would be moving only half as fast as mine. So, although the light is only hitting you at half-speed, your slower sensation of time makes it appear to be happening at normal speed.

SR says that each of us is somehow in a different time frame depending on how quickly we move relative to each other. The differences are very slight and only become noticeable when we move at near light speeds. In order for this theory to hold true SR also has the following requirements:

• that no material object can reach or exceed the speed of light

• that the mass of an object increases towards infinity as it nears light speed

• that the length of an object decreases towards zero as it nears light speed

In the following chapters I will discuss several aspects of SR, on why the assumptions behind them may be wrong, and how the experimental observations that seem to vindicate SR could be explained through other means.

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