Sunday Science: Special Relativity

Last week, we dealt with General Relativity (which is all about gravity). This week, we're looking at another theory from Einstein: Special Relativity (which does not include gravity).

This clip from Channel 4's wonderful comedy Father Ted actually explains the basics of Special Relativity quite nicely:

It's all about frames of reference. In the clip, Father Ted explains to Dougal that the toy cows in his hands are "small, but the ones out there are far away".

Special Relativity takes things one step further to include motion. It states that everything is moving relative to everything else.

Confused? Time to break out the Lego figures to help us explain.

Here's Ironman whizzing past Batman at a constant velocity of 750mph.

Ironman has no way to prove he's moving. It could be that Batman (and the Earth and everything on it) is moving backwards at 750 mph.

And under Special Relativity BOTH frames of reference are correct. It could be Ironman, it could be Batman moving at 750mph.

BUT this rule only applies under certain SPECIAL circumstances (hence, the name Special Relativity).

Ironman must be travelling at a constant velocity. In other words, he has to be travelling at the same speed and in a straight line.

If Ironman accelerates or changes direction, then Special Relativity no longer applies. But General Relativity does.

Special Relativity has many consequences for Ironman, Batman and our entire understanding of the universe:

1. Time changes,
2. Moving objects appear shorter to one another,
3. The world's most famous equation E=mc2 results.

We'll delve more into those three big scientific concepts soon. 

Suggested Further Reading and Watching

• Einstein's Special Relativity
• Theory of Relativity Explained in Seven Minutes

What is Sunday Science?

Hello. I'm the freelance writer who gets tech. I have two degrees in Physics and, during my studies, I became increasingly frustrated with the complicated language used to describe some outstanding scientific principles. Language should aid our understanding - in science, it often feels like a barrier.

So, I want to simplify these science sayings and this blog series "Sunday Science" gives a quick, no-nonsense definition of the complex-sounding scientific terms you often hear, but may not completely understand. 

If there's a scientific term or topic you'd like me to tackle in my next post, fire an email to  [email protected] or leave a comment below. If you want to sign up to our weekly newsletter, pop your email in the form below - thanks!