Time Dilation

Time Dilation has nothing to do with when you are at home for long periods with nothing to do.

It is a very complicated theory invented, or discovered, or worked out by Einstein. It is so complicated that few people understand it.

But you WILL.

Yes. I will explain it very simply and you'll be astounded by your new found knowledge. So astounded that you will probably sit down and be very pleased with yourself for a moment or two.

In fact you'll influence people and win friends when you explain it to them at parties and show off how clever you are.

First the technical bit.

Time Dilation is explained as: Time dilation is a difference in the elapsed time measured by two clocks, either due to them having a velocity relative to each other, or by there being a gravitational potential difference between their locations.

But forget all that for now. My lesson will make it simpler. 

Let us first consider how we see things. 

A clock for instance. Imagine a clock on a clock tower in a building like a church or town hall in town.

The light travels from the sun, (or from a lamp), at the speed of light, (let's ignore what the speed of light is for now).

Then the light hits the object, (the clock), and bounces back into your eyes and you see the clock. 

It's as simple as that. Light hits object. Bounces back into your eyes. You see the object. 

Which explains why you can't see the object in the dark and you hit your toe against something and you utter some expletive that we cannot mention here. Feel free to mention them in the comments box below.

OK, now that we've grasped the principle, let us imagine your are in the back seat of a car. You look from the window behind you and you see a clock in a clock tower behind the car. 

Concentrate now. Imagine that you are in a car with a back window, and not in a van or lorry with no back window.

Just help me get through this lesson, will you. Car ... you in back seat ... looking out of back window ... SIMPLE!

You look out of the back window and you see the clock. The light from the sun hits the clock, bounces into your eyes, and you see the clock; you even see the big hand move every minute.

Now imagine that the light is travelling from the sun at the speed of light. Also imagine that the car starts travelling fast forwards also at the speed of light. Can you imagine that? 

The car is travelling at gazillion miles per hour. 

The car's speed is the same as the speed of light.

The light is travelling from the sun to the clock at the speed of light. It is then travelling from the clock to your eyes also at the speed of light. 

But the car, with you in it, is also travelling at the speed of light. So the light bouncing back from the clock to your eyes will never catch up with you because you are travelling at the same speed of light.

So what happens ... ... ... ???

You will never be able to see the big hand on the clock move every minute. In fact you will not see the clock at all because the light bouncing from the clock never reaches you in time for you to see it.

It's as simple as that. Read the definition above again and it will make sense. 

Time dilation is a difference in the elapsed time measured by two clocks, either due to them having a velocity relative to each other, or by there being a gravitational potential difference between their locations.

The elapsed time between the two objects - sun and clock ... and clock and car - is the same. Or more if your car can drive faster than the speed of light. 

Now you can astound your friends at parties with this information.

I did. They listened carefully and all moved away and started talking about me. I think they were impressed by my knowledge.

What do you think?