This tool lets you view Minkowski spacetime diagrams. This will help you learn about special relativity.

The easiest way to learn how to use the tool is to listen to the Introduction. Or you can just read the text of the introduction.

I have recorded several sample drawings as lessons.

• The lesson on constant speed (or just view the text) shows some consequences of assuming the speed of light is constant.
• The lesson on time dilation (or just view the text) shows clocks in different reference frames advance at different rates.
• The lesson on length contraction (or just view the text) shows how the length of a moving object is shorter than a stationary one. It also answers the question can I shrink a long train enough to fit it into a short barn.
• The lesson on twin paradox (or just view the text) presents the twin paradox. What happens when two twins move away from each other and each one sees the other's clock slowing down?
• The lesson on FTL = time travel (or just view the text) shows that being able to send an instantaneous message would also allow you to send a message back in time.

Also, there is a page with some formulae and recommended further reading.

You may download this entire web page here: spacetime.tgz.