How can I calculate the general theory of relativity

Einstein's theory of relativity in 4 easy steps

Albert Einstein's Theory of Relativity is known for having predicted some really bizarre, but actual, phenomena. This includes the fact that astronauts age more slowly in space than humans on earth and that solid objects change their shape at high speed.

But if you look at Einstein's original publication from 1905, it is a very straightforward read. The text is simple and clear, its equations almost entirely algebra - nothing that would cause problems for a normal high school student.

That's because Einstein was never interested in fancy math and formulas. He liked to think visually, do thought experiments, and play around with ideas in his head until he could see the concepts and physical principles crystal clear in his mind's eye. (10 Things You (Probably) Did Not Know About Einstein)

The following outline shows how Einstein began his thought experiments at the age of 16, which eventually led him to the most revolutionary equation in modern physics.

1895: The run next to the beam of light

Einstein could hardly disguise his contempt for the strict, authoritarian educational methods of his home country Germany. In 1895 he was expelled from school for this reason and moved to Zurich. There, he hoped, he would attend the Federal Polytechnic School (now the ETH Zurich).

First, however, he wanted to spend a year preparing for a school in nearby Aarau. The facility emphasized methods such as independent thinking and the visualization of concepts, which was considered avant-garde at the time. In these carefree surroundings, he soon began to wonder what it would be like to walk next to a beam of light.

Einstein had already learned what a ray of light was in his physics class: oscillating electric and magnetic fields that spread at almost 300 million meters per second - that is, at the speed of light. If he were to run alongside at the same speed, Einstein thought, he should be able to look next to him and see the swaying fields hanging there seemingly stationary in space.

However, it was impossible. Such stationary fields would disregard Maxwell's equations. Everything that physicists knew about electricity, magnetism and light was laid down in these mathematical laws at that time.