Einstein's General Relativity and Field Equations
In 1907, Albert Einstein had, what he regarded as the "happiest thought of his life". He imagined a man falling from the top of a house - that shocks you? 😂. Yeah, that was all that is needed for him, to instigate this remarkable insight about "gravity". Isaac Newton did work on gravity too but he only calculated the strength but does not know exactly how gravity works or pulls its force. So, Einstein thought that a man falling from the top of the house will feel weightless i.e. the man won't feel his own weight. That, tells Einstein that gravity have to with motion. He thought about this for 8 years and finally, he was able to come about the remarkable theory of General relativity, in 1915, which explains how gravity really works. With the help of some of his mathematician friends, he was able to describe this with some elegant equations. Thus, the Einstein Fields Equation. Okay, let's get technical a little bit ... General Relativity tells us that...