General Relativity Explained simply and visually
General Relativity Explained simply and visually
3D gravity animation courtesy of: https://1ucasvb.tumblr.com/ When Albert Einstein first published the Special Theory of relativity in 1905, he was ridiculed. People thought it was just too weird and radical to be real. Einstein wasn’t satisfied with his theory either, because the theory did not apply if Gravity was present or if the observer was accelerating. One day, while observing a window washer on a ladder near his patent office, he had a thought experiments.
He imagined what would happen if the worker were to fall. He put himself in the window washer’s perspective, and imagined what he would experience as he was falling. He realized that if he was falling, gravity would be the only force acting on him. He would be accelerating towards the ground, but since the ground would not be pushing up on his body, he would feel no weight. And this would be no different than being weightless in space.
In a way gravity and acceleration were different ways to describe the same thing. The way to connect gravity in the theory of relativity was through the idea of acceleration, and this became the basis of general relativity.
Einstein imagined being in a room with no windows, and a bathroom scale. It would weigh 80 Kgs, What if the room was on a space ship accelerating in an upward direction at 9.8 m/s/s. He would feel the same weight. There would be no difference
He imagined what would happen if he took a flashlight and pointed it from one side of the room to the other, as the space ship was accelerating upwards. If he had a ruler, he could measure the height of the light on the other side of the room. He realized that the height measured on the wall would be lower than the source of the light, because the floor of the room would be rushing upwards at ever faster speeds, as the light was propagating across the room. The light beam would appear to curve downward.