Physics – Short animation, which was part of the Science Club series on BBC2 hosted by Dara O Briain,© BBC.
The story of physics is, for the most part, a tale of ever-increasing confidence. For 300 years, physics is all about observing and measuring, finding out how stuff works.
In the early 1600s, and Italian got the ball rolling by measuring and observing balls rolling. Galileo also turned to pendulums and dropped different-sized objects off the Leaning Tower of Pisa to see what would happen. And despite upsetting the Pope, his ideas apparently made Godfrey Croft. Galileo’s work became the rock on which modern physics is later free from angry Pope’s. Finally, Isaac Newton moved things on by abandoning balls and embracing apples.
Why he wondered, did they always fall downwards, not sideways, or up? By 1687, he had an answer. It was a force called gravity, which worked on balls and apples and planets, pulling them in nice, predictable orbits around the sun. Then, in the 1800s, James Clark Maxwell cast his eye over more mysteries. He showed how electricity and magnetism are related and can be combined as one force, electromagnetism. And the light had electric and magnetic parts and traveled in waves like water.
Physics was now on a roll, new discoveries built on earlier ones, and some even practical uses. Newton’s laws predicted the existence of natural Maxwell’s work give us radio and TV, and there’s nothing much more useful than that. Physicists seem to have mastered the universe. All that was left was to plug a few remaining holes. But by 1900, the holes were getting bigger.
The latest discoveries didn’t build on the old ones. Things like x-ray and radioactivity. Were just playing weird and in a bad way. All was not well in the world of physics. Top scientists, Lord Kelvin, saw dark clouds hanging over the subject. Then, in 1905, a Swiss patent clerk started a full-on storm, Einstein. 26-year-old Albert Einstein tore up the script.
First, he claimed the light is a kind of wave but also comes in packets or particles. Then, in the same year, he published his famous equation E equals MC squared, which says that mass and energy are equivalent. And if that wasn’t shocking enough, he released the mind-blowing results of a thought experiment.
So hold onto your head. It starts with the assumption that the speed of light in a vacuum is constant. Now imagine that someone watches a spaceship flying very fast. What they would see is a ship’s clock running slower than their watch. And the ship will actually shrink in size. Before the astronauts inside, all would be normal.
Eitan said the time and space could change. They are relative depending on; who’s observed. This is special relativity. Especially that might have been, but it wasn’t enough. Albert had only just started. Next, he showed how balls and apples weren’t the only things subject to gravity, light. Time and Space were also affected. Gravity slows downtime, and it warped space. The stronger it is, the more space is warped, and the more light is bent. Einstein calls this general relativity. His ideas shattered traditional physics. He’d open the door onto the weird world of the quantum, or cats can both be alive and dead. Or God plays dice and where everything is uncertain.
His famous equation leads to nuclear energy. With special relativity, the Large Hadron Collider will be pointless. General Relativity predicted those black holes and the Big Bang, an idea now endorsed federal church and cites Galileo would have been pleased. Well done, Albert