Notes for Sep 26

Hi everyone,

Next week we will be focusing on physics insights from two extremely famous physicists from history: Isaac Newton and Albert Einstein. Here are my notes.

Newton is famous because he figured out new laws of motion and gravitation that revolutionized our understanding of terrestrial and celestial motion. His insights systematized a huge heap of astronomical data, and are still technologically powerful enough to land men on the Moon! In particular, his theory of Universal Gravitation explained the motions of planets in our solar system, which had puzzled people for millennia. Along the way, Newton (co-)invented calculus. He was an intellectual giant in his day, and is still a physics rock star over 350 years later.

Einstein is famous because he also changed the way we think about the universe. In his case it was because he developed Relativity, a bit over a century ago. This week we will talk about Special Relativity, which is all about how the motion of objects differs in different frames of reference, and how to translate observations from one reference frame to another. Einstein’s central insight was that the speed of light is the same in all frames of reference. From this, he was led to the discovery that time is not absolute: it is RELATIVE. This startling conclusion will take some time to digest, and will be illustrated by two examples: (1) Rollerblader Relativity and (2) the Twin Paradox. What we will find out is that one observer might measure different times and lengths than another, but they are both right. It all hangs together mathematically because of the constancy of the speed of light.

Keep in touch as you start researching your LHC/Higgs essay. I think it should be straightforward, but if it isn’t, I’m here to help.

Cheers,
Prof. P.