Veritasium - Season 2011 (2011)

This is the first Veritasium science video. It addresses one of the most fundamental concepts in science: the idea that all things are made of atoms, tiny particles that are in perpetual motion. They attract each other when a little distance apart and repel when squeezed together.

JJ Thomson proposed the first model of the atom with subatomic structure. He had performed a series of experiments and was credited with the discovery of the first sub-atomic particle, the electron. He therefore proposed a new model of the atom called the plum pudding model. In this model, the plums represent negatively charged electrons which can be plucked out of the atom, leaving behind some positively charged pudding. In this film, cherry tart is used as a delicious substitute for plum pudding.

In the mid 1800's scientists successfully passed an electric current through a vacuum in a glass tube. They saw a glow from the tube that seemed to emanate from the negatively charged plate called the cathode. Since scientists didn't know what the glow was they called it a cathode ray. There was debate over whether the cathode ray was a wave phenomenon like light or a stream of negatively charged particles. JJ Thomson effectively resolved the debate in 1897 by performing a clever experiment that determined the charge to mass ratio of the particles making up the cathode ray. He also showed that this same particle was in all different cathode materials so it must be a constituent common to all atoms. This changed our understanding of the atom from the previous billiard ball model to Thomson's plum pudding model of the atom.

Scientists have to work with some very large and some very small numbers. To represent these numbers more easily, they use scientific notation. Scientific notation relies on powers of 10. This video gives examples of how to represent a large and small number and explains powers of ten.

🎶Well an atom's made of protons, neutrons, and electrons... 🎶