No matter how well you remember your physics classes, you most likely don't remember learning any stories in them. Theories and equations, yes, but not stories — yet each of those theories and equations has a story behind it, as does the entire scientific enterprise of physics they constitute. The video above from the BBC's Dara Ó Briain's Science Club provides an overview of the latter story in an animated four minutes, making it ideal for youngsters just starting to learn about physics. It will also do the job for those of us not-so-youngsters circling back to get a better grasp of physics, its discoveries and driving questions.
"The story of physics is, for the most part, a tale of ever-increasing confidence," says Ó Briain, a comedian as well as a television host and writer on various subjects. This version of the story begins with rolling balls and falling objects, observed with a new rigor by such 17th-century Italians as Galileo Galilei. Galileo's work became "the rock on which modern physics is founded," and those who first built upon that rock included Isaac Newton, who started by noticing how apples fall and ended up with a theory of gravity. Newton's work would later predict the existence of Neptune; James Clerk Maxwell, working in the 19th century, made discoveries about electromagnetism that would later give us radio and television.
For quite a while, physics seemed to go from strength to strength. But as the 20th century began, "the latest discoveries didn't build on the old ones. Things like x-rays and radioactivity were just plain weird, and in a bad way." But in 1905, onto the scene came a 26-year-old Albert Einstein, who "tore up the script by" claiming that "light is a kind of wave but also comes in packets, or particles." That same year he published an equation you'll certainly remember from your school days: E = mc2, which holds "that mass and energy are equivalent." Einstein proposed that, if "someone watches a spaceship flying very fast, what they would see is the ship's clocks running slower than their own watch — and the ship will actually shrink in size. But for the astronauts inside, all would be normal."
In other words, "time and space can change: they are relative depending on who's observing." Einstein called this "special relativity," and he also had a theory of "general relativity." That showed "how balls and apples weren't the only thing subject to gravity: light, time, and space were also affected. Gravity slows down time and it warps space." No matter how dimly we understand physics itself, we all know the major players in its story: Galileo and Newton made important early discoveries, but it was Einstein who "shattered traditional physics" and revealed just how much we still have to learn about physical reality. Still today, physicists labor to reconcile Einstein's discoveries with all other known facts of that reality. As frustrating as that task often proves, the kids who take an interest of their own in physics after watching the video will surely be heartened to know that the story of physics goes on.
Based in Seoul, Colin Marshall writes and broadcasts on cities, language, and culture. His projects include the book The Stateless City: a Walk through 21st-Century Los Angeles and the video series The City in Cinema. Follow him on Twitter at @colinmarshall or on Facebook.