In the late 1800s Marie Curie and others began to study radioactive materials. These are materials that emit high energy rays. At the time it wasn’t clear what these were, but there were initially three known types, called alpha, beta and gamma. Just how these materials could emit such high energy rays was a mystery, but after careful study it became clear that the atoms in the material would emit these rays when they transmute (or decay) into another kind of atom. For example, Uranium-238 will undergo alpha decay to become Thorium-234.
The Way the Universe Changed
At the end of the 1800s we finally knew how the universe worked. Newton’s laws of motion and gravity had been studied for 200 years, and had become the pinnacle of scientific precision. James Clerk Maxwell had unified the electricity, magnetism and light into a single elegant theory, and Darwin’s theory of evolution explained how living things were connected. There were still mysteries to be explored, but it seemed the grand structure of the universe was now known. We lived in a clockwork universe, where cause led to effect, where simple laws governed complex mechanisms. It was a proven world, as I’ve written about in an earlier series of posts.
Little Neutral One
Radioactive decay is where the atom of an unstable element can decay into another type of element, releasing energy in the process. One process by which this can occur is known as beta decay. When beta decay occurs an element such as caesium decays to barium. This process releases an electron, first known as a beta particle, hence the term beta decay.
Monopole Mystery
Many types of particles, such as protons and electrons, have electric charge. Electrons and protons are electric monopoles, though we don’t usually refer to them that way. This means they have a single charge, with protons being a positive monopole, and electrons being a negative one. In our everyday experience, electrons and protons (and neutrons) tend to be bound together into atoms. From at human-scale distances the positive and negative charges average out, so we don’t really notice them, but it is fairly easy to separate some of the positive and negative charges. If you’ve ever gotten a static shock, it’s because you’ve separated a few too many positive and negative charges, and the shock is them coming together again.
Inertia
In Marvel’s X-Men series, there is a character known as Juggernaut. His power is that once he is in motion, nothing can stop him. In physics terms, this means his inertia can’t be changed by some external force. That’s not how physics works, though that’s a minor detail in a universe that has a talking raccoon. But Juggernaut’s use of his skill is just one demonstration of a common misconception about inertia.
Isaac Newton, Jedi Knight
When last I mentioned Newton, I noted that Sir Isaac’s genius wasn’t simply due to his laws of motion and gravity, which weren’t all that original, but rather his application and interpretation of those rules.
Newton’s Apple
You probably know the story of Isaac Newton. He was sitting under an apple tree when he saw an apple fall to the ground. This inspired his idea of universal gravity. There’s long been some debate as to the truth behind this tale. The story comes most famously from “Memoirs of Sir Isaac Newton’s Life” by William Stukeley in 1752. Earlier mentions appear in works of Voltaire and Robert Greene. Whether true or not, it is a story we love to tell. It portrays Newton as a genius with a revolutionary insight.
Kepler’s Hypothesis
One of the common misconceptions presented in science is that it occurs in revolutionary steps. For example, the idea that Copernicus developed the heliocentric (sun-centered) model of the solar system, then Kepler showed that planets moved in ellipses and introduced Kepler’s laws, then Newton introduced the law of gravity that proved Kepler’s laws to be true. Each revolutionary idea replacing the previous one. But the real history is not quite so clean. Take for instance the development of Kepler’s laws.
Chain Reaction
It is often said that we are made of star stuff. Except for hydrogen, the atoms in our bodies were fused in supernovae, and in the cores of stars. What’s not often talked about is just how complex fusion is, and how difficult it is to do, even in the core of a star. Take, for example, the seemingly simple fusion of hydrogen into helium, which is the primary energy source of our Sun.