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.
Twilight Sparkle
If you live in the United States, you will likely take in an evening of fireworks. While you are enjoying them safely, you’ll notice that fireworks come in a variety of colors. The different colors are due to various metallic salts that are used in the fireworks. For example, reds can be created with strontium or lithium salts, orange with calcium, green with barium, blue with copper, and so on. A wide variety of colors can be produced by mixing these compounds as well.
Extraordinary Claims
A paper has recently been published in the New Journal of Physics claiming that the speed of light is wrong. This has triggered the usual headlines in the popular press, but as the saying goes, “extraordinary claims require extraordinary evidence.” So let’s look at the evidence behind this paper.
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.