Suppose you lose your baseball in the woods, and you and your friend decide to look for it. You know that either you will find it, or your friend will (or it will remain lost). Assuming the ball hasn’t been damaged, it won’t be the case that you and your friend each find half of the ball, or that you both find the ball in different locations. There is only one ball, and it has an exact location, even if you don’t know where it is. It can only be found once, and only by one of you.
Accepting a Compliment
If you shine ultraviolet light on a negatively charged metal such as zinc, it will begin to release electrons. This is known as the photoelectric effect, and it has some unusual properties. For example, if you change the frequency (color) of the light, then the energy of the released electrons will change. At higher frequencies the electrons have more energy, and at lower frequencies less energy. On the other hand, if you keep the frequency of light the same and vary the brightness, then the number of electrons released will vary. Brighter light causes more electrons to be released, while dimmer light releases less electrons.
Infinity and Beyond
Objects around us come in a variety of colors. The reason for this is that most objects will absorb certain wavelengths of light, while other wavelengths reflect off the object. So if you are wearing a red shirt for example, the colors such as green and blue are absorbed by the shirt, but red reflects off the shirt, so you only see red.
State of Decay
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.
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.
The 5th Dimension
From measurements of distant supernovae, we now know our universe is not only expanding, but that it is expanding at an ever increasing rate. This cosmic acceleration is driven by what we call dark energy. While we can see the effects of dark energy, and we know it makes up about 68% of our universe, we don’t really know what dark energy actually is. That means while the experimentalists scurry to get more data, the theorists work frantically to explain what’s going on.
Mirror Mirror
The idea of parallel worlds is widely used in science fiction. Most often this alternate world is either populated by our evil doppelgangers, or the alternate universe is just slightly different from ours, such as having zeppelins in a modern city. Then there is the “alternate history” fiction, where their world is identical except for a key moment in history. Lincoln survived, Harold Godwinson won the battle of Hastings, etc.
Making Waves
George Thomson had some big shoes to fill. His father J. J. Thomson had won the Nobel prize for the discovery of the subatomic particle now known as the electron, and George had become a physicist as well. Fortunately George Thomson did quite well for himself, and was also awarded a Nobel prize. In a way, George won his Nobel prize for proving his father wrong.