“Look in that mirror…I see a strong confident, beautiful young lady…Oh look you’re here too!” Well Mother Gothel from Disney’s “Tangled” will never be accused of being tactful, but her observation has some merit in the strange world of quantum mechanics or QM. QM is the orphan of Albert Einstein’s Special Theory of Relativity that deals with gravity of stars and planets and the speed of light. QM deals with the infinitesimal sizes of atoms and electrons. Since both are described by mathematics, you would think that they should somehow be equal, but the dirty secret of physics is the math used to describe these two phenomena can’t agree, and that’s just annoying!
The years before the Great War and a few years after, the parts of the atom were discovered; protons, neutrons and electrons were found to make up the structure of the atom. One thing found was that electrons pair up in the shells around the atom, two electrons per orbital. Think of them as two friends sharing a single bed. To get the most room, they sleep head to feet of the other. They are in exactly opposite positions and electrons pair up similarly, one spinning in a positive direction and the other negative. This is the only way to get two negatively charged particles to stay in the same “room”.
Now, in physics, and the math it uses, we are used to really good explanations, and we are dissatisfied with the often correct answer of “I don’t know”. Such an answer would be rightly rejected by an airplane engineer; every force that affects flight is known; but not so in atomic physics. In fact Werner Heisenberg told us we CAN’T know some things. We can only know the probability of something. For example, in our two friends sharing a room, we can only know they are in there, but not whose head is pointing north, only that one is and the other is pointing south. If we open the door, both get up and we lose the information of whose head is where. This caused Einstein to exclaim “God doesn’t play dice!” meaning that the Universe should have a correct answer, not just a probability, a term Einstein hated.
Einstein correctly showed that the speed of light was constant no matter what, but that time was not; it depended on the point of view of the person timing, and this is where stuff gets all tangled up, or as the movie says “Skip the drama, stay with Mama”. That is shown to be impossible, unless you have nine lives.
Entanglement is where two particles, and sometimes three, are associated with one another in such a way that they affect each other even if they are light years apart. Suppose I bought a pair of gloves from a hardware store. I lock one in a case and give it to you, and the other is locked in a case and I keep it. Now I put you on a rocket ship and have you fly to the Andromeda galaxy, 200 light years away. For argument sake we are in Gene Roddenberry’s Star Trek universe so it takes one commercial break for you to get there. We both have similar clocks and at an appointed moment in time, we open our cases. Up until we open our cases, we only have a probability of which glove we have; either right or left and the probability is fifty-fifty.
In fact for that kind of odds I’d place a pretty good bet as to which glove I have. But nothing is known until we open the cases. As soon as I open the case, I know which glove you have, even though you are 200 light years away. This appears to violate Einstein’s proof that nothing can go faster than the speed of light, but it appears that we just violated that. Except we didn’t.
You see, we didn’t really exchange any information, we just destroyed the probability of what that information was; the probability is 100% which glove the other has, which is no probability at all. Erwin Schrödinger came up with a famous thought experiment of a cat in a box with an atomic decay timer controlling some cyanide gas. As long as the box is closed, we only have a probability as to if the cat is alive or dead. We don’t know until we destroy the probability and we either bury the kitty, or (hopefully) we take the cat home and tell it to stay away from physicists!
This entanglement has been observed in electrons, atoms and molecules, and we are looking for it in organisms as well. This led to Einstein’s second most known quote; “I guess God plays dice after all”.