Electrons. Tiny, little, smaller-than-microscopic things that people tend to forget exist when going about their day to day lives. You learnt about them in science class. They have something to do with electricity. And they’re EVERYWHERE.
You probably are quite familiar with these concepts. But have you ever considered… just how creepy they are? The key to their creepiness lies in quantum theory. Quantum theory, by definition, is weird. As many famous physicists have said in varying different ways: “if you think you understand quantum mechanics, you really don’t”. Electrons as quantum particles act in weird ways. Weird and kinda creepy ways…
One of the first things you learn about if you do quantum physics is the double slit experiment. There are two tiny tiny slits in a wall, and something gets aimed at the two slits which then may or may not change the path of this ‘something’ which we then detect on the other side. Now, we can do this with an electron gun, shooting one electron at the two slits at a time. After doing this quite a few times (after all, repetition is a vital part of science!) what do we detect on the other side?
A wave interference pattern!
Yes. That’s right. If you thought an electron was as simple as a particle, you would be wrong. In this situation it acts like a wave! What’s weirder, is that only one electron is going through the two slits at a time. It’s almost like it somehow goes through both slits at the same time and interferes with ITSELF. Like, what the hell is an electron anymore? Do you know? Because I sure don’t.
Now we’re going to change the experiment a bit. We want to see exactly what’s going on at the slits, so we’re going to put a detector on one slit to tell us when an electron goes through it. Th at’ll settle things, right? We repeat the experiment exactly as before, using the electron gun to shoot one electron at a time towards the double slit. We look at the results and blink (a bit at them) in surprise. Th is time there is no interference, nothing more than a completely ordinary pattern as would be created by a particle. So that begs the question: Why does adding a detector completely change the results of the exact same experiment? How does the electron ‘know’ that there is a difference between the two? How can it be a wave in one experiment, and a particle in the other? What actually is an electron?
Time for round 2. There’s this thing in physics called Heisenberg’s uncertainty principle. One aspect of this principle is that it is impossible to predict where a quantum particle will be at any point in time. It’s possible to predict where it’s most likely to be, but not where it definitely will be. Th is means we have no idea where electrons are most of the time. Can we set up a detector saying when they’re at a certain point? Sure. But when that electron leaves that point we have no idea where in the universe it is. Theoretically, it could be at the other side of the universe. (Th at’s very unlikely, but the fact that the possibility exists is pretty cool and/or creepy, depending on your opinion.)
This is how Schrodinger’s cat thought experiment was thought of. The idea is that an electron is in a contained area. If the electron is in one half of this area at a certain time, a poison is released into a box with a cat in it. If the electron is in the other half, no poison is released and the cat will be fine. Th ere’s a 50/50 chance that the poison has been released, and we have no way of knowing if it has or not before opening the box with the cat in it. So the argument is, if we don’t open the box, the cat is in a superposition, being both dead and alive, and only opening the box will force the cat to be one way or another. Kinda weird, right?
Here’s another weird thing. Th e electron is being held back by an energy wall. It just doesn’t have the energy to jump over that wall. Th e poor electron 🙁
So what’s an electron to do?
Have you ever tried walking through a wall like the wizards do to get to Platform 9 3/4? Did it work out? Most likely your answer is ‘no’. (If your answer is ‘yes’ then please do write about it for Lot’s Wife. I want to read all about it.) It is an accepted fact. People just can’t walk through walls. Th at’s why the ability to do that would be ‘magical’. Now, electrons live in a different world than us. A world so tiny, the ‘magical’ becomes ‘normal’. What would you say if I told you that under the right circumstances electrons can barge right through that energy wall that was holding them back? Th at they can transmit information instantly from one electron to its partner which is faster than the speed of light? Th at people have successfully teleported electrons? Yes, that’s right, the quantum world is literally magical.
If you’re not creeped out by now, let me leave you with a final thought. Since there is a small probability that an electron could be anywhere in the universe, why can’t it be possible that every electron in the universe is actually the same electron, but everywhere at the same time?