How an electron “interferes with itself” ?


I’m having difficulty picturing how this happens. Can someone please explain?

In: 3

The ELI5 answer is: don’t imagine. Quantum physics is not something you can just visualize and expect the world to exactly look like that picture you have. That doesn’t mean visualization is not useful, but you must be mindful that visualization is just a calculation tool and is not supposed to represent what exactly happened.

One way to visualize the situation is to imagine that the electron split into multiple copies of itself when it has multiple paths, and then it merge back into itself again.

Another way of visualization is to think of electron as wave ripples in space (*one* electron being the entire ripple). Ripples can get split into multiple paths and interfere with themselves later.

You mean how an electron will repel from another electron?

You’re only considering the particle side of this, and not the wave. That’s the bit – electrons are part-particle, part-wave in their behavior. It’s not that the electron as a particle interferes with itself. It’s that the particle-wave duality of the electron means that it behaves in ways which might *seem* like a particle interfering with itself.

If you stare into the wave equations which people use to model such behavior, you’ll probably find that they don’t exactly lend themselves to direct interpretation for particle mechanics, like Newtonian physics might. That should be another indication to you that picturing an electron as if it *is* a particle which interferes with itself is a bad idea. Because it isn’t one. It just behaves like one would *if* it did. Which it can’t/doesn’t.

When an electron starts entering adulthood, its hormones are in chaos: it starts growing hair in its negative charge, its spin speed deepens and so on. At this age, it’s not uncommon for the electron to take suspiciously long showers where it… Well… Interferes with itself.

It’s a perfectly normal thing and it should not be stigmatized.

If you’re picturing an electron as a little negatively charged ball that floats around space, then your picture is not accurate. An electron is not a particle. It’s also not a wave. Although it does have properties of both a particle and a wave. The best analogy I have heard was if you imagine a cylinder in a box, and you can try to roll the cylinder, but you can’t open up and look inside the box. When you roll it along the x-axis, it rolls like a ball. When you roll it along the y-axis, it rolls like a cube. So you say “sometimes it’s a ball, and sometimes it’s a cube.” When in actuality, it’s neither, but it has properties of both.