Q&A: Quanta
Quanta
Question
Hello Michael. I’m not a physicist, so I don’t really understand the subject very well, so I’d appreciate it if you could correct me where I’m mistaken in the question.
So, from what I understood, superposition means that light is not a particle but a wave. I didn’t understand why people say it is in a superposition, meaning in two places at the same time, because then it is no longer a particle but a wave. What I mean is that the wave is found at several points because it is not a point; it is not here and there, because it does not have a defined point location, but rather a region in which it is found. So why do we say that it is in a superposition (that is, both here and there)?
Thank you very much.
Answer
There is no such thing as “the particle itself.” There is a wave function that represents it. That function can be a superposition of position states, and that is what is called a wave state. In such a state, when a position measurement is made, you can get several different results (the particle is located here or here or here. After the measurement it is a particle), and the wave is a combination of all those results with different weights. That is exactly the state of superposition.