I am currently undergoing a course on introduction to quantum mechanics and we took the historical approach. I'm currently at DeBroglie wavelength. He introduces the wave particle duality in matter, from which will arise the wavefunction of a particle for example. And we have seen that this wave can take a lot of forms and shares most properties of other waves that we have seen (e.g. water waves, electromagnetic waves, and so on), but I can't seem to grasp two things:
- We know that physical waves (water waves or sound) need a physical mean of propagation in order to transfer its energy, but electromagnetic radiation doesn't. It can propagate in vacuum! However, this idea that waves propagate in nothingness does not fit in my mindset, it just can't be! Although, one could argue that, for electric charges, the waves travel due to perturbations in their own field, since it extends itself to infinity and so any changes in the field would be noticeable (for photons I'll guess its a bit different, but that's another question). And so, it kind of has some "mean" to propagate, but I can't see where or "on what" do the wave functions live or travel! Do they simply "exist"? That can't be. What created them? and this leads me to the next question;
- What is the wavefunction driving force? we can easily create sound, and electromagnetic waves by applying some driving force to their system. But for a particle we assume that it merely has a wave associated to it. But how did it even get there in the first place? Does this wave exist from the beginning of time? We could say and argue intensely "It's a property of the particle!!! and when we "mess" with the particle we change the wave function so this wavefunction is always changing, but where does it come from??
I know that it will always be impossible to answer all the why's but if we have a theory that fits beautifully to our experimental data it's worthwhile to answer as many fundamental questions as possible