far far away's latest activity

That’s what I thought at first. But the issue is that the wave equation we usually deal with is the linear wave equation. In reality...

What do you mean? we can simply set $$u(x, t) = δ(x-ct)$$ This represents a delta pulse moving to the right at speed c. Isn’t this...

Thanks. Indeed, the size doesn’t matter. However, if that is taken as the definition, then in my view it’s not a simple or elegant one...

Yes, it's from Wikipedia https://en.wikipedia.org/wiki/Wave And it does use the word equilibrium.

I made that definition up myself, and I apologize — that was my mistake. Logically, I shouldn’t have done that. What I was really trying...

I definitely agree with you that "a theory is an attempt to describe the way Nature behaves". However, the statement “the words you use...

Thank you, but the resource you shared reads more like an extended introduction or overview of the concept of equilibrium rather than a...

I beg your pardon, I think your reasoning is flawed. What I quoted is very simple: Notice that there is no strict, universal definition...

The equilibrium situation is something we can define ourselves. It's the baseline or "rest state" against which disturbances are...

If you define a mass density field M(x,t) with equilibrium M=0, then the particle corresponds to a localized disturbance (M=1 at its...

But this also means a particle can be viewed as a wave if we take the statement from Wikipedia as the definition of waves.

OMG, thanks, that makes sense now. It means we have no rigorous definition here.

Okay, so now the problem becomes that a particle itself doesn’t necessarily have to propagate, right? Then what if I narrow the...

I understand that physics is grounded in empiricism, and I’m not denying that. But a physical theory, in addition to being based on...

You're trying to say that a wave must be periodic/oscillating? I don't think so.