I said that wrong.
The universe has exactly one amplitude. It does not have all the amplitudes of the constituent particles. It does not move in all the ways the constituent particles do.
I figured out why it looks like different particles have different frequencies, even if the universe only has one. I don't think I could explain it well though.
Our universe is not an energy eigenstate
How do you know? Each individual particle is not in an energy eigenstate, but that doesn't mean that the system isn't. If you add the waveform of a system where particle a has energy 1 and particle b has energy 2 to a system where particle a has energy 2 and particle b has energy 1, you end up with a system with an energy eigenstate of 3, but each particle is not in an energy eigenstate.
You could, in theory, check whether or not the universe you're in is where you'd expect a node to be, but if I understand this right, the nodes are all within tiny fractions of a Planck length of each other. You'd have to know the position of every particle in the universe with a root mean square error smaller than that.
How do you know?
The short answer is that energy eigenstates don't change over time, while the universe does.
If you add the waveform of a system where particle a has energy 1 and particle b has energy 2 to a system where particle a has energy 2 and particle b has energy 1, you end up with a system with an energy eigenstate of 3, but each particle is not in an energy eigenstate.
This is a good point. What I said didn't mean what I thought it meant. But this system seems like an example of the power of entanglement. If the particles were unentangled, ...
Timeless physics is what you end up with if you take MWI, assume the universe is a standing wave, and remove the extraneous variables. From what I understand, for the most part you can take a standing wave and add a time-reversed version, you end up with a standing wave that only uses real numbers. The problem with this is that the universe isn't quite time symmetric.
If I ignore that complex numbers ever were used in quantum physics, it seems unlikely that complex numbers is the correct solution. Is there another one? Should I be reversing charge and parity as well as time when I make the standing real-only wave?