Can Multiple Universes Coexist and Interfere with Each Other?

[michael879]

I just had this thought about multiple universes. Basically any time something in a universe changes, it splits (or maybe not, doesn't really matter for this). If some random event occurs (truly random, like a double slit experiment) multiple universes are formed, 1 for each outcome. The more alike two universes are the closer they are and the closer they are the more they interfere with each other. So for example if you have an electron in an atom in a superposition between two states. Since there hasnt been any decoherence, the universes are exactly alike except for this electron's energy state. The second you make a measurement, the two universes are suddenly no longer differing in just the energy state of the electron, but in the measurement also and they become farther apart.

This is one of the current theories right? here's my thought:
there should still be small amounts of interference between the universes. Has anyone tried a double slit experiment with decoherence and tried to pick up interference patterns? wouldn't that prove or disprove this theory? if you make the "measurement" small enough maybe?

maybe the double slit is a bad example. If you make a quantum computer using non-reversible gates there is heat emitted from the gates causing decoherence of the qubits. The universes would still be almost identical in that case...

 

[kvantti]

This is one of the current theories right? here's my thought:
there should still be small amounts of interference between the universes. Has anyone tried a double slit experiment with decoherence and tried to pick up interference patterns? wouldn't that prove or disprove this theory? if you make the "measurement" small enough maybe?

What you suggest is paradoxical, because decoherence is the process of losing quantum interference. So you can't have decoherence with interference...

 

[setAI]

What you suggest is paradoxical, because decoherence is the process of losing quantum interference. So you can't have decoherence with interference...

that is the practical case- but we should be rigorous here- technically you should not say that there is no interference between decohered systems- rather that at this time it is too expensive to detect the interference between decohered systems-

 

[michael879]

so wait, did I get the multiple universe theory right? I filled in a bunch of holes in my knowledge while writing that. we call any loss decoherence.. if there was a fractional loss in which a very small amount of quantum information remained it would still be called decoherence wouldn't it? anyway, have there been any experiments to test whether decoherence is always complete?