Nickyv2423 said:How does MWI deal with the destruction of interference in the double slit experiment when a detector is placed at the slits?
Nickyv2423 said:how does the interference go away?
Nickyv2423 said:Does the measuring device at the slits reshape the wave function in a way that makes it impossible to interfere with itself?
But in MWI, the universe doesn't actually branch/split off into new universes, that's a misconception. The universe already exists in a superposition, where all possible universes already exist.PeterDonis said:In the MWI, the wave function branches when the particle traversing the experiment reaches the detector. In one branch, the detector fires, and in the other, it doesn't. The state of the particle, the detector, and everything else in the universe in each branch is the appropriate one for the detector result (fire/not fire) for that branch.
It goes away in each branch because the state of everything in each branch has to be consistent with the detector result for that branch.
In the MWI, the particle by itself doesn't have a wave function. Only the entire system does. The presence of the detector at the slits changes the way the wave function of the entire system evolves, yes, because it changes the interactions that are present.
Nickyv2423 said:in MWI, the universe doesn't actually branch/split off into new universes, that's a misconception
Nickyv2423 said:The universe already exists in a superposition, where all possible universes already exist.
Oh, I think I miss understood you then. Are you saying that when a measurement is made the universe splits and creates new universes?PeterDonis said:If that terminology bothers you, just say the wave function of the overall system branches. The physics is the same either way.
If you're going to use this terminology, the set of "all possible universes" changes with time: it is different after the particle has passed the detectors at the slits because it now includes branches for the different possible measurement results at the detectors. So you could say the set of "all possible universes" is what branches. You're still just describing the same physics in different words.
Nickyv2423 said:Are you saying that when a measurement is made the universe splits and creates new universes?
MWI stands for Many-Worlds Interpretation, which is a theory in quantum mechanics that suggests that every possible outcome of a quantum event occurs in a separate parallel universe. According to MWI, interference is not destroyed but rather branches off into different universes.
In the double-slit experiment, a particle can behave as both a wave and a particle. In MWI, the particle exists in a superposition of all possible states and when it interacts with the environment, it creates multiple copies of itself in parallel universes. This explains the disappearance of interference patterns as each copy takes a different path.
Yes, MWI offers a solution to the measurement problem by suggesting that the observer and the observed are part of the same quantum system and that the measurement process creates multiple versions of the observer in different universes.
Unlike other interpretations that view the collapse of the wave function as a physical process, MWI sees it as a subjective experience of observers branching off into different universes. MWI also suggests that interference is not destroyed but rather exists in parallel universes.
While there is no direct evidence for MWI, it is a mathematically consistent interpretation of quantum mechanics and has not been disproven. The concept of parallel universes has also been explored in other areas of physics, such as string theory. However, further research and experimentation are needed to fully understand and validate MWI.