Comment on A note on the description complexity of physical theories

Wed, 10 Nov 2010 21:41:39 GMT

No.

What I am saying is to compute the answer using quantum mechanics.

The way to do it correctly, Copenhagen style, is to say "okay, the electron goes through the plate with two holes in it. But since, from the perspective of the electron, it can't go through two holes, the state of the electron on the other side should be entangled something like |10> + |01>. If we fast-forward to the screen, we get an interference pattern"

The way to do it correctly, MW style, is to say "okay, the electron has equal probability of going through each hole, so let's split into two worlds with equal phase. The detector will then observe the superposition of the two worlds, something like |10> + |01>, except fast-forwarded to the screen, so there should be an interference pattern."

If these two approaches look similar, there's a reason. And it's not that one is cribbing off the other! As you can see, introducing entanglement in the Copenhagen interpretation was definitely not arbitrary, but it is conceptually trickier than thinking through the same process using the MWI.

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