1-2g2t6 The effect of interference on a history depends on what other histories are present (e.g., Mach-Zehnder interferometer)

1-2g2c1 Testability matters only when you have a good explanation (hard-to-vary explanation)
5-2 What counts cannot be counted
1-2g1b What matters is the explanation, and not what you can see
1-2g2s7d A history has to be explained in multiversal terms. The true explanation of what happened involves many other instances of me.

1-2g2s4 Everyday objects are partitioned into nearly autonomous histories with one instance-position-speed, but every atom in those objects is a multiversal object not partitioned (i.e., fungible)
 #develop

From ToKCast 23

• Think of photons not as particles but as field (or probability) going through
• Phase shift occurs across the multiverse, and a history of a photon must invoke the other histories of the other photons
  • When that portion of photons go through the first silver-mirror, the distance it travels differ from those that reflect. This results in phase shift. If you change the distance between mirrors, or the thickness of them, you get different phase shift, that is, you can deterministically change which way the photon comes out (either 100% to the right, or 100% to the top, or anything in between, e.g., 75% to the right and 25% to the top).
• Universes differentiate then merge around that photon