1. Abandon for a moment the idea that we are special
2. Imagine what the most simplified agent that "experiences" things would look like. For example a simple machine that observed am experiment and reduces it into a simple "do I see interference bands or do I see only one band?" and records it to some simple memory.
3. Let the wave in superposition interact with the machine and compute what happens to the machine now that it is itself entangled with the wave
4. Very hard math
5. The machine is in a superposition state of various state, each observing the wave collapse
Let the wave in superposition interact with the machine
This is the key point right, that an observation cannot be made without a very real, physical, interaction, that necessarily influences the thing being observed?
Well yes that's technically true but that's not the kind of effect I meant.
After the interaction your become part of the same quantum system and that affects what you can observe next.
When you become a system where the state is a superposition of "electron spin up + you see an electron spin up" and "electron spin down + you see an electron spin down" then you when you observe the electron in spin down you'll always see the electron as spin down because, you guessed it, the "you" in this story is the "you see an electron spin down" you of the superposition of yous
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The easiest way to wrap your head around is to:
1. Abandon for a moment the idea that we are special
2. Imagine what the most simplified agent that "experiences" things would look like. For example a simple machine that observed am experiment and reduces it into a simple "do I see interference bands or do I see only one band?" and records it to some simple memory.
3. Let the wave in superposition interact with the machine and compute what happens to the machine now that it is itself entangled with the wave
4. Very hard math
5. The machine is in a superposition state of various state, each observing the wave collapse
This is the key point right, that an observation cannot be made without a very real, physical, interaction, that necessarily influences the thing being observed?
No, it's even more bind bending: the observation influences the observer!
An eye that isn't influenced by what it sees is usually called “blind”.
Well yes that's technically true but that's not the kind of effect I meant.
After the interaction your become part of the same quantum system and that affects what you can observe next.
When you become a system where the state is a superposition of "electron spin up + you see an electron spin up" and "electron spin down + you see an electron spin down" then you when you observe the electron in spin down you'll always see the electron as spin down because, you guessed it, the "you" in this story is the "you see an electron spin down" you of the superposition of yous