On 14 Jun 2017, at 19:11, John Clark wrote:
On Wed, Jun 14, 2017 at 5:01 AM, Bruno Marchal <[email protected]>
wrote:
>> Even the 2-slit experiment will not produce interference if
you remove the photographic plate and just allow the photons to
continue into infinite space after they pass the slits because then
the world splits but the two never recombine again so no interference.
> This is a bit weird. I would say that the interference are
still there, but that we can't see them.
I don't see why you would say that. We know for a fact from
experiment that you CAN place a detector next to one slit so you CAN
know which slit the photon went through, but if you do that then the
interference pattern disappears. How does the MWI explain that? It
says that when the photon approaches the 2 slits the universe
splits, but in one universe a record is made (in a computer or a
paper notebook or a human memory) that the photon went through the
left slot and in the other a record is made that the photon went
through the right slot. When the photon hits the photographic plate
it's destroyed but the 2 universes are still NOT identical because
they have different records, so they never merge back together,
there is nothing to interfere with, so nobody in either universe
sees a interference pattern.
It would work the same way if no record of which slots the photon
went through was made but you removed the photographic plate (or
brick wall) and so didn't destroy it and allowed the photon to
continue on for eternity after they pass the slits. The photons will
be on slightly different tracks for infinity and so the two
universes will never merge together into one and so there is no
interference between the two.
> Without the photographic plate, we can still introduce a
needle at a position where no photon will ever go,
Not after the photon passes the slits you can't, you could never
move your needle fast enough to get in front of it. And according
to Quantum Mechanics there is no place you can say with certainty
the photon will never go, but it can tell you that it is more likely
to go some places than others. You could make a calculation
beforehand and find a good point to place the needle and bet the
photon will not hit it, in most universes you will win your bet but
in some you will not. And one needle is not enough, to prove if
interference did or did not occur, you'd need lots of photons and
lots of needles, although a photographic plate would be much easier
to use.
OK. But so we agree.
> Interferences occur independently of our decision to observe
them.
Yes, observation has nothing to do with it if the MWI is
correct, however interference requires at least 2 things, and if
nothing interferes with the universe no interference pattern will be
produced; the 2 universes need to merge back together but that will
never happen if they remain different (because a record of which
slot the photon went through is different or because the path the
photon is taking on its infinite voyage is different).
OK.
Bruno
John K Clark
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
