On 15-05-2022 05:11, Brent Meeker wrote:

On 5/14/2022 3:55 PM, Bruce Kellett wrote:On Sun, May 15, 2022 at 1:17 AM smitra <smi...@zonnet.nl> wrote:On 13-05-2022 21:59, Brent Meeker wrote:Right CI doesn't explain the collapse and MWI doesn't explainthecollapse either but assumes it can be explained without newphysics.I hypothesize (not assume) that CI+ <non-zero minimumprobability> canexplain the collapse. I don't see any big advantage for MWIhere. The big advantage is that decoherence is a well researched area of (mathematical) physics, results like the density matrix becoming approximately diagonal, and relations between decoherence to entropy increase making it effectively irreversible are all rigorous results that are uncontroversial.But it is more than "effectively" irreversible because decohering information spreads at the speed of light, and in an expanding universe cannot be captured and reversed. This why I think there is some relation between the holographic principle, expansion of the universe, Hawking-Bekenstien entropy, and a non-zero minimum probability.

`It's still only effectively irreversible because nothing stops one from`

`reflecting all the escaping photons back. If we use mirrors that are`

`cooled to almost absolute zero, then the leakage of information from the`

`interior that results from having carried out a spin measurement there`

`can be made arbitrarily small, so the probability that the information`

`escapes from the confined region can be made arbitrarily small. There is`

`no connection between our ability to observe something and the processes`

`involved in making sure the photons don't escape, so whether or not`

`there are actually these supercool mirrors reflecting all the photons`

`back to recreate the initial state cannot be relevant.`

Saibal

BrentPeople may still have objections against the MWI, but they'll still accept these results on decoherence.Yes. And decoherence says that with time, the off-diagonal elements of the density matrix become arbitrarily small. If there is a smallest non-zero probability, then eventually these off-diagonal elements become zero. This reduces the pure state to a mixture. Which is to say that there is a collapse; unitary evolution ceases, and we have reached a classical world.Non-zero minimum probability on its own, however, does not cause a system to evolve in a non-unitary way.It does when decoherence is taken into account. See the above explanation. Bruce has not omitted anything. BruceBruce is omitting something here, perhaps some limits in which the time evolution operator becomes degenerate or something like that. But a product of two unitary transforms is a unitary transform, so the nth power of a unitary transform is also a unitary transform. There is no ay you can get anything non-unitary out of this, unless possibly in the limit of n to infinity.-- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visithttps://groups.google.com/d/msgid/everything-list/CAFxXSLSqWc3OwbenyDa_-0rjvBYVFqFSQhubXUEu6-Lxsb1XNw%40mail.gmail.com[1].-- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/82b201f4-8d24-14b1-91e7-f4cc50c85a56%40gmail.com [2]. Links: ------ [1] https://groups.google.com/d/msgid/everything-list/CAFxXSLSqWc3OwbenyDa_-0rjvBYVFqFSQhubXUEu6-Lxsb1XNw%40mail.gmail.com?utm_medium=email&utm_source=footer [2] https://groups.google.com/d/msgid/everything-list/82b201f4-8d24-14b1-91e7-f4cc50c85a56%40gmail.com?utm_medium=email&utm_source=footer

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