> On 2 Aug 2018, at 20:32, Brent Meeker <[email protected]> wrote: > > > > On 8/2/2018 2:07 AM, Bruno Marchal wrote: >> >>> On 1 Aug 2018, at 23:36, Brent Meeker <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>> >>> >>>> If the cat is always in a mixed state, discussing decoherence times in the >>>> context of this wf make no sense, at least to me. But if you insist on >>>> this, mustn't the overall wf be a mixed state, making the radioactive >>>> source, and so forth, also mixed states? >>> >>> An atom can be in a superposition of decayed and not decayed because it is >>> relatively isolated. >> >> An atom can be measured as being in a superposition state BY YOU because it >> is relatively isolated FROM YOU. > > That seems to imply the many-minds interpretation.
It is. > I'm saying the atom is isolated from anything thing that would record it's > decay (including the cat). If you open the box and find the cat is dead and > cold, you know that the cat died hours ago. It was not in a superposition up > until you opened the box. If the atom is in a superposition state, it will always remains in a superposition state like all atoms with which the atom will interact, including the cat, and including me when I will look at the cat. The linear contagion of the superposition happen to interaction. If the box in which the cat belong is well isolated, the cat superposition will not be lift to me. In practice, that is not possible, because we cannot isolate an object as complex as a macroscopic box, today at least. Bruno > > Brent > >> >> If an atom is in a superposition state, QM-without collapse explains this, >> and explain why you cannot directly see the superposition if you interact >> with the atom. But the superposition never disappeared, it has only be be >> contagious on your own state, and like in the WM-duplication, each “copies” >> see the atom like it has deciphered and lost its means to show >> interferences. >> >> Bruno >> >> >> >> >>> It doesn't radiate IR photons or have other interactions with the >>> environment. Haven't you read Schlosshauer's paper yet? >>> >>> Brent >>> >>>> AG >>>> >>>> Unrelated to this issue AFAICT. If the superposition with the cat used as >>>> a starting point for your decoherence analysis doesn't exist as >>>> representing anything, it's baffling that any conclusions can be reached. >>>> OTOH, if the two component states are mixed, that's a fact that seems >>>> never in evidence, certainly not in what I have read about decoherence >>>> theory. AG >>>> >>>> Brent >>>> >>>> >>>> >>>> , you have a two state system using the standard interpretation of >>>> superposition, meaning the system is in both states simultaneously, not a >>>> mixed state. AG >>>> >>>> Isn't this the standard interpretation of a superposition of states? AG >>>> >>>> >>>> >>>> It doesn't go away because the decoherence time is exceedingly short. >>>> >>>> Yes is does go away. Even light can't travel the length of a cat in a >>>> nano-second. >>>> >>>> And for this reason I still conclude that Schroedinger correctly pointed >>>> out the fallacy in the standard interpretation of superposition; namely, >>>> that the system represented by a superposition, is in all components >>>> states simultaneously. AG >>>> >>>> It's not a fallacy. It just doesn't apply to the cat or other macroscopic >>>> objects, with rare laboratory exceptions. >>>> >>>> Other than slit experiments where superposition can be interpreted as the >>>> system being in both component states simultaneously, why is this >>>> interpretation extendable to all isolated quantum systems? AG >>>> >>>> ?? Any system can be mathematically represented as being in a >>>> superposition of different basis states. It's just a consequence of being >>>> a vector in a vector space. Any vector can be written as a sum of other >>>> vectors. >>>> >>>> OK, never had a problem with this. AG >>>> >>>> Your use of the words "interpreted" and "this interpretation" is unclear. >>>> >>>> I am using those words as I think Schroedinger did, where he assumes a >>>> system in a superposition of states, is in all component states >>>> simultaneously. It is from that assumption, or interpretation, that he >>>> finds the contradiction or absurdity of a cat alive and dead >>>> simultaneously. AG >>>> >>>> >>>> ... >>>> -- >>>> 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] >>>> <mailto:[email protected]>. >>>> To post to this group, send email to [email protected] >>>> <mailto:[email protected]>. >>>> Visit this group at https://groups.google.com/group/everything-list >>>> <https://groups.google.com/group/everything-list>. >>>> For more options, visit https://groups.google.com/d/optout >>>> <https://groups.google.com/d/optout>. >>> >>> >>> -- >>> 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] >>> <mailto:[email protected]>. >>> To post to this group, send email to [email protected] >>> <mailto:[email protected]>. >>> Visit this group at https://groups.google.com/group/everything-list >>> <https://groups.google.com/group/everything-list>. >>> For more options, visit https://groups.google.com/d/optout >>> <https://groups.google.com/d/optout>. >> >> -- >> 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] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at https://groups.google.com/group/everything-list >> <https://groups.google.com/group/everything-list>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > -- > 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] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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