> On 8 Nov 2019, at 01:13, Alan Grayson <[email protected]> wrote: > > > > On Thursday, November 7, 2019 at 12:50:21 PM UTC-7, Brent wrote: > > > On 11/7/2019 6:21 AM, Bruno Marchal wrote: >> >>> On 6 Nov 2019, at 10:34, Philip Thrift <[email protected] <javascript:>> >>> wrote: >>> >>> >>> >>> On Wednesday, November 6, 2019 at 3:19:58 AM UTC-6, Bruno Marchal wrote: >>> >>>> On 5 Nov 2019, at 02:53, Alan Grayson <[email protected] <>> wrote: >>>> >>>> IIUC, as the temperature rises, interference in the double slit C60 >>>> experiment declines, and eventually disappears. I don't think this is >>>> really a which-way experiment because the interference >>>> disappears whether or not which-way is observed. How does this >>>> effect the collapse issue? Usually, IIUC, when interference ceases to >>>> exist, it implies collapse of the wf. So, is the C60 double slit >>>> experiment evidence for collapse of the wf? TIA, AG >>> >>> My two pre views posts explained exactly this, in the non-collapse frame. >>> It works for particles, Molecules and even macroscopic cats. The advantage >>> of the non-collapse quantum theory is that any interaction can be counted >>> as a measurement. So heat cannot not decrease interference, for the >>> technical factorisation reason already explained. >>> >>> Bruno >>> >>> >>> >>> >>> They've sent 2000-atom sized molecules through double slits. >>> >>> What about sending cats? >> >> You will loss the ability to get the interference, because it is hugely more >> complex to isolate a cat from the environment, so its alive or dead state >> will be pass on you unavoidably very quickly. See my explanation to Grayson >> why any (unknown) interaction of an object in a superposition state makes it >> logically impossible to remain in a superposition relatively to you. It uses >> only very elementary algebra. The quantum effect, to be exploited, require >> perfect isolation, which is impossible for most macroscopic object. But some >> “macro-superposition” have been obtained with superconducting device. In >> fact, superconductor is a quantum macroscopic effect. > > Aside from the isolation problems the de Broglie wavelength of a cat is > extremely small so to get an interference pattern the slit and slit spacing > must be correspondingly small. The C60 experiment was only made possible by > the development of the Tablot-Lau interferometer. > > Brent > > I've made this point before; the decoherence time for a cat is very very > short, but how does this effect the point Schroedinger wanted to make, since > the cat is in that paradoxical superposition for some short but finite > duration? AG
Once the cat is alive + dead, he remains in that state for ever. I don’t see any mean to avoid this without introducing non unitary phenomena. He accessibility to interference is very short, because we can’t isolate the cat, and the wave length is very tiny (making perhaps no sense in a GR accommodation of QM), but in pure elementary QM, superposition are forever. Bruno > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/bd809b30-38bf-403d-a673-0b4a46ea11cf%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/bd809b30-38bf-403d-a673-0b4a46ea11cf%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/2E00D986-C82A-43F0-9984-DFAF2FFBFD7E%40ulb.ac.be.
