On Tuesday, November 5, 2019 at 1:11:21 PM UTC-7, Brent wrote: > > > > On 11/5/2019 9:21 AM, smitra wrote: > > On 05-11-2019 02:53, Alan Grayson 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 > > > > > > Consider the C60 moving through one or the other slit and then ending > > up at some spot x on the screen. If the state of the rest of the > > universe when the C60 takes on slit is |A(x)> and it is |B(x)> if > > another slit is taken, then the interference pattern locally at spot x > > on the screen will be proportional to Re[<A(x)|B(x)>]. So, if there is > > perfect which way information for C60 that arrive in the neighborhood > > of spot x on the screen, then the two environmental states will be > > orthogonal and the interference will vanish. > > > > In case of the experiment in a thermal environment, the C60 will > > suffer collisions with photons. > > It's not collisions with photons from the environment. The C60s are > heated in the experiment, so it is IR emission from the C60 that puts > which-way information into the environment.
That's what I don't understand. If there's no detector focused on, or watching the slits, how can which-way information exist? All we observe is loss of interference without which-way information. What can we conclude from this? AG > The states |A> and |B> will be different due to these collisions, > > |A> and |B> are different ex hypothesi regardless of collisions or > emissions. > > Brent > > > as in every such case the state the universe ends up in will depend on > > which path the C60 took as the collision it suffered when it took one > > path would not have happened (instead another collision event at the > > another slit may have occurred). As the temperature rises, the > > interference pattern will then fade away as the number of C60 > > molecules that passed through without interactions near the slits will > > become small. > > > > Saibal > > > > > -- 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/0858313f-6347-4e44-859c-8a6fa80c9e43%40googlegroups.com.
