When a particle hits the screen in a double slit experiment, is that a measurement? AG
On Saturday, January 30, 2021 at 6:26:20 PM UTC-7 Alan Grayson wrote: > More Trump physics? What's a measurement? I have no clue. AG > > On Saturday, January 30, 2021 at 4:27:00 AM UTC-7 [email protected] > wrote: > >> On Fri, Jan 29, 2021 at 7:42 PM Bruce Kellett <[email protected]> wrote: >> >> > *There is no requirement for an infinite number of degrees of freedom.* >>> >> >> In physics there will never be a theory that requires infinite degrees of >> freedom, at least not until somebody performs an experiment with infinite >> accuracy, and I'm not holding my breath for that. >> >> > *Escape of just one IR photon to outer space is sufficient to destroy >>> reversibility.* >>> >> >> Sometimes, usually in fact, but not always. Not if 2 quite different >> events can produce the same identical photon that escapes into infinite >> space, and not if the photon is not even allowed to escape but Is absorbed >> by a photographic plate or a brick wall. A good example of this sort of >> thing would be the quantum eraser experiment, or the delayed choice >> experiment. Or just study how a Mach–Zehnder interferometer works. These >> experiments are possible but they're not easy because the experimenter must >> make sure that there's a difference between the two worlds but the >> difference must be very small so a practical way can be found to make the >> two worlds identical again so they can be nudged back together again into >> one world. >> >> *> The definition of 'world' in the context of QM is made exact precisely >>> because of this irreversibility.* >>> >> >> Only in pure mathematics are definitions precise, in science and and >> everything else they're just an approximation, a label for an idea >> learned through examples, a collection of words that are defined by other >> words. And Hugh Everett invented the theory but he didn't invent the phrase >> "Many Worlds", that was done by others and only gives a very approximate >> idea of what the theory is about. According to Everett the debate on if >> matter is made of particles or waves is over, it's made of waves. And in >> that theory the approximate definition of the world "world" is a collection >> of different waves that include at least one conscious being that is >> approximately the same in all of them. >> >> *> Worlds are well-defined * >>> >> >> Words are defined by other words and those words are in turn defined by >> yet more words. Even the word "defined" is defined by words. But whatever >> physical reality turns out to be at its most fundamental level I think we >> can be pretty sure it's not made of words. >> >> John K Clark See my new list at Extropolis >> <https://groups.google.com/g/extropolis> >> >> -- 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/d015390b-6080-4a85-b960-f1d889ff4383n%40googlegroups.com.
