The Guardian for this meeting was Gaya Ethaniel. Pema arrived to find Gaya afk ... and sat waiting for a couple of minutes >.<
Pema Pera: Hi Gaya!
Pema Pera: Gaya?
Gaya Ethaniel: Hello Pema :)
Gaya Ethaniel: I was reading online ... sorry.
Gaya Ethaniel: How are you?
Pema Pera: I'm fine, and I'm in Tokyo again, which makes it possible to attend your slot :-)
Gaya Ethaniel: ^.^
Pema Pera: How are you?
Gaya Ethaniel: I'm doing well thanks :)
Gaya Ethaniel: I read something peculiar today ... don't really understand it. Maybe you can?
Gaya Ethaniel looks up ...
Gaya Ethaniel: In qm, the definition of the object itself may be dependent crucially on observation - what does this mean?
Pema Pera: it means that you cannot describe the state of any object independent of a measurement
Pema Pera: in classical mechanics, if you have a box with a piece of fruit in it
Pema Pera: you may not know whether the piece of fruit is an apple or an orange
Gaya Ethaniel: I suppose not ...
Pema Pera: or even if you know it is an apple, you may not know whether the apple sits straight up or upside down in the box
Pema Pera: but you generally assume that there is one particular fruit, with one particular observation
Gaya Ethaniel thinks ... but
Pema Pera: even before you look -- looking just records what was already there
Pema Pera: yes?
Gaya Ethaniel: What we observe doesn't match what something really is though I thought ...
Pema Pera: no, that is a more philosophical question -- what qm says is much more straightforward
Gaya Ethaniel: oh
Pema Pera: it would be as if we could do a number of measurements on the piece of fruit in a box
Pema Pera: or in a group of boxes
Gaya Ethaniel: ah ... ok
Pema Pera: and then it would turn out to no single description could have possible applied to all boxes
Pema Pera: let me be more precise
Gaya Ethaniel: ok
Pema Pera: imagine that you prepare one hundred apples, all exactly in the same way, and all of them in the same kind of box
Pema Pera: now if they were very small apples, so that the quantum mechanical effects would be obvious
--BELL--
Gaya Ethaniel: ok ... all same apples in all same boxes ...
Pema Pera: then it could turn out that different measurements on different boxes would not leave room for *any* particular state that the hundred identical apples would be in: each measurement would tell you something different; some of the measurements some allow you to imagine what the apples could have looked like, but other measurements would contradict that picture
Pema Pera: so in a very real sense, you could say that the very act of observing changed the *history* of the apples.
Gaya Ethaniel: Why are they in different states?
Pema Pera: normally, when we disturb a system, we can understand that that changes the future of the system
Pema Pera: they are not in any state particular state until we measure them -- as far as we know, at least
Pema Pera: and the concept of "state" does not apply
Pema Pera: this is the "weird" aspect of quantum mechanics
Pema Pera: everything is indeterminate to some extent until you measure the system
Gaya Ethaniel: So ... our act of measurement ... the interaction somehow changes the objects?
Pema Pera: yes, in the past as well as in the future
Gaya Ethaniel: ooo how peculiar ... to hear about such a thing from a scientist ...
Pema Pera: it is *very* peculiar
Gaya Ethaniel giggles quietly.
Pema Pera: and ordinary logic does not apply
Pema Pera: :-)
Gaya Ethaniel: It's somehow wonderfully weird.
Gaya Ethaniel: So in qm, subject is as important as object then?
Gaya Ethaniel: And the interactions between
Pema Pera: yes, matter is far more wonderful, literally full of wonder, than anybody could have possibly expected a century ago
Pema Pera: yes, indeed
Gaya Ethaniel: ah ...
Pema Pera: there are no well defined objects without subjects interacting with them . . .
Pema Pera: they only come in pairs
Gaya Ethaniel: What triggered such a change in the view?
Pema Pera: experiments!
Pema Pera: and then a theoretical description was found to explain the experiments in the way I just sketched very roughly
Gaya Ethaniel: ah ...
Pema Pera: the theory is very precise and mathematically clear
Pema Pera: the interpretation is weird, when we try to picture it
Gaya Ethaniel: I find that a little difficult to believe ... the theories behind these ideas are precise and clear?
Pema Pera: the mathematics is very precise, and well defined -- and the experiments agree with the mathematical descriptions to better than one part in a trillion
Pema Pera: so that is an incredibly precise confirmation that the mathematics is correct
Gaya Ethaniel: Then ... why the interpretations so strange?
Pema Pera: but the interpretation of how we can picture the objects is difficult
Gaya Ethaniel: ah ... ok
Pema Pera: we have to let go of the idea that an object exists before it is measured
Pema Pera: in some way, we help to create reality simply by watching it
Gaya Ethaniel giggles ... how wonderful that sounds Pema!
Pema Pera: it really is wonderful . . .
Gaya Ethaniel: btw do you know a scientist called David Bohm?
Pema Pera: yes
Pema Pera: he was very original, and thought deeply about these questions
Gaya Ethaniel: ah ... ok but it seems his views weren't accepted very widely right?
Pema Pera: his particular interpretation is one of many, and not widely accepted
Pema Pera: but his way of asking questions was very influential
Gaya Ethaniel: ah ... that's good to hear :)
Pema Pera: often asking the right question is more important than coming up with a definitive solution
Pema Pera: btw, another way of saying what I just said was to use the words of Heisenberg, one of the people who discovered qm:
Pema Pera: "in the experiments about atomic events we have to do with things and facts, the phenomena that are just as real as any phenomena in daily life. But the atoms or elementary particules themselves are not realy ; they form a world of potentialities or possibilities rather than one of things or facts
Gaya Ethaniel: oh, they are possibilities ... wow
--BELL--
Gaya Ethaniel: Do you think even asking questions, as in mental activities, affect things?
Pema Pera: if someone asks you whether you like the Beatles, or Michael Jackson, you may already have an opinion; but if someone asks you your opion about a group or singer whom you have not heard very often, or about whom you don't have a strong opinion, you may have to think about an answer on the spot; in that case the question itself triggers an answer -- and there was no answer before the question was asked. The answer remained a possibility until the question was phrased. In that sense, qm tells us that particles remain potential until you ask them what state they want to be in :-).
Gaya Ethaniel: ah :)
Pema Pera: imagine a fruit that is neither an apple or an orange -- by looking at the fruit it then has to decide which face to show . . .
Gaya Ethaniel giggles. Where do scientists get inspirations for such an example.
Pema Pera: from nature, from experiments!
Pema Pera: they had to abandon their old ideas kicking and screaming
Pema Pera: but they had not choice!
Gaya Ethaniel: Or they were hippies heheheh
Pema Pera: there was simply no other way to look at it, no way to hang on to any picture of objects-with-state before measurements
Gaya Ethaniel: Sorry bad joke, I got the fruit in my head now and am listening.
Pema Pera: well, they didn't start as hippies, but they were forced to become more so, you could say
Gaya Ethaniel: ah ok
Pema Pera: no, it's an apt picture
Pema Pera: nature forced them to be free from their preconceived ideas, to drop those
Gaya Ethaniel: It's not easy I suppose to do that.
Pema Pera: I wish this would be taught in high school, to everybody
Gaya Ethaniel: No I only learnt the classical physics.
Pema Pera: it's the core of science of the twentieth century
Pema Pera: yes, STILL children learn classical physics -- science from TWO centuries ago!
Gaya Ethaniel: It could at least prevent me from reading fictions during physics classes for sure.
Pema Pera: it's a crime, really
Pema Pera: our educational system
Gaya Ethaniel: It is interesting ... :)
Gaya Ethaniel: qm ... I was a bit bored by the classical approach.
Pema Pera: it would be like teaching geography, as if the US is still an English colony
Gaya Ethaniel: yeah ... true
Gaya Ethaniel: When I was younger, it could be that teachers themselves didn't understand qm
Gaya Ethaniel: Or didn't know how to explain it
Pema Pera: oh, sure, the whole educational structure is wrong, way behind
Gaya Ethaniel: It is a shame ... hope that changes.
Pema Pera: so we need teachers willing to teach teachers how to teach qm
Gaya Ethaniel: yes!
Pema Pera: it can be done, if there is the political will
Pema Pera: I've often thought of getting involved in that
Gaya Ethaniel: Sounds great
Pema Pera: but there is only so much I can do in one lifetime ....
Gaya Ethaniel: That's true :)
Pema Pera: for now, PaB is more important for me, but perhaps I will find the time in the next few years
Pema Pera: ah. sorry, have to run -- a RL dinner appointment
Gaya Ethaniel: Enjoy your dinner Pema :) See you soon.
Gaya Ethaniel: Thank you for the discussion.
Pema Pera: thanks for your questions -- I hope my answers were not too lengthy :)
Gaya Ethaniel: Not at all, very easy to understand :)
Pema Pera: I like these 1 am sessions -- nice sometimes to be able to stay on one topic!
Gaya Ethaniel: :)
Pema Pera: I enjoy larger groups too -- the best thing is to have sometimes large, sometimes small groups
Pema Pera: each has its advantages
Gaya Ethaniel: Yes I like the variety :)
Pema Pera: bye, Gaya!
Gaya Ethaniel: bfn
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