David Finkelstein - Why is the Quantum so Mysterious?

David in trying to understand what our world is all about quantum theory is extremely important and it is extremely strange and I come to you to try to help me to understand what it means and how we should think about it is it that it seems illogical to you well to have something in two different places at the same time is illogical entanglement is illogical where there's this seemingly communication across distances beyond the speed of light but it's not a communication uh a probabilistic functions where things are described by probabilities not facts you can't know positions and momentum particles there's a lot of strange things well the real secret is that it seems illogical because it is it involves a revision of the fundamental laws of logic as we've already pointed out by Niels Bohr very soon after the invention of quantum theory by him and Heisenberg he said you mustn't apply logic to the atom you must reason about it in the following way and usually this is expressed as a revision in the laws of probability in this incredible situation where opening a window can darken a room one window open certain amount of Illumination gets in you open another room gets darker it's called interference of probabilities or probability amplitudes you know possibilities of cancellation that you couldn't dream of until you got down to the quantum level of detail I should mention these windows have to be damn small hey I mean you know it's it's absolutely illogical and you're telling me that I I I that you have to get rid of the normal logic that we have I mean that that's so much a part of it I can't tell you what you have to do no in fact half the physicists simply say don't try to understand quantum theory just play the game like a chess game just follow the rules and take what you get and it works and it works every time okay most successful Theory we have but but that's not good enough well if you want to understand it then you have to be willing to go inside out what you think are the laws of logic and work on them it's just hardly learning a new language take me on the journey um for me it uh it actually began in high school when I heard of none Aristotelian logic and ran around trying to find out what they were talking about and then in college I came across quantum theory and it was presented revision of logic that I've been looking for for those years so I came in from from left field as it were most people meet quantum theory as a problem I met it as a solution I like it but the solution is is because it it it contradicts the normal logic that we are comfortable with in our world yes there's Einstein's geometry contradicts the normal geometry we find in our world yes I think Darwin said if something doesn't seem surprising it's because it was helpful in our evolution millions of years ago anything that comes along that's new has to seem surprising or it's probably wrong because we weren't so our genes didn't select for that not to be surprising there's a certain logic and a certain geometry they're really wired into us right I mean we know how to catch a ball for example without taking a long course in Bowl catching right right because we had to do that evolutionary right but if you want to learn Quantum logic you have to do a few simple exercises so you're gonna carry on three polarizers it's very easy to demonstrate the peculiarity of quantum logic with photons and broad daylight okay so what are the kinds of logical laws we have to give up and what do we have to accept there are many many ways of expressing the change each person finds his own way to live with it okay none of them are understandable in the intuitive sense all of them involve radical rethinking um I've mentioned the rethinking changing the law is a probability instead of adding probabilities you introduce numbers which can be positive or negative and add them that's where the cancellations come from so when you add things that they can add or they can cancel right and in our normal World they would only add right and another way to put it which is actually I think deeper and um preferred in were there circles is to say that the order in which you make tests on a system affects the answer okay now in normal arithmetic if you add or you multiply the order that you do things that doesn't matter and also if you ask questions ordinarily changing the order of the questions shouldn't change the answers okay but good lawyers know that if you ask questions in the right order you can leave the witness and all physicists leave the witness in quantum theory you can get almost any answer you like by asking the right sequence of questions and those answers can be radically different from each other right with the same set of questions it's just the order that you answer you can drastically change the outcome just by changing the order a little bit not a little bit a lot total change in order same questions just change in order different answers right and uh there is a kind of arithmetic logic that was introduced by George boole in the last century Boolean algebra it's called one of his axioms is a b equals ba right A B doesn't equal ba aside from that he was right in Quantum right exactly at the microscopic level in fact if a and b are tests of the kind that pool is talking about usually the product a b isn't even a test it's something more General logic doesn't close on itself anymore it flows into Dynamics there's no clear boundary between logic and the rest of thinking all right taking a deep breath and understanding that what can we infer from that what what does it mean to say that that the normal ways of thinking about our logic doesn't apply what well first of all the nearly drove Heisenberg crazy what does it mean to say a b doesn't equal BA 2 times 3 equals three times two right why should it be different for physical variables and finally he realized it means that if you know one of them you can't know the other if they were both numbers of course they'd commute so they can't both be numbers if you know one you must be a little bit ignorant about the other so the Heisenberg uncertainty principle flowed out of this order of Independence okay and help helps us to understand it but it's the order dependence which is the fundamental thing and the uncertainty principle that's the way of explaining it to people now that uncertainty principles that you can't know the position and the momentum of a of a microscopic object at the same time and the more you know one the less you know the other so if you can be absolutely precise about the position you have absolutely no knowledge whatsoever of the momentum and vice versa now as you can imagine this changed physically drastically physics before this was called classical physics today and physics afterwards called quantum physics and in mathematical circles sometimes it's just called non-commutative physics commutative means that the order doesn't matter right exactly and non-communitive means that the order does matter how you ask the question uh affects the answer right now when I came across this revised logic back in college at the as a result of the writings of the mathematician John for Neumann um I realized immediately of course we all know that geometry is an exercise in logic you're chained to logic that means you're changing geometry and uh it hadn't been done it seemed like a seemed like a good life's work and I've been working on that ever since the quantization of geometry

Channel: Closer To Truth

Views: 21,979

Keywords: closer to truth, robert lawrence kuhn, David Finkelstein, quantum theory, superposition, Quantum mechanics, particles, cosmos, cosmology

Id: WyQl5ROF0Vo

Length: 8min 23sec (503 seconds)

Published: Sun Jul 30 2023