Nobel Prize for Physics 2022 awarded to 3 scientists for work in Quantum Mechanics
Posted: Sat Oct 08, 2022 11:44 am
https://www.nobelprize.org/prizes/physics/2022/summary/
One of the most important aspects of this award was that 2 of the awardees were very important figures in developing and experimenting on Bell's Theorem, which I find to be one of the most fascinating aspects of Quantum Mechanics.
When Quantum Mechanics came on the scene, it stated that certain properties of particles - like the spin of a photon for example - were not just unkown before measurement, but the value of the property itself was not set in stone. So when you measure the spin, you're not measuring some pre-existing fact, you're in essence forcing the photon to take on a certain value for spin by measuring it, a value it didn't have before measurement.
A lot of scientists at the time didn't really like this idea, especially because it had some weird implications for entangled particles. Einstein famously opposed these ideas, and called the implications with entangled particles 'spooky action at a distance'. Einstein preferred the idea that there was something more tangible to spin, and that the QM picture of this property was wrong or incomplete in some way.
Bell's Theorem is a set of probabilities that Quantum Mechanics predicts for certain measurements that are paradoxical if you take an Einsteinian view. Bell's Theorem basically says, if the probabilities work out the way Quantum Mechanics says they should, then it's incompatible with the Einsteinian view, called "local realism", and the QM idea that the spin really is indeterminate before measuring must be true.
Unfortunately Einstein died before Bell's Theorem was proposed, and long before it was tested, so we'll never get his thoughts on these new experiments. However, the experiments are in (they have been for some time, actually, the awards are not necessarily for recent work), and the Quantum Mechanics approach looks like it's the right one now.
One of the most important aspects of this award was that 2 of the awardees were very important figures in developing and experimenting on Bell's Theorem, which I find to be one of the most fascinating aspects of Quantum Mechanics.
When Quantum Mechanics came on the scene, it stated that certain properties of particles - like the spin of a photon for example - were not just unkown before measurement, but the value of the property itself was not set in stone. So when you measure the spin, you're not measuring some pre-existing fact, you're in essence forcing the photon to take on a certain value for spin by measuring it, a value it didn't have before measurement.
A lot of scientists at the time didn't really like this idea, especially because it had some weird implications for entangled particles. Einstein famously opposed these ideas, and called the implications with entangled particles 'spooky action at a distance'. Einstein preferred the idea that there was something more tangible to spin, and that the QM picture of this property was wrong or incomplete in some way.
Bell's Theorem is a set of probabilities that Quantum Mechanics predicts for certain measurements that are paradoxical if you take an Einsteinian view. Bell's Theorem basically says, if the probabilities work out the way Quantum Mechanics says they should, then it's incompatible with the Einsteinian view, called "local realism", and the QM idea that the spin really is indeterminate before measuring must be true.
Unfortunately Einstein died before Bell's Theorem was proposed, and long before it was tested, so we'll never get his thoughts on these new experiments. However, the experiments are in (they have been for some time, actually, the awards are not necessarily for recent work), and the Quantum Mechanics approach looks like it's the right one now.