Notes on Quantum Weirdness by Hans Christian von Baeyer
QBism, which combines quantum theory with probability theory moves the focus from the object of observation to the subject, suggesting that "the wave function is a subjective property of the observer" not a property of the object begin observed (which created the problem of the cat in Schrodinger's box being both alive and dead simultaneously). The wave function that the cat is either dead or alive is only a description of the observer's belief and not a description of the cat or the objective datum.
Now, how do I make sense of that?
First, what is meant here by probability (I'll worry about quantum theory in a bit). von Baeyer argues that there are two competing theories of probability: the first is the one that most of us are familiar with, frequentist probability: an events probability is its relative frequency in a series of trials (how often will the coin turn up heads?). The second is Bayesian probability and is a measurement of the degree of belief of the observer of an event. The first is obviously more scientific in the sense that it is objective and verifiable (it does not depend on the observer). In Bayesian probability, the observer can use both objective data and subjective estimates. The Bayesian observer has more flexibility in his interpretation because degrees of belief are not fixed and unusual or random data can be quickly taken into account. Strangely, to me, there is a law, Bayes law, that allows you to calculate the effect of new information on the estimate of a probability, which, I believe, measures the observer's personal degree of belief. So, you could combine the frequentist probability for an event with the Bayesian probability to get an idea of both what the observer thinks subjectively, given his or her experience, and what the data suggests.
To help make sense of these complex ideas,
I went to the internet. But, I was unable to find anything geared toward the beginner. So, I am guessing that in order to really understand these ideas, one must be much further advanced in physics. What I did find, eventually, was a link to Christopher Fuch's website. Fuchs is one of the originators of these ideas when he wrote an essay in 2002 with Carlton CAves on Quantum probablities and Bayseian Probabilities. So, I sidetracked into his website. . . see post on Fuch's website
But I found the notion of qbism as an epistemology approach to be fascinating. Of course, I may be completely misunderstanding it. But, what it generates for me is the notion that our subjective response to an event can be measured and perhaps even predicted. How much use could such a measurement be in other areas of interpretation? Could you have a number for your degree of belief for an interpretation of a book? Or how about your degree of belief that Iraq has weapons of mass destruction? Or does degrees of belief not work like that?
Now, how do I make sense of that?
First, what is meant here by probability (I'll worry about quantum theory in a bit). von Baeyer argues that there are two competing theories of probability: the first is the one that most of us are familiar with, frequentist probability: an events probability is its relative frequency in a series of trials (how often will the coin turn up heads?). The second is Bayesian probability and is a measurement of the degree of belief of the observer of an event. The first is obviously more scientific in the sense that it is objective and verifiable (it does not depend on the observer). In Bayesian probability, the observer can use both objective data and subjective estimates. The Bayesian observer has more flexibility in his interpretation because degrees of belief are not fixed and unusual or random data can be quickly taken into account. Strangely, to me, there is a law, Bayes law, that allows you to calculate the effect of new information on the estimate of a probability, which, I believe, measures the observer's personal degree of belief. So, you could combine the frequentist probability for an event with the Bayesian probability to get an idea of both what the observer thinks subjectively, given his or her experience, and what the data suggests.
To help make sense of these complex ideas,
I went to the internet. But, I was unable to find anything geared toward the beginner. So, I am guessing that in order to really understand these ideas, one must be much further advanced in physics. What I did find, eventually, was a link to Christopher Fuch's website. Fuchs is one of the originators of these ideas when he wrote an essay in 2002 with Carlton CAves on Quantum probablities and Bayseian Probabilities. So, I sidetracked into his website. . . see post on Fuch's website
But I found the notion of qbism as an epistemology approach to be fascinating. Of course, I may be completely misunderstanding it. But, what it generates for me is the notion that our subjective response to an event can be measured and perhaps even predicted. How much use could such a measurement be in other areas of interpretation? Could you have a number for your degree of belief for an interpretation of a book? Or how about your degree of belief that Iraq has weapons of mass destruction? Or does degrees of belief not work like that?
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