We still use the term "planet" to reference those objects in the sky called planets, even though the word "planet", historically speaking, means "wandering god". But rather than change the word we've just changed the meaning of the word. And it was the invention of the telescope that altered the...
Thanks Ruth. Had a quick read. That's really quite interesting. I must follow it up in more detail. I spent some time with the original TI theory many years ago and found it quite interesting at the time. A nice feature of such is the time symmetric structure of such.
Yes, that's right. We can only assume there is true randomness. And we can only assume there isn't. Mathematics, as it is currently constituted, enforces one of these assumptions. Statistics, on the other hand doesn't care, which allows either cases (information vs noise) to remain in play...
Why is red light red? It's silly to say "we don't know yet" because the very thing we do know, if only for ourselves, is that red light gives us a particular sensation we can call red. What we don't know is how to formulate that in mathematical terms. I might see red light as cyan, and you...
As I understand it the wave function of entangled photons should be considered as belonging to both photons (or both photons as belonging to one and the same wave function), in the sense that subsequent detections will conform to the same pure state (rather than a mixed state) - so detection of...
Making the assumption that we have sent exactly one single photon, prior to subsequent detection of it, is not really possible. For how do we know a single photon has been sent if it hasn't been detected? While the rate of detections give us a rate of emission, and possible way of knowing a...
I think Bill is making a distinction between the system describing the atomic system and the cat. One can (pursuing silences in Copenhagen) enlarge the scope of that system to include the cat, the robot who opens the box, etc. Or one can contain it to the atomic system.
One can also (pursuing a...
Yes, the issue pivots on whether there is, or is not, regardless of whether we can know such or not, hidden variables (otherwise known as demons) that create what we otherwise nominate as true randomness - in which case true randomness would be a fiction. It would be, instead, what we'd...
In mathematics there is no such thing as pure randomness. In mathematics we can only approximate such an idea, with some help from statistics. For example, we can write an algorithm for a random number generator. But we'll call the results of such an algorithm "pseudo-random" in order to...
The state of the cat before opening the box can be regarded as no different from the state of the cat after opening the box.
Before opening the box we can say the cat is alive or dead.
And after opening the box? Well we find the cat is ... as described ... alive or dead.
C
The problem is in the questions asked, such as "how can it be like that", the first answer to which is to be found in the detector pattern obtained - that its not a question of how it can be like that but, given that it actually is like that, how might one rationalise it (amongst other things...
I'd agree with the quote from John Baez.
The difference between Bayes and Copenhagen is that Bayes is completely compatible with and assumes classical realism (classical probability) whereas Copenhagen ultimately isn't. One can use Bayes in a coin flip experiment, and one can even use Bayes in...
Thanks Bhobba, that's well summarised.
The only point I'd disagree with is the idea that Bohr would hold either the wave function (the mathematical formalism) to be subjective, or what it represents to be subjective. In Copenhagen (as much as other interpretations) the wave function still...
Einstein treats the wave function (or psi-function as he calls it) as an "ensemble" description of something more detailed to be found or inferred. By an ensemble description, Einstein means by such a description that such a description is incomplete, meaning that the description is more like...