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Mar
6
comment Is a heated tungsten filament in a “pure state” or a “mixed state”?
Oh come on now. Let's take a SMALL filament...consisting of four or five atoms of tungsten. Are you claiming that you can't write the Schroedinger equation for this system, just like you do for the hydrogen atom, and calculate the eigenstates which form a complete basis for representing the state of the "filament"? And that, at any instant in time, the state of the filament cannot be represented as a superposition of those eigeinstates, each with an exact complex-numbered value? And is that not a pure state in every sense of the word?
Mar
6
comment Is a heated tungsten filament in a “pure state” or a “mixed state”?
You betray your own answer with the phrase "practically unrecoverable". My question is not about the practicality of writing down this or that wave function. It is not about whether there are a "great number of interactions". It is about whether, in the deepest sense, there is a precise form to the n-dimensional wave function which QM tells us is the true representation of a physical system.
Mar
6
revised Is a heated tungsten filament in a “pure state” or a “mixed state”?
added 1271 characters in body
Mar
5
asked Is a heated tungsten filament in a “pure state” or a “mixed state”?
Mar
4
comment Is there a charge density in quantum mechanics?
Thanks, Lewis. That is helpful...but I'm not sure I want to get sidetracked by the computational problem. I think I understand that the charge density which arises in MFT may be merely an approximation, but my question is...outside of the computational problem...whether underneath it all, in large multi-body systems, there is a REAL charge density...at least as real as the charge/probability density we get by squaring the wave function for a single electron. In other words, what you call an approximation is at least an approximation of something real, whether you call it charge or probability.
Mar
4
comment Is there a charge density in quantum mechanics?
If you believe there is a charge density in QM, then why the hell did you shut my question down?
Mar
4
comment Is there a charge density in quantum mechanics?
@CuriousOne At least you have enough guts to go out on a limb and admit you are guessing that there is indeed such a thing as charge density. But for a guy who doesn't know for sure whether or not there is a charge density in QM, you've got a lot of nerve voting to shut down my question. You should be ashamed of yourself.
Mar
4
comment Is there a charge density in quantum mechanics?
Oh come on. Is there or isn't there a charge density in quantum mechanics?
Mar
4
comment Is there a charge density in quantum mechanics?
The "regular contributors" who shut down my other question claimed they couldn't understand what I meant by charge density in quantum mechanics. Then let them answer the question here: is there or isn't there such a thing as charge density? They're quick to shut me down, but not so quick to answer my questions.
Mar
4
comment Is there a charge density in quantum mechanics?
I don't care if it was shut down by Archimedes Plutonium. I know censorship when I see it.
Mar
4
asked Is there a charge density in quantum mechanics?
Feb
25
comment SPDC and single photon production
And if there are no pea-shooters for photons, how can there be pea-shooters for electrons? This calls into doubt the whole double-slit paradox of "what happens if you shoot one electron at a time at the double slit?" There is no mystery if you cannot isolate the experiment down to one electron at a time.
Feb
25
comment SPDC and single photon production
The discrepancy between an SPDC-source and a true "pea-shooter" source has huge implications. What about Bell's Theorem and the EPR paradox? For year's we've been told that quantum mechanics gives us a stark choice: local reality or causality but not both. Does this paradigm survive the new theoretical analysis of SPDC-based sources?
Feb
25
comment SPDC and single photon production
I wrote an article a few years ago called "There Are No Pea-Shooters for Photons". Maybe I was lucky but I think I got it right. There is an awful lot of nonsense written that starts with the premise "let's say you shoot a single photon at a target...". You can find the article here: fqxi.org/data/essay-contest-files/…
Feb
24
comment How precise must the energies match for absorption of photons?
Oh come on. I did the calculation in this blogpost three years ago: marty-green.blogspot.ca/2012/02/semi-classical-calculation.html
Feb
23
comment How precise must the energies match for absorption of photons?
So you're agreeing that I get the right anwr.
Feb
23
answered How precise must the energies match for absorption of photons?
Feb
18
answered Can a system be engineered to cause a standing wave resonance with gravity waves?
Feb
13
comment Why are magnets in form of hollow sphere not a magnetic monopole?
If your experiment succedes you'll get the Nobel Prize.
Feb
13
comment Why are magnets in form of hollow sphere not a magnetic monopole?
You don't need space between the magnets for the field lines to loop around. The field lines from North Dakota will loop back through South Dakota and Minnesota.....cancelling out the fields from those neighboring states. That's why there is no net field and you can't construct a magnetic monopole.