Seasons
This is a forum or general chit-chat, small talk, a "hey, how ya doing?" and such. Or hell, get crazy deep on something. Whatever you like.
Posts 3,964 - 3,975 of 6,170
Are we embarrassing you with all this girl talk? We may be talking about waves, but at least we're not discussing periods!
embarassed? Not in the least. I have been married for long enough that there is very little that could embarass, surprise or mystify me about the female psyche or biology.
Except perhaps, there is one thing that I have never understood - why are there always at least 4 combs, 2 hairbrushes and an acre of disposable tissues in an average handbag? And what on earth accounts for the other several kilos of "stuff"?
I've gone camping with less gear than my wife regards as essential for the shortest of trips beyond the front door!
The electromagnetic wave is a different wave entirely
Well, this is what I keep agreeing with you about. My point about numbers in [0,1] versus complex numbers is something else. I thought that you were aguing like this:
(a) In order to interfere subtractively, waves have to be able to take on negative values. But probabilities are never negative, they are all numbers between 0 and 1, inclusive. Therefore, if Psi were a probability, it couldn't interfere.
This also seems to be the drift of Penrose's argument, "In the first place, ... in the two-slit experiment." Indeed, I agree with everything Penrose says there.
Now, I agree with (a), both the reasoning and the conclusion. I agreed with the Penrose critique of the phrase "probability wave" the first time you mentioned it, with the minor reservation that it has become so common to call it the "Probability wave" that many people do so even though they know that it is technically incorrect.
OK, so he has proved that a common idiom is actually conceptually sloppy if taken literally. That is a critique of language, not of physical theory. Because I agree, however, I have tried to always say "Psi", not "the probability wave," or even "the probability amplitude wave." And I think I have been fairly successful, so I remain puzzled at your repeating this point.
Psi does, however, "give" (to use your word) the probabilities, in that, given Psi, one can calculate the probabilities from it. The method of calculation of Psi is such that even though Psi itself generally has complex values, the calculated probabilities end up in [0,1], as they should. This is what is assured by normalization and complex conjugation, and that is why I found it relevant to mention them.
embarassed? Not in the least. I have been married for long enough that there is very little that could embarass, surprise or mystify me about the female psyche or biology.
Really? I've had a few relationships in my time, (not a large sample perhaps, but long-term qualitative studies that have fostered some familiarity with the male gender) and I must admit there are times given male behaviors will still surprise and yes, even embarrass me (though sometimes the surprises may be pleasant too). Women must be easier to understand than men are. All this time men I know have said that women are crazy, it was just part of your gender's projections of your own complex illogical testosterone-colored world.
Except perhaps, there is one thing that I have never understood - why are there always at least 4 combs, 2 hairbrushes and an acre of disposable tissues in an average handbag? And what on earth accounts for the other several kilos of "stuff"?
People expect us to have all that crap. I try not to carry a purse, but you have to put your wallet somewhere, and the cell phone, and keys...etc. Most of my clothes simply don't have good pockets for all that and even those with pockets would have odd bulges if I actually put stuff in the pockets (not that everything I own is skin-tight but women's clothes are cut differently than men's clothes). If I could con the man I am with into carrying everything I would never have a purse.
My father, who is admittedly in his 80s and not like "modern" men, carries a hanky, wallet, keys, cough drops, nail clippers, plastic comb and eyeglasses in various pockets. Men's pants and jackets seem built for that. Maybe I should just wear men's clothes.
I've gone camping with less gear than my wife regards as essential for the shortest of trips beyond the front door!
Camping must be easy in Scotland. I need a tent, sleeping bag, swiss army knife, basic foods and other items when I venture out. Yes, I also make room in the pack for chocolate. Ruffing it is no reason to be uncivilized.
Posts 3,964 - 3,975 of 6,170
There once was a lawyer named Rex
Whose subtext transformed into text
When facing exposure
he said with composure
"de minmus non curat lex"
Whose subtext transformed into text
When facing exposure
he said with composure
"de minmus non curat lex"
Irina,
No you don't, because I never said that the wavefunction for light was the same as the classical electromagnetic wave. In fact, I said that they weren't.
But it is. My objection is that the electromagnetic light wave is not the probability wave. The light does have electromagnetic wave-like properties (as well as particle-like properties,) and it is precisely this electromagnetic aspect of the wavicle that propagates.
Dear Psimagus:
you write:
It is psi that gives the probability, and this is never a negative value, thus cannot act in true "wave" fashion to exhibit destructive interference.
Psi gives the probability, but it isn't itself the probability. One gets the probability of (e.g.) the particle's being in a given spatial region by integrating Psi*Psi, the square of the modulus of (normalized) Psi, over the region [Psi* being the complex conjugate of Psi
You can integrate, conjugate, square, triangulate, or dance it round a maypole naked with ribbons in its hair. It doesn't change the fact that the "probability wave" (be it Psi, its modulus, or any function thereof,) is not the same as the electro-magnetic wave nature of the quantum (whether we call that a "light wave", a "pilot wave", a "carrier wave", or any other Bohmian euphemism.) The electromagnetic wave is a different wave entirely, as my previous ref. makes clear ("The Schrodinger wave equation does not describe an ordinary electromagnetic wave but a probability wave"http://www.electrogravity.com/AVECWAVE/AVecWave.pdf)
(yes, Bev, I am a great fan of complex conjugation)]. This gives a positive real number betweeen zero and one, as desired for a probability. Psi itself, however, is not so restricted. In fact, Psi typically takes on complex values.
Therefore, there is no problem with Psi exhibiting characteristically wavish phenomena such as diffraction and interference.
I would say there would be every problem, but whether or not that is so isn't relevant - while you claim the "personality wave" to actually be the electromagnetic quantum wave, any modelled quantum behaviour will unavoidably seem bizarre.
I'll take the opportunity to requote my previous refs, if I may, since the originals are now a good few pages back, but remain unaddressed:
"In accordance with this probability interpretation, it is not uncommon for the wavefunction to be called a 'probability wave'. However, I think that this is a very unsatisfactory description. In the first place psi(x) itself is complex, and so it certainly cannot be a probability. Moreover, the phase of psi (up to an overall constant multiplying factor) is an essential ingredient for the Schroedinger evolution. Even regarding |psi|^2 (or |psi|^2/||psi||) as a 'probability wave' does not seem very sensible to me. Recall that for a momentum state, the modulus |psi| of psi is actually constant throughout the whole of spacetime. There is no information in |psi| telling us even the direction of motion of the wave - it is the phase alone, that gives this wave its 'wavelike' character.
Moreover, probabilities are never negative, let alone complex. If the wavefunction were just a wave of probabilities, then there would never be any of the cancellations of destructive interference. This cancellation is a characteristic feature of quantum mechanics, so vividly portrayed in the two-slit experiment!" [Penrose The Road to Reality chap.21.9 p.519]
"The carrier of the non-local instantaneous action is the wavefunction similar to the de Broglie pilot wave and the reaction is the net observable local space result. The Schrodinger wave equation does not describe an ordinary electromagnetic wave but a probability wave, and the probability wave determines all of the action and reaction of the total electrogravitational interaction."
http://www.electrogravity.com/AVECWAVE/AVecWave.pdf
Since you clearly disagree, could you provide any counter-reference to indicate
a) propagation of the probability wave, or
b) equivalence of the probability wave and electromagnetic wave?
But it is. My objection is that the electromagnetic light wave is not the probability wave. The light does have electromagnetic wave-like properties (as well as particle-like properties,) and it is precisely this electromagnetic aspect of the wavicle that propagates.
you write:
It is psi that gives the probability, and this is never a negative value, thus cannot act in true "wave" fashion to exhibit destructive interference.
You can integrate, conjugate, square, triangulate, or dance it round a maypole naked with ribbons in its hair. It doesn't change the fact that the "probability wave" (be it Psi, its modulus, or any function thereof,) is not the same as the electro-magnetic wave nature of the quantum (whether we call that a "light wave", a "pilot wave", a "carrier wave", or any other Bohmian euphemism.) The electromagnetic wave is a different wave entirely, as my previous ref. makes clear ("The Schrodinger wave equation does not describe an ordinary electromagnetic wave but a probability wave"
Therefore, there is no problem with Psi exhibiting characteristically wavish phenomena such as diffraction and interference.
I would say there would be every problem, but whether or not that is so isn't relevant - while you claim the "personality wave" to actually be the electromagnetic quantum wave, any modelled quantum behaviour will unavoidably seem bizarre.
I'll take the opportunity to requote my previous refs, if I may, since the originals are now a good few pages back, but remain unaddressed:
"In accordance with this probability interpretation, it is not uncommon for the wavefunction to be called a 'probability wave'. However, I think that this is a very unsatisfactory description. In the first place psi(x) itself is complex, and so it certainly cannot be a probability. Moreover, the phase of psi (up to an overall constant multiplying factor) is an essential ingredient for the Schroedinger evolution. Even regarding |psi|^2 (or |psi|^2/||psi||) as a 'probability wave' does not seem very sensible to me. Recall that for a momentum state, the modulus |psi| of psi is actually constant throughout the whole of spacetime. There is no information in |psi| telling us even the direction of motion of the wave - it is the phase alone, that gives this wave its 'wavelike' character.
Moreover, probabilities are never negative, let alone complex. If the wavefunction were just a wave of probabilities, then there would never be any of the cancellations of destructive interference. This cancellation is a characteristic feature of quantum mechanics, so vividly portrayed in the two-slit experiment!" [Penrose The Road to Reality chap.21.9 p.519]
"The carrier of the non-local instantaneous action is the wavefunction similar to the de Broglie pilot wave and the reaction is the net observable local space result. The Schrodinger wave equation does not describe an ordinary electromagnetic wave but a probability wave, and the probability wave determines all of the action and reaction of the total electrogravitational interaction."
Since you clearly disagree, could you provide any counter-reference to indicate
a) propagation of the probability wave, or
b) equivalence of the probability wave and electromagnetic wave?
embarassed? Not in the least. I have been married for long enough that there is very little that could embarass, surprise or mystify me about the female psyche or biology.
Except perhaps, there is one thing that I have never understood - why are there always at least 4 combs, 2 hairbrushes and an acre of disposable tissues in an average handbag? And what on earth accounts for the other several kilos of "stuff"?
I've gone camping with less gear than my wife regards as essential for the shortest of trips beyond the front door!
Dear Bev (3963):
I was referring, of course, to an apparatus that generates vibrations, i.e., waves, for the purpose of displaying diffraction, interference, and other wave phenomena, to aid in our discussion of Quantum Mechanics. What did you think I meant?
(3964) Isn't it "minimis"? Ablative plural?
I was referring, of course, to an apparatus that generates vibrations, i.e., waves, for the purpose of displaying diffraction, interference, and other wave phenomena, to aid in our discussion of Quantum Mechanics. What did you think I meant?
(3964) Isn't it "minimis"? Ablative plural?
(a) In order to interfere subtractively, waves have to be able to take on negative values. But probabilities are never negative, they are all numbers between 0 and 1, inclusive. Therefore, if Psi were a probability, it couldn't interfere.
This also seems to be the drift of Penrose's argument, "In the first place, ... in the two-slit experiment." Indeed, I agree with everything Penrose says there.
Now, I agree with (a), both the reasoning and the conclusion. I agreed with the Penrose critique of the phrase "probability wave" the first time you mentioned it, with the minor reservation that it has become so common to call it the "Probability wave" that many people do so even though they know that it is technically incorrect.
OK, so he has proved that a common idiom is actually conceptually sloppy if taken literally. That is a critique of language, not of physical theory. Because I agree, however, I have tried to always say "Psi", not "the probability wave," or even "the probability amplitude wave." And I think I have been fairly successful, so I remain puzzled at your repeating this point.
Psi does, however, "give" (to use your word) the probabilities, in that, given Psi, one can calculate the probabilities from it. The method of calculation of Psi is such that even though Psi itself generally has complex values, the calculated probabilities end up in [0,1], as they should. This is what is assured by normalization and complex conjugation, and that is why I found it relevant to mention them.
Psimagus:
As to the electrogravity.com requote, I remain puzzled as to why, after apparently quoting the abovementioned Penrose argument with approval, you then proceed to quote (also with apparent approval) a passage in which the term "probability wave" is used for Psi.
And I remain utterly mystified by your claim that I "clearly disagree." I agree that Psi in Quantum Mechanics is not the same as the electromagnetic wave in Classical Physics, and I have said this many times. Quantum Mechanics claims to supercede Classical Electromagnetic Theory, not to reformulate it.
As to the electrogravity.com requote, I remain puzzled as to why, after apparently quoting the abovementioned Penrose argument with approval, you then proceed to quote (also with apparent approval) a passage in which the term "probability wave" is used for Psi.
And I remain utterly mystified by your claim that I "clearly disagree." I agree that Psi in Quantum Mechanics is not the same as the electromagnetic wave in Classical Physics, and I have said this many times. Quantum Mechanics claims to supercede Classical Electromagnetic Theory, not to reformulate it.
Since Psi itself is not a probability, it can take on negative values. Hence, there is no problem with Psi diffracting, or interfering with itself; or at least, not the problem suggested by argument (a) in message 3968.
In predicting what will appear on the screen in the two-slit experiment, we first find out what happens to Psi: Psi propagates from the source, passes through the slits, diffracts, interferes with itself, and arrives at the screen. Although Psi itself oscillates, the modulus (a.k.a. amplitude) of Psi has a fixed value at each point on the screen, just as a sound may have a fixed loudness at some point, even though it is a wave phenomenon. The probability that a scintillum will appear in a region is greater in those regions in which the average value of Psi is greater. I.e., the 'louder' Psi is, the more likely it is for there to be a scintillum.
In predicting what will appear on the screen in the two-slit experiment, we first find out what happens to Psi: Psi propagates from the source, passes through the slits, diffracts, interferes with itself, and arrives at the screen. Although Psi itself oscillates, the modulus (a.k.a. amplitude) of Psi has a fixed value at each point on the screen, just as a sound may have a fixed loudness at some point, even though it is a wave phenomenon. The probability that a scintillum will appear in a region is greater in those regions in which the average value of Psi is greater. I.e., the 'louder' Psi is, the more likely it is for there to be a scintillum.
Wow Schroedinger's chocolate bunny ate my last post! Good thing I looked in the toaster. Look what popped up.
(3964) Isn't it "minimis"? Ablative plural?
Yes. I make typos in all languages. I don't pay attention to correct forms of word in Latin any more than I do in English. This surprises you? :-)
If Psimagus is correct about my crossed-wires forming anagrams in a language no one knows yet, than minimus is correct, but the message is entirely different than the one I intended. I fear the world is not yet ready for that true message however. Scoff if you will, those of us with strange mutant neurological issues hold the key to survival of this species.
Yes. I make typos in all languages. I don't pay attention to correct forms of word in Latin any more than I do in English. This surprises you? :-)
If Psimagus is correct about my crossed-wires forming anagrams in a language no one knows yet, than minimus is correct, but the message is entirely different than the one I intended. I fear the world is not yet ready for that true message however. Scoff if you will, those of us with strange mutant neurological issues hold the key to survival of this species.
Really? I've had a few relationships in my time, (not a large sample perhaps, but long-term qualitative studies that have fostered some familiarity with the male gender) and I must admit there are times given male behaviors will still surprise and yes, even embarrass me (though sometimes the surprises may be pleasant too). Women must be easier to understand than men are. All this time men I know have said that women are crazy, it was just part of your gender's projections of your own complex illogical testosterone-colored world.
People expect us to have all that crap. I try not to carry a purse, but you have to put your wallet somewhere, and the cell phone, and keys...etc. Most of my clothes simply don't have good pockets for all that and even those with pockets would have odd bulges if I actually put stuff in the pockets (not that everything I own is skin-tight but women's clothes are cut differently than men's clothes). If I could con the man I am with into carrying everything I would never have a purse.
My father, who is admittedly in his 80s and not like "modern" men, carries a hanky, wallet, keys, cough drops, nail clippers, plastic comb and eyeglasses in various pockets. Men's pants and jackets seem built for that. Maybe I should just wear men's clothes.
I've gone camping with less gear than my wife regards as essential for the shortest of trips beyond the front door!
Camping must be easy in Scotland. I need a tent, sleeping bag, swiss army knife, basic foods and other items when I venture out. Yes, I also make room in the pack for chocolate. Ruffing it is no reason to be uncivilized.
Bev (3972):
Oh, Dear, Bev, I'm sorry! I had some vague idea at the time that it would be funny, but if I had a reason for thinking that, it has flown the coop now! Of course, you are entiled to typos, yust liek hte rets uv uts! Sometimes my insanity outruns my coping mechanisms. [Psi]
Oh, Dear, Bev, I'm sorry! I had some vague idea at the time that it would be funny, but if I had a reason for thinking that, it has flown the coop now! Of course, you are entiled to typos, yust liek hte rets uv uts! Sometimes my insanity outruns my coping mechanisms. [Psi]
Irina,
As to the electrogravity.com requote, I remain puzzled as to why, after apparently quoting the abovementioned Penrose argument with approval, you then proceed to quote (also with apparent approval) a passage in which the term "probability wave" is used for Psi.
Because the terminology is not, in itself, very important. Our understanding of what it describes is what's important. Much as I have a natural sympathy for Penrose's pedantry, I am realist enough to know when a cause is lost. "probability wave" has been common parlance for too many decades to hope to change it now without causing a great deal more confusion than we clear away.
And I remain utterly mystified by your claim that I "clearly disagree."
Well, mainly statements along the line of "My view is that it's the wave, psi, which propagates" [#3807, your emphasis.] But perhaps I'm misinterpreting that when I understand it to mean that you claim psi propagates (my objection is not to the common parlance description of it as a "wave", merely to the nature of the thing. Psi is continuous, and does not propagate.)
I agree that Psi in Quantum Mechanics is not the same as the electromagnetic wave in Classical Physics, and I have said this many times. Quantum Mechanics claims to supercede Classical Electromagnetic Theory, not to reformulate it.
Very well, if we're agreed that it's the electromagnetic wave, not the probability wave, that propagates
Could you remind me of your view of quantum tunnelling? (I've lost track amid all these posts, I'm afraid.)
Because the terminology is not, in itself, very important. Our understanding of what it describes is what's important. Much as I have a natural sympathy for Penrose's pedantry, I am realist enough to know when a cause is lost. "probability wave" has been common parlance for too many decades to hope to change it now without causing a great deal more confusion than we clear away.
Well, mainly statements along the line of "
Very well, if we're agreed that it's the electromagnetic wave, not the probability wave, that propagates
Could you remind me of your view of quantum tunnelling? (I've lost track amid all these posts, I'm afraid.)
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