what physicists use to do for saving Quantum Mechanics

[pedrone]

Consider a hydrogen atom.

There is attraction between the proton and the electron. So, suppose that (when the hydrogen atom will emit a photon) the electron moves from one level to another, by covering the space between the two levels.

Well, as there is a proton-electron Coulombic attraction, the electron is submitted to an acceleration (or deceleration), and according to Maxwell's theory the electron should have to emit a continuous espectrum (photons).

But this does not occur. It was not observed experimentally.

That's why the quantum theorists proposed the following: the electron does not move throughout the space that separates two levels

In other words: according to Quantum Mechanics, the electron disapears from its place in a level, and it appears instantaneously in another place of the other level, without to cross the space that separates the two levels.

Such Quantum Mechanics proposal is something like that called by Einstein to be "phantasmagoric", since only a ghost can do disapear from a place and to appear instantaneously in another place, without covering the space between the two places.


However, in 1989 Hans Dehmelt awarded the Nobel Prize with an experiment that disproves such Quantum Mechanics assumption.

In his experiment, Dehmelt showed that the electron covers the space between the two levels of energy in the atoms.

Therefore, Dehmelt experiment proves that Quantum Mechanics is wrong.

But as the quantum physicists cannot accept any theory which denies Quantum Mechanics, they discovered a way so that to save their theory again: they invented a theory in order to descredit Dehmelt experiment.
In this way, quantum theorists claimed that in Dehmelt experiment "the atom is dressed", and that was the reason why in his experiment it "seems" that the electron covers the space between levels, but acctually it does do it.
And so Quantum Mechanics was saved again.

This is the strategy used often by the quantum physicists, when a new experiment proves that Quantum Mechanics is wrong.


Do you remember other experiment which denies Quantum Mechanics, but the physicists rejected it by using such smart strategy ?

[dafydd]

Consider the lily.......

[MattusMaximus]

However, in 1989 Hans Dehmelt awarded the Nobel Prize with an experiment that disproves such Quantum Mechanics assumption.

In his experiment, Dehmelt showed that the electron covers the space between the two levels of energy in the atoms.

Therefore, Dehmelt experiment proves that Quantum Mechanics is wrong.

You know that we can actually look up why Dehmelt was awarded the Nobel prize... (http://nobelprize.org/nobel_prizes/physics/laureates/1989/press.html)
... In 1973 Dehmelt succeeded for the first time in observing a single electron in a trap, and two years later he introduced a method for "cooling" the electron - two inventions which improved accuracy considerably. The g-factor anomaly has now been determined by Dehmelt and his co-workers with an accuracy of a few parts in a billion, and this, together with corresponding theoretical calculations, constitutes one of the most critical tests we have of QED.

... A frequency stability of the same order might also be possible with the ion-trap technique. The method is based on an idea of Dehmelt in observing what is termed the quantum jump in a single ion in a trap. Laser radiation corresponding to two different transitions is used - one to a strong transition and one to a very weak one. The former is used for detecting the latter, which is very narrow and cannot be observed directly.

The realisation of methods of the extreme precision that now seems possible opens completely new opportunities for testing fundamental principles in quantum physics, gravitation theory and other branches of basic physics.

In other words, it was a spectacularly precise test which actually confirmed modern quantum theory - the exact opposite of what you stated.

You fail, pedrone.

[dafydd]

Why did he link to it? A six year old child could have spotted that it is in total contradiction to his claim. What is going on here?

[PixyMisa]

I think perhaps he's just not terribly bright.

[Ziggurat]

That's why the quantum theorists proposed the following: the electron does not move throughout the space that separates two levels

In other words: according to Quantum Mechanics, the electron disapears from its place in a level, and it appears instantaneously in another place of the other level, without to cross the space that separates the two levels.

Well, no. That isn't actually what quantum mechanics predicts. That's often given as a shorthand description for those who can't understand the math, or for those who don't want to deal with the full complexity of the problem, but in fact the time evolution of the wave function is NOT discontinuous. Quantum mechanics predicts NO discontinuities in the time evolution of a wave function. The Schrodinger equation explicitly prohibits such events. Your entire concept of quantum mechanics is wrong from the start, and all your conclusions about its invalidity therefore have no basis.

Do you remember other experiment which denies Quantum Mechanics, but the physicists rejected it by using such smart strategy ?

As has been explained above, you haven't actually provided a first example.

[Dancing David]

Ziggy,
For us math low level people. Are you saying that 'quantum jumps' actually are not jumps?

ETA: there is a continuous transtion from one state to the next?

[EdipisReks]

I think perhaps he's just not terribly bright.

add in a bit of illusory superiority (http://en.wikipedia.org/wiki/Illusory_superiority), and i think we might have a answer to dafydd's question.

[Ziggurat]

Ziggy,
For us math low level people. Are you saying that 'quantum jumps' actually are not jumps?

ETA: there is a continuous transtion from one state to the next?

Yes, the transition from one state to another is continuous, though that answer deserves some clarification.

In quantum mechanics, we can describe the state of a particle as a linear combination of some basis set of states. Mathematically speaking, this is exactly equivalent to saying that a vector in 3D space can be written as a combination of x, y, and z components (our basis set). It's often convenient to use energy eigenstates (states with definite energies) as our basis states.

When the electron in an atom undergoes a transition from one state to another, that's mathematically equivalent to "rotating" in some phase space. The amplitudes of the component vectors change continuously as one rotates.

If one looks at the expectation value of energy during a transition from one energy eigenstate to another energy eigenstate, that value also changes continuously during transition. The tricky part, and probably the most relevant qualifier in regards to my response, is that this is the expectation value which is changing continuously. When we're in a superposition state with (for example) a 50/50 mixture of a high-energy state and a low-energy state, the expectation value is simply their average. If it's not an even mixture, then it's a weighted average. But if you perform a measurement, you will not get the (weighted) average. You will get either the high-energy value or the low-energy value, with the probability of each determined by the amplitudes of your superposition (the same factor that determines the weighting for the average).

So expectation values change continuously. But they change continuously as shifting probabilities between two discrete values, in the case of energy. There's quite a bit more to be said about what exactly a measurement is in quantum mechanics, but that's too broad a subject to adequately address in this response.

[pedrone]

Desconfiando da intuição semi-clássica de Dehmelt, alguns físicos teóricos usaram a mecânica ondulatória para mostrar que não ocorreriam períodos escuros. Logo em seguida, porém, em 1986, experimentos mostraram que Dehmelt estava certo! Observaram-se períodos escuros! Mas então... ocorreriam saltos quânticos de maneira objetiva nos átomos?
http://www.fis.ufba.br/dfg/pice/ff/ff-25.htm

TRANSLATION:
Distrusting of the half-classic intuition of Dehmelt, some theoretical physicists had used the wave mechanics to show that dark periods would not occur. Immediately afterwards, however, in 1986, experiments had shown that Dehmelt was certain! Dark periods had been observed! But then… would occur quantum jumps in objective way in atoms?
:)

[MattusMaximus]

Yes, the transition from one state to another is continuous, though that answer deserves some clarification.

In quantum mechanics, we can describe the state of a particle as a linear combination of some basis set of states. Mathematically speaking, this is exactly equivalent to saying that a vector in 3D space can be written as a combination of x, y, and z components (our basis set). It's often convenient to use energy eigenstates (states with definite energies) as our basis states.

When the electron in an atom undergoes a transition from one state to another, that's mathematically equivalent to "rotating" in some phase space. The amplitudes of the component vectors change continuously as one rotates.

If one looks at the expectation value of energy during a transition from one energy eigenstate to another energy eigenstate, that value also changes continuously during transition. The tricky part, and probably the most relevant qualifier in regards to my response, is that this is the expectation value which is changing continuously. When we're in a superposition state with (for example) a 50/50 mixture of a high-energy state and a low-energy state, the expectation value is simply their average. If it's not an even mixture, then it's a weighted average. But if you perform a measurement, you will not get the (weighted) average. You will get either the high-energy value or the low-energy value, with the probability of each determined by the amplitudes of your superposition (the same factor that determines the weighting for the average).

So expectation values change continuously. But they change continuously as shifting probabilities between two discrete values, in the case of energy. There's quite a bit more to be said about what exactly a measurement is in quantum mechanics, but that's too broad a subject to adequately address in this response.

This is a great explanation, Zig. Thanks!

For those who don't necessarily have the background to fully understand what Zig wrote, I think that perhaps this link to Wikipedia (and more importantly, the associated animated gif image) (http://en.wikipedia.org/wiki/Schr%C3%B6dinger_wave_equation#Single_particle_in_ a_potential) might help you understand what he's saying. For purposed of this discussion, I would focus on parts G & H of the image at that link: notice that the solutions in G & H to the Schrodinger equation are smooth & continuous (i.e., there are no sudden gaps in the line).

I hope this helps to further clarify what Zig posted.

[dafydd]

add in a bit of illusory superiority (http://en.wikipedia.org/wiki/Illusory_superiority), and i think we might have a answer to dafydd's question.

No might about it.

[Reality Check]

http://www.fis.ufba.br/dfg/pice/ff/ff-25.htm

What a big liar you are, pedrone :D!
Read the first sentence on the web page:

Occur quantum jumps in atoms or not? The atomic model of Bohr (1913) left the impression that yes, despite the wave mechanics of Schrödinger (1926) indicate no.
...
We will examine these results, taken by Shimony as "among the most dramatic in the history of optics." We will see, however, that wave mechanics would eventually triumphing, making use of notions of "dressed atom" and "measuring null result", and transferring the discontinuity to the collapses accompanying comments.

This contradicts your OP since the Bohr model is not modern quantum mechanics which starts with the Schrödinger equation.
So
That's why the quantum theorists proposed the following: the electron does not move throughout the space that separates two levels

should read: That's why the quantum theorists proposed the following: the electron moves throughout the space that separates two levels.
and
In his experiment, Dehmelt showed that the electron covers the space between the two levels of energy in the atoms.
The author goes onto basically saying what Ziggurat has already stated. There is a discontinuity but it is not in the position or energy of the electron. It is in the wave function collapse. The concept of the dressed atom (http://en.wikipedia.org/wiki/Light_dressed_state) is applicable because the experiment uses laser beams.

[pedrone]

Desconfiando da intuição semi-clássica de Dehmelt, alguns físicos teóricos usaram a mecânica ondulatória para mostrar que não ocorreriam períodos escuros. Logo em seguida, porém, em 1986, experimentos mostraram que Dehmelt estava certo! Observaram-se períodos escuros! Mas então... ocorreriam saltos quânticos de maneira objetiva nos átomos?
http://www.fis.ufba.br/dfg/pice/ff/ff-25.htm

TRANSLATION:
Distrusting of the half-classic intuition of Dehmelt, some theoretical physicists had used the wave mechanics to show that dark periods would not occur. Immediately afterwards, however, in 1986, experiments had shown that Dehmelt was certain! Dark periods had been observed! But then… would occur quantum jumps in objective way in atoms?
:)
In short:

In 1986 Dehmelt published his experiment.
;)
In 1987 the theorists proposed a new theory:

Dressed-atom theory of stimulated pair transitions
Phys. Rev. A 35, 2164–2174 (1987)
http://pra.aps.org/abstract/PRA/v35/i5/p2164_1


Notice that earlier the Dehmelt experiment the theorists did not suppose the possibility that atom could be "dressed", in spite of they ought to expect it, by considering the foundations of Quantum Mechanics.

So, after Dehmelt experiments in 1986, the theorists at once had created the "Dressed-atom theory", so that to avoid that Quantum Mechanics should be contradicted by his experiment
:)


I suppose the theorists will do the same regarding cold fusion.
And after the definitive cold fusion confirmation by experiments (probably the Rossi-Focardy experiment), the theorists will claim that the nucleus is "dressed", and that's why cold fusion occurs.
:D
And at once the theorists will propose the "dressed-nucleus theory"
:p

[Reality Check]

In short:

In 1986 Dehmelt published his experiment.
;)
In 1987 the theorists proposed a new theory:

Dressed-atom theory of stimulated pair transitions
Phys. Rev. A 35, 2164–2174 (1987)
http://pra.aps.org/abstract/PRA/v35/i5/p2164_1

Notice that earlier the Dehmelt experiment the theorists did not suppose the possibility that atom could be "dressed", in spite of they ought to expect it, by considering the foundations of Quantum Mechanics.
...

In short: You are ignorant of the way science works :jaw-dropp!
Science is driven by empirical data. If the data says that a theory needs to be created to explain the data then the theory is created.

Even shorter: You are wrong :jaw-dropp!
In 1977: Dressed-atom description of resonance fluorescence and absorption spectra of a multi-level atom in an intense laser beam (http://iopscience.iop.org/0022-3700/10/3/005/)
Cohen-Tannoudji, C.; Reynaud, S.

[pedrone]

In short: You are ignorant of the way science works :jaw-dropp!
Science is driven by empirical data. If the data says that a theory needs to be created to explain the data then the theory is created.

Even shorter: You are wrong :jaw-dropp!
In 1977: Dressed-atom description of resonance fluorescence and absorption spectra of a multi-level atom in an intense laser beam (http://iopscience.iop.org/0022-3700/10/3/005/)
Cohen-Tannoudji, C.; Reynaud, S.
wow!
so dressed-atom is used often when experiments disprove Quantum Mechanics...
:p

[pedrone]

In short: You are ignorant of the way science works :jaw-dropp!
Science is driven by empirical data. If the data says that a theory needs to be created to explain the data then the theory is created.

Even shorter: You are wrong :jaw-dropp!
In 1977: Dressed-atom description of resonance fluorescence and absorption spectra of a multi-level atom in an intense laser beam (http://iopscience.iop.org/0022-3700/10/3/005/)
Cohen-Tannoudji, C.; Reynaud, S.
:D
but I not sure the dressed-nucleus theory will succeed to expain cold fusion
:D

[Reality Check]

wow!
so dressed-atom is used often when experiments disprove Quantum Mechanics...
:p
wow! So you remain ignorant
:jaw-dropp

The dressed atom theory existed before the experiment. It is a result of applying quantum mechanics to an atom in a laser beam.

[Reality Check]

:D
but I not sure the dressed-nucleus theory will succeed to expain cold fusion
:D
:eye-poppi
but I am sure that you have no idea what the dressed-nucleus theory is and that it has nothing to do with fusion.
:eye-poppi

[Dancing David]

Yes, the transition from one state to another is continuous, though that answer deserves some clarification.

In quantum mechanics, we can describe the state of a particle as a linear combination of some basis set of states. Mathematically speaking, this is exactly equivalent to saying that a vector in 3D space can be written as a combination of x, y, and z components (our basis set). It's often convenient to use energy eigenstates (states with definite energies) as our basis states.

When the electron in an atom undergoes a transition from one state to another, that's mathematically equivalent to "rotating" in some phase space. The amplitudes of the component vectors change continuously as one rotates.

If one looks at the expectation value of energy during a transition from one energy eigenstate to another energy eigenstate, that value also changes continuously during transition. The tricky part, and probably the most relevant qualifier in regards to my response, is that this is the expectation value which is changing continuously. When we're in a superposition state with (for example) a 50/50 mixture of a high-energy state and a low-energy state, the expectation value is simply their average. If it's not an even mixture, then it's a weighted average. But if you perform a measurement, you will not get the (weighted) average. You will get either the high-energy value or the low-energy value, with the probability of each determined by the amplitudes of your superposition (the same factor that determines the weighting for the average).

So expectation values change continuously. But they change continuously as shifting probabilities between two discrete values, in the case of energy. There's quite a bit more to be said about what exactly a measurement is in quantum mechanics, but that's too broad a subject to adequately address in this response.

Thanks, very cool and as always counter intuitive.

[Loss Leader]

But as the quantum physicists cannot accept any theory which denies Quantum Mechanics, they discovered a way so that to save their theory again: they invented a theory in order to descredit Dehmelt experiment.


Um ... the truth or falsity of your claim aside ... Isn't this the way science is supposed to work?

A theory is proposed that accounts for all observable phenomena. Its predictions about future phenomena are tested. If they are not observed, the test is scrutinized. If it is repeatable, the theory is changed. Scientific theories may change all at once in sudden revolutions, or gradually evolve.

So, isn't that what happened in your example?

Also, wouldn't young physicists looking to make a name for themselves be very happy if they could overturn orthodoxy? The most famous names in science did just that. Newton's calculus was an impossibly complicated mess that could barely be understood (almost none of his terminology even survives), but he gets the credit because he was the first.

Last, does this have to do with the fact that you are championing the work of a person whose experiments cannot be recreated, whose conclusions cannot find a peer-reviewed publisher, and whose patents are too vague even to be acceptable? If so, can you tell me how fusion was achieved without the production of gamma radiation?

[theprestige]

...ocorreriam saltos quânticos de maneira objetiva nos átomos?

[B]TRANSLATION:

...would occur quantum jumps in objective way in atoms?

Minor nitpick: presented as a question, the phrase should actually be translated "...would quantum jumps objectively occur in atoms?"

(Presented as a statement, the phrase would be translated "... quantum jumps would objectively occur in atoms.")

[dafydd]

:eye-poppi
but I am sure that you have no idea what the dressed-nucleus theory is and that it has nothing to do with fusion.
:eye-poppi

Does he think that it is a nucleus spruced up for a night on the town?

[randman]

Well, no. That isn't actually what quantum mechanics predicts. That's often given as a shorthand description for those who can't understand the math, or for those who don't want to deal with the full complexity of the problem, but in fact the time evolution of the wave function is NOT discontinuous. Quantum mechanics predicts NO discontinuities in the time evolution of a wave function. The Schrodinger equation explicitly prohibits such events. Your entire concept of quantum mechanics is wrong from the start, and all your conclusions about its invalidity therefore have no basis.



As has been explained above, you haven't actually provided a first example.
I agree he's wrong but don't think your comment below is entirely correct.

but in fact the time evolution of the wave function is NOT discontinuous. Quantum mechanics predicts NO discontinuities in the time evolution of a wave function.

[Ziggurat]

I agree he's wrong but don't think your comment below is entirely correct.

How so?

The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. People frequently discuss the measurement process as if it were discontinuous, but 1) that's not the only way to handle it (for example, Everett's Many Worlds interpretation), and 2) even when you do treat the measurement process as a discrete, discontinuous collapse, you're not using the Schrodinger equation. Collapse is basically what happens when you STOP using quantum mechanics, and brush everything about the measurement process itself under the rug.

So I'll stand by what I said about quantum mechanics not having discontinuous time evolution.

[WhatRoughBeast]

If so, can you tell me how fusion was achieved without the production of gamma radiation?

Loss Leader, I hate to even seem to even partly support Pedrone, but you've missed something. The patent application by He Who Must Not Be Named (not Voldemort) specifically calls for gamma radiation subsequent to beta+ decay as the primary energy transfer mechanism.

And the Swedish Professor report makes no mention of radiation measurement during the Demonstration Which Must Not Be Named, only before and after.

[Loss Leader]

Loss Leader, I hate to even seem to even partly support Pedrone, but you've missed something. The patent application by He Who Must Not Be Named (not Voldemort) specifically calls for gamma radiation subsequent to beta+ decay as the primary energy transfer mechanism.

And the Swedish Professor report makes no mention of radiation measurement during the Demonstration Which Must Not Be Named, only before and after.


Thanks for the correction. Was there any shielding for gamma radiation at all during the Demonstration Of Doom? Did anybody turn into Lou Ferrigno?

[randman]

How so?

The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. People frequently discuss the measurement process as if it were discontinuous, but 1) that's not the only way to handle it (for example, Everett's Many Worlds interpretation), and 2) even when you do treat the measurement process as a discrete, discontinuous collapse, you're not using the Schrodinger equation. Collapse is basically what happens when you STOP using quantum mechanics, and brush everything about the measurement process itself under the rug.

So I'll stand by what I said about quantum mechanics not having discontinuous time evolution.
Basically, you are arguing MWI which was obvious from the terminology. Keep in mind that math showing the probability of something happening is not the same as being physically continuous.

Say I write an equation where "A" has a 20% probability to show up at points 1-5. That doesn't mean "A"'s path there is necessarily continuous.

[randman]

JUst add a little more on the wave function collapse or decoherence, etc,......I don't see how there isn't some sort of discontinuity involved. In MWI, there would be a continuous linear progression from what I've been told about the idea, but there is a lateral discontinuity within the universe (the Multiverse). There are universes that are no longer continuous in this scenario with each other. I know you may be technically talking of continuity in time, but there is a fairly major spatial discontinuity here being proposed as the solution.

If you think the particle as existing more in a wave-like trajectory, then collapsing into a single path, that's a form of discontinuity it seems to me. It doesn't just narrow down for example.

If you think of it as not really in a wave-like trajectory or a single path but as a mere potential for discrete form, then you really are talking about even it's past "becoming" due to "measurement" or sufficient interaction. That's not really continuous in one sense because the measurement/observation/interaction event causes it to exist not just as potential but in discrete form even from the trajectory it would have had to have taken in the past (if it were discrete).

I also question the whole concept of continuous in time. What evidence do we have there is such a thing as a unit of time. If there were one fundamental unit of time, nothing would be moving as time is just a measurement of changes. If nothing was moving, then the universe would be frozen (Lynd's argument). Moreover, since things experience different rates of what we call time, which just means the changes around them occur faster or slower from their vantage point based on their relative velocity, you should expect some fuzziness, jumping and quantization. That's because from any one vantage point, something else is always not in an exact, precise position. This inherent imprecision is more evident with particles because they are so small.

[Ziggurat]

Basically, you are arguing MWI which was obvious from the terminology.

I don't actually like MWI. I find it deeply unsatisfying, though I recognize that's not exactly a rigorous objection. But more to the point, I'm not actually arguing in favor of it. Rather, I'm arguing against a naive Copenhagen interpretation.

Keep in mind that math showing the probability of something happening is not the same as being physically continuous.

The evolution of the wave function is the only time evolution that quantum mechanics actually describes. And that's always continuous. So on what basis can one claim that anything in quantum mechanics is not continuous with respect to time?

[randman]

I don't actually like MWI. I find it deeply unsatisfying, though I recognize that's not exactly a rigorous objection. But more to the point, I'm not actually arguing in favor of it. Rather, I'm arguing against a naive Copenhagen interpretation.



The evolution of the wave function is the only time evolution that quantum mechanics actually describes. And that's always continuous. So on what basis can one claim that anything in quantum mechanics is not continuous with respect to time?
See my second response above.

[Ziggurat]

JUst add a little more on the wave function collapse or decoherence, etc,......I don't see how there isn't some sort of discontinuity involved.

Your measurement process isn't instantaneous. It always takes time to do a measurement. So there is time for the system to evolve, continuously, from whatever superposition state it stated in to whatever state your measurement yields. There's not necessarily any need for a discontinuity even during "collapse". In fact, quantum mechanics doesn't allow for such a discontinuity. To get a discontinuity, something other than quantum mechanics has to happen. That's a possibility, of course. But as a practical matter, "collapse" of the wave function always happens when you stop using quantum mechanics because it simply becomes too difficult.

In MWI, there would be a continuous linear progression from what I've been told about the idea, but there is a lateral discontinuity within the universe (the Multiverse). There are universes that are no longer continuous in this scenario with each other.

That is, I think, an misunderstanding of MWI.

Let's take the simplest example, a particle in a superposition state of spin up and spin down. We measure this particle. MWI would say that since the particle was in a superpositions state, the detector (which is now entangled with the particle because of the measurement process) is now ALSO in a superposition state. And when we look at the detector, we become entangled, and also become a superposition state.

Of course, we never "observe" ourselves or our detectors as being superpositions. According to MWI, that's just the result of the two parts of our superposition not interacting with each other. The part of the wave function of ourselves which observed a spin up doesn't interact with the part of the wave function of ourselves which observed a spin down. So each part of our linear combination will behave as if the wave function has collapsed, even though no actual collapse happened. There is no spatial discontinuity either. The two parts of our spin superposition occupied the same space, so do we.

I also question the whole concept of continuous in time.

If time isn't continuous, then standard quantum mechanics is wrong anyways. If the real world has discrete time, that still can't make a theory based on continuous time predict a discontinuity. It just means the theory is wrong, but we're talking about the predictions of the theory.

What evidence do we have there is such a thing as a unit of time. If there were one fundamental unit of time, nothing would be moving as time is just a measurement of changes. If nothing was moving, then the universe would be frozen (Lynd's argument).

Um... you seem to be arguing in favor of continuous (not discrete) time.

[randman]

Your measurement process isn't instantaneous. It always takes time to do a measurement. So there is time for the system to evolve, continuously, from whatever superposition state it stated in to whatever state your measurement yields. There's not necessarily any need for a discontinuity even during "collapse". In fact, quantum mechanics doesn't allow for such a discontinuity. To get a discontinuity, something other than quantum mechanics has to happen. That's a possibility, of course. But as a practical matter, "collapse" of the wave function always happens when you stop using quantum mechanics because it simply becomes too difficult.



That is, I think, an misunderstanding of MWI.

Let's take the simplest example, a particle in a superposition state of spin up and spin down. We measure this particle. MWI would say that since the particle was in a superpositions state, the detector (which is now entangled with the particle because of the measurement process) is now ALSO in a superposition state. And when we look at the detector, we become entangled, and also become a superposition state.

Of course, we never "observe" ourselves or our detectors as being superpositions. According to MWI, that's just the result of the two parts of our superposition not interacting with each other. The part of the wave function of ourselves which observed a spin up doesn't interact with the part of the wave function of ourselves which observed a spin down. So each part of our linear combination will behave as if the wave function has collapsed, even though no actual collapse happened. There is no spatial discontinuity either. The two parts of our spin superposition occupied the same space, so do we.



If time isn't continuous, then standard quantum mechanics is wrong anyways. If the real world has discrete time, that still can't make a theory based on continuous time predict a discontinuity. It just means the theory is wrong, but we're talking about the predictions of the theory.



Um... you seem to be arguing in favor of continuous (not discrete) time.
I think you are stretching things. For example:

Your measurement process isn't instantaneous. It always takes time to do a measurement. So there is time for the system to evolve, continuously, from whatever superposition state it stated in to whatever state your measurement yields. There's not necessarily any need for a discontinuity even during "collapse". In fact, quantum mechanics doesn't allow for such a discontinuity.

First, who says it's not instantaneous. Doesn't matter how long it would you or I to measure something, it's the interaction at some stage. Moreover, the amount of time isn't relevant. It's the discontinuous change in spatial occupancy from one state to another without intermediate states.

Let's take the simplest example, a particle in a superposition state of spin up and spin down. We measure this particle. MWI would say that since the particle was in a superpositions state, the detector (which is now entangled with the particle because of the measurement process) is now ALSO in a superposition state. And when we look at the detector, we become entangled, and also become a superposition state.

That's not how I have heard it explained but there appear to be different MWI versions so maybe I heard a different one.

Of course, we never "observe" ourselves or our detectors as being superpositions. According to MWI, that's just the result of the two parts of our superposition not interacting with each other. The part of the wave function of ourselves which observed a spin up doesn't interact with the part of the wave function of ourselves which observed a spin down. So each part of our linear combination will behave as if the wave function has collapsed, even though no actual collapse happened. There is no spatial discontinuity either. The two parts of our spin superposition occupied the same space, so do we.

Ok, let's just push this out a little further. A particle somewhere interacts with something, must be gazillions of instances of this throughout the universe, the way I have heard it is the particle's seeming collapse is just that it takes on path in one universe and another in a different one, and so there are really a whole lot of alternate universes including very many we don't even exist in at all. So there is definitely a separation and difference between those universes and this one. We are not in super-positional states in the overwhelming majority of these universes within the multiverse's evolution.

What you explain as MWI seems more like the idea that all we have is the quantum state of possibilities and would seem to open the door to even universes or places within this universe where if there were people there, they might experience very different things, maybe as someone posted on another thread, gravity working the opposite way, but when we look in that direction, we only see the potential based on where we are at....but that's a different topic.

If time isn't continuous, then standard quantum mechanics is wrong anyways.


Not really and no more than anything else. Math generally assumes units of time. It is an idealization that works because of the statistical likelihood, but if there is no unit of time, and I don't see how there could be, everything in the physical world is discontinuous to some degree.

Think of it like the surface of a very smooth ball. It seems continuously smooth, and is sufficiently so for us to calculate things, but in reality, it's surface is fractal and changing.

There is no absolute continuity in all likelihood of time because there is no unit of time. If you imagine one, you could imagine dividing it further.

Plus and getting back to relativity, everything is always experiencing some difference in time, however slight, based on speed, right? So if you pick any interval of so-called time from one vantage point, something else is moving during that same interval because it's experience of time is different even if only very slightly so.

Therefore, there is no precise definite position of anything, just within a certain approximation even if that approximation is relatively very precise from a human perspective.

[W.D.Clinger]

How so?

The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. People frequently discuss the measurement process as if it were discontinuous, but 1) that's not the only way to handle it (for example, Everett's Many Worlds interpretation), and 2) even when you do treat the measurement process as a discrete, discontinuous collapse, you're not using the Schrodinger equation. Collapse is basically what happens when you STOP using quantum mechanics, and brush everything about the measurement process itself under the rug.

So I'll stand by what I said about quantum mechanics not having discontinuous time evolution.
Basically, you are arguing MWI which was obvious from the terminology. Keep in mind that math showing the probability of something happening is not the same as being physically continuous.

Say I write an equation where "A" has a 20% probability to show up at points 1-5. That doesn't mean "A"'s path there is necessarily continuous.
Schrödinger's equation says nothing about probabilities.

Had randman possessed even the dimmest understanding of Schrödinger's equation, he would not have written such nonsense.


JUst add a little more on the wave function collapse or decoherence, etc,......I don't see how there isn't some sort of discontinuity involved. In MWI, there would be a continuous linear progression from what I've been told about the idea, but there is a lateral discontinuity within the universe (the Multiverse). There are universes that are no longer continuous in this scenario with each other. I know you may be technically talking of continuity in time, but there is a fairly major spatial discontinuity here being proposed as the solution.
:confused:

The conclusion I draw from the above is that randman doesn't understand the mathematical concepts of continuity and discontinuity.

Schrödinger's equation doesn't even make sense unless the wave function is continuous and differentiable with respect to time. With respect to other variables in phase space, the only possible source of discontinuity is the Hamiltonian itself.


If you think the particle as existing more in a wave-like trajectory, then collapsing into a single path, that's a form of discontinuity it seems to me. It doesn't just narrow down for example.
Schrödinger's equation says absolutely nothing about "collapsing".


If you think of it as not really in a wave-like trajectory or a single path but as a mere potential for discrete form, then you really are talking about even it's past "becoming" due to "measurement" or sufficient interaction. That's not really continuous in one sense because the measurement/observation/interaction event causes it to exist not just as potential but in discrete form even from the trajectory it would have had to have taken in the past (if it were discrete).
Even if that made any sense, it would have nothing to do with Schrödinger's equation.


I also question the whole concept of continuous in time. What evidence do we have there is such a thing as a unit of time. If there were one fundamental unit of time, nothing would be moving as time is just a measurement of changes. If nothing was moving, then the universe would be frozen (Lynd's argument). Moreover, since things experience different rates of what we call time, which just means the changes around them occur faster or slower from their vantage point based on their relative velocity, you should expect some fuzziness, jumping and quantization. That's because from any one vantage point, something else is always not in an exact, precise position. This inherent imprecision is more evident with particles because they are so small.
The conclusion I draw from the above is that randman doesn't understand the mathematical concept of "continuous in time."

The concept of continuity with respect to time does not depend upon randman's notion of "a unit of time." randman's notion of "a unit of time" must differ from the Newtonian and Einsteinian notions, because the Newtonian and Einsteinian notions do not preclude motion.

The rest of randman's paragraph consists of even more unsupported assertions that, because they don't even follow from randman's mistakes, are fairly characterized as non-sequiturs.

[randman]

Forgot to respond to this:

Um... you seem to be arguing in favor of continuous (not discrete) time.

I am saying there is neither continuous, nor discrete, time. Time is just spatial relationship in one sense (sequence of spatial changes), but I'd go further and define space a little differently. It's because there is no discrete unit of time that what seems to be time is not so smooth and discontinuous to some degree.

[randman]

WD jumps in with his usual nonsense, having no clue what's being discussed and believing he understands it, quotes some math, but hasn't even grasped, nor considered what he is responding to.

Hey wd, how do you know a mathematical point in time exists in the universe?

[W.D.Clinger]

WD jumps in with his usual nonsense, having no clue what's being discussed and believing he understands it, quotes some math, but hasn't even grasped, nor considered what he is responding to.

Hey wd, how do you know a mathematical point in time exists in the universe?
Your question is naive, both philosophically and physically.

People who haven't yet understood the basics of freshman calculus shouldn't be lecturing physicists and mathematicians on quantum mechanics and continuity.

[WhatRoughBeast]

Thanks for the correction. Was there any shielding for gamma radiation at all during the Demonstration Of Doom? Did anybody turn into Lou Ferrigno?

The article describing the test claimed 2 cm lead thickness on the demo unit, and that the unit was operated "in a shielded room" (no further detail). Since the patent application claims a reasonable energy of 10 MeV per nucleus, and beta+ decay gives 2 gammas, the nominal gamma radiation from the process is 5 MeV. I have no idea what the half-value thickness for lead / 5 MeV is, but for 100 keV it's .012 cm, and for 500 keV it's .42 cm, so I have real doubts about the utitlity of a piddling 2 cm. A rough linear extrapolation give a half value of something like 70 cm.

Oooh. You don't think they might be (gasp) faking it, do you?

If the Hulk made an appearance, nobody made a fuss about it.

[Reality Check]

WD jumps in with his usual nonsense, having no clue what's being discussed and believing he understands it, quotes some math, but hasn't even grasped, nor considered what he is responding to.

Hey wd, how do you know a mathematical point in time exists in the universe?
Hey randman, why are you displaying so much ignorance of QM by posting this. What W.D.Clinger stated is standard QM that you can verify just by looking at Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) says nothing about probabilities.
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) has to be continuous in time because it is differentiated by time.
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) does not describe any collapse of the wave funciton. It describes the continuous evolution of the wave function.
Hey randman, do you know that a mathematical point in time is defined to exist in the universe? This was first stated by this guy Euclid 2300 years ago in terms of a general geometry.

[randman]

Your question is naive, both philosophically and physically.

People who haven't yet understood the basics of freshman calculus shouldn't be lecturing physicists and mathematicians on quantum mechanics and continuity.
So you cannot answer but choose not to admit it.

Ok.

[Ziggurat]

First, who says it's not instantaneous.

Quantum mechanics, for one.

Doesn't matter how long it would you or I to measure something, it's the interaction at some stage.

And the interaction takes time. The only way the interaction could produce a truly instant effect is if the interaction potential was infinite (and not just at a point), but that's completely unphysical.

Moreover, the amount of time isn't relevant.

It's absolutely relevant. If the time for measurement is finite, and you don't track what happens during the measurement process (which... we don't), then how can you tell that what happened was a discrete collapse and not a continuous time evolution? Well, you can't.

It's the discontinuous change in spatial occupancy from one state to another without intermediate states.

But quantum mechanics says that it IS a continuous change. Now, maybe quantum mechanics is wrong, but we're discussing what quantum mechanics says, and it says that changes are all continuous.

That's not how I have heard it explained

I've heard lots of wrong explanations about lots of different aspects of quantum mechanics.

What you explain as MWI seems more like the idea that all we have is the quantum state of possibilities and would seem to open the door to even universes or places within this universe where if there were people there, they might experience very different things, maybe as someone posted on another thread, gravity working the opposite way

No. What I explained would not allow for anything like alternative versions of physics.

Not really

Yes, really. You can't take a derivative with respect to a discrete variable. And a time derivative is not only a central feature of the Schrodinger equation, it's also the part that's sensitive to the time dependence of the wave function.

and no more than anything else.

The fact that other theories would also have problems with discrete time doesn't make the problems that standard quantum mechanics has with discrete time just disappear.

One might be able to reformulate a nonstandard quantum mechanics that used discrete time, but that is, well, non-standard. So we can expect that at least some of its predictions will be different from standard quantum mechanics.

Math generally assumes units of time.

A unit of time is not the same as discrete time. I'm not sure why you have these concepts conflated. Perhaps you think that a unit of time is somehow tied to a quantization of time - ie, your units are some multiple of some fundamental quantization of time. If time is discrete, then indeed the fundamental quantization of time would be the most meaningful units of time. But there is absolutely no need for time to be quantized in order to have units. Our units of time are arbitrary, but that's not a problem.

Think of it like the surface of a very smooth ball. It seems continuously smooth, and is sufficiently so for us to calculate things, but in reality, it's surface is fractal and changing.

Most surfaces are not fractal. They may not be smooth down to the atomic level, but fractal does not simply mean rough.

There is no absolute continuity in all likelihood of time because there is no unit of time.

There are units of time. They're arbitrary, but that's exactly what one should expect from continuous time. I'm at a loss as to why you think otherwise, so I'm not sure what to say to convince you if you won't accept my word for it.

[randman]

Hey randman, why are you displaying so much ignorance of QM by posting this. What W.D.Clinger stated is standard QM that you can verify just by looking at Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) says nothing about probabilities.
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) has to be continuous in time because it is differentiated by time.
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) does not describe any collapse of the wave funciton. It describes the continuous evolution of the wave function.
Hey randman, do you know that a mathematical point in time is defined to exist in the universe? This was first stated by this guy Euclid 2300 years ago in terms of a general geometry.
So you claim there is such a thing as base unit of time, just as in math? In the physical universe?

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period. He's also just spouting bs. For example, in saying the equation describes an evolution and not a collapse, he is just inserting his own interpretation for a math equation. The word "evolution" is not in the equation. Nor is collapse.

To try to determine what happens, one needs to actually become aware of the physical process involved. WD isn't and doesn't realize this is necessary.

[Ziggurat]

So you claim there is such a thing as base unit of time, just as in math? In the physical universe?

What the hell is a "base unit" of time? And how does that differ from an ordinary unit of time?

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period.

Not really. Collapse is what "happens" when you want to stop using quantum mechanics.

He's also just spouting bs. For example, in saying the equation describes an evolution and not a collapse, he is just inserting his own interpretation for a math equation.

No, he is not. He's stating a fact. You can think of collapse as part of the theory of quantum mechanics if you want to (though that simply becomes a semantic question of what you wish to include under that heading), but it sure as hell is NOT part of the Schrodinger equation. On this point, there can be no serious debate. The math is unambiguous: the Schrodinger equation does not, and cannot, describe a discrete collapse process.

The word "evolution" is not in the equation. Nor is collapse.

The words don't need to be. The math still describes a continuous time evolution, not a discrete collapse. "d/dt" is pretty clear.

To try to determine what happens, one needs to actually become aware of the physical process involved. WD isn't and doesn't realize this is necessary.

WD knows more about quantum mechanics than you do.

[randman]

Quantum mechanics, for one.



And the interaction takes time. The only way the interaction could produce a truly instant effect is if the interaction potential was infinite (and not just at a point), but that's completely unphysical.



It's absolutely relevant. If the time for measurement is finite, and you don't track what happens during the measurement process (which... we don't), then how can you tell that what happened was a discrete collapse and not a continuous time evolution? Well, you can't.



But quantum mechanics says that it IS a continuous change. Now, maybe quantum mechanics is wrong, but we're discussing what quantum mechanics says, and it says that changes are all continuous.



I've heard lots of wrong explanations about lots of different aspects of quantum mechanics.



No. What I explained would not allow for anything like alternative versions of physics.



Yes, really. You can't take a derivative with respect to a discrete variable. And a time derivative is not only a central feature of the Schrodinger equation, it's also the part that's sensitive to the time dependence of the wave function.



The fact that other theories would also have problems with discrete time doesn't make the problems that standard quantum mechanics has with discrete time just disappear.

One might be able to reformulate a nonstandard quantum mechanics that used discrete time, but that is, well, non-standard. So we can expect that at least some of its predictions will be different from standard quantum mechanics.



A unit of time is not the same as discrete time. I'm not sure why you have these concepts conflated. Perhaps you think that a unit of time is somehow tied to a quantization of time - ie, your units are some multiple of some fundamental quantization of time. If time is discrete, then indeed the fundamental quantization of time would be the most meaningful units of time. But there is absolutely no need for time to be quantized in order to have units. Our units of time are arbitrary, but that's not a problem.



Most surfaces are not fractal. They may not be smooth down to the atomic level, but fractal does not simply mean rough.



There are units of time. They're arbitrary, but that's exactly what one should expect from continuous time. I'm at a loss as to why you think otherwise, so I'm not sure what to say to convince you if you won't accept my word for it.
You are going to need to back some things up. For example, you say quantum mechanics says it's not an instant collapse or whatever.

Evidence of that claim?

The only way the interaction could produce a truly instant effect is if the interaction potential was infinite (and not just at a point), but that's completely unphysical.


I don't see the "infinite" part but there may well be an "unphysical" aspect to QM. How do entangled particles act as one system, regardless of distance, (instant action), since they are spatially separated but informationally one system?

They are informationally connected without seeming physical connection.....I prefer the term "immaterial" and informational over unphysical.

It's absolutely relevant. If the time for measurement is finite, and you don't track what happens during the measurement process (which... we don't), then how can you tell that what happened was a discrete collapse and not a continuous time evolution? Well, you can't.


Well, let me put it another way to help clarify this. The measurement dictates what the particle did before it got there. It's not in respect to time. No matter how far the particle traveled such as in Wheeler's thought experiment of traveling across the universe, the measurement dictates what it did a very long time ago then or put another way, what state it is in at that space-time coordinate.

I know MWI has a different explanation but you said you agreed with the Copenhagen interpretation.

And a time derivative is not only a central feature of the Schrodinger equation, it's also the part that's sensitive to the time dependence of the wave function.

Yea well, we came up with quantum physics before the equation was written. It's been important but if incomplete, we can hopefully write some better equations. I recognize the equation's inconsistency with relativity in respect of time, which to me is evidence it's something that is helpful and works but is incomplete.

Keep in mind the Schroedinger equation is not all of quantum physics. The particles behave the way they do regardless of our mathematical precision and abilities.

Our units of time are arbitrary, but that's not a problem.


That's what I am saying. It's not a physical thing but a mathematical convenience which works because we don't need but so much precision. We pick a unit of time which is just an interval of time and write an equation saying relative to everything else, all these things experience the same interval of time, but it's not really the case. It just works because it's such a good approximation.

Most surfaces are not fractal. They may not be smooth down to the atomic level, but fractal does not simply mean rough.

You get the point though, right? What is smooth from one perspective is not so from another. What we think of as time is like that.

Pick any interval of time where you believe at that vantage point, one is motionless. Over that same interval, something else has moved. There is no absolute fixed relative positions relative to everything else. It's always a little indeterminate if only on the smallest of degrees.

There are units of time. They're arbitrary, but that's exactly what one should expect from continuous time. I'm at a loss as to why you think otherwise, so I'm not sure what to say to convince you if you won't accept my word for it.

There are arbitrary intervals of relative space that we label units of time that we use in math. Sure. But there is no fundamental unit of time existing outside of our just labeling an interval of time as unit of time.

Any so-called point in time is just an interval of change. Nothing is moving through time, for example. Everything is just in a moving spatial relationship with other things. It's not smooth in part because for some things, the movement of other things is much faster ("time" slowing down) than for other things ("time" speeding up).

Also, because there is no unit of time, energy such as photons must be quantized. In other words, since a "unit of time" is just an interval of spatial changes (not smooth either), particles are quantized, existing as packets of information for what we might call that space-time coordinate. It cannot be any other way precisely because there is no physical (non-arbitrary) unit of time. It's always an interval.

[Loss Leader]

Oooh. You don't think they might be (gasp) faking it, do you?


I think they may have invented a nickel battery. A hundred years late.

[W.D.Clinger]

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period.
More accurately, it's part of the Copenhagen metaphysics you've been advocating. There are several equally viable alternative interpretations of quantum mechanics in which there is no collapse.


He's also just spouting bs. For example, in saying the equation describes an evolution and not a collapse, he is just inserting his own interpretation for a math equation. The word "evolution" is not in the equation. Nor is collapse.
We've been telling you (http://forums.randi.org/showthread.php?postid=7054294#post7054294) that Schrödinger's equation says nothing about collapse. You're the one who's been claiming that "the Schroedinger equation is a description of the collapse of the wave function." (http://forums.randi.org/showthread.php?postid=7048690#post7048690)

If you understood the mathematical notation used by Schrödinger's equation, you'd realize that it states a constraint on the evolution of the wave function over time. Combine that with the full Hamiltonian and appropriate initial or boundary conditions, and you'll get a complete description of the wave function's evolution over time.

That's just math. Deny it all you want, but your denials are more likely to impress truthers, birthers, and creationists than the more technically savvy audience that reads this subforum.

[Reality Check]

So you claim there is such a thing as base unit of time, just as in math? In the physical universe?

I do not make any such claim. The defintion of a mathematical point in time exists is the answer to your question.

I will claim that as far as we know time is continuous for the simple reasons that

all of the theories that work, work with continuous time
there is no experimental evidence (AFAIK) that time is discontinuous (that there is a "base unit of time").
This may change if experimental results show that that time is discontinuous.

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period.

You are being obtuse: WD's comments were accurate because you
wrote
Originally Posted by randman http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7085098#post7085098)
Originally Posted by Ziggurat http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7084497#post7084497)
...
The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. ...

Say I write an equation where "A" has a 20% probability to show up at points 1-5. That doesn't mean "A"'s path there is necessarily continuous.

The equation in question is Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

That displays ignorance of QM because
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) states nothing about probabilities.
Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) needs the wave function to be continuous in time because the wave function is differentiated w.r.t time.
That what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, is true. It is not part of what you wrote which is all about Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

[randman]

You can think of collapse as part of the theory of quantum mechanics if you want to (though that simply becomes a semantic question of what you wish to include under that heading), but it sure as hell is NOT part of the Schrodinger equation.

Quantum physics is more than the Schrodinger equation. That's where he errs and now you as well.

But as far as the wave function, it does not say what the particle is, in terms of it's nature. WD constantly talks as if it does but that's simply not true.

It describes behavior but not what the particle is, and to go around pretending he and other quantum physicists at that time came to full agreement on what the wave function describes as far as the particle's nature is a fallacy, one which WD seems to often ascribe to.

Maybe I can find someone else's words....here's how wiki says it.

The Schrödinger equation details the behaviour of ψ but says nothing of its nature. Schrödinger tried to interpret it as a charge density in his fourth paper, but he was unsuccessful.[12] In 1926, just a few days after Schrödinger's fourth and final paper was published, Max Born successfully interpreted ψ as a probability amplitude.[13] Schrödinger, though, always opposed a statistical or probabilistic approach, with its associated discontinuities—much like Einstein, who believed that quantum mechanics was a statistical approximation to an underlying deterministic theory— and never reconciled with the Copenhagen interpretation.[14]

http://en.wikipedia.org/wiki/Schrödinger_equation#Historical_background_and_dev elopment

[Dancing David]

So you cannot answer but choose not to admit it.

Ok.

So which part of Scroedinger equations say there is a discontinuity in the transition?

[Dancing David]

Quantum physics is more than the Schrodinger equation. That's where he errs and now you as well.

And what do you have to describe it better and make predictions?


But as far as the wave function, it does not say what the particle is, in terms of it's nature. WD constantly talks as if it does but that's simply not true.

It describes its behavior, you can't even do that.

So wwhat will you replace Schroedinger's equations with?

Hmmm....?


It describes behavior but not what the particle is, and to go around pretending he and other quantum physicists at that time came to full agreement on what the wave function describes as far as the particle's nature is a fallacy, one which WD seems to often ascribe to.

You can't describe it except as it behaves, your sophistry belongs in R&P.


Maybe I can find someone else's words....here's how wiki says it.



http://en.wikipedia.org/wiki/Schrödinger_equation#Historical_background_and_dev elopment

And you can't decribe its nature either, so what describes its behavior better than QM?

Hmmm?

[W.D.Clinger]

Quantum physics is more than the Schrodinger equation. That's where he errs and now you as well.
As I noted just a few posts above, it was randman who's been insisting that "the Schroedinger equation is a description of the collapse of the wave function. ("http://forums.randi.org/showthread.php?postid=7048690#post7048690)"


But as far as the wave function, it does not say what the particle is, in terms of it's nature. WD constantly talks as if it does but that's simply not true.

It describes behavior but not what the particle is, and to go around pretending he and other quantum physicists at that time came to full agreement on what the wave function describes as far as the particle's nature is a fallacy, one which WD seems to often ascribe to.
randman is not telling the truth.

I have never claimed that the wave function or Schrödinger equation say anything at all about what a particle is or the "nature" of a particle. randman invented that straw man out of whole cloth. Apparently, randman would rather tell a lie than admit to a mistake.

[Reality Check]

Quantum physics is more than the Schrodinger equation. That's where he errs and now you as well.
That is right.
But your comment was about the Schrodinger equation. That is where you erred. That is where posters have been correcting you.

[Ziggurat]

You are going to need to back some things up. For example, you say quantum mechanics says it's not an instant collapse or whatever.

Evidence of that claim?

The Schrodinger equation.

It permits no discontinuous solutions.

What about that is hard to see?

I don't see the "infinite" part

Then you don't know where to look. Which means you don't really understand the Schrodinger equation. Nothing wrong with that, but if you don't understand it, then a more modest approach would make a better impression.

A discontinuity in time means an infinite time derivative. If you've got an infinity on one side of your equation, you need an infinity on the other side. That requires an infinite potential. Which... don't exist.

but there may well be an "unphysical" aspect to QM.

There are aspects of quantum mechanics which are unsettling and which we don't understand well. But that doesn't make them unphysical.

Infinite potentials, though? Yeah, that's unphysical. And not just because it seems wrong.

I prefer the term "immaterial" and informational over unphysical.

You are using those words to describe something completely different than what I mean by the term. By "unphysical" I mean it does not exist in the real world.

Infinite potentials don't exist in the real world. They are unphysical. Delta function potentials are another example: I can solve the Schrodinger equation for such a potential (it's a standard textbook problem, in fact), but it's just a mathematical exercise, because no such potentials exist.

Well, let me put it another way to help clarify this. The measurement dictates what the particle did before it got there.

No, it doesn't. In fact, such an interpretation pretty much conflicts with direct experimentation like sequential Stern-Gerlach (http://en.wikipedia.org/wiki/Stern-Gerlach#Sequential_experiments).

I know MWI has a different explanation but you said you agreed with the Copenhagen interpretation.

No, actually, I didn't say that.

Yea well, we came up with quantum physics before the equation was written.

The development of quantum mechanics started before the Schrodinger equation, yes. But much of that prior work (such as the Bohr model of the atom) has since been discarded.

If you want to talk about what standard quantum theory is, today, then it mostly centers around the Schrodinger equation.

It's been important but if incomplete, we can hopefully write some better equations.

Of course it's incomplete. It doesn't mesh with general relativity, for example. But we have nothing to indicate that any more complete theory will introduce any time discontinuities. That's a possibility (because pretty much by definition, you don't know what's in an unknown theory), but it's also irrelevant to the question of what quantum mechanics, as it exists today, says about the matter.

I recognize the equation's inconsistency with relativity in respect of time

That's been solved with relativistic quantum mechanics. But relativistic quantum mechanics still requires continuous time evolution.

Keep in mind the Schroedinger equation is not all of quantum physics. The particles behave the way they do regardless of our mathematical precision and abilities.

In other words, theory isn't reality. Yes. But so what? The question was about what the theory predicted. The theory does not predict discontinuous time evolution. If such discontinuities exist (we have no evidence that they do), they cannot be described by the theory.

That's what I am saying. It's not a physical thing

Our units of time are just as real, just as physical, as our units of distance. Which are also arbitrary. In fact, they are either both arbitrary or neither arbitrary, since they have a fixed relationship to each other.

So is a meter "not a physical thing"? Are any of our units "physical things"? Because they're basically all arbitrary.

We pick a unit of time which is just an interval of time and write an equation saying relative to everything else, all these things experience the same interval of time, but it's not really the case. It just works because it's such a good approximation.

I have no idea what you mean by this. But perhaps it's worth pointing out that our physics equations are independent of our choice of units.

You get the point though, right? What is smooth from one perspective is not so from another. What we think of as time is like that.

That has no relevance to the question of what the theory of quantum mechanics says about time. The theory may be wrong, but I'm not wrong about what the theory says.

Also, because there is no unit of time, energy such as photons must be quantized. In other words, since a "unit of time" is just an interval of spatial changes (not smooth either), particles are quantized, existing as packets of information for what we might call that space-time coordinate. It cannot be any other way precisely because there is no physical (non-arbitrary) unit of time. It's always an interval.

I think you're seriously confused about what quantization of photon energy means. It's a quantization of the relationship between energy and frequency. Nothing about that relationship (which, BTW, isn't even unique to photons) quantizes time itself. Quite the reverse: it's implicit in that relationship that time is continuous. Frequency, and energy, still remain continuous.

[Vorpal]

randman, you are simply wrong about what the Schrödinger equation says.

Your criticism of Ziggurat's description of QM boils down to the fact that it's different from the presentations of QM in introductory textbooks (e.g., Griffiths), in which collapse is non-unitary and discontinuous. And happens when Schrödinger equation is no longer applied, rather than described by the equation, as has been explained by others multiple times.

But even saying that Ziggurat's statements contradict the literal naive Copenhagen formulation is not much of a criticism, especially since...
(1) it's for practical purposes consistent, as they approximate one another;
(2) it's theoretically superior to it, by not postulating a completely new kind of non-unitary process,
(3) it's actually a gloss of, or at least consistent with, more developed formulations of QM in which collapse is an actually approximation of a continuous, unitary process (cf. decoherence).

Eh, at least that's the way this dispute looks to me.

[randman]

As I noted just a few posts above, it was randman who's been insisting that "the Schroedinger equation is a description of the collapse of the wave function. ("http://forums.randi.org/showthread.php?postid=7048690#post7048690)"


randman is not telling the truth.

I have never claimed that the wave function or Schrödinger equation say anything at all about what a particle is or the "nature" of a particle. randman invented that straw man out of whole cloth. Apparently, randman would rather tell a lie than admit to a mistake.
Nice leaving out the quote in context, which imo, is just straight-out lying about what I wrote. Here is the whole quote:

Quantum physics is more than the Schrodinger equation. That's where he errs and now you as well.

But as far as the wave function, it does not say what the particle is, in terms of it's nature. WD constantly talks as if it does but that's simply not true.

Here is where you basically lied again. I wrote:

Originally Posted by randman
If you think the particle as existing more in a wave-like trajectory, then collapsing into a single path, that's a form of discontinuity it seems to me. It doesn't just narrow down for example.

You responded with more nonsense pretending I had mentioned the Schrodinger equation when I had not.

Schrödinger's equation says absolutely nothing about "collapsing".

Over and over again, you respond to my discussions of quantum physics describing what happens with absurd rants about the Schrodinger equation, which you yourself claim does not even describe the wave function's collapse or whatever you wan to call it, and yet seem to think that suffices to explain away what we observe in experiments.

It's sheer ignorance on your part. Moreover, you describe what most physicists believe as something I made up and metaphysics, namely the Copenhagen interpretation, further showing your ignorance and hostility.

The Copenhagen interpretation is an interpretation of quantum mechanics. Amongst physicists, it is the most widely accepted[citation needed] of the various competing interpretations of quantum mechanics.

http://en.wikipedia.org/wiki/Copenhagen_interpretation

As far as Schrodinger's equation, it's worth noting it was not designed as a wave/particle equation but as a wave equation. If we are to talk of particles then, we have to consider what is physically being described, which is my point. To describe it as a physical thing instead of a mathematical description of a physical thing is an error though we may do so as a means of short-hand.

[randman]

Ziggarut, you stated:

The Schrodinger equation.

It permits no discontinuous solutions.

What about that is hard to see?


The equation is not the physical thing of itself, and we discussed not the Schrodinger equation but quantum physics as a whole so it's disingenuous for you to say there is no discontinuity in quantum physics and then cite the schrodinger equation, especially as you so staunchly say the equation does not address the collapse, which may be true viewing particles as a wave. That was a mistake on my part but it doesn't change anything as far as our discussion.

You stated you believed in the Copenhagen interpretation. It's not naive to say the interpretation involves something most often called a "collapse" and since you are arguing the Schrodinger equation does not address that, it's a bit silly to cite it as evidence that does address it, isn't it?

[randman]

Also, 2 questions may help.

1. Does the Schrodinger equation describe wave/particle duality?

2. Is wave/particle duality part of quantum physics?

[Vorpal]

There's more evidence to support the statement "most physicists consider 'which QM interpretation is right' to be a waste of time" than evidence for "most physicists accept Copenhagen." Or any other particular interpretation.

[Ziggurat]

Over and over again, you respond to my discussions of quantum physics describing what happens with absurd rants about the Schrodinger equation, which you yourself claim does not even describe the wave function's collapse or whatever you wan to call it, and yet seem to think that suffices to explain away what we observe in experiments.

But we don't observe the wave function collapse. We observe results which we can describe in terms of a collapse, but alternative explanations are available. That's the part you're stuck on: you think that collapse is some real, observed process. If it is real, then it's actually something that quantum mechanics does not describe. If there is actually a real, discrete collapse, what causes collapse? When and how does it happen? There are no answers to that question, in part because we've never observed collapse. It's hard to call collapse a part of quantum mechanics when quantum mechanics cannot tell us when it happens, or even that it happens at all. It isn't necessary. We don't need it. Occam's razor.

It's sheer ignorance on your part. Moreover, you describe what most physicists believe as something I made up and metaphysics, namely the Copenhagen interpretation, further showing your ignorance and hostility.

Again, WD knows more about quantum mechanics than you do.

As far as Schrodinger's equation, it's worth noting it was not designed as a wave/particle equation but as a wave equation.

No, actually, that point isn't worth noting. You're drawing a distinction between particles and waves which simply doesn't exist in quantum mechanics.

To describe it as a physical thing instead of a mathematical description of a physical thing is an error though we may do so as a means of short-hand.

Once could say that about any theory. While it's always good to keep in mind that a theoretical description is not the same thing as the reality, that still has no relevance to our current discussion, which is about what the theory says.

[randman]

I think you're seriously confused about what quantization of photon energy means. It's a quantization of the relationship between energy and frequency. Nothing about that relationship (which, BTW, isn't even unique to photons) quantizes time itself. Quite the reverse: it's implicit in that relationship that time is continuous. Frequency, and energy, still remain continuous.

I didn't say that. I said that time is not quantized and also not absolute, nor continuous and cited Lynd's published paper which most don't like around here as the reason for the quantization of particles.

Since there is no fundamental physical unit of time, any arbitrary unit of time is just an interval of a sequence of events. Since an interval means movement, that means something is in more than one place. It's position is not completely precise, ever.

Moreover, one object's interval and perspective on how fast the universe is moving (except the speed of light) differs from another based on relative speed (relativity). So even if one thought there was an indivisible base unit of time, there would always be something else that has moved during that same interval.

So without a unit of time, there is no continuous time, really no time at all. There are intervals of spatial relationships with different observations of how fast things are moving (time dilation).

So something occupying an interval of spatial change would have to be quantized. Depending on the perspective, it has a packet of information (perspective on what it is) from various viewpoints.

[Reality Check]

Also, 2 questions may help.

1. Does the Schrodinger equation describe wave/particle duality?

2. Is wave/particle duality part of quantum physics?
Start with the fact that the Schrodinger equation is not all of quantum physics.
The answers are:
1. No
2. Yes.

[randman]

There's more evidence to support the statement "most physicists consider 'which QM interpretation is right' to be a waste of time" than evidence for "most physicists accept Copenhagen." Or any other particular interpretation.

That may be true but to call it some randman metaphysical nonsense as if I just dreamed it up, as WD does, is just ignorant.

[randman]

Start with the fact that the Schrodinger equation is not all of quantum physics.
The answers are:
1. No
2. Yes.

That is what I started with. The discussion here is about whether quantum physics indicates discontinuities.

[randman]

But we don't observe the wave function collapse. We observe results which we can describe in terms of a collapse, but alternative explanations are available. That's the part you're stuck on: you think that collapse is some real, observed process. If it is real, then it's actually something that quantum mechanics does not describe. If there is actually a real, discrete collapse, what causes collapse? When and how does it happen? There are no answers to that question, in part because we've never observed collapse. It's hard to call collapse a part of quantum mechanics when quantum mechanics cannot tell us when it happens, or even that it happens at all. It isn't necessary. We don't need it. Occam's razor.



Again, WD knows more about quantum mechanics than you do.



No, actually, that point isn't worth noting. You're drawing a distinction between particles and waves which simply doesn't exist in quantum mechanics.



Once could say that about any theory. While it's always good to keep in mind that a theoretical description is not the same thing as the reality, that still has no relevance to our current discussion, which is about what the theory says.
You claimed to hold to the Copenhagen interpretation which does say we see the collapse (that the lab results indicate that). Now you are acting like it's not even part of quantum physics.

[Ziggurat]

The equation is not the physical thing of itself

That might be relevant if the question was whether physical things change discontinuously. But that wasn't the question, so that point is not relevant.

and we discussed not the Schrodinger equation but quantum physics as a whole

Quantum physics as a whole is not the physical thing itself either. So that point is likewise not relevant.

so it's disingenuous for you to say there is no discontinuity in quantum physics and then cite the schrodinger equation

Not at all.

The Schrodinger equation does not permit discontinuities in time. So either you're claiming that Quantum Mechanics is internally inconsistent, or you're claiming that quantum physics says that the Schrodinger equation doesn't always apply. The former claim is... silly. The latter claim is unsupported.

You stated you believed in the Copenhagen interpretation.

No I didn't. That's the second time you've claimed that, but it never happened. You won't be able to find a quote of me saying that either.

It's not naive to say the interpretation involves something most often called a "collapse"

But it is naive to call an interpretation of the theory part of the theory itself. Especially since the interpretation is inherently unscientific (ie, untestable). That is, in fact, why they call it an interpretation: because it isn't part of the theory. It's frequently taught alongside the theory, but that's a pedagological artifact.

[Ziggurat]

You claimed to hold to the Copenhagen interpretation

No I didn't. Stop repeating a lie.

[randman]

JUst add a little more on the wave function collapse or decoherence, etc,......I don't see how there isn't some sort of discontinuity involved. In MWI, there would be a continuous linear progression from what I've been told about the idea, but there is a lateral discontinuity within the universe (the Multiverse). There are universes that are no longer continuous in this scenario with each other. I know you may be technically talking of continuity in time, but there is a fairly major spatial discontinuity here being proposed as the solution.

If you think the particle as existing more in a wave-like trajectory, then collapsing into a single path, that's a form of discontinuity it seems to me. It doesn't just narrow down for example.

If you think of it as not really in a wave-like trajectory or a single path but as a mere potential for discrete form, then you really are talking about even it's past "becoming" due to "measurement" or sufficient interaction. That's not really continuous in one sense because the measurement/observation/interaction event causes it to exist not just as potential but in discrete form even from the trajectory it would have had to have taken in the past (if it were discrete).

I also question the whole concept of continuous in time. What evidence do we have there is such a thing as a unit of time. If there were one fundamental unit of time, nothing would be moving as time is just a measurement of changes. If nothing was moving, then the universe would be frozen (Lynd's argument). Moreover, since things experience different rates of what we call time, which just means the changes around them occur faster or slower from their vantage point based on their relative velocity, you should expect some fuzziness, jumping and quantization. That's because from any one vantage point, something else is always not in an exact, precise position. This inherent imprecision is more evident with particles because they are so small.

Please note my comments above. WD's absurd rants about the Schrodinger equation as refutation of my post means nothing as I didn't discuss the equation in this post. The simple fact is we are discussing whether there are discontinuities in quantum physics.

[randman]

No I didn't. Stop repeating a lie.
I thought you did and was not lying per se, but just incorrect in recalling what you believe.

The thing is, however, you seem to be simply dodging the issues I raised, and erroneously claim I am presenting a naive Copenhagen interpretation. Unless you just are calling anyone that accepts what we observe as naive, namely that measuring the which-way path after the fact shows the particle having travelled a which-way path and measuring after the fact the particle without being able to tell, it travels more wave-like.

[Reality Check]

That is what I started with. The discussion here is about whether quantum physics indicates discontinuities.
Wrong. You stated with Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).
Originally Posted by randman http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7085098#post7085098)
Originally Posted by Ziggurat http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7084497#post7084497)
...
The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. ...

Say I write an equation where "A" has a 20% probability to show up at points 1-5. That doesn't mean "A"'s path there is necessarily continuous.
Your statement is wrong.

The answer to "whether quantum physics indicates discontinuities" is yes it does indicate them.
There is the continuous evolution of the Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) between measurements. When a measurement happens there is a discontinuous evolution to a specific state. That is a discontinuous change in the wave function.
N.B. This has nothing to do with time. It chugs along as usual. It just happens that the wave function collapse happens at a specific time.

[randman]

The Schrodinger equation does not permit discontinuities in time. So either you're claiming that Quantum Mechanics is internally inconsistent, or you're claiming that quantum physics says that the Schrodinger equation doesn't always apply. The former claim is... silly. The latter claim is unsupported.

Once again, you are simply dodging the issue by pretending we were only discussing the Schrodiner equation when the context related to pedrone's comments on "QUANTUM THEORISTS".

I agreed that he didn't have it all correct but stated you were not entirely correct, and that's true. Merely commenting on the Schrodinger equation is not an answer to the idea there are discontinuities in quantum physics that quantum theorists try to address.

[randman]

Wrong. You stated with Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

Your statement is wrong.

The answer to "whether quantum physics indicates discontinuities" is yes it does indicate them.
There is the continuous evolution of the Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) between measurements. When a measurement happens there is a discontinuous evolution to a specific state. That is a discontinuous change in the wave function.
N.B. This has nothing to do with time. It chugs along as usual. It just happens that the wave function collapse happens at a specific time.
No, the context was pedrone's comment on quantum theorists. Though I agreed he didn't have everything correct, he was right that quantum theorists do try to address discontinuities in quantum physics.

Zigg was wrong to give some pat and dismissive answer based on the Schrodinger equation. You have to look at my comments in light of the train of thought in the discussion.

[Ziggurat]

The thing is, however, you seem to be simply dodging the issues I raised

I've addressed as many issues as I could make sense of. What I have avoided I did so because it didn't even make enough sense to form any response to. You're not satisfied with my answers. But that's not really my fault, or my problem. Meanwhile, much of what I've corrected you on (like your seriously flawed concept of units) you seem to have simply ignored.

and erroneously claim I am presenting a naive Copenhagen interpretation. Unless you just are calling anyone that accepts what we observe as naive, namely that measuring the which-way path after the fact shows the particle having travelled a which-way path and measuring after the fact the particle without being able to tell, it travels more wave-like.

Um... perhaps you should try writing this again, because I can't make heads or tales of what the hell you're trying to say. It might help if you actually indicate what sort of experiment you're talking about. Is this two-slit diffraction? I can't even tell.

[randman]

But it is naive to call an interpretation of the theory part of the theory itself. Especially since the interpretation is inherently unscientific (ie, untestable).

How is it untestable? Are not the delayed-choice quantum eraser, the Aspect experiments and Zeilinger's quantum teleportation experiments tests?

They are, and they are considered to rule out hidden variable theories.

MWI may not be testable, however, at least as far as I know, and that's because of the discontinuity (though not linearly) between the alternate universes.

[Ziggurat]

Merely commenting on the Schrodinger equation is not an answer to the idea there are discontinuities in quantum physics that quantum theorists try to address.

It's not an answer which satisfies you. But it's an answer. And aside from appealing to wave function collapse (which you can't even demonstrate is real), you have given no reason to believe otherwise.

[randman]

I've addressed as many issues as I could make sense of. What I have avoided I did so because it didn't even make enough sense to form any response to. You're not satisfied with my answers. But that's not really my fault, or my problem. Meanwhile, much of what I've corrected you on (like your seriously flawed concept of units) you seem to have simply ignored.



Um... perhaps you should try writing this again, because I can't make heads or tales of what the hell you're trying to say. It might help if you actually indicate what sort of experiment you're talking about. Is this two-slit diffraction? I can't even tell.
Ok, recent experiments confirm some things. In the delayed-choice quantum eraser experiments and others, we see that measuring a particle's which-way path (set up the experiment that can determine after the fact which path the particle traversed) yields a result of the particle taking one path.

If we run the same experiment so that when we detect the particle but cannot tell which path it went on, the interference pattern (wave-like behavior) reappears.

It's important to note the measurement is after the fact. So determining after it has travelled which way it went actually results in it having travelled a single path even though the measurement was after it had already travelled it.

These experiments were set up to show it's not some mechanical interference that causes the "collapse" but the potential for specific knowledge.

They are generally considered to rule out hidden variables theories.

[Ziggurat]

How is it untestable? Are not the delayed-choice quantum eraser, the Aspect experiments and Zeilinger's quantum teleportation experiments tests?

Nope. None of them prove collapse. Nor can they. If they could, they would rule out the Many Worlds Interpretation. But it hasn't been ruled out. The very fact that people call these "interpretations" and not "theories" should tip you off to the fact that, as of yet, there IS no way to distinguish between them.

They are, and they are considered to rule out hidden variable theories.

See that word there?

Do you understand its significance?

[randman]

It's not an answer which satisfies you. But it's an answer. And aside from appealing to wave function collapse (which you can't even demonstrate is real), you have given no reason to believe otherwise.
You don't think the Aspect and Zeilinger experiments and the quantum eraser and delayed-choice experiments and others demonstrates it?

What do you think they demonstrate?

They either demonstrate a collapse or there are a gazillion alternate universes within the Multiverse.

[randman]

Nope. None of them prove collapse. Nor can they. If they could, they would rule out the Many Worlds Interpretation. But it hasn't been ruled out. The very fact that people call these "interpretations" and not "theories" should tip you off to the fact that, as of yet, there IS no way to distinguish between them.



See that word there?

Do you understand its significance?
They do demonstrate a collapse. You have to come up with something unobserved, MWI, in order to say there is no collapse.

They demonstrate as much as anything is in science. Of course, you can come up with an alternative theory invoking unobserved things but that's likely true for anything and everything that is demonstrated.

Science demonstrates things but cannot prove them.

On your last question......technically, others call hidden variables "interpretation" rather than theory but if you boil everything down epistemologically, you could call anything in science a theory. Even facts are based on assumptions. We assume we and other people exist, etc,....

[Ziggurat]

You don't think the Aspect and Zeilinger experiments and the quantum eraser and delayed-choice experiments and others demonstrates it?

Nope.

What do you think they demonstrate?

Looking at the Aspect experiment, for example, it demonstrates entanglement and a violation of Bell's inequality, thereby disproving local hidden variables theories. But we don't need collapse to happen. We could have Many Worlds. We could also have some finite-time process which smoothly evolves the wave function from its superposition state to the measured spin eigenstate. It doesn't need to be collapse.

[Ziggurat]

They do demonstrate a collapse. You have to come up with something unobserved, MWI, in order to say there is no collapse.

Collapse itself has never been observed.

Seriously, how can you distinguish between a discrete collapse and a continuous time evolution during measurement? You can't.

[Reality Check]

No, the context was pedrone's comment on quantum theorists.
No. Your reply was in the context of Ziggurat's post:
Originally Posted by randman http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7085098#post7085098)
Originally Posted by Ziggurat http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=7084497#post7084497)
...
The Schrodinger equation describes the time evolution of the wave function. Solutions to that equation do not permit temporal discontinuities. ...


Say I write an equation where "A" has a 20% probability to show up at points 1-5. That doesn't mean "A"'s path there is necessarily continuous.
You were wrong.

Going back one post the context is still Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) :
I agree he's wrong but don't think your comment below is entirely correct

but in fact the time evolution of the wave function is NOT discontinuous. Quantum mechanics predicts NO discontinuities in the time evolution of a wave function.


Ziggurat was correct that there are no discontinuities in the time evolution of a wave function.
There is a discontinuity in the wave function at a measurement (which is not time evolution)

[randman]

No. Your reply was in the context of Ziggurat's post:

You were wrong.

Going back one post the context is still Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) :

Ziggurat was correct that there are no discontinuities in the time evolution of a wave function.
There is a discontinuity in the wave function at a measurement (which is not time evolution)
No, I was replying to his response to pedrone and I was correct. He wasn't entirely correct as saying the Schrodinger equation says such and such means nothing. He hand-waived the whole discontinuity being in quantum physics. You yourself admit that quantum physics has discontinuities.

[Vorpal]

QM by itself is silent about whether or not it has discontinuities. In rigorous formulations of QM, there is a postulate that after a measurement of an observable, the state is in the eigenspace of that observable that corresponds to the measured value. But the exact dynamics of what happens during measurement and how the state winds up in the appropriate eigenspace are not directly addressed.

That measurement process is discontinuous is a a feature (or defect, depending on point of view) of a particular interpretation of QM, rather than QM itself.

[Reality Check]

No, I was replying to his response to pedrone and I was correct. He wasn't entirely correct as saying the Schrodinger equation says such and such means nothing. He hand-waived the whole discontinuity being in quantum physics. You yourself admit that quantum physics has discontinuities.
You are still wrong. There are no discontinuities in Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation). He was entirely correct to state that.

I never stated that there are discontinuities in Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).
There are discontinuities in the part of quantum physics where measurements are made. That is usually described as a wave function collapse in the Copenhagen interpretation. That has nothing to do with the continuous time evolution of Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation).

ETA
randman: Try to understand this: Schrödinger's equation (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation) is a part of quantum physics. It is not all of quantum physics. There are other parts that describe measurements and it is there those parts that 'indicate' discontinuities. The purpose of several interpretations is to remove these discontinuities.

[W.D.Clinger]

randman is upset with me because I have quoted him accurately and in context. I invite all readers to examine the context by following links given below.

On 4 April, in another thread, randman wrote:

Maybe you should look at the debate over indeterminancy or the Uncertainty principle as a basic starter and also realize the Schroedinger equation is a description of the collapse of the wave function. That's what it is. So saying the wave function does not collapse but citing the equation is pretty stupid. In MWI, they try to do away with the collapse in favor of decoherence.

You appear to understand neither.
From the highlighted claim, and the sentence that follows, it is clear that randman believes the Schrödinger equation describes collapse.

Today, in this thread, I (and others) pointed out that Schrödinger's equation does not describe collapse. randman described my comments as "stupid" and "bs":

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period. He's also just spouting bs. For example, in saying the equation describes an evolution and not a collapse, he is just inserting his own interpretation for a math equation. The word "evolution" is not in the equation. Nor is collapse.
It isn't just my opinion. As I (and others) have pointed out, the mathematical notations used to write Schrödinger's equation imply evolution in time while ruling out any discontinuity in time.

In response, randman began to pretend "the equation" he mentioned twice in the highlighted prose above wasn't Schrödinger's equation at all:

You responded with more nonsense pretending I had mentioned the Schrodinger equation when I had not.


Over and over again, you respond to my discussions of quantum physics describing what happens with absurd rants about the Schrodinger equation, which you yourself claim does not even describe the wave function's collapse or whatever you wan to call it, and yet seem to think that suffices to explain away what we observe in experiments.

It's sheer ignorance on your part. Moreover, you describe what most physicists believe as something I made up and metaphysics, namely the Copenhagen interpretation, further showing your ignorance and hostility.
When randman accuses me of giving him credit for inventing the Copenhagen interpretation, he is lying.

He has done that before. As I wrote on 22 March (http://forums.randi.org/showthread.php?postid=7004999#post7004999):

The Copenhagen interpretation dates back to 1927 or so. If randman thinks I was accusing him of having invented that interpretation, he is mistaken. I was stating the rather obvious fact that randman has accepted some variation of the Copenhagen interpretation as one of the things he personally believes.



After all of the foofaraw above, randman finally got around to admitting he was wrong about the Schrödinger equation. Even then, he buried his admission within an attack on the honesty of another poster:

The equation is not the physical thing of itself, and we discussed not the Schrodinger equation but quantum physics as a whole so it's disingenuous for you to say there is no discontinuity in quantum physics and then cite the schrodinger equation, especially as you so staunchly say the equation does not address the collapse, which may be true viewing particles as a wave. That was a mistake on my part but it doesn't change anything as far as our discussion.


Although randman has (sort of) admitted he made a mistake when he claimed that Schrödinger's equation describes waveform collapse, he continues to berate me for having called his attention to that error:
Please note my comments above. WD's absurd rants about the Schrodinger equation as refutation of my post means nothing as I didn't discuss the equation in this post. The simple fact is we are discussing whether there are discontinuities in quantum physics.
:rolleyes:

[MattusMaximus]

wow!
so dressed-atom is used often when experiments disprove Quantum Mechanics...
:p

Why did you lie in the OP about Dehmelt's work which earned him the Nobel prize in physics? Why did you blatantly misrepresent his work as concluding the exact opposite of what he actually concluded?

[MattusMaximus]

I am saying there is neither continuous, nor discrete, time. Time is just spatial relationship in one sense (sequence of spatial changes), but I'd go further and define space a little differently. It's because there is no discrete unit of time that what seems to be time is not so smooth and discontinuous to some degree.

Errr, what?

And what reason does randman have for making such "definitions", besides the fact that he appears to have gone to the school of let's-make-up-our-own-laws-of-physics? :rolleyes:

[MattusMaximus]

So you claim there is such a thing as base unit of time, just as in math? In the physical universe?

WD's comments were stupid because what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period. He's also just spouting bs. For example, in saying the equation describes an evolution and not a collapse, he is just inserting his own interpretation for a math equation. The word "evolution" is not in the equation. Nor is collapse.

To try to determine what happens, one needs to actually become aware of the physical process involved. WD isn't and doesn't realize this is necessary.

So this explains why physicists have been utterly unable to apply these notions of the Schrodinger equation and broader quantum mechanics to, say, make fanciful devices such as lasers and computers, right?

And randman claims that others are not aware of the physics involved :rolleyes:

[dlorde]

That may be true but to call it some randman metaphysical nonsense as if I just dreamed it up, as WD does, is just ignorant.
.
It might be ignorant if that is what he had said - but he didn't say that. What he did say was:...what occurs in the wave function collapse or decoherence or whatever is part of quantum physics, period.
More accurately, it's part of the Copenhagen metaphysics you've been advocating. There are several equally viable alternative interpretations of quantum mechanics in which there is no collapse.

He's clarifying that the wave function collapse is a metaphysical part of the Copenhagen interpretation you were advocating.

Not at all what you are accusing him of (not that you haven't dreamed up some metaphysical nonsense - but that wasn't it).

[DC]

:D:D:D
you are wrong

:rolleyes::rolleyes::rolleyes:

[MRC_Hans]

Why did you lie in the OP about Dehmelt's work which earned him the Nobel prize in physics? Why did you blatantly misrepresent his work as concluding the exact opposite of what he actually concluded?

It's yet another of these arguers from ignorance or misrepresentation. :rolleyes:

What they basically do is declare that they don't understand how a gearbox works, then proceed to argue that cars can't run because the RPM range of the engine cannot match the RPM range of the wheels.

Hans :dio: