Incredibly huge inconsistency of modern physics

[wollery]

Originally Posted by wogoga

Look at any visualisation of the cristal structure of diamond. The nuclei have a strong positive charge (6 protons versus 2 electrons), whereas each of the four bonds surrounding a carbon atom consists of an electron pair. The negative charge of such a pair is a strong adhesive between two neighbouring nuclei. The hardness of diamonds is due to the short distance between the positive nuclei and the negative electron pairs, resulting in huge electrostatic attraction. Because the electron pairs are (physically) stationary, a diamond is a good insulator and can only be deformed by breaking the bonds between atoms and thus resulting in fragmentation of the crystal.

Cheers, Wolfgang

Ah, I see you're using the simplified model they teach in high school to people who aren't sophisticated enough to grasp the elegant weirdness of quantum mechanics.

[Ziggurat]

Originally Posted by wollery

Ah, I see you're using the simplified model they teach in high school to people who aren't sophisticated enough to grasp the elegant weirdness of quantum mechanics.

Indeed. It's not a bad handwaving model, and it's close enough to the real thing to get some of the essentials across, but as you point out, it's still wrong. In more technical terms, I don't think you can actually form an orthogonal basis set of electron states that way.

[wogoga]

Originally Posted by Reality Check

Just in case you are interested here is one of the tests of the fact that photons follow all paths in a system: Elitzur-Vaidman bomb-tester

Wikipedia on Elitzur-Vaidman bomb-tester:

Start with a Mach-Zehnder interferometer and a light source which emits single photons. When a photon emitted by the light source reaches a half-silvered plane mirror, it has equal chances of passing through or reflecting. On one path, place a bomb for the photon to encounter. If the bomb is working, then the photon is absorbed and triggers the bomb.

On Mach-Zehnder interferometer:

The Mach-Zehnder interferometer is a device used to determine the phase shift caused by a small sample which is placed in the path of one of two collimated beams (thus having plane wavefronts) from a coherent light source.

On collimated light:

Collimated light is light whose rays are nearly parallel, and therefore will spread slowly as it propagates. The word is derived from "collinear" and implies light that does not disperse with distance. ... Collimated light is sometimes said to be focused at infinity. Thus as the distance from a point source increases, the spherical wavefronts become flatter and closer to plane waves, which are perfectly collimated.

On coherence length

In physics, coherence length is the propagation distance from a coherent source to a point where an electromagnetic wave maintains a specified degree of coherence. The significance is that interference will be strong within a coherence length of the source, but not beyond it. ... Helium-neon lasers have a typical coherence length of 20 cm, while semiconductor lasers reach some 100 m. Fiber lasers can have coherence lengths exceeding 100 km.

In addition to an arbitrary use of statistics, the central fallacy of such experiments lies in the fact that photons are 'social particles', which tend to come into existence and travel together in the same state. Wikipedia on stimulated emission:

In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. The perturbing photon is not destroyed in the process (cf. absorption), and the second photon is created with the same phase, frequency, polarization, and direction of travel as the original.

So already the central premise of this QM thought experiment, namely that one single photon functions as two collimated beams of coherent light, is an impossibility. Coherence is a property only of groups of photons and not of single photons. A single photon cannot have different phases, frequencies, polarizations, and directions of travel. (Yes, I know, Heisenberg's authority ...).

On the one hand, it is very astonishing how little research has been done on coherence of light. On the other hand, this is understandable, because the acknowledgement that photons normally appear as coherent groups undermines even on the theoretic side the beloved strangeness of the world of quanta. Interference effects which are now assumed to result from interference of photons with themselves can then easily be explained by interference between photons belonging to a same coherence group, but having taken different paths before reuniting again.

So the meaning of this interesting quote (Wikipedia on Bell test experiments)

Nevertheless, despite all these deficiencies of the actual experiments, one striking fact emerges: the results are, to a very good approximation, what quantum mechanics predicts. If imperfect experiments give us such excellent overlap with quantum predictions, most working quantum physicists would agree with John Bell in expecting that, when a perfect Bell test is done, the Bell inequalities will still be violated.

actually is this (see also):

We must admit that strictly speaking, these experiments are imperfect (i.e. not good enough in order to decide the question). However, we as working quantum physicists devoutly believe that also perfect experiments would confirm that Bohr is right and Einstein wrong.

Cheers, Wolfgang

[Reality Check]

Originally Posted by wogoga

Wikipedia on Elitzur-Vaidman bomb-tester:

Start with a Mach-Zehnder interferometer and a light source which emits single photons. When a photon emitted by the light source reaches a half-silvered plane mirror, it has equal chances of passing through or reflecting. On one path, place a bomb for the photon to encounter. If the bomb is working, then the photon is absorbed and triggers the bomb.

On Mach-Zehnder interferometer:

The Mach-Zehnder interferometer is a device used to determine the phase shift caused by a small sample which is placed in the path of one of two collimated beams (thus having plane wavefronts) from a coherent light source.

On collimated light:

Collimated light is light whose rays are nearly parallel, and therefore will spread slowly as it propagates. The word is derived from "collinear" and implies light that does not disperse with distance. ... Collimated light is sometimes said to be focused at infinity. Thus as the distance from a point source increases, the spherical wavefronts become flatter and closer to plane waves, which are perfectly collimated.

On coherence length

In physics, coherence length is the propagation distance from a coherent source to a point where an electromagnetic wave maintains a specified degree of coherence. The significance is that interference will be strong within a coherence length of the source, but not beyond it. ... Helium-neon lasers have a typical coherence length of 20 cm, while semiconductor lasers reach some 100 m. Fiber lasers can have coherence lengths exceeding 100 km.

In addition to an arbitrary use of statistics, the central fallacy of such experiments lies in the fact that photons are 'social particles', which tend to come into existence and travel together in the same state. Wikipedia on stimulated emission:

In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. The perturbing photon is not destroyed in the process (cf. absorption), and the second photon is created with the same phase, frequency, polarization, and direction of travel as the original.

So already the central premise of this QM thought experiment, namely that one single photon functions as two collimated beams of coherent light, is an impossibility. Coherence is a property only of groups of photons and not of single photons. A single photon cannot have different phases, frequencies, polarizations, and directions of travel. (Yes, I know, Heisenberg's authority ...).

On the one hand, it is very astonishing how little research has been done on coherence of light. On the other hand, this is understandable, because the acknowledgement that photons normally appear as coherent groups undermines even on the theoretic side the beloved strangeness of the world of quanta. Interference effects which are now assumed to result from interference of photons with themselves can then easily be explained by interference between photons belonging to a same coherence group, but having taken different paths before reuniting again.

So the meaning of this interesting quote (Wikipedia on Bell test experiments)

Nevertheless, despite all these deficiencies of the actual experiments, one striking fact emerges: the results are, to a very good approximation, what quantum mechanics predicts. If imperfect experiments give us such excellent overlap with quantum predictions, most working quantum physicists would agree with John Bell in expecting that, when a perfect Bell test is done, the Bell inequalities will still be violated.

actually is this (see also):

We must admit that strictly speaking, these experiments are imperfect (i.e. not good enough in order to decide the question). However, we as working quantum physicists devoutly believe that also perfect experiments would confirm that Bohr is right and Einstein wrong.

Cheers, Wolfgang

What a waste of your time - did you look at the actual experiment that verified the bomb tester?

There are plenty of single photon emitting devices around. They are a standard part of physics. They are usually diodes not lasers (devices that use simulated emission).

Bell tests have nothing to do with the Elitzur-Vaidman bomb-tester.

But if you want somthing more to misinterpret completely then have a look at Wheeler's delayed choice experiment (also experimentally verified).

[Ziggurat]

Originally Posted by wogoga

So already the central premise of this QM thought experiment, namely that one single photon functions as two collimated beams of coherent light, is an impossibility. Coherence is a property only of groups of photons and not of single photons. A single photon cannot have different phases, frequencies, polarizations, and directions of travel.

Not so. A photon can very easily be put in a superposition state, with different components of that superposition state having different phases and directions of travel. That, in fact, is the heart of the two-slit single-photon interference effect.

Quote:

Interference effects which are now assumed to result from interference of photons with themselves can then easily be explained by interference between photons belonging to a same coherence group, but having taken different paths before reuniting again.

Except you can observe those same effects even when you only use one photon at a time. But perhaps you weren't aware that it's actually fairly easy to do such an experiment, and it's been done lots of times. How, pray tell, do you propose to explain that?

[The Man]

Originally Posted by wogoga

<sinped preceeding BS>....

experiments would confirm that Bohr is right and Einstein wrong.

Cheers, Wolfgang

So are you inferring that Einstein was correct about something?

From one of the links you provided to your writings on other forums

Quote:

Simple black hole paradox refuting General Relativity:
http://members.lol.li/twostone/E/paradoxGR.html
Why SR does not explain MMX:
http://members.lol.li/twostone/E/refutationSR.html
Spaceship paradox refuting Special Relativity:
http://members.lol.li/twostone/E/paradox.html

It would seem that the only person you think is always correct is you.

[wogoga]

Originally Posted by Reality Check

There are plenty of single photon emitting devices around. ... But if you want something more to misinterpret completely then have a look at Wheeler's delayed choice experiment (also experimentally verified).

All the 'delayed choice' stuff of such quantum interference experiments only serves as a distraction from the essential weaknesses of such experiments. The latest experiment seems to be Experimental Realization of Wheeler's Delayed-Choice Gedanken Experiment, Science, 2007 (preprint). The authors use a 'single-photon source' "based on the pulsed, optically excited photoluminescence of a single N-V color center in a diamond nanocrystal". The following quotes are from a page dealing with exactly this 'single-photon source':

We consider the emission of a single nitrogen-vacancy (N-V) colour centre in diamond, a system which has an unsurpassed photostability even at room temperature.

The N-V centres consist of a substitionnal nitrogen atom (N) and a vacancy (V) in an adjacent lattice site. They are created by irradiation of a diamond sample with high-energy electrons followed by annealing at 800°C. At small electron exposure doses, the N-V centre density is small enough so that single N-V colour centres can be spatially isolated and detected using standard confocal microscopy. Their fluorescence then appears as bright spots when the sample is scanned with strongly focused green laser radiation.

The fluorescence spectrum of the colour centre consists of a narrow zero phonon line (ZPL) at approximatively 1.945 eV (wavelength 637.7 nm) and a broad phonon wing with a width of about 300 meV (wavelength of about 100 nm FWHM).

So 'single-photon sources' can be bright spots with a continuous spectrum primarily in the range between 600 nm to 800 nm.

... Furthermore, the small volume of diamond excited by the pumping laser yields very low background light. Such property is also of crucial importance for single photon emission, since residual background light will contribute to a non-vanishing probability of having more than two photons within the emitted light pulse.

Nanostructured samples are prepared by starting with type Ib synthetic diamond powder (de Beers, Netherlands). The diamond nanocrystals are size-selected by centrifugation, yielding a mean diameter of about 90 nm.

Diamond is said to be a Type 1b diamond, if the nitrogen atoms are evenly spread out throughout the carbon lattice (source). This type contains 500 ppm of nitrogen (source). The density of diamond is 3.5 g/cm³ and the weight of 6*10²³ diamond atoms is 12 g. A spherical diamond with a diameter of 90 nm has a volume of 0.38*10^-15 cm³ and a weight of 1.34*10^-15 g.

So typical nano-crystals consist of around 67 million atoms and around 33 thousand potential 'color centers'. In addition to that, it seems that even more than one nano-crystal is used:

A polymer solution containing selected diamond nanocrystals is deposited by spin-coating onto the surface of a dielectric mirror, resulting in a 30-nm-thick polymer layer holding the nanocrystals.

'Single photons' emitted by the N-V colour centre are produced in this way:

Under pulsed excitation with a pulse duration shorter than the excited-state lifetime, a single dipole emits photon one by one. To excite the N-V colour centre in such conditions, we use a home-built pulsed laser at a wavelength of 532 nm. The laser system delivers 800 ps pulses with energy 50 pJ.

The energy of a 532-nm-photon is 3.7*10^-19 Joule. So a pulse of 5*10^-11 Joule still consists of 1.3 * 10⁸ photons. The belief that such a pulse results in the emission of exactly one suitable photon is rather wishful thinking, especially if we also take into account (quotes from):

If an atom is already in the excited state, it may be perturbed by the passage of a photon which has a frequency v corresponding to the energy gap of the excited state to ground state transition. In this case, the excited atom relaxes to the ground state, and is induced to produce a second photon of frequency v. The original photon is not absorbed by the atom, and so the result is two photons of the same frequency. This process is known as stimulated emission. The rate at which stimulated emission occurs is proportional to the number of atoms in the excited state, and the radiation density of the light. The base probability of a photon causing stimulated emission in a single excited atom was shown by Albert Einstein to be exactly equal to the probability of a photon being absorbed by an atom in the ground state.

The critical detail of stimulated emission is that the induced photon has the same frequency and phase as the inducing photon. In other words, the two photons are coherent. It is this property that allows optical amplification, and the production of a laser system.

If the higher energy state has a greater population than the lower energy state (N1 < N2), then the emission process dominates, and light in the system undergoes a net increase in intensity.

Cheers, Wolfgang

[Reality Check]

Hi Wolfgang ,
You should have read the first paragraph:

Quote:

We use a single nitrogen-vacancy (N-V) color center in a diamond nanocrystal. The N-V centers are created by irradiation of type Ib diamond sample with high-energy electrons followed by annealing at 800◦C1. Under a well controlled irradiation dose, the N-V center density is small enough to allow independent addressing of a single center using standard confocal microscopy.

and the description of the source:

Quote:

Confocal microscopy setup. The 532 nm pulsed excitation laser beam is tightly focused on a diamond nanocrystals with a high numerical aperture (NA=0.95) microscope objective. The photoluminescence of the N-V color center is collected by the same objective and then spectrally filtered from residual pumping light. Following standard confocal detection scheme, the collected light is focused onto a 100 μm diameter pinhole. To identify a well isolated photoluminescent emitter, the sample is first raster scanned. For the center used in the experiment, a signal over background ratio of about 10 is achieved.

The source collects the emission from one (a single) nitrogen-vacancy (N-V) color center in a diamond nanocrystal. A laser system is used to put this one color center into an excited state using 800 picosecond pulses. The color center has time to emit 1 (one, single, not more than 2, an integer between 0 and 2, etc.) photon to go into a stable state before the next pulse arrives.

Quote:

The laser system delivers 800 ps pulses with energy 50 pJ, high enough to ensure efficient pumping of the color center in its excited level.

There is no simulated emission since there is not a population of excited states to be simulated (just 1 color center is excited).

A single photon source emits single photons. That is a fact. If it was an apparatus producing multiple photons at a time then they would not call it a single photon source.
You are essentially calling the authors liars.