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Johnny Boy wrote:
"Electrons are localised waves they are not particles "waving" their tails"

Please assume that this DUH is 72 point font: Bold faced.

You still don't get it.

Electrons are not waves.
Electrons are not particles.
Electrons are electrons.

A map of the state of New York is not the state of New York. A map of the andromeda galaxy is not a galaxy. And an analogy of electron properties is not an electron.

I understand your reasoning, which is the standard dogma leading to the non-causal absurdities when interpreting quantum mechanics. I am arguing that your reasoning is outdated, and should never have been believed. This is the bad legacy that a brilliant scientist called Heisenberg left behind. As Einstein anticipated, this reasoning is just plain wrong. How can an atomic orbital represent a moving charged-entity (whatever it might be) without having to radiate EM radiation? The Heisenberg uncertainty relationship for position and time relates to the relationship between position and k-space which every wave-function has to have; IT IS NOT UNCERTAINTIES IN THE POSITION AND MOMENTUM OF A POINT PARTICLE OWING TO INBUILT STATISTICS IN THE UNIVERSE (GOD REALLY DOES NOT PLAY DICE!!!). To say that an electron is an electron is an electron is acceptable as a religious mantra, but is not good science!

Dear D A, Do you always have to go off on a tangent? You know well that the "standard dogma" that I have been referring to is the interpretation of quantum physics; NOT the validity of physics. Can you explain to me in detail how the the Copenhagen interpretation of quantumm mechanics, as such, has been instrumental in placing a man on the moon?

This interpretation, introduced by Bohr, Heisenberg and Born, married physics to metaphysics. Physics is based on two questions: "why? and how?". Bohr's statement of complementarity stated that in the quantum world it is futile to ask questions like: "Why does an electron act as either a particle or a wave?" or "How does it manage to do so?" No wonder those people practising metaphysics and mysticism welcome this interpretation with open arms, and mouth the mantra: an electron is an electron is an electron! Maybe it IS a mystic world, but as a scientist I refuse to accept that there are aspects of Nature about which I should not ask "how" or "why"; even when my head is bitten of by you and Uncle Al when I do so.

Now let us consider Heisenberg's interpretation of his own uncertainty relationship for position and momentum. According to this interpretation both position and momentum of a free electron cannot manifest simultaneously; however, all experimental data on the free electron can be accurately modelled as the movement of a particle with a centre of charge and a centre of mass! This is the experimental fact. No experiment has ever shown that an electron ejected by a cathode becomes "uncertain". All the electrons follow well defined classical paths which can only manifest if momentum and position manifest simultaneously for their centres of mass. If this were not the case, the movement of a free electron would have been akin to Brownian movement. Has this ever been observed? If it were the case we would not have had electron microscopes or electron accelerators. What happens when the electron moves with a constant velocity? Since it follows a classical path, it means that its centre of mass MUST be stationary within the inertial reference frame moving with it! Now let us in addition, consider a "vacuum foam" of energy. As Uncle Al pointed out, an electron cannot be stationary when one has such a vacuum energy; however, this is at variance with experiment (as outlined above). How did Heisenberg, address this problem? He stated that the "electron's path only comes into existence when it is observed". Another metaphysical concept. It implies that if there is no observer, there would be no path; however, an electron in free flight within an electron accelerator is not "observed" but it still follows a definite path which requires the manifestation of both momentum and position at all instants of time. But notwithstanding this experimentally verifiable fact, Heisenberg postulated that it is impossible for both momentum and position to manifest at the same time (unless the electron is observed). Is observation not a "measurement"? So this implies that when you measure you CAN observe both the position and momentum of the centre of mass of a free electron. This is also the experimental fact. As I scientist I rather believe experimental results than an interpretation that is at variance with experiment. My model of the electron as a localised wave with a centre of charge and thus a centre of mass, removes these contradictions. It also gives a possible reason why the mass of an electron consists entirely of electromagnetic energy.

"And, of course, what Al said ... but you are confusing things. Zero rest mass has absolutely nothing, nada, zilch, to do with whether something is divisible"

Okay, so maybe I didn't research the proper scientific meaning of mass. Consider this then, a simple, easy to visualise example. I weigh 62Kg -on earth; divide that by two till you reach a ridiculously small number, call it x. Now let's say that x is what the smallest particle ever or ever-to-be discovered weighs -on earth. x is without a doubt greater than zero, therefore it can be divided by two to produce a positive number. So when I do this and get a new number, z, I am asking what z is the weight of -on earth.

How sad, you wont answer my question.

what z is the weight of -on earth?

This is unbelievable! Why won?t anyone answer my question?

perhaps because your question, as stated is unanswerable. While it's true that numbers can be infinitely divided, objects cannot. A piece of cherry pie can only be divided down so far before you come to molecules of cherry pie. At some point, the division has to stop because the fraction of a molecule of cherry pie is not cherry pie. so it is with quarks. Thus while you numerically can divide indefinitely, with objects there are limits.

I hope that helps.

Amaranth

there have been many experiments that have indicated that it is a particle instead of a wave.

there have been many experiments that have indicated that it is a wave instead of a particle.

there was even an experiment at one point that indicated that it was neither, but something else that had characteristics of both. few ppl agreed with the test result of this.

the only thing test have proven: if you believe its a particle, you ll find evidence of it. if you believe its a wave, you ll find evidence of this too. neither side is willing to give up.

if you follow one of the theories of the early universe (first few seconds: yes da, i know that they don't "know" what it was like but many ppl have made theories about it, many of which are opposing) it suggest that before their were particles there was just energy. the corollary of this is that if you divide particles up enough, you end up with energy. and of course there are scientist that say that that particular theory is a bunch of malarkey

"so what proof is there that a photon is a particle and not a wave?"

Photons striking a surface have an impact which can be measured.
The impact is proportional to the energy carried,
(inverse to the wavelength), and indicates the
energy, (by E=MC<2), is all the mass there is.

However photons also demonstrate interference,
a wave property.

Wave? Particle? Wavicle? - Pick your choose.

I am a self confessed waveist and my arguments are thus:

a) On the macro scale we know all about particles so it's natural to "force" the world we can't see to look like the one we can.

b) The evidence for the "particle" nature of matter generally comes from interactions involving atoms, essentially the movement of an electron from one orbital to another. Atoms are most successfully described by assuming they consist of waves.

b.1) The description of a photon passing through a transparrent medium involves the exitation (vibration or distortion and relaxation) of an array of electron orbits (all wave mechanics) nullifying the original photon and retransmitting it, typically to give a slower speed of light. If the photon happens to be absorbed by a single atom during this process (see complexity theory as to why this is likely to happen) then it seems just as remarkable that the movements of all the electron work together to make just one atom get exited (as opposed to the photon being trasmitted unaltered*).

c) People like the probability view of quantum mechanics because it restores the idea of free will. It also adds a "mystery" factor a.k.a. accept this as an act of faith.

The best knowledge we have about electrons is that they are neither particles nor are they waves. The best knowledge we have is that sometimes they have behaviours that can be explained with math that describes particle beahviour. Sometimes they have behaviours that can be explained by math that describes wave behaviour.

And sometimes they have behaviours that can NOT be explained by either. For example:
http://polyticks.com/psi/orbitals.htm
and
http://www.physlink.com/Education/AskExperts/ae619.cfm
Look for the phrase "all possible paths."

I suppose I agree with you in the sense that electrons (and all matter for that matter(!)) are not waves as we know them "up here" in the macro world, neither are they particles. However I think the accepted probability expalantion where things swap from wave to particle is a fudge to let us do the maths.

Particleness is an emergent property of the correct wave equation (possibly never to be discovered).

I agree with you it is a fudge. It is possible to derive a clearly defined interface which demarcates when one can consider an electron as a "particle" (which it is not) and when wave-superpositions (i.e. QM) has to be used. When an electron-wave do not overlap sufficiently with other surrounding electron-waves, it experiences the other waves as point particles. This is simply the result one expects from Gauss' law when one views a distributed charge from outside. Similarly the electron waves around a nucleus do not overlap with the waves of the nucleons; therefore an orbital electron experiences the nucleus as a point charge. The amount of overlap that can be tolerated, while still experiencing other surrounding waves as points, is determined by the uncertainty in position (delta)r around the centre of mass (charge) of the wave, and is given for identical adjacent waves as 2*beta*(delta)r; where it seems that beta is equal to the square root of 2. It is at this distance between the s-orbitals that two approaching hydrogen atoms bond chemically. The two s-orbitals cannot experience each other as point charges anymore; their distributed charges coalesce and the covalent bond comes into existence owing to this entanglement of the two electrons.

It is zero, QED demands it and experiment has confirmed it. The CURRENT upper limit on the photon mass is 6*10^-17 eV.

Yes, it is the photon.

that is assuming that a photon is a particle and not an energy wave. last i saw neither side had yet to prove sufficently that the opposite camp conceeded to the arguement.

Mass is inertia; and inertia means that a "particle" can be stationary within an inertial reference frame. The photon ALWAYS move with speed c relative to ALL inertial reference frames. Therefore it has no mass but only kinetic energy. The photon IS divisible. In Compton scatterring a part of it can be absorbed so that a part with less energy remains. I also believe that at a double slit it splits up in two equal parts to move through both slits at the same time so that the two parts can interfere with each other on their way to the screen. At the diffraction screen the interfered wave collapses in order to be absorbed by one of the atoms (the statistical spread of points for different photons collapsing is determined by Heisenberg's Uncertainty Relatiionship for energy and time). If just behind the slit one places a detector to determine through which slit the photon came, the split-photon collapses to a point in order to be "seen" by the detector. The two parts does then not exist anymore and the interference pattern cannot manifest.

Remember, Planck's relationship only says that light with a frequency nu cannot have a lower energy that h times nu. It says NOTHING about the spatial extent of a lightwave. The latter is determined by the boundary conditions.

JB wrote:
" I also believe that at a double slit it splits up in two equal parts to move through both slits at the same time so that the two parts can interfere with each other on their way to the screen."

This one part of your post is at odds with most physicist's understanding of what happens. I believe the most reasonable, if you can call it that, explanation is that the photon takes ALL POSSIBLE paths to the target.

I have my personal ideas about this but they are the stuff of which laughter is often the result.

I believe that this is exactly where we all went wrong. It gives me pain to say this because I am a GREAT ADMIRER of Feynman; however, he is not totally incorrect (he is not even wrong). Just as one can create music from digital code, one can create some semblence of reality from Feynman diagrams; however, this is creating "reality" from "virtual reality". The photon is NOT a "particle" taking ALL paths; it is simply a wave which can "morph" into different shapes depending on the boundary conditions it encounters. Thus it can be stetched right across the Universe as in the case of the micro-wave background radiation; but when you observe it, it near-instantaneously "collapses" to be absorbed by the detector. Once one accepts the fact that a wave entity (which we call a photon) can be stretched over the Universe and "collapse" near-instantaneously to fill a small volume so that it can be absorbed by a detector, all "mysteries" in physics become causal.

Reasonable enough that I'll give you a peek under the covers of my thinking.

I think we need one spatial dimension that is disconnected from space-time and stands on its own. One place that an entity can be in which the concept of time is irrelevant.

If such exists it solves numerous problems in physics. The slit being one of them. But another being the old "spooky action at a distance" conundrum.