0 Members and 1 Guest are viewing this topic.
This topic came up in another thread recently: http://www.thenakedscientists.com/forum/index.php?topic=27444.0Since it's gotten a lot of discussion, I think it deserves its own thread. So the question is this: do electrons necessarily rotate? What kinds of rotation do electrons experience? Are there physical consequences of these rotations?
i contrast this to the actions of a knuckleball in baseball & would guess they gotta have some spin
I agree on that spin is defined as having an 'angular momentum' but there is one important word missing.. . . Intrinsic . . .
"Experimental evidence like the hydrogen fine structure and the Stern-Gerlach experiment suggest that an electron has an intrinsic angular momentum, independent of its orbital angular momentum. These experiments suggest just two possible states for this angular momentum, and following the pattern of quantized angular momentum, this requires an angular momentum quantum number of 1/2".
"Ralph Kronig, one of Landé's assistants, suggested in early 1925 that it was produced by the self-rotation of the electron. When Pauli heard about the idea, he criticized it severely, noting that the electron's hypothetical surface would have to be moving faster than the speed of light in order for it to rotate quickly enough to produce the necessary angular momentum. This would violate the theory of relativity."
The definition of intrinsic is as follows " Belonging to a thing by its very nature." In the same way as photons are intrinsically massless and timeless.
"As the name suggests, spin was originally conceived as the rotation of a particle around some axis. This picture is correct in so far as spins obey the same mathematical laws as do quantized angular momenta. On the other hand, spins have some peculiar properties that distinguish them from orbital angular momenta: * Spin quantum numbers may take on half-integer values; * The spin of a charged particle is associated with a magnetic dipole moment with a g-factor differing from 1. This is incompatible with classical physics, assuming that the charge and mass of the particle are distributed evenly in spheres of equal radius. Particles with half-integer spin obey Fermi-Dirac statistics, and are known as fermions. They are required to occupy antisymmetric quantum states (see the article on identical particles.) This property forbids fermions from sharing quantum states – a restriction known as the Pauli exclusion principle2.
"Particles with integer spin, on the other hand, obey Bose-Einstein statistics, and are known as bosons. These particles occupy "symmetric states", and can therefore share quantum states. The proof of this is known as the spin-statistics theorem, which relies on both quantum mechanics and the theory of special relativity. In fact, "the connection between spin and statistics is one of the most important applications of the special relativity theory".So we have a definition coined because it reminded us about angular momentum, not that it was anything like it. So, to treat it as a rotation seems less than correct.
That's a cop-out non-answer, yor-on. Really. It's like saying surpasseth all human understanding.
No problem with that. The moebius strip exhibits this feature, as does the Williamson / van der Mark and the Qiu-Hong Hu electron models. See http://arxiv.org/abs/physics/0512265 for the latter. This might not be mainstream yet, and it has not yet hit the media or the textbooks. But I assure you, the moot word is yet.
And as for the Pauli exclusion principle, two waves can ride over one another, but two whirlpools cannot overlap. It's a rather simple picture once you see it, and it works.
I'm sorry yor-on, but it's not scientific to say it's something intrinsic that we cannot understand. That's not enough to oppose deductive logic backed by evidence and peer-reviewed papers.
Look to pair production, where mass and charge and all those electron properties are created by doing something to light so that it no longer propagates linearly at c.
The one and very important feature that I have never had a clear answer for is:- Is bandwidth an inherent property of a single photon or is it only observable in collections of photons from a particular source? and I have asked this question of some pretty good scientists. The only reply i have ever received is That is a good question I will have to think about it.I have never been able to think up an experiment that could prove this either way so maybe this question just cannot be answered.
But as I'm, ah, ever so slightly weird myself I think I get it, a very nice explanation. In that motto a superposition will be how you define a given wave by using approximations to narrow it down to a 'best answer'? But can there be a definite answer to such a procedure, doesn't it just goes on and on? But very very good explanation of the mathematic principle for it. Sweet one JP.
And a 'wavepacket', if you tried to define it like this, or could I see this as a 'reversed wavepacket procedure' sort of? You should be able to do this both ways mathematically, shouldn't you? I think of a wave packet as what it seems to say, like a 'packet of waves' together.
This one though, could you expand on how you mean here?"Why this is important is that in quantum mechanics, you choose what you want to measure, and then essentially "write" your wave in terms of other waves that have well-defined values of that quantity and then your measurement picks one wave from among these. It can only pick one answer, so it picks among them randomly (with some rules giving the probabilities of picking each particular answer)."
Hey, I know what it reminded me of now A analogue signal to digital, right? And that makes sense, it's 'cut outs' right? A way to treat the universe as 'quanta' so to get a 'over see able' system?Or am I bicycling in the blue younder again?
No I was referring to jPs apparent insistence that photon wave packets only included a single frequency pure sinusoid. Note they could contain a single frequency gaussian amplitude modulated sinusoid. This would produce the normal line widths observed in spectrum lines. This is probably the best way to imagine what the waveform of a photon is like.
But Farsight, you will need to be able to explain the properties of an electron going through a Stern-Gerlach magnet too for your proposal to become a theory, don't you agree? Or maybe you already have?
Atom smasher shows vacuum of space in a twist Ephemeral vortices that form in the vacuum of space may have been spotted for the first time. They could help to explain how matter gets much of its mass.Most of the mass of ordinary matter comes from nucleons – protons and neutrons. Each nucleon, in turn, is made of three quarks. But the quarks themselves account for only about 1 per cent of the mass of a nucleon. The remainder of the mass comes from the force that holds the quarks together. This force is mediated by particles called gluons.A theory called quantum chromodynamics is used to calculate how quarks and gluons combine to give mass to nucleons, but exactly how this phenomenon works is not fully understood.One possibility is that the fields created by gluons can twist, forming vortex-like structures in the all-pervasive vacuum of space, and when quarks loop through these vortices, they gain energy, making them heavier.Now the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) in Upton, New York, has seen signs of such vortices...
Farsight: in addition to the properties you have discussed, the electron model that you propose which dimensions would have? Does the model also predict the wavelike properties of the electron?
This really is leading edge stuff, see this week's New Scientist and the article on page 15 http://www.newscientist.com/article/dn18526-atom-smasher-shows-vacuum-of-space-in-a-twist.html.
It's three-dimensional, lightarrow, like a bagel with a twist only there's no actual surface to it. I wouldn't say the model predicts the wavelike properties of the electron, because that's what we observe. Rather it explains them because it describes the electron as a double-wrapped electromagnetic wave going round and round in a circle.
No, I didn't look for it. I know it anyway. That's easy.