What exactly is an electron?

DonJStevens

In post # 47, a minimum electron radius value, (3Gm/c^2) was noted. From this radius, a fundamental mass value is defined, using a ring shape with the angular momentum (h/4pi). The charge spins at light velocity so that the effective mass times velocity times radius will equal angular momentum.
m c (3Gm/c^2) = h/4pi
(m)^2 = (h/4pi) (c/3G)
m = (hc/12pi G)^1/2
m = (1/2) (2/3)^1/2 (Planck mass)
I suggest this mass value is the fundamental value that has a specific relationship to the electron mass, the muon mass and the tau mass.
The photon wavelength that has energy to produce two particles with each particle mass value equal to (hc/12pi G)^1/2 is (3pi hG/c^3)^1/2 meter. This wavelength is:
wavelength = 2pi (3/2)^1/2 (Planck length)
The ratio of this fundamental wavelength to the wavelength (h/2mc) is approximately 1.025x10^-22 to one. I will suggest that this is also equal to [h/(2pi)^2] divided by (2mc^2) where the m value is the electron mass. This ratio is 1.025028393x10^-22. If these ratio values are precisely correct then the true G value must be very close to 6.671745197x10^-11. Improved experiments will determine if this is correct.

kended

First off I'm no physicist but an EE. So my question might seem odd, but in light of everything that was said until now, why has nobody (except for one guy I believe) proposed string theory to try to explain what elementary particles are (electron included)? Is this because it is still an "unproven" (untested) theory?

String theory seems to be acknowledged by many recognized scientists, so perhaps it is a valid one at answering the initial question: what is an electron?

Btw, what a great forum this is. Just recently found it. Since then I just can't help but try to read every single posts. Waaa, I'm going crazy :)

DonJStevens

Hi kended, String Theory and Quantum Gravity are well covered in the book by Lee Smolin, titled Three Roads To Quantum Gravity. Much work is needed if string theory is to accomplish its objective. A quote from the book follows:
"Modern physicists try -- to explain particles in terms of fields. But this does not eliminate all problems. Some of the most serious of these problems have to do with the fact that theory of fields is full of infinite quantities. They arize because the strength of the electric field around a charged particle increases as one gets closer to the particle. But a particle has no size, so one can get as close as one likes to it. The result is that the field approaches infinity as one appraches the particle. This is responsible for many of the infinite expressions that arize in the equations of modern physics."
He suggests, we may deny that space is continuous and so it is impossible to get arbitrarily close to a particle. We may also replace particles by little loops or strings. String theory is interesting but it is not yet mature enough to explain specifics such as electron mass.

kended

Thanks for your reply DonJStevens.

I think I may have to read some more on this subject. It seems though that the book was written in 2002. So perhaps has the subject evolved a bit since then.

Now with the very recent "supposed" discovery (measurement) of the Higgs-Boson, I read that string theorists are even more excited as this would somehow fit their theory in relation to particle mass.

Anyhow I just thought that instead of saying that we "don't really know what an electron is", I would rather try to explain it using string theory that many great minds do believe in and where the mathematical constructs apparently make sense that is, until proven right.

Btw, your former job sounded very cool :)

Dickfore

The charge radius of an elementary particle has nothing to do with the spatial distribution of its charge. The charge radius is a length scale characterizing a scattering cross-section.

In Quantum Field Theory, elementary particles are thought as excitations of the corresponding matter field that propagate carrying energy-momentum. These excitations may be created and destroyed by the action of sources. Consequently, the energy of the field's excitation due to two sources differs from the sum of the energy of the field's excitation due to the separate presence of each source. This is interpreted as a potential energy of interaction of two sources due to the exchang of virtual particles.

The sources of some kinds of particles become quantum operators themselves corresponding to a (conserved) Noether current density corresponding to a continuous symmetry of the theory. For example, the free-electron Lagrangian has a global U(1) symmetry, corresponding to the invariance of the Lagrangian with respect to an arbitrary change in phase of the "electron field". The corresponding noether current is the electric current density, that acts as a source term for the "photon field". The photon "listens" to the electric charge in its vicinity and mediates the electromagnetic interaction. Since the range of the interaction is infinite, the photons are massless, and there is only a kinetic term for the photon field. This effectively describes Quantum Electrodynamics (QED), the simplest (Abelian) gauge theory of the Standard model.

wizwom

So a photon that undergoes pair production does so because of because it is a perturbation energetic enough to inititiate the pair's own standing waves. But why at one point, not another? Why don't we just see a pair and the lower energy photon from, for instance, Co60, but instead see a high energy photon and the pair production photons later? Is that because this "Noether" field has to be in the correct configuration locally for the pair production to occur, or because the virtual particle must form, which isn't a given, but a statistical process?

g.lemaitre

I just want to point out to the OP. You're getting down to the basic building blocks of matter. When ever you describe something, call it E, you break it down or you reduce it to it's parts or its properties, X Y and Z. I think Vanhees said it perfectly:

It is so difficult to describe an electron because you're running up against the basic building blocks of the universe which cannot in principle be described. Notice that Vorhees described an electrong in terms of charge, mass, spin, and the forces with which it participates. So we have some reduction. But charge, mass, spin we cannot reduce those entities to anything else, at least not now, and they remain in principle undescribable.

Gunter.x

Despite of the great success of mathematics one should reconsider the building blocks from time to time.

Dirac invented his equation to describe the properties of spin 1/2 particles. The interaction of electrons are perfectly described by this equation.

Especially D. Hestenes investigated this equation in detail and found a description of the electron: The electron is circulating with speed of light which is described by the Zitter-Bewegung, generates an angular momentum - the spin, and with E = h x nu the Compton wavelength defines the circumference of the circulation.

But why the charge should circulate is still open.

All models in the past ignore the synchrotron radiation of the charge.
Even in classical physics a circulating charge embedded in its synchrotron radiation yields the angular momentum of the particle, the Compton wavelength as the wavelength of the radiation and the classical electron radius is the result of quantum mechanic interaction with the singularity. Circulation with v = c yields mass = field energy.

The spherical solution of the radiation just guides the charge onto a circular orbit and is thus the reason for the circulating charge.

Details are in G. Poelz "On the Wave Character of the Electron"
http://arxiv.org/abs/1206.0620

Atom1

This is a very good question to pose, as quoted by many people have tried to make a modle of a electron while its basic formation is known for the most part it would be a good project to go into to try and look inside of the electron

Drakkith

We've tried. We can't find anything inside it. And by "we" I mean thousands of people using multiple particle colliders and other experiments over the last 50 years.

xristy

Since MacGregor and Rivas have been mentioned perhaps it is worth mentioning a moderately priced collection of papers What is the Electron?, edited by Simulik that includes papers by each of the them as well as others. It's quirky and in print.

DonJStevens

I obtained the book, What is the Electron, yesterday. Thank you xristy for mentioning this. The Einstein question (on back cover of book) is so very significant.

When he was asked what he thought about the large numbers of short lived heavy particles being produced in high-energy accelerators, Einstein pondered the question and replied, "You know, it would be sufficient to really understand the electron."

At the time little attention was paid to his remark. Yet the electron remains as mysterios today as it was in Einstein's time. The electron will be less mysterious if we learn why all electrons are identical. J. A. Wheeler said "That an electron here has the same mass as an electron there is also a triviality or a miracle." (see page 1215 of book Gravitation)

Drakkith

You could expand your statement to include all fundamental particles, as they are all identical to other particles of the same type.

DonJStevens

Drakkith, you are so correct, all particles of the same type are identical. This implies that nature has a specific set of requirements that must be precisely met for each particle (type). We expect that theorists will determine and define these strictly imposed requirements. The electron requirements will most probably be the first that we will understand.

Drakkith

Perhaps Don. We'll have to wait and see!

DonJStevens

We can see now what some theorists have recently written about the electron. In post # 59 a paper by G. Polz was referenced. In this paper the electron is analyzed as a toroidal ring. The author (G. Polz) also references other papers that are interesting to all who want to know more. The referenced paper by Williamson and van der Mark analyzes the electron as a photon trapped in a toroidal path. As we come closer to a correct electron model, the desire to understand becomes ever more intense. As Drakkith said: We'll have to wait and see!

DonJStevens

The book, What is the Electron? noted in post #62 is interesting. The Wave Structure of Matter is discussed (page 227 - page 250). From page 240: "Schrodinger and Clifford predicted that charge was due to wave structures in space. - - We observe this process and call it charge. But as Clifford and Schrodinger wrote, there is no charge substnce involved. It is a property of the wave structure at the center."

This book allows us to see some concepts by theorists who want to help us understand the electron. Thank you xristy for noting this book.