Aeschylus

No as I said before any attempt to define a radius for the electron is arbitary as it is so for any elemnatry particle. Classically you can assign the electron what is known as it's Compton radius, but there is no reason to think of that as it's true radius. We do not in general include gravity in fundmantal descriptions of the electron and we do not expect general relativty to work on this level anyway, besides which singularities such as those caused by a mass occupying aregion smaller than it's Schwarzchild radius do not have infinite mass.

Yep, electrons are point particles in the fact that any radius that you assign to them will be arbitary.

When a particle and it's antiparticle annihilate, they can produce almost anything as long as conservation laws are obeyed. The low energy (i.e. when the two particles have kinetic energy that is negligible compared to their rest energy, in the centre of mass frame) case of electron-positron annihilation produces two photons, but that's not always the case for example in annihilations of a certain (higher) enrgy you would expect the products to be hadrons.

First of all I'll say it's axiomatic to quantum theory that the operators of observables have the same relationship to each other as the observables do in classical physics For exmaple the momentum operator and the part of the Hamiltionan operator correspondign to kinetic enrgy are related by: [math]-\frac{\hbar^2}{2m}\nabla^2 = \frac{1}{2m}\hat{P}^2[/math] which compares to: [math]K.E. = \frac{p^2}{2m}[/math] Actually showing the clasical limit of quantum mechanics is alot harder and a lot more advanced, but I imagine you would start to see it if you choose a large mass for the object you want to describe.

Yes, I've said sevral times that the communications channel isn't importnt bar any practical difficulties it may present, so yes radio wave scould be used to carry this data. If one of your particles ineracts with another particle it can destroy the experiment, loomk at the short distances entanlglemnt experiments are usually done at, tho' I believe one was performed over a distace of a few km recently.

It's true, the KE of any partilce is not given by 1/2 mv^2 except in the degenrate case. But if were going to triple nitpick, the last formula doesn't give you the energy of a massless particle as it's undefined for v = c.

What it means is that onece your in the black hole, you will meet the singularity in a finite time.

All worldlines in a black hole intesect the singularity.

No.

No, we can';t actually use quantum entanglement for FTL communication which is a stromng indictaioon it is not FTL communication. We should prefer the explanation that does not involve FTL communictsaion as other versions are non-relativstivc. Infact this is not a fudge factor in any way as it's simply what the orthodox interpretation was saying all along.

You have to understand that there is no reason to think of it as FTL communicatio, these days it's just seen as denmonstrating the fact that the collapse of he wavefunction is a nonlocal event.

[math]\gamma \to e^+ e^-[/math] The above formula for the case of a photon in a vacuum is impossible as it violates four momentum. What you are looking for is something like this: [math]\gamma\gamma \to e^+ e^-[/math]

1) minor nitpick: mass, by the defintion of mass, does not increase with speed. 2) accelerating to the speed of light is impossible. For example: this cannot be acheived with a finite accelartion. 3) the energy of a photon is related to it's frequency/wavelength, formulas like KE = 1/2 mv^2 will not give you the KE of a massless particle like a photon.

EPR apparently demonstrates FTL communication the orthodox view is that it does not actually demostarte this at all.

I need to poitn out a few things: That's a very unorthodox view and I don't know why anyone would expect a telecommunications engineer to have any real knowledge of this area. The whole piece is a non-story really because, nothing new is actually being proposed - no-one at the present time has found even a theoretical way to transmit information faster than light using QM, all the article is is a collection of speculative quots.

I imagine it is the quickest way. Looking at my textbook I can see no reasaon why that QT would have a distance limit, though i imgaine that it could cause problems.

No, it's just important that you recognize that EPR doesn't necessarily mean FTL communication.

It's just a fundamental property of nature.

I must of submitted it at the same time you were working on the thread, cos I got a "you do not have permission to access this page" when I submitted it. I'll summarize it for the moment: 1) quantum teleportation still has all the problems of 'classical teleportation', it only gets aroun the 'no clones theorum' of quantum mechanics 2) quantum teleporation cannot be used to end information, in order to acheive teleportation information must be sent from one location to another using a classical communications channel (for example a laser, a telephone or even a carrier pigeon). This also means teleporation is not instanateous.

Erm what just happened? I just wrote a long post on why quantum teleportation was unlikely to be of practical use, yet the forum has gobbled it up, along with the last few posts on this thread.

And all you need to do is to prove that gamma is undefined and hence the Lorentz transformation only gives results that are undefined, which is a fairly trivial exercise.

The problem is the formulas don't work as gamma is undefined, all specila relativity says is that it is impossible for any object with non-zero mass to travel at c, also we can't define a frame of refernce for anything travelling at c such as a photon.