Faster than light

[fafalone]

Originally posted by Radical Edward

yes. electrons often travel faster than light.

 

 

I've never heard of this, especially considering electrons have some mass.

[superchump]

Originally posted by fafalone

I've never heard of this, especially considering electrons have some mass.

 

KHinfcube22 never specified "in a vacuum". I'm assuming Radical Edward is talking about chekhov radiation.

[JaKiri]

Originally posted by fafalone

A singularity is an infinitely small point, the escape velocity approaches infinity as you approach the singularity.

 

No it isn't.

 

It requires infinite energy to remove oneself from a black hole, not infinite velocity.

 

For any singularities to exist by your definition, there would have to be infinite mass at this point, and thus all of the universe would have infinite gravity.

[fafalone]

So what is the mass of a singularity?

[JaKiri]

Originally posted by fafalone

So what is the mass of a singularity?

 

What kind of question is that?

 

To use the cliché, 'How long is a piece of string'?

[superchump]

Originally posted by fafalone

So what is the mass of a singularity?

 

 

Directly proportional to the Schwarzschild

radius of a black hole.

 

At least for Schwarzschild Black Holes.

[dluther]

Try reading to book faster than the speed of light... very interesting!

[Raider]

For any singularities to exist by your definition, there would have to be infinite mass at this point, and thus all of the universe would have infinite gravity.

 

This is not true. Singularities have infinite density because they occupy infintely small space. They do not have infinte mass in finite space.

 

edit:bag tag

[KHinfcube22]

but black holes do weigh a lot, even giga tons for the tiny ones.

[MajinVegeta]

Yes, they have infinitely small mass. Are you having trouble comprehending infinity? I could explain it quite conceptually (with a hint of math) if you like.

 

What's the difference between a "regular" black hole, and a schwartzchild black hole? Don't they all emit schwartzchild radiation?

[JaKiri]

Originally posted by Raider

This is not true. Singularities have infinite density because they occupy infintely small space. They do not have infinte mass in finite space.

 

I would comment, but I won't until I consult a tome of authority, which unfortunately I am lacking at this location.

[MajinVegeta]

Originally posted by Radical Edward

yes. electrons often travel faster than light.

 

That would not make sense. For one, electrons are classified as leptons. Leptons only travel at c. I could say more, but it would be pointless as the aforementioned is sufficient.

[JaKiri]

Originally posted by MajinVegeta

That would not make sense. For one, electrons are classified as leptons. Leptons only travel at c. I could say more, but it would be pointless as the aforementioned is sufficient.

 

He may well be referring to quantum tunneling effects, or has been previously been mentioned 'speed of light in a medium'.

[Radical Edward]

Originally posted by MrL_JaKiri

He may well be referring to quantum tunneling effects, or has been previously been mentioned 'speed of light in a medium'.

 

both actually. I was being annoyingly vague on purpose.

[Radical Edward]

Originally posted by MajinVegeta

That would not make sense. For one, electrons are classified as leptons. Leptons only travel at c. I could say more, but it would be pointless as the aforementioned is sufficient.

 

massless leptons don't only travel at c. Only force carriers do that, and afaik they are all bosons which is a good job otherwise lasers wouldn't work. Neutrinos are leptons, but they are a grey area, so I will ignore them for the purposes of this answer as I don't know. Although attempts to combine electroweak and strong force often suggest small neutrino masses, and even some experiments are suggesting that neutrinos have a mass too.

 

(edited a bit - I had leptons and fermions mixed up)

[fafalone]

Only massless leptons travel at c. A particles classification as a lepton has little to do with its velocity. If an electron was travelling at c, it would have infinite mass, since its rest mass is non-zero, unlike another lepton-- the photon, which has zero rest mass and travels at c.

[Radical Edward]

leptons interact weakly don't they? I don't recall the photon interacting weakly.

[fafalone]

Photons do interact in the form of energy transfer... certainly you've heard of photons breaking chemical bonds.

[Radical Edward]

that is an electromagnetic interaction though, not a weak one.

[fafalone]

what about electroweak unification?

[Radical Edward]

I know of it, but not enough to comment, other than I believe that it is only relevant in high energy scenarios, and not when considering chemical bonds. However if you know enough about electroweak unification to demonstrate that a photon is a lepton, then I would be glad to hear it.

 

all the tables of leptons I ever see look like in here

[fafalone]

The standard model has its problems...

 

But if you had to classify a photon particle (think wave-particle duality, so it's certainly not a very good way of classifying it), it's more like a lepton than a meson or baryon.

[Radical Edward]

I think of photons as excitations of the electromagnetic field mostly, you are right though that the particle issue is a grey one, but then it is for electrons and so on too, which also have a wave nature.

 

From my understanding, Leptons and Quarks make up matter (Quarks only really exist within Mesons and Baryons at low energies) and both consist of three families electron, muon, tau plus neutrinos for the leptons... and for quarks up,down and so on. The force carriers are not lumped into these categories, as they are not in themselves regarded as matter (although they may have mass)

[Raider]

Yes, they have infinitely small mass.

 

That is the first time i've ever seen anyone say that. Typo?

[MajinVegeta]

The most important point, Radical Edward, is that if electrons did travel at c+, then, we wouldn't be able to detect them in the first place.