zhermes said:
There are many reasons for EM radiation, first and foremost black-body radiation from anything at non-zero temperature--and that's the primary mechanism of emission in BH jets. Also, any acceleration of charged particles emits radiation e.g. http://en.wikipedia.org/wiki/Larmor_formula"
Thanks for this link. This is new information to me. I thought particles could express all their energy as motion up to a certain velocity.
There is no limit to how small of an increment of acceleration can be made, and an infinite amount of energy can therefore be absorbed as you accelerate something towards the speed of light--there is no need to dissipate energy. Also, being a little nit-picky, photons are be definition not fields, and most certainly do NOT accelerate to c, they're always going at c.
This is how I see this, and it may be misguided: if a particle is traveling at close to C, let's say 99.5%C (I'm not a physicist so excuse me if I'm overlooking something in choosing this as an arbitrary speed for discussion's sake). For the particle to accelerate from 99.5% to 99.6%C it has to jump forward in its inertial frame a certain distance, which would be relatively far compared with the same acceleration taking place at a fraction of C, right? So such a jump seems analogous to the jump that occurs between molecules in chemical reactions or static-electricity sparks, or in LED emissions. In other words, an abrupt particle-jump emits radiation, imo, because of a ratio between its energy and the distance across which it is accelerated, hence dissipation of surplus energy - or maybe better stated as the particle's energy getting ahead of itself.
The temperature (which is average kinetic energy, not "heat") is undefined INSIDE the event horizon. The event horizon itself has a low, finite temperature--but that's unrelated. The condition of the contents of a black hole is also undefined, but definitely not simply a plasma. The "size" of the contents of a black-hole are millions of times smaller than a single atom, if they have any "size" at all.
LOL! You say they're undefined and then proceed to define what they're not. The only thing I meant by "plasma" is that nuclear particles are compressed beyond the isolating-force of their electron shells. All I meant is that very heavy particles are moving at extremely close proximity, which involves a lot of particulate momentum counteracting a lot of particle attraction. In any case, my point was that I think whatever the state of material inside a BH, it must have a limit as to how much energy it can absorb as changes of phase/state. After that, I would expect energy to be expressed as system-level motion (i.e. turbulence or spin).
If infinite phase/state changes are possible, then BH's could infinitely absorb energy. Likewise, if energy can be sustainably transformed into matter or otherwise increase the gravitation, then the event horizon would simply expand indefinitely. Still, I don't see why a BH couldn't spin fast enough to cause it to split into multiple smaller BHs. System-level motion is different than particle-energy or radiation.
The black-hole as a whole will have some kinetic energy, the whole thing can move. Otherwise the KE gets converted to mass-energy, just adding to the mass of the BH itself.
How does KE get converted into mass-energy exactly?
For a BH to split into smaller ones, the smaller ones would have to escape each others event horizons, which is not possible. For the same reason the BH forms in the first place, there is no source of energy which can resist the gravitational pull/collapse.
Not if gravity is being expressed in the re-sphering of the two halves. Think about a ball of water in zero-gravity. No drop of water can escape the surface tension of the water, but when elongated enough, the ball will split as the two sides re-sphere according to the surface tension being distributed to the ends instead of the center.
There is no need to "express" energy, I don't know what you mean by that. Energy is never 'competing' against gravity, only other forces are--and in the case of a BH--they always lose. It doesn't matter how much mass/energy is in the black-hole, that just makes the BH bigger and stronger.
All gravitational systems express energy as motion. This could be rotation or orbiting satellites. Planets, moons, and other satellites maintain radial distance from their fulcrum according to their velocity which "competes" with gravity to establish the object's distance from the center of gravity. If velocity wins, the object's distance from the center increases. If gravity wins, velocity isn't sufficient to maintain orbit altitude and the object begins to fall deeper into the gravity well.
A planet whose rotation increases sufficiently would overcome its own gravity and fragment into divergent pieces. As long as the planet's gravity is sufficient to overcome the momentum of its constituent parts/particles, the planet remains intact. Heavier particles require more energy to overcome gravity so they can withstand greater velocities and lower gravitation before floating away.
Take a practical example: First make a chart correlating Earth's rotational speed with its rate of gravity at sea level. Then find the rotational speed at which water boils at 0C. Then figure out the point where gravity is no longer sufficient to prevent the water molecules from blowing away into solar orbit. Eventually, I assume you'd reach a point where the spin would overcome the force holding the core together and the planet would split into multiple moons in mutual orbit.
Seriously, though: What do you base your notion that matter keeps breaking down into increasingly small particles of matter? You say "string," but what is that? A vibrating segment of pure energy that doesn't move at C? By "phase change," I generally mean re-configurations of matter-energy that would allow it to be compressed infinitely. If there is a limit to matter-energy compression, then energy within a BH would have to be expressed in some other way for it to be conserved, no?
