MigL

These are two different models, but both make valid predictions for their area of applicability. Their use is dictated by the circumstances, and generally, the Newtonian force is an extremely good approximation ( and much more simple ) of Einsteinian space -time curvature at the low mass-energy ( or low space-time curvature ) limit.

Keeping things as simple as possible... The best analogy I can come up with is that the gradient of a field is like a slope ( well, for gravity, it IS a slope ), which converts, or trades, the potential energy of a test mass/charge to kinetic energy. Potential being maximized at one extreme while kinetic is maximized at the other, i.e. a ball on top of a hill has potential, once it starts rolling down the hill, it loses potential in exchange for kinetic ( speed ) and at the bottom f the hill, it has maximum kinetic ( speed ) but no potential left. There are, of course various types of fields, scalar, vector even tensor, and don't necessarily have higher potential at larger separations; like charges ( + and +, or - and - ) have higher potential at lower separations. This is what provides the incentive for motion of a test particle ( electron, proton, ball, etc. ) subjected to a field. With charges, it gets a little more complicated yet, as each individual charge is also a source or sink of its own field, and in semi-conductors, arrangements of excess/absence of charges is used to create potential 'steps' for a diodes and transistors.

Sorry, I tend to use mass/energy for eV ( probably GeV for gravitons ) even though they are massless. ( they would have to be or gravity wouldn't have infinite range ) I was never any good at remembering proper terminology.

Just to be clear... ( or at least, as I understand things ) You are better off considering the interaction as due to a field, which in the case of gravity, would be space-time geometry. This is a 'classical' view, however. And it so happens that when you quantize a field ( any field ! ), quantum field theory dictates the existence of mediator bosons, or excitations of this quantum field. Certain properties of the field ,then, dictate the properties of this mediator boson ( spin and mass/energy ), which has been named the graviton. Now, although we haven't been able to quantize the gravitational field yet, we can do an end run around the problem, and look for particles with that spin and mass/energy; and, if they are found, it would be confirmation that gravity CAN be quantized. Although I'm not sure if the LHC can achieve the kind of energies that would manifest gravitons. I assume they'd be pretty heavy.

Light, or any signal, loses energy climbing OUT of a gravitational well, i.e. it is red-shifted/loses frequency or waves per second. Light, or any signal, gains energy falling INTO a gravitational well, i.e. it is blue-shifted/gains frequency or waves per second.

No, gravitational time dilation doesn't work that way.

Light is both , a clock and a signal. It is climbing out of the gravity well, and its wavelength stretched/ frequency reduced, and then falling back into the gravity well, with the reverse effects. You would think there would be no difference to what the infalling observer sees reflected from the mirror, as opposed to the faraway observer who only sees the signal climbing out. Of course this only applies before the infalling observer crosses the event horizon, after he crosses no signal/ information can travel to the mirror anymore. Strange's post #2 indicates that the Event Horizon is defined by the radius Rs=2GM/c^2, while the escape velocity is Ve=root[2GM/R]. Simple substitution when R=Rs gives Ve=root[c^2]=c. I.E. When radius is equal to the event horizon, the escape velocity is c. ( no matter what g, the gravitational field strength, is )

Working across frames is always difficult/tricky. Consider an observer in freefall crossing the event horizon. He ( if he had the time ) would measure the event horizon moving radially outward at the speed of light. Similarly, he would measure the speed of a photon emitted radially outward to be c . This is all perfectly valid so far, it is only when you consider a far-away observer's viewpoint, that, since event horizon and photon are moving outward at the same speed , then they must be stationary with respect o each other. And this analysis would be wrong because that far-away observer is mixing frames. @imatfaal I thought I had posted #7 as a response to Janus on the other thread about escape velocity at the event horizon ( BH question ). As it makes little sense here, could you please move it back ?

There is no valid frame for light, nor for events at, or inside, the event horizon.

I'll try this again... In any valid frame the speed of light is measured to be c . Once you start making measurements 'across' frames, things tend to get quickly screwed up. Since energy is also frame dependant, I prefer to think of the photon being infinitely red-shifted to zero energy. To a semi-local observer ( you cannot be local with a photon ), it would still have some energy, but to a non-local observer it would simply disappear.

What're you guys, going camping ? Why do you need so much gear when you leave the house ? ( I've heard about you Europeans and your man-purses )

But the event horizon is not a surface. It is a mathematical construct. By definition, the radial distance at which light/information can no longer escape to the observable universe as a result of gravity or space-time curvature. And this happens at equivalent gravity or space-time curvature. As a result, the event horizon is dark, and we lose all information regarding the former matter other than mass/energy, charge and ang. momentum. ( at least until Quantum Gravity Theory tells us differently )

It is our ( well, not really mine ) fault... We voted for, and elected, a moron.

I hope you don't mean that, because the Republicans took a stupid position, and a lot of the inciting comes from the right, it excuses what has happened ( possibly due to media incitement ).

Good to see the Senate, led by a vocal J McCain, finally approve a sanction against Russia for unlawfully meddling with the American election. Now we await action against the President for his collusion.

"the even bigger idiots, who get their 'news' from the likes of Daily Mail, are spurred on to take things even farther" was said by someone with foresight. ( OK, it was me in post #22 ) And sure enough a bigger idiot named J Hodgkinson comes along...

This is probably off-topic... But what is it with you British guys and your audio cables ? Spending all sorts of money on 'fancy' directional ( ? ) cables, vac tube amps and the like ? Heck some guys spend more on their cables than their player or speakers. And then listen to mp-3 files ! ( although a lot still like scratchy, wowie, roll-off-at-hi-frequency vinyl discs because like tubes, they have a 'warmer' sound )

You will never see a photon 'hover'. It will be red-shifted to a near infinite wavelength, but will always move at c. You can't use a mathematical prediction of relativity ( Black Holes ) to disprove one of the basic tenets of relativity.

What are you starting, a museum ? I used a TRS-80 model 1 ( with 16k of memory ! ) as a controller for my undergrad thesis. And built a ZX-81 kit for my first computer. They almost seem more quaint than vacuum tubes/crts.

Light does not 'hover', accelerate or decelerate. It is constrained to move at c at all times because it is a massless particle.

Sorry, no more models. But, then again, no model is perfect. The only perfect model of reality, is reality itself, as even GR fails at some boundaries. And that doesn't negate its usefulness.

Canada has a 'first-past-the-post system, but I'm familiar with the Italian proportional representation system. Italy has about 10 parties with 5% vote and about 30 if you use 1% as the cut off point. They have never had a majority government since WW2, and most of the governments are dysfunctional, lasting barely 6 months at a time. But maybe it has nothing to do with the proportional representation system. ( just Italian corruption and incompetence ) I'm of the opinion that first-past-the-post is more workable, but with just two parties there is too much polarization as the Americans prove. I would think about 4 parties would be ideal.

A cat. They've got it made.

Don't have a problem with the zero sum energy model, but there are various issues associated with the negative mass model.

Energy conservation is a result of the Lagrangian being symmetric ( more exactly, the action of a system, the integral over time of the Lagrangian ) under continuous translations in time ( Noether's theorem ). By definition, there cannot be symmetry in time, at the beginning of time. So why assume energy has to be conserved at the beginning of time ?