One theory that I have read is that time comes to a stand still at the event horizion of a black hold, so if time is not moving is that infinite acceleration or no acceleration?

BULLFOX  ! Thanks for the reply, and your correct about the event horizon, time relative to an observer does stop., so it should give rise to the greatest amount of G acceleration of an object, out side the event horizon. If we could determine the maximum acceleration using special relativity, we could determine the validity of the existance of black holes. An experiment in math to determine this is to take an object that is 186,275,000 miles (one light second) and accelerate the object to a point where the spatial dimension in the direction of travel will shrink at a velocity equal to the speed of light relative to an observer in a rest frame of refference, this should give the maximum acceleration for this object, then equate this to the schwarzschild radius with the same deminsion, and determine the equivalent mass, this should be equal, if not a question exists about black holes. The accuracy of the length of the test object would be a critical issue, it must be exact. We would need to substitute C into the equation to eliminate error. The limit for a photon of zero mass, would be C per Planck time. Just think about this problem it may have errors. Thanks.

The Theory of special relativity is based on C being constant in all frames.  If you make C a variable then you are outside of SR theory and on your own.

Back in SR theory, acceleration is not limited.  F=mA applies (but m is a velocity dependent variable in SR).  Theoretically you can always apply a bigger force to a particle so instantaneous acceleration also increases.  Of course if the force is held constant, as soon as the mass speeds up the mass increases and the acceleration decreases again but this does not preclude adding more force yet again.

 So within SR switching the limit from the frst derivative (speed) to the second derivative (acceleration) doesn't work.

Nice try though. 

PH

porcupinehill ! According to special relativity, you'r correct. According to General relativity, I think you must be wrong, if light, can not escape a black hole, because the speed of light is constant, right?

I think I see what you mean primordial. 

The apparent acceleration from an outside reference frame appears to be limited near a black hole but I think that is just time dilation.  The mass itself can still experience any acceleration from 0 to any arbitrarily high number in its own frame.  At any rate, as a mass approaches an event horizon any acceleration, no matter how big the rocket, aproaches 0 in the Earth observer's time.  Clearly 0 is not a sensible maximum acceleration so It doesnt look like you can assign an acceleration limit from either of those frames.

 This is usually done with escape velocities.  As one approaches a black hole the velocity (relative to the black hole) required to escape goes up.  The event horizon is at the distance where the escape velocity = c.  inside all world lines lead to the singularity.  Outside worldlines can lead to the singularity or away depending on the relative velocity tensor.

It is rather mind bending for sure.

PH

PH

porcupinehill ! Thank you for your point of view. I've had problems with black holes as an object that can dilate time to an absolute zero in a relativistic space-time universe, although I was able to except an absolute( relativistic velocity), the velocity of light, where time or spacial dimensions have values always greater than zero, but some where less than infinity, and have relativistic values.  I would like to ask you to consider one of my questions I have about black holes. If gravity propagates at C how can the presence of the gravity of its mass escape the event horizon.

Hello primordial,

 That is certainly a cool question!

 A graviton carries gravitational force like gluons carry the nuclear force. Gravity exists around a massive object due to the curvature of the surrounding space .  Graviton transfers are required for changes in the gravitational field but not to maintain it.  In other words Gravitons do not need to travel from the singularity like photons from a star illuminating the surrounding space in order to maintain the gravitational field. 

So what about changes in the gravitational field required to increase the size of the event horizon when more mass falls into the hole?  Well... the old horizon becomes veiled so no gravitons need to travel (from an outside frame's point of view) to change the space at the old horizon.  Only outside the event horizon does time need to continue at a non zero rate in order for the horizon to expand.  Outside the event horizon time does continue forward although slowly in an outside frame.

so no paradox.

Whew!

PH

porcupinehill ! Thank you for your response. I appreciate a thinking person, however I can't say I agree with you, on this little problem. May I present to you another, as you may know, it appears gravity and time dilation have an affect on the relative energy of electromagnetic waves, but do not change their relative velocity, now is it possible in your opinion for an electromagnetic wave to have a effective negative relative energy due to red shift or any other relativistic effect? More to come later.

Hi Primordial,

Energy is frame dependent.  This is true in classical physics too.  For instance kinetic energy of a pitched baseball:

KE = 1/2 mv^2

IF you are a batter, v = ~ 40m/s so the KE is a real positive number

If you are moving with the ball  v = 0 in your frame.  The KE =0.  THere is no physical change to the baseball when you change frames but the energy is different.

 Another kind of parallell phenom is adiabatic heating of air in the mountains.  As air rises on an upslope it decompresses and cools.  The temperature is lower but no heat trasfer took place.  It heats as it decends with no energy absorbed ffom the environment.

 I see no paradox with red shifting electromagnetic waves in the energy balance.  If you maintain a constant measurement frame enegy is conserved.  Change frames (say...from the emmitting frame to the measurement frame) and you get different answers.  Like with the ball there is no change to the physical system, only a change to the measurer!

PH

porcupinehill ! Thank you for your answer. I was just trying to justify Mr. Hawking's black hole, in my own brain.

Primordial,

Hope this exchange helped you as much as me.  It sure introduced me to new ideas about black holes...Strange beasts to be sure!

 Great thread. 

PH

I don't think that gravity in a black hole (or singularity) is infinite, just stronger than light's ability to escape it.

If it were truly infinite, than it's effects across space would be infinite. Yet, as is obvious, we are not being sucked into black holes.

A finite gravitational field would decrease in strength with distance, An infinite gravitational field would not decrease with distance because it is infinite.

I remember some physicist saying that a black hole cannot have a stronger total gravitational force than the mass that made it.

Time is an illusion!  Let me explain.

Because Time is an illusion, what we perceive as Time is mearly a tool of measure, and not a state. We actually exist in Space only. We are able to perceive only a fraction of the change in space due to an ocular and technological limitation.

The closer we get to attaining the speed of light, the easier it is to perceive the changes in Space.

For example, let say a ruler which is infinitly equally divided represents a linear path in Space. We are only able to perceive an object travelling this path once every 100 increments due to inherent limitations. Now, increase your speed to half the speed of light. You now see the object once every 50 increments, so on and so forth until you achieve the speed of light in which case everything would be static.

porcupinehill ! Thank you very much for reading my problems.

LachapelleC ! You have a good point, and I suppose you could look at the whole universe in that light, it would take some time, or should I say equivalent space, for me to reason the manifestation of all the interactions derived in the universe in spacial terms, however it really does sound correct. Thanks for your insight.

sbbbugsy ! Yes much of what you say in my opinion is correct #1 "I don't think that gravity in a black hole (or singularity) is infinite, just stronger than light's ability to escape it." , I would add this to this statement( with significant energy).  #2 "A finite gravitational field would decrease in strength with distance"   #3 "I remember some physicist saying that a black hole cannot have a stronger total gravitational force than the mass that made it. " I would also think that the gravitational energy, that has changed the mass, that comprises the black hole, would have its equal mass, added to the black hole, provided it was not dissipated during the forming of what Mr. Hawking calls a black hole. The other statement " An infinite gravitational field would not decrease with distance because it is infinite." would depend on, if the distance was infinite or not. Plus, to me the word infinite, is difficult to concieve. I also have problems with Mr. hawking's black hole, I think time will tell us more about the thing he calls a black hole. Thank you for your insight.

Well Primordial, I thought I would "invade" your space for a bit and thank you for going with the questions, insights, flights of fancy, and contributions. I DO like your idea of there perhaps being what we can term as negative energy photons...go with it if you can. Maybe that could expain a certain aspect escape from a black hole as we see it nowadays. I do believe there are other aspects we are ignorant about and black holes are not what we conjecture now....I truly believe that. Think of two electrons orbiting each other. Positive energy  photon exchange makes the orbit ellipsoid...negative energy photon exchange makes the orbit circular....two momentum characteristics that evolve towards each other from all perspectives.

Keep it up Primordial....I like the way you are going....we are all wrong a lot of the times, but I do believe you can get some things in the right direction of original thought.

Peace.

dnatech ! Thank you for taking the time to read my idea.