QM + GR = black holes cannot exist

[Dr_Toad]

Here.

I note that you said "an impossibly accurate clock" and bowling ball versus feather in a vacuum. The key that hasn't been addressed to my satisfaction is the "at the same time" part. Explain why that is crucial to your nitpicking.

 

[OnlyMe]

Sorry guys, I didn't mean/expect for that to lead us off track. It was just an example.

The math here is pretty straightforward, but what matters is accepting the concept. Newton's equation for gravitational force is:

f=GmM/r^2

Where:
f = force
G = gravitational constant
m = mass 1
M = mass 2
r = radius (distance from center of object)

Deriving graviational acceleration goes like this:

f/m = GM/r^2

Substitute f=ma (a=f/m):

a = GM/r^2

So if you plug in the earth's radius and mass, you get 9.81 m/s^2. That's the part that everyone agrees with. For example, paddoby's explanation, above.

But you are missing the other half of the problem. Gravitational attraction is mutual so the same force acts on both objects. Earth pulls down on that bowling ball with a force of 16 lb, which means the bowling ball pulls up on the earth with a force of 16 lb. So the bowling ball (and the feather) also accelerates objects toward it. Yes, that force/acceleration is vanishingly small (and therefore impossible to prove experimentally for a bowling ball, feather and earth), but it still exists. For larger objects it matters a lot: it causes the objects to wobble when they orbit their common center of mass instead of the simplified explanation that considers the larger of the two objects to be stationary. The moon orbiting the Earth causes the earth to wobble by thousands of miles, for example. This principle is how many exoplanets are discovered.

That's a good point Russ.

However, even though the mass of the bowling ball will have a greater affect on how much the earth falls towards the common center of mass, as long as they are dropped toward the earth side by side, their combined affect on the earth benefits both. Meaning any reduction in the distance of the fall is the same for both, the feather and the bowling ball.

As far as GR and classical physics is concerned the only issue is the fact that each object's inertia is proportional to its mass.., and they both hit the ground at the same time.

Unless, you drop the feather and the bowling ball toward the earth from sufficiently far away from eachother, that they pull the earth in different directions, as far as the earth is concerned it is the mass of both objects that is pulling on it.

Drop them from equal distances, at the same time, from opposite sides of the earth and you are right, the bowling ball will hit the ground first.

Any difference that may exist when they are dropped side by side, would be like debating the difference between 1 and 0.999...

Even if you were dealing with more massive objects, unless you separate them by sufficient distance from oneanother, that they pull the earth in two separate directions, the results would be the same.., or within that margin of error described as the difference between 1 and 0.999...

I think your point would be of more significance if the issue were the fundament character of inertia itself, but that would seem to me to be an issue for QM, which has not yet been successfully addressed. For the case discussed here, I don't think it would apply for any test masses, unless you change the distance between the objects being dropped.

 

[Dr_Toad]

So "vanishingly small" takes care of the "impossibly accurate clock". Given that, I'll offer a vanishingly small apology.

 

[RJBeery]

So "vanishingly small" takes care of the "impossibly accurate clock". Given that, I'll offer a vanishingly small apology.

"Impossibly accurate clock" for Galileo's time. We certainly have the ability to measure the difference of thousandths of seconds today, which was the difference between the golf ball and the bowling ball I laid out in my thread actually relating to this subject. Why this discussion isn't being carried on over there, I'm not sure.

That being said, apologies on this forum are "impossibly rare" so I tip my hat to you, Dr_Toad.

 

[Dr_Toad]

Thank you very much. My hat appears to be attached to my avatar, damn it.

 

[brucep]

Frankly, I'm pretty disappointed by you and others on this issue.

Why's that? What issue are you referring to? The issue where you want to convince the crank that his analysis is bogus for the umpteenth time or the issue where the same crank show's how clueless he is for the umpteenth time when he claims different objects fall at different rates in a vacuum?

 

[RJBeery]

Why's that? What issue are you referring to? The issue where you want to convince the crank that his analysis is bogus for the umpteenth time or the issue where the same crank show's how clueless he is for the umpteenth time when he claims different objects fall at different rates in a vacuum?

Have you had a chance to look at my thread on Galileo? http://www.sciforums.com/threads/galileo-was-technically-wrong.142700/

If you have an issue with the math please let me know what it is.

 

[tashja]

Tashja, thanks so much for reaching out to some experts.

You're welcome, RJ. I've got another one for you.

RJBeery: Start with an existing black hole and an event horizon radius R at time T. Say the black hole is being "fed" an infinite series of golf balls, one after the other, which are all stamped numerically such that the current golf ball external to the event horizon is 1.0 * 10^32.

Now, starting at time T, run the clock backwards to T_past until R_past = R/2. What does the scene look like? Do golf balls with numbers less than 1.0 * 10^32 appear?

Prof. Dolan: You have to more precise on stating the questions. Appear to whom? How are you measuring T? Time as measured by an observer infinitely far away from the black hole is not the same as time for an observer falling with a golf ball.

RJBeery: If they do then there is a time T_crossover such that T_past < T_crossover < T where we could have witnessed the event horizon expand due to matter crossing it. In my understanding of GR, this cannot happen because golf balls external to the event horizon remain theoretically observable (with perfect instrumentation) forever.

Prof. Dolan: An observer at infinity will never see a golf ball fall into a static black hole that has already been established, they will see the golf balls get dimmer and dimmer, more and more red-shifted and slower and slower as they approach the event horizon, but they will never see them actually cross it in any finite time, according to their clock. The golf balls will appear to get frozen to the event horizon. An observer falling with a golf ball will see the golf ball cross the horizon in a finite time and nothing untoward happens (assuming the black hole is much bigger than a golf ball --- if they are of similar size the golf ball will be ripped apart by tidal forces as it approaches the event horizon).

If the black hole is made up of nothing but golf balls then there is no black hole there, and no event horizon, when the first few balls fall towards the centre. It would require a certain number of golf balls to be compressed into a small volume before an event horizon forms (unless these are really weird golf balls which themselves are already black holes!). Once the matter becomes compacted enough for an event horizon to form an observer at infinity will never see a golf ball actually cross the event horizon, but a local observer falling with a golf ball, will see it cross the horizon. If time is run backwards then a local observer travelling with a golf ball will be spat out of the black hole at some stage while an observer at infinity would just see golf balls detach themselves from the event horizon and travel outwards, brightening up as they come out.

One can imagine black holes with the time reversed, they have been dubbed white-holes, but there is no evidence that they exist.

Hope this helps,
Brian

 

[RJBeery]

[QUOTE="Prof Dolan]Once the matter becomes compacted enough for an event horizon to form an observer at infinity will never see a golf ball actually cross the event horizon[/QUOTE]

Thanks again Tashja. While this is at the very least consistent with my understanding of the currently accepted explanation, I continue to fret about it. If the event horizon has "formed", what is it composed of? If we can see the golf balls arbitrarily near R=0, and can do so for eternity, are we not receiving information, for eternity, from the region near R=0? What about when the supposed event horizon has reached a thousand light-years in radius? We continue to see the golf balls near R=0 but their image has been pushed to the event horizon boundary?

I'm not really asking these questions to anyone in particular, I'm describing why I have a difficulty accepting the current explanations. Clearly, no one who frequents this forum will have any satisfactory answers and it appears that experts in the field have come to accept the standard explanations at face value.

 

[brucep]

Have you had a chance to look at my thread on Galileo? http://www.sciforums.com/threads/galileo-was-technically-wrong.142700/

If you have an issue with the math please let me know what it is.

The math is juvenile nonsense. You chose to pick values to do the calculation and get the arithmetic you want. A better way to check if this is real natural phenomena is to run experimental tests rather than relying on contrivance calculations from somebody as clueless as you're with respect to physics in general.

http://www.physlink.com/education/askexperts/ae6.cfm

Galileo is wrong? Don't think so. Science has been checking this since it was first known. Why don't you EVER check to see what you're saying doesn't wind up with your foot in mouth? When are you going to use your math prowess to check out why they're no preferred coordinate systems? Why I'm actually right about that and your analysis never is? In this thread you, once again, quote mine a serious analysis to support your erroneous pov. At least that was interesting with respect to actual content. Doesn't have anything to do with verifying your analysis.

 

[RJBeery]

The math is juvenile nonsense. You chose to pick values to do the calculation and get the arithmetic you want. A better way to check if this is real natural phenomena is to run experimental tests rather than relying on contrivance calculations from somebody as clueless as you're with respect to physics in general.

http://www.physlink.com/education/askexperts/ae6.cfm

Galileo is wrong? Don't think so.

I explicitly analyzed objects dropped separately, while your link says:

two objects will reach the ground at the same time if they are dropped simultaneously from the same height

If you feel I have somehow cherry-picked the arithmetic could you please specifically point to the area of contention?

 

[paddoboy]

1. Of course not.
3. Because the definition of the event horizon is such that anything outside of it can escape, in theory. If it can be seen then it can escape (in theory).

Bullshit. Nothing within 1.5 Schwarzchild radius can ever escape the EH of a BH, except for light itself.

4. Again, depends on which model we're discussing. "Commonly accepted" model of GR says the EH grows as matter passes through it. I'm claiming this does not happen.

You can claim all you like.....You are wrong.

6. The contradiction, for the 10th time, is that the commonly explained description of the GR black hole grows as matter passes into it, yet GR also claims that matter never passes through the event horizon.

A deliberate dishonest misinterpretation of the situation, so often used by God Botherers and other cranks.
Whether matter passes through the EH, depends on the FoR.

 

[brucep]

Bullshit. Nothing within 1.5 Schwarzchild radius can ever escape the EH of a BH, except for light itself.



You can claim all you like.....You are wrong.





A deliberate dishonest misinterpretation of the situation, so often used by God Botherers and other cranks.
Whether matter passes through the EH, depends on the FoR.

 

[brucep]

I explicitly analyzed objects dropped separately, while your link says:

If you feel I have somehow cherry-picked the arithmetic could you please specifically point to the area of contention?

There's years of experimental evidence which show your CALCULATED analysis is juvenile. Surely you're going to continue to believe you have a clue. Regardless what anybody else has to say or show you. LOL.

 

[RJBeery]

The math is juvenile nonsense. You chose to pick values to do the calculation and get the arithmetic you want. A better way to check if this is real natural phenomena is to run experimental tests rather than relying on contrivance calculations from somebody as clueless as you're with respect to physics in general.

http://www.physlink.com/education/askexperts/ae6.cfm

Galileo is wrong? Don't think so. Science has been checking this since it was first known. Why don't you EVER check to see what you're saying doesn't wind up with your foot in mouth? When are you going to use your math prowess to check out why they're no preferred coordinate systems? Why I'm actually right about that and your analysis never is? In this thread you, once again, quote mine a serious analysis to support your erroneous pov. At least that was interesting with respect to actual content. Doesn't have anything to do with verifying your analysis.

Hi Bruce, if you continue to have a problem with my analysis of Galileo could you please indicate which part of the math you have a problem with? Preferably in the appropriate thread. Thanks

Surely you don't believe that a black hole would take 1.4 seconds to fall to Earth from a distance of 10 meters?

 

[RJBeery]

Bullshit. Nothing within 1.5 Schwarzchild radius can ever escape the EH of a BH, except for light itself.

This is false.

 

[paddoboy]

This is false.

No its not.
At 1.5 Schwarzchild radius is where light can orbit a BH.
Anything closer then this, would need to be going faster then "c"
Do you know of anything that exceeds "c" [other then spacetime]

 

[brucep]

Hi Bruce, if you continue to have a problem with my analysis of Galileo could you please indicate which part of the math you have a problem with? Preferably in the appropriate thread. Thanks

Surely you don't believe that a black hole would take 1.4 seconds to fall to Earth from a distance of 10 meters?

your juvenile analysis makes a prediction which has been experimentally falsified many times over many experiments. So I don't need to bother with any further problems with your analysis. You should figure it out for yourself and in the process actually gain some scholarship from learning what's wrong with your juvenile analysis. Or as you will do: nothing that could possibly conflict with what you think the science is.

For the earth falling into a Schwarzschild black hole, along the radial path, GR predicts

dr_shell/dt_shell = (2M_meter/r)^1/2 (Just like Newton)

For the case of a solar mass M_meter = 1477m

r = 2M+10m = 2964m

= (2954m/2964m)^1/2

dr_shell/dt_shell = .998311665 (c=1)

You figure out dt for the 10 meters from 2964m to r=2M.

Guess what the coordinates dr_shell/dt_shell are coordinates you think are non preferred. They're local Schwarzschild coordinates. Pretty sure something traveling that fast will cross 10m faster than 1.4 seconds. LOL. Where did you get that figure of 1.4 seconds? Probably some bullshit analysis. Keep in mind that you brought this to this thread.

 

[paddoboy]

No its not.
At 1.5 Schwarzchild radius is where light can orbit a BH.
Anything closer then this, would need to be going faster then "c" to escape the BH's clutches.
Do you know of anything that exceeds "c" [other then spacetime]

 

[RJBeery]

No its not.
At 1.5 Schwarzchild radius is where light can orbit a BH.
Anything closer then this, would need to be going faster then "c"
Do you know of anything that exceeds "c" [other then spacetime]

*than

A simple radial path would require an escape velocity < c outside of the Schwarzschild radius. I determined long ago that you have no knowledge of interest to me.