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JEROME - Black holes do not exist

Make believe!!!

Dark energy is the make believe that is used to justify the theory in spite of the data.

Actually, GNOME, dark energy was in the theory from almost the very beginning.

Einstein noticed that there is one single parameter which can be added to general relativity (that's right: after including that parameter the theory can be shown to be essentially unique, which is very rare among theories of physics). He called it the cosmological constant, and he noticed that when it was positive and took just precisely the right value it allowed a steady-state universe solution to the equations (which is actually unstable, although I'm not sure if he understood that). At the time (but for only a few more years after) astronomers believed the universe to be in a steady state, so this was desirable.

That same cosmological constant is the simplest and best explanation for the acceleration observed today. It fits the data perfectly, and (not that it matters) it's not something that was "added" recently - it was in the theory from the very beginning. It should be regarded as one of two parameters in general relativity that needs to be fixed by data (the other one is Newton's universal constant of gravitation, which controls the force of gravity between two masses). Now it's been fixed by data.
 
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While there are certainly deep mysteries associated with gravity, they have nothing to do with basic orbital dynamics.

You are wrong. I was talking about the errors in this thread, where somebody said the ISS was falling.

The misunderstanding about relativity and gravity are numerous in this thread. The fundamental misunderstanding, which you don't suffer of course, is that zero-G means free fall.

If you simply think about it for a moment, there is no place in the Universe that is zero-G. The term means that YOU, the observer, are currently not accelerating. Being at the bottom of a gravity well, the surface of a planet or moon, means you are accelerating. Thrust, or braking thrust, means acceleration. A vector change can mean acceleration.

Gravity is the same as acceleration.

If you are not accelerating, there is no gravity. Of course there are countless bodies warping spacetime, "pulling" on each other, the entire Galaxy is moving towards a super cluster, but none of that matters to the observer. In the sense of zero-G.

Even our buddies in the plane making a parabolic arc, they are gravity free for a few minutes. Even if it is free fall in that case.

Why? Because the term we really need to introduce is "weightlessness". I'm going to write it as Wss because that is a damn lot of typing to say each time. Wss is what a body experiences when it is in free fall, or in orbit, or far from any gravity source. And we all know what Wss is, because it is a real thing.

Stand on a roof and have your buddy throw a hammer up to you, if you catch it at the top of the throw, before it starts falling, it weighs nothing. As soon as you grab it you can feel the weight, because now you are resisting gravity, but objects, and people, when not accelerating, are weightless. Ws for short. Damn typing.

At the top of the arc while diving, you can feel the effect. Or while floating in water. Which is exactly why we use dive tanks to train for space. Before anyone starts correcting me, mass does not change, but weight is a function of acceleration. Mass is the same, but weight changes. Throw a scale with a weight on it up in the air, at the peak, and while falling, the object no longer weighs anything!

Because scale and object are both falling. Now that IS falling. But in orbit, or in Wss, there is no weight, because there is zero-G. Gravity all around, but to the observer, the object that is Ws, no gravity.

It is the most bizarre thing, hence Einstein was a genius for figuring it out. Gravity is the same as acceleration, in the reference frame of the observer. No acceleration, relative to the observer, no gravity.

Our falling elevator is exactly what the ZGX uses to create Wss. Albert would have loved it. Stephen certainly did.

Getting back to black holes, as to not completely go off topic, what about a huge gravity source?

Like our mystical super massive black hole. Which in theory warps space time so much NOTHING can escape. We call it the event horizon.

While many have tried, our friend J seems immune to convincing. But what about our BH? I'm imagining a super super giant, the mass of an entire galaxy, crushed by gravity to a singularity, smaller than an electron. It sits at the center of an event horizon. Total blackness. Only quantum tunneling allowing it to slowly evaporate through virtual photons.

Our galaxy sized mass is in there, spinning like crazy, all crushed down into quarks or something. And way far away from this imaginary point, the event horizon, where all light and radiation "falls", spinning like crazy, never to be seen again.

Matter is ripped into energy as it nears, and even the energy goes down the hole. Not because gravity is a force that "pulls" on photons. But because spacetime is so warped, the photons curve, and can not be seen again, curving their way down to a black singularity.

Gravity does not effect photons. No matter how much gravity there is, it can't slow down a photon. Speed of light and all.

So, imagining our vast and enigmatic BH, what strikes me as strange, is this.

Gravity escapes the event horizon. So gravity is not effected by gravity. Or warped spacetime. Gravity IS warped spacetime.

But what about the magnetic field? Which we theorize is due to virtual photons. Does the magnetic field of our spinning massive singularity not escape the event horizon?

At which point we run smack in to the mental wall. The one old Albert himself didn't like. Where math and formulas and theory replace observation and reality.

Of course I could be wrong, and some really smart person will be along to explain why. No no, not the insulting trolls who just say, "You are an idiot" or "You don't know what you are talking about", but the smart dude who will explain why.

word
 
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You are wrong.

I'm an expert on this topic, robinson.

I was talking about the errors in this thread, where somebody said the ISS was falling.

That is not an error, at least not if you relax a little about the meaning of the word "fall".

Consider a rock tossed up in the air. You might say that it's falling the entire time (including the first half of its motion when it's moving up), or you might say that it's only falling after it reaches the top of its arc and begins moving down. In the context of physics the first meaning is actually better, and that's the sense in which the ISS is falling.

The misunderstanding about relativity and gravity are numerous in this thread. The fundamental misunderstanding, which you don't suffer of course, is that zero-G means free fall.

You are simply confusing yourself (and potentially some others reading this thread). There is no "fundamental misunderstanding" here, other than possibly yours. "Free fall" - in the sense described above - and zero-G are indeed precisely the same (locally). That's called the equivalence principle, and it's the basis of Einstein's general relativity.

If you simply think about it for a moment, there is no place in the Universe that is zero-G. The term means that YOU, the observer, are currently not accelerating. Being at the bottom of a gravity well, the surface of a planet or moon, means you are accelerating. Thrust, or braking thrust, means acceleration. A vector change can mean acceleration.

Falling freely means no acceleration. "zero-G" isn't a property of the place, it's a property of the observer.

Gravity does not effect photons. No matter how much gravity there is, it can't slow down a photon. Speed of light and all.

Totally wrong - gravity affects everything, including gravity. Why do you think black holes are black? Haven't you ever heard of gravitational lensing? (Actually I know you have, because we've had this conversation before.)

At which point we run smack in to the mental wall. The one old Albert himself didn't like. Where math and formulas and theory replace observation and reality.

No, not really.

Of course I could be wrong, and some really smart person will be along to explain why. No no, not the insulting trolls who just say, "You are an idiot" or "You don't know what you are talking about", but the smart dude who will explain why.

You don't know what you are talking about. :)

If you want me to explain (more than I already have), ask something specific.
 
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You actually agreed with me on several key points. But this lack of precision in terms will not do.

I'm an expert on this topic, robinson.

That is not an error, at least not if you relax a little about the meaning of the word "fall".

In technical writing, precise meaning is the order of the day. Falling means something in technical terms, when speaking of orbiting bodies or to be precise, in Aerospace terminology[source]. Let me help you out here.

fall
Of a spacecraft or spatial body, to drop toward another spatial body under the influence of the latter's gravity.

free fall
1. The fall or drop of a body, such as a rocket, not guided, not under thrust, and not retarded by a parachute or other braking device.
2. The free and unhampered motion of a body along a Keplerian trajectory, in which the force of gravity is counterbalanced by the force of inertia. See weightlessness.

weightlessness
1. A condition in which no acceleration, whether of gravity or other force, can be detected by an observer within the system in question.
Any object failing freely in a vacuum is weightless, thus an unaccelerated satellite orbiting the earth is weightless although gravity affects its orbit. Weightlessness can be produced within the atmosphere in aircraft flying a parabolic flightpath.
2. A condition in which gravitational and other external forces acting on a body produce no stress, either internal or external, in the body.

See? When scientist and engineers who know about this stuff talk about it, they use clearly defined terms, to avoid misunderstandings. The very definition shows how what we use to describe objects and systems is important, as well as agreement on what the term means.

Which is why I introduced weightlessness, Wss, even if I am loath to type it out each time.
 
Take a few hours to familiarize your self with the proper terms, and we can a meaningful discussion here.

Of course non technical people may misunderstand, but this is an educational process. Using the wrong terms, or worse, changing the meaning of a term, only leads to confusion.

As most times, I included a helpful link to let anyone interested do their own reading. And to show that it isn't me you are disagreeing with, it is the body of scientist who actually put the ISS and other stuff in orbit. They know about these things.
 
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fall
Of a spacecraft or spatial body, to drop toward another spatial body under the influence of the latter's gravity.

This definition is completely useless for this discussion, since it doesn't define "drop towards". Does the tossed stone "drop towards" the earth while it's on its way up? It certainly accelerates towards the earth - is that considered "dropping" and therefore falling, or not?

free fall
1. The fall or drop of a body, such as a rocket, not guided, not under thrust, and not retarded by a parachute or other braking device.
2. The free and unhampered motion of a body along a Keplerian trajectory, in which the force of gravity is counterbalanced by the force of inertia. See weightlessness.

Which is precisely how everyone else in this thread used that term. And if the two definitions are supposed to be equivalent, then both "fall" and "drop" do include motion away from the body (but acceleration towards), just as everyone here but you was using the term.

See? When scientist and engineers who know about this stuff talk about it, they use clearly defined terms, to avoid misunderstandings. The very definition shows how what we use to describe objects and systems is important, as well as agreement on what the term means.

Exactly.

Feel free to correct me Sol, but this seems to address some of your questions:

http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_gravity.html

Eh? What questions? Did you mean "robinson" when you said "sol"? If so, I'm deeply offended. :p
 
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Take a few hours to familiarize your self with the proper terms, and we can a meaningful discussion here.

Please take sometime (however long you need) to understand the concepts involved and not just the common terminology. You do realize that dictionaries (even ones on Aerospace terminology) give only common usage, which is why there is often more then one “definition” (or common usage) for a given word.


Of course non technical people may misunderstand, but this is an educational process. Using the wrong terms, or worse, changing the meaning of a term, only leads to confusion.

Even Technical people may misunderstand and the key is to be willing to be educated by this (or any) process from the people who do understand. Once you do understand the concepts you will find the use (or lack) of specific terminology to be less confusing and even some flexibility in terminology may help in explaining the concepts to non technical people.

Simply thinking you understand the terminology without trying to understand the concepts that terminology is based on leads to even more confusion.


As most times, I included a helpful link to let anyone interested do their own reading. And to show that it isn't me you are disagreeing with, it is the body of scientist who actually put the ISS and other stuff in orbit. They know about these things.


Wow, that’s a new one, argument from lack of authority. So disagreeing with you is disagreeing with them because you read some definitions on an Aerospace terminology website. No we are most certainly disagreeing with you.

As an engineer I designed cable trunks used and destroyed with each launch of the space shuttle during the initial phases of the ISS construction. Hardly a significant contribution, but it does put me at least within one of the extremities of that “body”. What type of authority would you require for one to lack in order for you to feel them entitled to argue from that authority?

A sad sate of affairs it would be if the only people who understood and could explain orbital mechanics were those that have put something into orbit. An even sadder state of affairs would be if anyone could claim they can speak for any authority, that they are not authorized to represent, but themselves.

So, clearly being more a part of the “body of scientist who actually put the ISS and other stuff in orbit” then you, I can say both sol invictus and MattusMaximus assertions about orbits and freefall are correct and concise. That you claim to argue on behalf of the “scientist and engineers who know about this stuff” having only read some definitions in an Aerospace terminology web site only demonstrates your unwillingness to learn from the “scientist and engineers who know about this stuff” about the actual concepts and not just the terminology.
 
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Even Technical people may misunderstand and the key is to be willing to be educated by this (or any) process from the people who do understand. Once you do understand the concepts you will find the use (or lack) of specific terminology to be less confusing and even some flexibility in terminology may help in explaining the concepts to non technical people.
The three things that are the most important to understand, CONCEPT, CONCEPT and then there is CONCEPT, words mean nothing without CONCEPT, I have been saying this for years, I really don’t care what you call it, if you don’t know the CONCEPT they are meaningless.

JEROME has proven this time and time again.

Paul

:) :) :)
 
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This definition is completely useless for this discussion, since it doesn't define "drop towards". Does the tossed stone "drop towards" the earth while it's on its way up? It certainly accelerates towards the earth - is that considered "dropping" and therefore falling, or not?

Now you are being dense. Focusing on minute, rather than the larger issue. Which is slightly off topic, but who really cares.

I noticed you completely avoided all the Black Hole stuff as well. Quit acting like those you criticize for avoiding a conversation.
 
Please take sometime (however long you need) to understand the concepts involved and not just the common terminology.

Don't take a dump in the virtual punch bowl. I only brought up terminology to correct bad information in regards to gravitation, posted by others.

You are avoiding that conversation.
 
I don't really enjoy pointing out other peoples errors, they might just be having a bad day. Here is part of what started the terminology discussion. We can talk about CONCEPTS in regards to this if you wish.

There are multiple errors in these statements, no matter what terminology you use. But if you use exact technical terms, the errors are glaring.

This is a common misconception about orbital motion. The people inside the ISS are not weightless - true weightlessness is defined as a total lack of gravity.

Wrong. No matter how you try to fudge the terms.

The reason why the astronauts aboard the ISS appear weightless is because they are in a state of perpetual free-fall around the Earth. They are falling towards the Earth at precisely the same rate as the Earth is curving away from beneath them, thus they never hit the ground - they just keep going around and around...

Again that is a way to try and tell school children about orbits, but it is not what really is going on.

.

And not only is the ISS falling, but everything inside of it is falling as well. So, from the point of view of an astronaut inside the ISS, you have the sensation of "weightlessness" - it's just like when you're on a roller coaster that hits the big drop on the ride.

Wrong wrong wrong. I explained why earlier.

You feel much lighter than normal because the coaster is falling out from underneath you. Now imagine the coaster falling completely out from underneath you for an extended time, then you'll get the idea of apparent weightlessness in action.

Like I said, read the NASA page and learn the correct terms for these things.

You feel Ws because you are falling, not the coaster falling from under you. Same thing for free fall, you and the coaster are both falling.

As the example of a falling scale pointed out, it IS weightlessness when both objects are falling. But it is NOT the same thing as Wss from an orbit. The ISS is not falling, it is in orbit. Which is clearly explained and differentiated on the terminology page.

Which is why I pointed to the terms, rather than making somebody feel bad, by pointing out how wrong they are.

Nobody likes to be wrong, much less have it pointed out in exacting detail!
 
Perhaps MM is distinguishing microgravity in the case of the ISS, as opposed to weightless. I fail to see that the objects inside the ISS are not essentiallly weightless, lacking weight, since they will register nothing on a spring scale. What experiment could distinguish this from items in a "no gravity" situation?
 
Maybe somebody should respond to the training tank example as well.

With neutral buoyancy, people and objects underwater are weightless (Ws). That is why it is used to train for the Wss of space.

Gravity isn't gone, it just doesn't matter. You will have no weight on a scale. Just like any other case where you are Ws.

Free fall, orbit, on your way to the moon, on your way out of the solar system, there are specific instances where we describe something or somebody as weightless. A scale shows no weight.

Mass is the same (ignoring realtive mass from velocity), but depending on the situation, you can be weightless. But not falling.

Free fall is a specific term for falling into a gravity well. The difference between that sort of Ws and the others, is you are accelerating the entire time. In water, in orbit, in outer space, you are not accelerating, but there is no gravity. Zero-G

Now back to that Black Hole ...
 
:p

Eh? What questions? Did you mean "robinson" when you said "sol"? If so, I'm deeply offended.
Sorry 'bout that, spot of brain fade; I actually meant to say that you should feel free to correct my impression that it answers some of robinson's questions...
 
Yay! Back to the hole issue. A dark problem.

To recap, what about a huge gravity source?

Like our mystical super massive black hole. Which in theory warps space time so much NOTHING can escape. We call it the event horizon.

While many have tried, our friend J seems immune to convincing. But what about our BH? I'm imagining a super super giant, the mass of an entire galaxy, crushed by gravity to a singularity, smaller than an electron. It sits at the center of an event horizon. Total blackness. Only quantum tunneling allowing it to slowly evaporate through virtual photons.

Our galaxy sized mass is in there, spinning like crazy, all crushed down into quarks or something. And way far away from this imaginary point, the event horizon, where all light and radiation "falls", spinning like crazy, never to be seen again.

Matter is ripped into energy as it nears, and even the energy goes down the hole. Not because gravity is a force that "pulls" on photons. But because spacetime is so warped, the photons curve, and can not be seen again, curving their way down to a black singularity.

Gravity does not effect photons. No matter how much gravity there is, it can't slow down a photon. Speed of light and all.

So, imagining our vast and enigmatic BH, what strikes me as strange, is this.

Gravity escapes the event horizon. So gravity is not effected by gravity. Or warped spacetime. Gravity IS warped spacetime.

But what about the magnetic field? Which we theorize is due to virtual photons. Does the magnetic field of our spinning massive singularity not escape the event horizon?

At which point we run smack in to the mental wall.

If we add in another BH of the same size, orbiting each other, what about that? Now we have gravity and magnetism and two event horizons. Imagine the problem there.
 
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I'm perfectly willing to defer to the experts, but I don't understand the fine distinctions they are making between "feeling weightless" and "weightless". The cartoon of the projectile being fired at 8 km/sec is just what we all understand.

My understanding is that if a skydiver jumps out of a balloon, and in free fall, he is accelerating at the rate of the gravitational acc rate caused by the earth, and if he were in a vacuum, he would be weightless. If he is in orbit, he is just falling on a different trajectory, (because of his lateral speed with regard to the earth, but is still weightless but will never hit the ground. If he is headed to Mars, he may not be falling, but this is just because of the semantics of the word, but he is still weightless, since he is not accelerating.

It is possible I am all wrong in this, but it is what I know at this point.
 
Yay! Back to the hole issue. A dark problem.

If we add in another BH of the same size, orbiting each other, what about that? Now we have gravity and magnetism and two event horizons. Imagine the problem there.

is it OK to delay the charge/magnetism issue and start off with two rather large (massive) black holes orbiting each other? does having two event horizons cause a problem?

nothing really noticable happens at the event horison of a really big BH, so i don't see any difficulty posed by having "two".

of course you might worry about what eventually happens to stuff that falls into the overlap of the two, and therefore finds itself inside "both"; but then questions about what is inside either/any EH cann't really answered without going there, no? and if you do, you cannot report back ...
 

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