KingMerv00
Penultimate Amazing
Don't hurt me, I don't think I said anything wrong. Mostly because I hardly said anything at all.
JEROME - Black holes do not exist
- Thread starter Reality Check
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Don't hurt me, I don't think I said anything wrong. Mostly because I hardly said anything at all.
MattusMaximus
Intellectual Gladiator
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arthwollipot
Limerick Purist Pronouns: He/Him
MattusMaximus, thank you for that concise and helpful physics lesson. Hopefully it will help Jerome to understand why the bowling ball doesn't move as far as the golf ball when you kick it.
And I have to say, I believe that this discussion of gravity is directly appropriate to the OP - since black holes are artifacts of gravity. I'm just waiting to see whether Jerome understood MM's lesson.
And I have to say, I believe that this discussion of gravity is directly appropriate to the OP - since black holes are artifacts of gravity. I'm just waiting to see whether Jerome understood MM's lesson.
Belz...
Fiend God
You're conveniently ignoring my second question:
What is a force if not a relationship between two objects, JEROME ?
Second, I believe the answer to your question is that the differences in mass of the two objects is too small. I'd say the moon probably has a greater gravitational interraction with the Earth.
Belz...
Fiend God
Nobody is. You just don't understand how this works. And you're using your ignorance as some sort of a reason to doubt what people who really know how it works say.
What the hell ?
Dancing David
Penultimate Amazing
Dancing David
Penultimate Amazing
Thanks MM, that was nice. (The explanation)
How did you get Santa in a straight jacket?
How did you get Santa in a straight jacket?
Upchurch
Papa Funkosophy
And yet, when I explained how you measure the force of gravity of a single orange and I calculated it's gravitational field, you ignored it completely.
Here it is again. Do try to pay attention this time.
You measure it's mass.
Assumptions
I don't happen to have an orange handy to measure, so for argument's sake and ease of mathematics, let's say it has a mass of 100 grams or 0.1 kg. Let's also assume that an orange is spherical and has roughly uniform density and that we're dealing with Newtonian distances.
It is entirely likely that none of these assumptions will be true for any specific orange, but this is a first-approximation calculation. If you want to get more specific, we can make better assumptions later.
Calculation
The Newtonian equation for the force of gravity is
[latex]$$ F = G\frac{m_1 \times m_2}{r^2} $$[/latex]
Where,
[latex]$$ F = (6.67 \times 10^{-11}\frac{N m^2}{kg^2}) \frac{{0.1 kg} \times m_2}{r^2} $$[/latex]
simplifying
[latex]$$ F = (6.67 \times 10^{-12}\frac{N m^2}{kg}) \frac{m_2}{r^2} $$[/latex]
So, the attractive force between an orange of mass 0.1 kg and another object is directly proportional to the mass of the second object and inversely proportional to the square of the distance between them. Ignoring the distance element for a second, we can calculate the strength of the orange's gravitational field by using an m2 of 1 kg and then multiplying the result by the actual mass of the second object when it is known. In other words:
[latex]$$ F = (6.67 \times 10^{-12}\frac{N m^2}{kg}) \frac{1 kg}{r^2} $$[/latex]
simplifying
[latex]$$ F = (6.67 \times 10^{-12}N m^2) \frac{1}{r^2} $$[/latex]
Answer
From this, we can now plot the strength of the gravitational force radially outward from the orange as a function of distance
r = 1 meter: F = 6.67 x 10-12N
r = 2 meter: F = 1.67 x 10-12N
r = 3 meter: F = 7.41 x 10-13N
etc.
Again, the strength of that field is multiplied by the mass of the object (in kg) the field is acting upon.
That's how you measure the gravitational force, in Newtons, of an orange. You measure it's mass and calculate the strength of its gravitational field radially outward.
If you'd like the calculation to be more specific, I need more details.
Assumptions
I don't happen to have an orange handy to measure, so for argument's sake and ease of mathematics, let's say it has a mass of 100 grams or 0.1 kg. Let's also assume that an orange is spherical and has roughly uniform density and that we're dealing with Newtonian distances.
It is entirely likely that none of these assumptions will be true for any specific orange, but this is a first-approximation calculation. If you want to get more specific, we can make better assumptions later.
Calculation
The Newtonian equation for the force of gravity is
[latex]$$ F = G\frac{m_1 \times m_2}{r^2} $$[/latex]
Where,
- F = Force measured in Newtons
- G = gravitational constant = 6.67 × 10−11 N m2 kg-2
- m1 = mass of the orange in kg = 0.1 kg
- m2 = mass of whatever the gravity of the orange is acting upon in kg.
- r = the distance from the center of orange to m2
[latex]$$ F = (6.67 \times 10^{-11}\frac{N m^2}{kg^2}) \frac{{0.1 kg} \times m_2}{r^2} $$[/latex]
simplifying
[latex]$$ F = (6.67 \times 10^{-12}\frac{N m^2}{kg}) \frac{m_2}{r^2} $$[/latex]
So, the attractive force between an orange of mass 0.1 kg and another object is directly proportional to the mass of the second object and inversely proportional to the square of the distance between them. Ignoring the distance element for a second, we can calculate the strength of the orange's gravitational field by using an m2 of 1 kg and then multiplying the result by the actual mass of the second object when it is known. In other words:
[latex]$$ F = (6.67 \times 10^{-12}\frac{N m^2}{kg}) \frac{1 kg}{r^2} $$[/latex]
simplifying
[latex]$$ F = (6.67 \times 10^{-12}N m^2) \frac{1}{r^2} $$[/latex]
Answer
From this, we can now plot the strength of the gravitational force radially outward from the orange as a function of distance
r = 1 meter: F = 6.67 x 10-12N
r = 2 meter: F = 1.67 x 10-12N
r = 3 meter: F = 7.41 x 10-13N
etc.
Again, the strength of that field is multiplied by the mass of the object (in kg) the field is acting upon.
That's how you measure the gravitational force, in Newtons, of an orange. You measure it's mass and calculate the strength of its gravitational field radially outward.
If you'd like the calculation to be more specific, I need more details.
Do you understand now that the force of gravity can be measured?
I tend to agree with you. I've read multiple descriptions of the process, but for the sake of this discussion, you might think it would be educational to have a description, especially from one of the really smart members, of just one black hole, so we can discuss it.
What is the nearest black hole to us? That would be a good example to start with. What are the properties we can observe? What is the mass? The spin? Is it isolated or a double start system? Can we have just one simple description, in the interest of having a real conversation about it?
How hard can that be? We see hundreds and hundreds of dumb postings that contain little substance. How about talking about the black beast itself, rather than what so and so believes or doesn't believe?
Paulhoff
You can't expect perfection.
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dlorde
Philosopher
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Perhaps not strictly true AIUI - mass can escape via 'evaporation' (the escape of virtual particle partners), and I heard recently that information can escape in some form or other...
Upchurch
Papa Funkosophy
Could be this one 1600 light years away.
The problem is that these are not simple things to measure. (Okay, the double star system question is fairly simple. The one linked above is a double star system.)
It's like being handed a box. You know there is something in the box, but you aren't allowed to open it. Then, you are told to find out as much as you can about the object in the box. Since you can't open the box, you have to deduce as much as you can based on what happens around the box. These deductions are not easy and they are not simple.
I know.
In a thread that is about Black Holes (BHs), you might think a description of one, as well as the theory describing how it came to be, would be useful if you want to convince a skeptic that such a thing exists.
Or, to discuss a possible problem with such a theory. That nobody has stepped up to the plate, seems a little odd. After all, we have a dozen people battering Jerome over the matter, but nobody has described just what it is they are so mad about, because Jerome doesn't believe them.
In a thread that is about Black Holes (BHs), you might think a description of one, as well as the theory describing how it came to be, would be useful if you want to convince a skeptic that such a thing exists.
Or, to discuss a possible problem with such a theory. That nobody has stepped up to the plate, seems a little odd. After all, we have a dozen people battering Jerome over the matter, but nobody has described just what it is they are so mad about, because Jerome doesn't believe them.
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Upchurch
Papa Funkosophy
I thought this thread was directed at Jerome?
It isn't that people are mad that Jerome doesn't believe anyone. It is that he will not address literally the hundreds of responses to his questions and pleas for proof. Or, if he does, he summarily dismisses them with no adequate explanation as to what he finds wrong with them.
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Paulhoff
You can't expect perfection.
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So the shrinkage of earth down to a size that makes into a black means nothing.OK, for those in the know.
The escape velocity of the Earth is 11.186 km/s
The escape velocity of the Moon is 2.38 km/s
We can work out the Moon’s escape velocity once knowing the Earth’s escape velocity, size and weight, and knowing the Moon’s size and weight.
So the moon is about .27265 is size of the earth, worked out above.
The mass of the moon is about 1/81 that of the Earth’s mass.
So if the earth was shrunk to the size of the moon, the escape velocity would be
.27265 ^ .5 = .5221, then we divide .5221 into 1 and get 1.91153
1.91153 time 11.186 km/s equals 21.425 km/s for the new size of the earth.
But the moon is 1/81 of the earth mass, so…….
81 ^ .5 = 9, then we divide 9 into 1 and get .11111
.11111 times 21.425 km/s we get 2.38 km/s for the moon’s escape velocity.
Now lets play with the shrinkage of the earth some more, let’s shrink is down to a radius of .82296 cm.
.82296 cm = 1.39755 ^ -9 of the Earth’s radius,
(1.39755 ^ -9) ^ .5 = 3.738 ^ -5
3.738 ^ -5 divide into 1 = 26,749.5
26,749.5 times Earth’s escape velocity of 11.186 km/s equals 299,200 km/s.
Does anybody but one person on this thread know what the last speed is about equal too.
Paul
Paul
Perhaps, but it sets a bad precedent to start threads that are only about one person. This is a science forum, not a place for personal discussions and trolling.
That may be, but so far nobody has described what it is that they claim Jerome doesn't believe in. The person who claims something exists, is under the gun to describe what it is they are talking about, as well as the evidence for it.
I looked at quite a few sources about Black Holes, and found them lacking in one critical area. But how can one discuss something, if the something can't be described? Much less the theory behind it put forth?
Does anyone have a credible source about Black Holes we can agree on?
Upchurch
Papa Funkosophy
But many of us have been putting forth descriptions and evidence for black holes, even so far as to try to explain how gravitation works to Jerome when he didn't understand the basic principles of that.
I don't understand. What don't you understand about black holes? What sort of description are you looking for?
If you are looking for a quick summary, that's easy. A black hole is an object so massive and dense that no light can escape from it. That's it. If you have an object that light cannot escape due to the object's gravity, it's a black hole.
Upchurch
Papa Funkosophy
Upchurch
Papa Funkosophy
(Sorry I had to do this piecemeal.)
You won't find a much more creditable and authoritative source in text book form. You almost have to go to the journals and papers to find more updated info.
Yes, Gravitation by Misner, Thorne, and Wheeler is the text book on General Relativity. It took me a bit to find my copy. Part VII of the book deals with "Gravitational Collapse and Black Holes".
You won't find a much more creditable and authoritative source in text book form. You almost have to go to the journals and papers to find more updated info.