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Black hole vs Earth - ripped apart or sucked in?

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Original post by Callum Scott
Whether or not the Earth falls towards a black hole is clearly not dependent upon where you stand. Whether the Earth falls into the black hole is, however. I know general relativity is still a theory, but so is Newton's theory of gravitation. General relativity is vastly superior to Newton's theory and predicts a whole range of things that seemed outlandish when compared to Newton's, but all turned out to be true. The predictions it makes and the evidence we've found to confirm them are all linked to the predictions we have about black holes, so why should we not trust those predictions?

Einstein's certainly isn't 'true', but it represents reality vastly more accurately than Newton's does, since it jumps on the fact that the speed of light is limited. It has its flaws, like how it can't be coalesced with quantum mechanics; like at all. But overall, it's an incredibly accurate theory; and while future theories will be different, I guarantee they will all stand on the foundations set by Einstein's theory, just as Einstein's used the law of gravitation.

Newton's LAW was that of universal gravitation. That every body attracts each other body in the universe with a force equal to the product of their masses divided by the square of their distance apart; a new idea for his time, and a law that still stands. His LAW was not that F = GMm/r^2 [his theory of gravitation!], because with general relativity, and the issues that arise from newton's theory of gravitation, this theory is clearly not an accurate representation of reality in all cases.

and finally, the reason that black holes can't exist in newton's theory is precisely because they won't be black holes. Black holes warp spacetime so much that , once the light is inside, light has no other direction to move other than radially inwards. black holes also doppler shift light so much due to its immense gravity that it drops way below the detectable wavelengths and hence appears black. In Newton's theory, there is no spacetime, there is absolute space and absolute time, which are each independent. Also, only objects with mass are affected in Newton's theory, meaning that light is not affected by gravity. So it would be able to pass through a so called 'black' hole... Also, c would not be a speed limit for objects with mass either, so even normal objects could escape -- not making it much of a formidable foe.


Our subject matter is not whether or not Einstein's theory is superior, but if his theory gives us the answer.

What you said as Newton's universal law of gravitation is his formula in words.

Even Newton's law predicts that black holes are black because the light is no longer able to escape the field for us to see the it. Yes, general relativity predicts that black holes wrap spacetime but Scientific progress is much more complex than what we are trying to say here. General relativity was solely formulated with reference to uniformly accelerating reference frames whose mathematical formulation was that of differential geometry. The geometry of time and space in general relativity is clearly a result of the mathematical formulation, not of the Physics.

By the way, there is no point having discussion about things whose foundation is yet to be understood and learned. Discussing about general relativity and space time geometry will just impair our memory and creativity.
Wait, do your answers necessarily contradict one another? Mehrdad jafari said that the Earth will probably be torn apart - and, at least from the Earth's point of reference, that's what (we think) ultimately happens to it, isn't it, no matter if it happens inside or outside the event horizon?

By "torn apart", does that mean chunks of it get physically torn off, or does it mean the whole Earth first gets stretched thinner and thinner? If it was just a (far less massive) human and not an entire planet, would the human get "torn apart" in the same way?
Original post by MrLatinNerd
Wait, do your answers necessarily contradict one another? Mehrdad jafari said that the Earth will probably be torn apart - and, at least from the Earth's point of reference, that's what (we think) ultimately happens to it, isn't it, no matter if it happens inside or outside the event horizon?

By "torn apart", does that mean chunks of it get physically torn off, or does it mean the whole Earth first gets stretched thinner and thinner? If it was just a (far less massive) human and not an entire planet, would the human get "torn apart" in the same way?


I'm stopping replying to this thread soon; I'm gonna be here forever. When something is torn, it tears into pieces, splits, is cut; broken. The problem I had was that he said it would be torn no matter what; which isn't true. Then he said Newton's theory is true and Einstein's is fatally flawed -- both false statements when talking about black holes. Then a bunch of completely false things are said that he goes back on later, without admitting he was wrong, just to carry on the argument a little longer. He also started off saying that he doesn't read about things that give him general understanding, what he says is his own reasoning; then argues with modern science and claims that modern science is too complex for either of us to understand, so there's no point arguing.

To clarify one extra thing though: I thought that a law was something irrefutable, and having read Newton's law of universal gravitation, I thought it had been mathematically proven to be the only way gravity would work. Now, I realise that's bs, nothing scientific can be irrefutable, apart form mathematical proof. A scientific law is basically an observation about reality that abides to a set of mathematical formulae; but is typically only true for a given range of variables. For example: Hooke's law is true, but only up until the limit of proportionality is reached; just as Newton's law of universal gravitation is true, but only for weak gravitational fields.
[I use the word 'true' to mean that reality follows these laws within the specified range; not literally, fundamentally true.]

@Mehrdad jafari
And for the love of god, can you not try to discredit the validity of general relativity, one of the foundations of modern science, something that made ludicrous predictions about reality that have turned out to be true when we looked, with apparently such little understanding or knowledge of its concepts; just to win an argument.
Original post by Callum Scott
I'm stopping replying to this thread soon; I'm gonna be here forever. When something is torn, it tears into pieces, splits, is cut; broken. The problem I had was that he said it would be torn no matter what; which isn't true. Then he said Newton's theory is true and Einstein's is fatally flawed -- both false statements when talking about black holes. Then a bunch of completely false things are said that he goes back on later, without admitting he was wrong, just to carry on the argument a little longer. He also started off saying that he doesn't read about things that give him general understanding, what he says is his own reasoning; then argues with modern science and claims that modern science is too complex for either of us to understand, so there's no point arguing.

To clarify one extra thing though: I thought that a law was something irrefutable, and having read Newton's law of universal gravitation, I thought it had been mathematically proven to be the only way gravity would work. Now, I realise that's bs, nothing scientific can be irrefutable, apart form mathematical proof. A scientific law is basically an observation about reality that abides to a set of mathematical formulae; but is typically only true for a given range of variables. For example: Hooke's law is true, but only up until the limit of proportionality is reached; just as Newton's law of universal gravitation is true, but only for weak gravitational fields.
[I use the word 'true' to mean that reality follows these laws within the specified range; not literally, fundamentally true.]

@Mehrdad jafari
And for the love of god, can you not try to discredit the validity of general relativity, one of the foundations of modern science, something that made ludicrous predictions about reality that have turned out to be true when we looked, with apparently such little understanding or knowledge of its concepts; just to win an argument.


When did I say newton's theory is true and that Einstein's is false? I said in one sense none of the is true and in another sense both are true. Why are you twisting my words? You were doing the same in other thread too. What I said about black hole was solely based on newton's understanding of gravity. It might not be accurate but it's better than accepting ideas blindly by reading ideas on wikipidea. Of course I'm not like you who would go online and search about the structure of time and space when I have no idea how newton arrived at his law of gravity. That's what it means by not reading general ideas. You again twisted my words there which is normal. Modern science is never complex (which I think for you is). I said the scientific progress is complex which you will never get taught because it's far too dangerous for young people to realise that the science they learn at school is essentially about business. I think this clarifies your last point too.
(edited 8 years ago)
Original post by Mehrdad jafari
When did I say newton's theory is true and that Einstein's is false? I said in one sense none of the is true and in another sense both are true. Why are you twisting my words? You were doing the same in other thread too. What I said about black hole was solely based on newton's understanding of gravity. It might not be accurate but it's better than accepting ideas blindly by reading ideas on wikipidea. Of course I'm not like you who would go online and search about the structure of time and space when I have no idea how newton arrived at his law of gravity. That's what it means by not reading general ideas. You again twisted my words there which is normal. Modern science is never complex (which I think for you is). I said the scientific progress is complex which you will never get taught because it's far too dangerous for young people to realise that the science they learn at school is essentially about business. I think this clarifies your last point too.


'You're twisting my words', I said, that you said, that Einstein's was fatally flawed, not false, because you mentioned it was yet to be proven; which is evidently not true. I'm linking articles from wikipedia because it's the most efficient method of displaying information on a given topic. I could link you to the amazon page for "A brief history of time" by Stephen Hawking, "Relativity" by Albert Einstein, or a useful channel with a PhD physicist teaching about spacetime and other interesting physics misconceptions, but I doubt you'd care to sit through them all to get the gist of my argument. I hardly see what difference 'twisting your words' and saying 'modern science' made to my point. You said that there's no point discussing something whose foundation is yet to be understood; I said that it was too complex for us to understand... plus, your comment including the phrase "scientific progress" carried no meaning anyway; it's pretty much given that black holes warp spacetime, since everything does.

The problem I had is that there is a much better, way more accurate, amazingly interesting theory known as general relativity, that specialises in incredibly strong gravitational fields. A question about incredibly strong gravitational fields is posted, and you replied with an answer that isn't always correct, using an outdated theory that isn't accurate when it comes to these situations, using your own reasoning, saying that this is what would happen and you could prove it using newton's law of gravity; phrasing it in such a way to suggest that Newton's law is fundamentally true and isn't wrong; then saying that nothing can be fundamentally true... it all got me riled up.
No one knows. That's because such event couldn't be observed.
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Reply 26
If a black hole appeared near earth, it really depends HOW near. It you replaced the sun with a black hole of the same mass, not much would change with regards to orbital dynamics.

I think some people have an over-dramatised idea of what a black hole is- it's a lump of mass that other massive objects will orbit around like normal. The only difference comes when you get extremely close to the event horizon which, for a black hole with the sun's mass, is (from memory) a sphere with radius 4 km.

To actually "rip a planet apart" you'd need an extremely massive black hole to appear very very close to the planet.
Original post by Callum Scott
'You're twisting my words', I said, that you said, that Einstein's was fatally flawed, not false, because you mentioned it was yet to be proven; which is evidently not true. I'm linking articles from wikipedia because it's the most efficient method of displaying information on a given topic. I could link you to the amazon page for "A brief history of time" by Stephen Hawking, "Relativity" by Albert Einstein, or a useful channel with a PhD physicist teaching about spacetime and other interesting physics misconceptions, but I doubt you'd care to sit through them all to get the gist of my argument. I hardly see what difference 'twisting your words' and saying 'modern science' made to my point. You said that there's no point discussing something whose foundation is yet to be understood; I said that it was too complex for us to understand... plus, your comment including the phrase "scientific progress" carried no meaning anyway; it's pretty much given that black holes warp spacetime, since everything does.

The problem I had is that there is a much better, way more accurate, amazingly interesting theory known as general relativity, that specialises in incredibly strong gravitational fields. A question about incredibly strong gravitational fields is posted, and you replied with an answer that isn't always correct, using an outdated theory that isn't accurate when it comes to these situations, using your own reasoning, saying that this is what would happen and you could prove it using newton's law of gravity; phrasing it in such a way to suggest that Newton's law is fundamentally true and isn't wrong; then saying that nothing can be fundamentally true... it all got me riled up.


If you don't know what it means when a theory is yet to be proven then please don't make my words your own thoughts. It seems that I would have to tell you what it means so that I could argue with you but when you have time to search through physics articles then you could search to see what it means. Cool! If you can link articles from a range of updated journals then that's good but you have come to accept that they're correct just by force of custom, but you cannot begin to explain why they are they way they are. But I think such a statement about wrap space time would satisfy the curiosity of the original poster. And yes, it seemed that in every comment you replied you had gone and read graduate physics articles which you and I wouldn't understand, that's why I said there is no point discussing things whose foundation is yet to be understood (which I hardly think you know what it means). I started talking about why Einstein's theory cannot be the right theory (even though it can explain observation with the greatest accuracy), and hence the "scientific progress" but I'm not surprised if you don't know what meaning it carries when most or all of your time is spent with learning graduate articles online or equations when clearly you are not aware of how these things have come into "existence".

Yes, I don't disagree with the fact that general relativity can provide a more accurate explanation to the question but what is the point of it when you don't even know why it is. For example, you could get closer to a massive black hole and not fall than to a smaller black hole why that's just speculation and discussing it only damages memory and the creativity. I said I could prove my explanation with reference to newton's law because the idea of black hole was predicted before general relativity and I said that doesn't mean it's true. Of course you think that Einstein's theory is true when it explains the consequences of gravity but you will soon realise that his theory only explains what it has predicted, just as Newton's can.
I think it's time we wrapped up this thread. Thanks for the informative answers that have helped me better understand the complicated nature of black holes, and thanks especially to Callum. Yes, we may be "speculating" to an extent (with appropriate mathematical/scientific reasoning), but surely that's better than using a theory that we KNOW is significantly inaccurate when dealing with strong gravitational fields? I think that, with our available knowledge and theories, these sorts of (not necessarily true) predictions are as good as it gets - at least until we discover something better.
Original post by MrLatinNerd
I think it's time we wrapped up this thread. Thanks for the informative answers that have helped me better understand the complicated nature of black holes, and thanks especially to Callum. Yes, we may be "speculating" to an extent (with appropriate mathematical/scientific reasoning), but surely that's better than using a theory that we KNOW is significantly inaccurate when dealing with strong gravitational fields? I think that, with our available knowledge and theories, these sorts of (not necessarily true) predictions are as good as it gets - at least until we discover something better.


Thank you! :adore:
Somebody can still real articles and books and get a general understanding of the consequences of a theory without completely understanding the mathematics of it. I have an idea of the maths; i.e. the Schwarzschild radius is directly proportional to the mass, but the tidal force is inversely proportional to the square of the distance, meaning that larger black holes can, and are predicted to, not 'rip apart' objects until they're within the event horizon. Also, I'd veto that the detailed -- frame of reference dependant -- explanation given by general relativity is much more 'satisfying'.

@Mehrdad jafari
But I must make one point because it really p**** me off... can you please stop being so bloody condescending. Everything you speak reeks of 'I know more than you', despite some of the statements you make being completely false! You use incorrect terminology, then when I use the same false terms, you jump on me like I'm f***ing stupid. I know nothing can be proven, unless things are defined to be true -- that's what I said to begin with, you said Einstein's theory was "yet to be proven", implying that 'proof' was an actual possibility, which made me cater my post to somebody that thinks proof is synonymous with evidence. You initially disagreed with me on many things that you now apparently agree with; it's all a fruitless argument that I think has its root in the fact that text messages are not a good method of conveying thoughts and opinions; especially since we each have no idea of one another's actual understanding of the topic. Can we please end it here...
Reply 30
The behaviour of black holes is fairly well understood. The confusion in this thread is not a result of humankind's ignorance, but of answers from people who have not yet learnt the science.
Original post by mik1a
If a black hole appeared near earth, it really depends HOW near. It you replaced the sun with a black hole of the same mass, not much would change with regards to orbital dynamics.

I think some people have an over-dramatised idea of what a black hole is- it's a lump of mass that other massive objects will orbit around like normal. The only difference comes when you get extremely close to the event horizon which, for a black hole with the sun's mass, is (from memory) a sphere with radius 4 km.

To actually "rip a planet apart" you'd need an extremely massive black hole to appear very very close to the planet.


Or a small one next to the planet :awesome:
Original post by Callum Scott
Thank you! :adore:
Somebody can still real articles and books and get a general understanding of the consequences of a theory without completely understanding the mathematics of it. I have an idea of the maths; i.e. the Schwarzschild radius is directly proportional to the mass, but the tidal force is inversely proportional to the square of the distance, meaning that larger black holes can, and are predicted to, not 'rip apart' objects until they're within the event horizon. Also, I'd veto that the detailed -- frame of reference dependant -- explanation given by general relativity is much more 'satisfying'.

@Mehrdad jafari
But I must make one point because it really p**** me off... can you please stop being so bloody condescending. Everything you speak reeks of 'I know more than you', despite some of the statements you make being completely false! You use incorrect terminology, then when I use the same false terms, you jump on me like I'm f***ing stupid. I know nothing can be proven, unless things are defined to be true -- that's what I said to begin with, you said Einstein's theory was "yet to be proven", implying that 'proof' was an actual possibility, which made me cater my post to somebody that thinks proof is synonymous with evidence. You initially disagreed with me on many things that you now apparently agree with; it's all a fruitless argument that I think has its root in the fact that text messages are not a good method of conveying thoughts and opinions; especially since we each have no idea of one another's actual understanding of the topic. Can we please end it here...


I think it's you who is condescending. You first got on my comment as if you knew what was going on and I said my comment was a suggestion. Clearly if you read my comments again then you will know that I don't know more than I have learned. Cool! I probably don't know the correct terminology because but you do. And Einstein's theory is a theory, that's why it's yet to be fully justified.

The things I disagreed with you are clear, you just seem to incorporate your irrelevant thoughts into your comments as if I changed my mind. Good for you!
Original post by Mehrdad jafari
I think it's you who is condescending. You first got on my comment as if you knew what was going on and I said my comment was a suggestion. Clearly if you read my comments again then you will know that I don't know more than I have learned. Cool! I probably don't know the correct terminology because but you do. And Einstein's theory is a theory, that's why it's yet to be fully justified.

The things I disagreed with you are clear, you just seem to incorporate your irrelevant thoughts into your comments as if I changed my mind. Good for you!


[comment about how condescending this is and the vagueness of 'fully justified']
(edited 8 years ago)
Original post by Callum Scott
[comment about how condescending this is and the vagueness of 'fully justified']


I don't need to explain my comments again. You need to get a private tutor if that doesn't sound condescending
Original post by Mehrdad jafari
I don't need to explain my comments again. You need to get a private tutor if that doesn't sound condescending


A private tutor? to teach condescension? Half of the things you say make no sense, that's probably why you feel they're being misinterpreted; or "twisted".

"That's why it's yet to be fully justified"...what does that even mean?!
Proven, maybe? it cannot be 'proven' in the same sense that maths formulae can; you know that.
Evidence to support it, maybe? there are immense quantities of evidence in support for it; you know that. But you keep on saying it as if it means something!

But you're right, you don't need to 'explain' your comments again, because quite frankly, I'm tired of them
Original post by Callum Scott
A private tutor? to teach condescension? Half of the things you say make no sense, that's probably why you feel they're being misinterpreted; or "twisted".

"That's why it's yet to be fully justified"...what does that even mean?!
Proven, maybe? it cannot be 'proven' in the same sense that maths formulae can; you know that.
Evidence to support it, maybe? there are immense quantities of evidence in support for it; you know that. But you keep on saying it as if it means something!

But you're right, you don't need to 'explain' your comments again, because quite frankly, I'm tired of them


To explain to you my comments. Although a friend of yours is enough for that, I said a tutor so that you don't take the meaning of comments how you would like them to be.

And we don't want to prove it as with the mathematical formulae because we can't.
You have probably forgotten the fact that there were also "immense" amount of evidence proving Newton's law of gravity. But I won't keep saying it because you won't, and you don't want to, get the point. The last bit of your post was extra!
(edited 8 years ago)
Original post by Mehrdad jafari
To explain to you my comments. Although a friend of yours is enough for that, I said a tutor so that you don't take the meaning of comments how you would like them to be.

And we don't want to prove it as with the mathematical formulae because we can't.
You have probably forgotten the fact that there were also "immense" amount of evidence proving Newton's law of gravity. But I won't keep saying it because you won't, and you don't want to, get the point. The last bit of your post was extra!


I'm not saying that Einstein's theory is fundamentally true, i.e. that it is unable to be surpassed. 1) It will be surpassed, I have said this multiple times, but you still think I'm a ****ing moron, when in my eyes, you're the one ignoring my points. 2) I posted them 2 things as possible suggestions as to what you meant by "fully justifiable", because that statement makes no bloody sense! but you instead ignore my question asking you what you meant, and instead of using your reply to answer the question, you used it to demean and go on the attack again.
Original post by Callum Scott
I'm not saying that Einstein's theory is fundamentally true, i.e. that it is unable to be surpassed. 1) It will be surpassed, I have said this multiple times, but you still think I'm a ****ing moron, when in my eyes, you're the one ignoring my points. 2) I posted them 2 things as possible suggestions as to what you meant by "fully justifiable", because that statement makes no bloody sense! but you instead ignore my question asking you what you meant, and instead of using your reply to answer the question, you used it to demean and go on the attack again.


You were stating your point as if Einstein's theory was the most correct theory of all time and that the consequences predicted by it are the only valid predictions. That's not a problem because they are valid for the time being, that's why I said his theory is yet to be proven because we take it for granted that most of the predictions made by his theory are true.

Anyway, as mike1a stated, we haven't (fully) learnt science yet to have anything to say on the topic because science is a spectrum with both ends namely learned and the unlearned, with us (not you) on the unlearned end.

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