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Black hole vs Earth - ripped apart or sucked in? watch

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    I mean, it's pretty obvious that if a black hole appeared near the Earth, then it would be attracted towards it and eventually be destroyed either due to spaghettification, "termination" (if firewalls exist) or something else, but what exactly would happen to the Earth as it got pulled into the black hole? Would it get ripped apart, or would it be pulled in in one piece?

    Thanks!
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    I suspect that the impending deadline for your Y9 Physics homework would matter a good deal less.
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    (Original post by MrLatinNerd)
    I mean, it's pretty obvious that if a black hole appeared near the Earth, then it would be attracted towards it and eventually be destroyed either due to spaghettification, "termination" (if firewalls exist) or something else, but what exactly would happen to the Earth as it got pulled into the black hole? Would it get ripped apart, or would it be pulled in in one piece?

    Thanks!
    Likely torn apart.
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    (Original post by MrLatinNerd)
    I mean, it's pretty obvious that if a black hole appeared near the Earth, then it would be attracted towards it and eventually be destroyed either due to spaghettification, "termination" (if firewalls exist) or something else, but what exactly would happen to the Earth as it got pulled into the black hole? Would it get ripped apart, or would it be pulled in in one piece?

    Thanks!
    Well, I was going to say that things would be torn apart due to tidal forces; but after some videos like this and researching it before I posted an uneducated comment; apparently for supermassive blackholes such as the one in the centre of our galaxy, spaghettification will occur while you are inside the event horizon (approx 0.1 seconds away from the centre) -- contrary to popular [and my previous] belief. I thought that you'd be torn apart as soon as you got anywhere near it, but the fact you can pass through it and still be intact is insane!

    Apparently tidal forces at the event horizon are inversely proportional to the square of the mass:

    F_T \propto\frac{1}{M^2}

    So for smaller black holes, you'd actually experience stronger tidal effects than at a supermassive black hole! (at the event horizon)

    However, there's the complication of general relativity [I'm trusting my knowledge on this one], from an outside observer's perspective, we would see the Earth get squished into an infinitesimally thick layer on/slightly above the event horizon; which I'll read more about, since I don't completely understand why (something to do with the presence of such extreme mass warps spacetime so much that we see the passage of time on the in-falling Earth to be much slower than of our own, but I'm not certain). But in any case, from the point of view of somebody outside the blackhole, it would take an infinite amount of time to watch something 'pass through' the event horizon and because of this; it just isn't possible.

    So I guess the answer is technically neither, it isn't 'sucked' in, it's more sucked 'on' xD But if you were on the Earth at the time; you'd certainly experience passage through the event horizon; and as you neared the centre, you'd be horrifically torn apart

    I thank you for teaching me something new!
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    (Original post by Callum Scott)
    Well, I was going to say that things would be torn apart due to tidal forces; but after some videos like this and researching it before I posted an uneducated comment; apparently for supermassive blackholes such as the one in the centre of our galaxy, spaghettification will occur while you are inside the event horizon (approx 0.1 seconds away from the centre) -- contrary to popular [and my previous] belief. I thought that you'd be torn apart as soon as you got anywhere near it, but the fact you can pass through it and still be intact is insane!

    Apparently tidal forces at the event horizon are inversely proportional to the square of the mass:

    F_T \propto\frac{1}{M^2}

    So for smaller black holes, you'd actually experience stronger tidal effects than at a supermassive black hole! (at the event horizon)

    However, there's the complication of general relativity [I'm trusting my knowledge on this one], from an outside observer's perspective, we would see the Earth get squished into an infinitesimally thick layer on/slightly above the event horizon; which I'll read more about, since I don't completely understand why (something to do with the presence of such extreme mass warps spacetime so much that we see the passage of time on the in-falling Earth to be much slower than of our own, but I'm not certain). But in any case, from the point of view of somebody outside the blackhole, it would take an infinite amount of time to watch something 'pass through' the event horizon and because of this; it just isn't possible.

    So I guess the answer is technically neither, it isn't 'sucked' in, it's more sucked 'on' xD But if you were on the Earth at the time; you'd certainly experience passage through the event horizon; and as you neared the centre, you'd be horrifically torn apart

    I thank you for teaching me something new!
    Wow! Thanks for this response - it really clarified things - and it's good to know that you've learned something too . Although I do now have another, slightly related question: You can rip apart an object on Earth if you apply *enough* force (probably a huge amount), can't you? As in, just by pulling on something with a strong enough force, you might be able to rip a chunk of it off. Why exactly does this happen - is it to do with how strong the intermolecular bonds are or something...? And if so, can you rip apart something like that in a vacuum, e.g. space? In our pretend scenario, does a black hole exert a strong enough force (in an appropriate direction) for it to be able to physically "rip out" a chunk of the Earth?

    (Original post by Profesh)
    I suspect that the impending deadline for your Y9 Physics homework would matter a good deal less.
    I'm in year 12, and I'm pretty sure year 9 physics is nowhere near enough for my question. Some people are just curious about things and ask questions even if they don't have any homework.
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    (Original post by MrLatinNerd)
    I mean, it's pretty obvious that if a black hole appeared near the Earth, then it would be attracted towards it and eventually be destroyed either due to spaghettification, "termination" (if firewalls exist) or something else, but what exactly would happen to the Earth as it got pulled into the black hole? Would it get ripped apart, or would it be pulled in in one piece?

    Thanks!
    It would be ripped apart. Because a black hole has a extraordinary strong gravitational field, the difference in distance in the field means that the force exerted om the "bottom" of the earth as it falls into a black hole is significantly greater than the force exerted on the "top" of the earth. As a result the bottom of the earth will be accelerated into a black hole at a much higher rate than the top of the earth, ripping the earth apart. You can also prove this mathematically
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    (Original post by Callum Scott)
    Well, I was going to say that things would be torn apart due to tidal forces; but after some videos like this and researching it before I posted an uneducated comment; apparently for supermassive blackholes such as the one in the centre of our galaxy, spaghettification will occur while you are inside the event horizon (approx 0.1 seconds away from the centre) -- contrary to popular [and my previous] belief. I thought that you'd be torn apart as soon as you got anywhere near it, but the fact you can pass through it and still be intact is insane!

    Apparently tidal forces at the event horizon are inversely proportional to the square of the mass:

    F_T \propto\frac{1}{M^2}

    So for smaller black holes, you'd actually experience stronger tidal effects than at a supermassive black hole! (at the event horizon)

    However, there's the complication of general relativity [I'm trusting my knowledge on this one], from an outside observer's perspective, we would see the Earth get squished into an infinitesimally thick layer on/slightly above the event horizon; which I'll read more about, since I don't completely understand why (something to do with the presence of such extreme mass warps spacetime so much that we see the passage of time on the in-falling Earth to be much slower than of our own, but I'm not certain). But in any case, from the point of view of somebody outside the blackhole, it would take an infinite amount of time to watch something 'pass through' the event horizon and because of this; it just isn't possible.

    So I guess the answer is technically neither, it isn't 'sucked' in, it's more sucked 'on' xD But if you were on the Earth at the time; you'd certainly experience passage through the event horizon; and as you neared the centre, you'd be horrifically torn apart

    I thank you for teaching me something new!
    Those technical terms and definitions are :hide:
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    (Original post by Mehrdad jafari)
    It would be ripped apart. Because a black hole has a extraordinary strong gravitational field, the difference in distance in the field means that the force exerted om the "bottom" of the earth as it falls into a black hole is significantly greater than the force exerted on the "top" of the earth. As a result the bottom of the earth will be accelerated into a black hole at a much higher rate than the top of the earth, ripping the earth apart. You can also prove this mathematically
    Did you read the other comments?

    "Inside or outside the event horizon:

    The point at which tidal forces destroy an object or kill a person will depend on the black hole's size. For a supermassive black hole, such as those found at a galaxy's center, this point lies within the event horizon, so an astronaut may cross the event horizon without noticing any squashing and pulling, although it remains only a matter of time, as once inside an event horizon, falling towards the center is inevitable. For small black holes whose Schwarzschild radius is much closer to the singularity, the tidal forces would kill even before the astronaut reaches the event horizon.[5][6] For example, for a black hole of 10 Sun masses[note 2] and the above-mentioned rope at 1000 km distance, the tensile force halfway along the rope is 325 N. It will break at a distance of 320 km, well outside the Schwarzschild radius of 30 km. For a black hole of 10,000 Sun masses it will break at a distance of 3200 km, well inside the Schwarzschild radius of 30,000 km."

    Source:
    https://en.wikipedia.org/wiki/Spaghettification
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    (Original post by Callum Scott)
    Did you read the other comments?

    "Inside or outside the event horizon:

    The point at which tidal forces destroy an object or kill a person will depend on the black hole's size. For a supermassive black hole, such as those found at a galaxy's center, this point lies within the event horizon, so an astronaut may cross the event horizon without noticing any squashing and pulling, although it remains only a matter of time, as once inside an event horizon, falling towards the center is inevitable. For small black holes whose Schwarzschild radius is much closer to the singularity, the tidal forces would kill even before the astronaut reaches the event horizon.[5][6] For example, for a black hole of 10 Sun masses[note 2] and the above-mentioned rope at 1000 km distance, the tensile force halfway along the rope is 325 N. It will break at a distance of 320 km, well outside the Schwarzschild radius of 30 km. For a black hole of 10,000 Sun masses it will break at a distance of 3200 km, well inside the Schwarzschild radius of 30,000 km."

    Source:
    https://en.wikipedia.org/wiki/Spaghettification
    I honestly don't read about stuff which would gave me only a general understanding. Also my comment was only a suggestion and it was merely my own reasoning.
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    (Original post by Mehrdad jafari)
    I honestly don't read about stuff which would gave me only a general understanding. Also my comment was only a suggestion and it was merely my own reasoning.
    "It would be ripped apart."
    "You can also prove this mathematically."

    I understand that it was your own reasoning, but at least check if it's correct before answering the question :eviltongue:
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    (Original post by Callum Scott)
    "It would be ripped apart."
    "You can also prove this mathematically."

    I understand that it was your own reasoning, but at least check if it's correct before answering the question :eviltongue:
    Yeah, exactly. So you really think anything that can be proven is correct? Not in science. We only explain things.

    By proving it mathematically I meant using our classical understanding of gravity, Newton's law of gravity. Yes you can prove it but it doesn't mean it's the correct. In fact, if you would like to know, we never know which theory is correct even if we happen to arrive at a correct one.
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    (Original post by Mehrdad jafari)
    Yeah, exactly. So you really think anything that can be proven is correct? Not in science. We only explain things.

    By proving it mathematically I meant using our classical understanding of gravity, Newton's law of gravity. Yes you can prove it but it doesn't mean it's the correct. In fact, if you would like to know, we never know which theory is correct even if we happen to arrive at a correct one.
    "You can also prove this mathematically." was a quote from you...

    and yes, I understand how the scientific method works. The only things that are true in our reality are the things that are defined to be so.
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    (Original post by Callum Scott)
    "It can also be proven mathematically." was a quote from you...

    and yes, I understand how the scientific method works. The only things that are true in our reality are the things that are defined to be so.
    Yes, that was a quote from me and I explained what it meant in my previous comment if you read it again, and if you know how scientific progress works.
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    (Original post by Mehrdad jafari)
    Yes, that was a quote from me and I explained what it meant in my previous comment if you read it again, and if you know how scientific progress works.
    "It would be ripped apart" -- a definite answer implying that, to the best humanity's knowledge, this is what would occur.

    "You can also prove this mathematically" -- an attempt to back up the seemingly definite answer with mathematical proof

    "So you really think anything that can be proven is correct? Not in science." -- A statement saying that mathematically proven ideas aren't necessarily a correct representation of reality

    ...
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    (Original post by Callum Scott)
    "It would be ripped apart" -- a definite answer implying that, to the best humanity's knowledge, this is what would occur.

    "You can also prove this mathematically" -- an attempt to back up the seemingly definite answer with mathematical proof

    "So you really think anything that can be proven is correct? Not in science." -- A statement saying that mathematically proven ideas aren't necessarily a correct representation of reality

    ...
    Yes, as a general statement, this is what would occur, there is no doubt about that. And if you want I can prove it to you using newtons law of gravity.

    Yes, that's why I don't think you are aware of the scientific paradigm.

    Even what you said in your answer is the same answer, it's just more specific, according to modern theory of gravity.
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    (Original post by Mehrdad jafari)
    Yes, as a general statement, this is what would occur, there is no doubt about that. And if you want I can prove it to you using newtons law of gravity.

    Yes, that's why I don't think you are aware of the scientific paradigm.

    Even what you said in your answer is the same answer, it's just more specific, according to modern theory of gravity.
    Newtonian gravity and general relativity are completely separate ideas... Black holes wouldn't even exist in newton's gravity because the speed of light and thus the speed of the gravitational force carrier is presumed to be infinite -- so no event horizon.

    There obviously is doubt about the Earth being torn apart by a black hole, it would depend on the frame of reference and the size of the black hole.
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    (Original post by Callum Scott)
    Newtonian gravity and general relativity are completely separate ideas... Black holes wouldn't even exist in newton's gravity because the speed of light and thus the speed of the gravitational force carrier is presumed to be infinite -- so no event horizon.

    There obviously is doubt about the Earth being torn apart by a black hole, it would depend on the frame of reference and the size of the black hole.
    They are both the theories of gravity, except the fact that Newton's has turned out to be a law because of its empirical accuracy and Einstein's is yet to be proven. So they are the same thing.

    The idea of black hole existed way before the formulation of general relativity, in fact when light was thought to be constituted of particles (as reasoned by Newton), and so it was predicted that in a strong gravitational field even the particles of light cannot escape the field.

    Certainly a black hole will have enough gravitational force to torn the earth a part if it was to fall towards it. We are talking about what would happen, not what you would see.
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    (Original post by Mehrdad jafari)
    They are both the theories of gravity, except the fact that Newton's has turned out to be a law because of its empirical accuracy and Einstein's is yet to be proven. So they are the same thing.

    The idea of black hole existed way before the formulation of general relativity, in fact when light was thought to be constituted of particles (as reasoned by Newton), and so it was predicted that in a strong gravitational field even the particles of light cannot escape the field.

    Certainly a black hole will have enough gravitational force to torn the earth a part if it was to fall towards it. We are talking about what would happen, not what you would see.
    What would happen and what you would see are directly related. and general relativity is yet to be 'proven'?! are you being serious?!

    Newton may have said that the particles of light travels at a fixed speed, i'm not sure, but his theory of gravitation was certainly dependent upon the fact that gravity was transmitted from A to B instantly -- hence no black holes. A black hole, as reasoned in my first comment on this thread would not always tear the Earth apart. It is dependent upon the size of the black hole, whether it's rotating or not, whether you're observing this all from the Earth or observing from a distance; and of course, whether they exist in your gravitational model.

    Why General/Special Relativity is better:
    Spoiler:
    Show
    Newton's was known to be inaccurate because of its lack of precision when predicting the orbit of mercury; Einstein's predicted that the orbit would precess due to frame dragging from the sun... and it does. Einstein's also predicts that time dilates when velocities approach the speed of light -- observed in particles with short lifetimes that exceed this lifetime due to time running slower. General relativity predicts that objects with mass don't just attract each other, anything with energy attracts each other -- which was observed when stars that would normally be masked behind the sun were in fact visible because their light was warped around the sun. Then there's E = mc^2 being a direct result of all of this stuff -- the equation that allows particle accelerators to work, the sun to fuse hydrogen and nuclear fission to take place -- all apparently impossible with Newton's theory.


    "Newton's law has since been superseded by Einstein's theory of general relativity, but it continues to be used as an excellent approximation of the effects of gravity in most applications. Relativity is required only when there is a need for extreme precision, or when dealing with very strong gravitational fields, such as those found near extremely massive and dense objects, or at very close distances (such as Mercury's orbit around the sun)."

    Source:
    https://en.wikipedia.org/wiki/Newton...al_gravitation
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    (Original post by Callum Scott)
    What would happen and what you would see are directly related. and general relativity is yet to be 'proven'?! are you being serious?!

    Newton may have said that the particles of light travels at a fixed speed, i'm not sure, but his theory of gravitation was certainly dependent upon the fact that gravity was transmitted from A to B instantly -- hence no black holes. A black hole, as reasoned in my first comment on this thread would not always tear the Earth apart. It is dependent upon the size of the black hole, whether it's rotating or not, whether you're observing this all from the Earth or observing from a distance; and of course, whether they exist in your gravitational model.

    Why General/Special Relativity is better:
    Spoiler:
    Show
    Newton's was known to be inaccurate because of its lack of precision when predicting the orbit of mercury; Einstein's predicted that the orbit would precess due to frame dragging from the sun... and it does. Einstein's also predicts that time dilates when velocities approach the speed of light -- observed in particles with short lifetimes that exceed this lifetime due to time running slower. General relativity predicts that objects with mass don't just attract each other, anything with energy attracts each other -- which was observed when stars that would normally be masked behind the sun were in fact visible because their light was warped around the sun. Then there's E = mc^2 being a direct result of all of this stuff -- the equation that allows particle accelerators to work, the sun to fuse hydrogen and nuclear fission to take place -- all apparently impossible with Newton's theory.


    "Newton's law has since been superseded by Einstein's theory of general relativity, but it continues to be used as an excellent approximation of the effects of gravity in most applications. Relativity is required only when there is a need for extreme precision, or when dealing with very strong gravitational fields, such as those found near extremely massive and dense objects, or at very close distances (such as Mercury's orbit around the sun)."

    Source:
    https://en.wikipedia.org/wiki/Newton...al_gravitation
    Whether or not you see the earth falling towards a black hole is not dependent on what would actually happen to it. Yes, I'm being serious. General theory is still a theory.

    That's true! What I was saying was that Newton's theory was a theory at the time. It could, and still can, explain many of the consequences of gravity. Of course, this didn't turn out to be the correct theory but that doesn't make Einstein's correct. In fact, even Einstein's is not the correct one. Nor any other will be. newton's theory predicted the existence of a black hole but the explanations of were not accurate or correct ( for example, the gravitational interaction between two masses in instantaneous. I don't see why that would violate the existence of a black hole).

    The spoiler is just what I said. I don't have to explain everything about Newton's law of gravity to say why it was to be a law. Even Einstein's theory cannot explain all the consequences of gravity. Hence, the same thing as the Newton's
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    (Original post by Mehrdad jafari)
    Whether or not you see the earth falling towards a black hole is not dependent on what would actually happen to it. Yes, I'm being serious. General theory is still a theory.

    That's true! What I was saying was that Newton's theory was a theory at the time. It could, and still can, explain many of the consequences of gravity. Of course, this didn't turn out to be the correct theory but that doesn't make Einstein's correct. In fact, even Einstein's is not the correct one. Nor any other will be. newton's theory predicted the existence of a black hole but the explanations of were not accurate or correct ( for example, the gravitational interaction between two masses in instantaneous. I don't see why that would violate the existence of a black hole).

    The spoiler is just what I said. I don't have to explain everything about Newton's law of gravity to say why it was to be a law. Even Einstein's theory cannot explain all the consequences of gravity. Hence, the same thing as the Newton's
    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.
 
 
 
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