Black Hole/White Hole
White holes are 100% theoretical mathematical ideas. They have never been proven. Black holes are real. We do not know what's on the other side of them. What if when we get pulled through a black hole, we are stretched through a ridiculously small wormhole and emerge out of a white hole in another universe?
Comments (79)
Is a white hole a mathematical necessity? Does the math suggest its existence?
That's assuming general relativity provides us with an accurate model of things at this scale. But we can consider that the concept of "event horizon" is evidence that general relativity doesn't provide us with an accurate model.
Whether GR is accurate or not doesn't change the astronomical data. There is something there. Our understanding of it might be inaccurate, but that doesn't change the data.
It does change whether what we are seeing is a black hole, because a "black hole" is not a theory-free observation, it is a theoretical entity that happens to fit observations in the context of modern physics and astronomy. That is not to say that there is something particularly suspect about black holes: we could say the same about just about anything: atoms, eclipses, electrical currents, etc.
The only really suspect thing about black holes is the theoretically-predicted singularity at their center - many consider this to be problematic as such, and especially so if we assume that quantum mechanics is valid at the same time.
The only thing that's definitely there is numbers from our instruments that don't match what we're expecting given our current gravitational models. So we make up something to explain the unexpected numbers.
They match what we're expecting given our current gravitational models to a high degree of accuracy.
I'm not sure I understand, are you saying that black holes are merely theoretical? Perhaps elements of the subject do not completely ameliorate its external properties, but the emission of electromagnetic wavelengths from quasar radiation have been observed where redshift surveys that use parametrical time delays have been compared. That is, the interaction between matter and electromagnetic radiation - visible through the wavelengths of spectral lines - have been observed.
https://academic.oup.com/mnras/article/337/1/109/1034129/Measuring-the-black-hole-masses-of-high-redshift
White holes are hypothetical though.
No, my mind was addled by mathematical structuralism, point taken.
The structure and apparent motion of stars doesn't match what we're expecting given our gravitational model. Hence the need to invent black holes.
No. Black holes are a generic prediction of General Relativity. If GR is our gravitational model, then black holes are part of the package.
That they're consistent with GR doesn't make them a prediction of GR. We invented them so that they'd be consistent with GR, otherwise we'd need to retool our gravitational theory.
I agree with this. There are areas where GR has difficulties, one being the phenomenon which is called a black hole. It's not that GR predicted these things, more the opposite, it's a place where GR cannot predict. This indicates that GR is an incomplete, or deficient theory for representing gravitation.
We "invented" them only in the same sense that we "invent" solutions to equations. Black holes are what we can expect to see, given GR. And what we do see is in close agreement with what we expect to see. So whatever semantic point you are trying to score, it is irrelevant. Black hole physics is not an ad hoc addition to our gravitational models, as you implied.
I don't see how this could be true. What is it inherent within GR which would make you expect to see a black hole?
General Relativity is a theory of gravitation that lawfully relates the distribution of energy and momentum in space-time with the metric of space-time (thus specifying its "curvature"). It follows from this lawful relation (i.e. Einstein's field equations) that whenever a spherical distribution of mass achieves a density such that it is contained within its Schwarzschild radius, then the escape velocity at the surface attains the speed of light. Past this point, the mass can't possibly not collapse into a singularity (and there can't possibly not occur the formation of an event horizon at the Schwarzschild radius) consistently with Einstein's field equations.
It also is the case that for a stellar mass to achieve a density such that it is contained within its Schwartzschild radius is a very common occurrence with dying stars only slightly more massive than our Sun, or with dense galactic cores.
Of course. General relativity is a deterministic theory. It only tells you what to expect given some empirically realized initial conditions. Likewise, there isn't anything inherent to Newtonian mechanics which would make you expect to find a billiard ball in a pocket. But, given that some billiard balls are subjected to impacts thus and so and then let roll freely, then they are expected to end up in a pocket. Likewise, given that some stars naturally evolve in such a way that they contract within their Schwartzschild radii, then they are expected to become black holes.
So the issue here, appears to be that since there are such objects, black holes, whose mass is contained within the Schwartzchild radius, doesn't this indicate that GR is inadequate for understanding some aspects of the universe?
Ha. A paid up member of the flat earthers. It's only a rumour things disappear over the horizon because the world is curved.
Quoting Metaphysician Undercover
Another flat earther. In 1915, Schwarzchild had already extracted the basic cosmological implication of general relativity being true. A dense enough lump of matter would have to produce the local curvature that would become a complete gravitational collapse. That comes directly out of the equations.
And it is one of the ironies of intellectual history that Roy Kerr announced his simplification of Einstein's equations that could account for a realistic solution for a spinning black hole at the very same conference called to discuss the discovery of quasars. Unlucky for Kerr, it took quite a few more years for it to be realised that quasars were the product of black holes. So at the conference many wandered off or catnapped as he gave what seemed like an obscure mathematical technical paper at the time.
Now of course astronomers are drumming up public money so they can take a "photograph" of Sagittarius A*, the super massive black hole at the centre of our own galaxy.
It's merely a theory of gravitation. It is adequate for the very restricted purpose of understanding the phenomenon of gravitation as a manifestation of the metric of space-time (and what it is that determines this metric: spatial distributions of energy and momentum). But it is also limited in scope since it is a "classical" theory that becomes inadequate for energy and density scales where quantum fluctuations become relevant. Hence, we can't really know, within the general relativity framework, what happens to the metric of space-time near singularities or in the very early universe.
What a load of rubbish. If something is inconceivably dense like a black hole, even without the emission of radiation including light, it doesn't mean it is without energy and they have been detected through the x-rays emitted by expelled gas falling toward a black hole. It's not an invention.
Solving equations has nothing to do with positing real ontological entities.
"Spacetime curvature" isn't a real thing, because space/time aren't anything like substances. "Spacetime curvature" is at best a manner of speaking to account for observational data re existents.
That is a thoughtless and irrelevant retort. The question that started this line of discussion was whether black holes were "invented" in order to accommodate some observations that, as you said, did not fit existing gravitational models. That is exactly backwards. The observations that we now attribute to black holes fit our gravitational models like a glove.
Not so.
Relativity was/is falsifiable, but has since been verified on several occasions.
It is used in GPS today.
Black holes are predictions of relativity, and has not been falsified per se.
That said, relativity's domain of applicability doesn't quite include the micro-domain of quantum mechanics, so there's not really any telling what may happen in a super-dense super-high-temperature black hole, where relativity suggests a singularity.
Tests of special relativity (Wikipedia article)
Tests of general relativity (Wikipedia article)
So the Schwarzchild principle does not follow directly from GR then, it follows from the assumption of a "spherical distribution of mas" in conjunction with GR. Such a spherical symmetry is just an ideal, like a perfect circle, there is no such thing in reality.
Quoting apokrisis
Are you claiming that a description which is based in the assumption of an ideal spherical symmetry is ontologically real? You are just committing the very same error as Aristotle when he assumed perfect, eternal, circular motions for the orbits of the planets. Such perfect circles are not ontologically real.
If it's not a "perfect sphere", then it's just some other shape, that can be modeled sufficiently accurately with the Schwarzschild radius for these purposes.
From wikipedia, it is based in the assumption of a speherical symmetry. But this simply assumes the traditional Newtonian representation of gravity, as a point particle at the gravitational centre of the massive object. I don't believe that such a symmetry has any basis in reality, it's just a theoretical convenience. So there is no reason to believe that the phenomena known as black holes are really similar to the theoretical black holes.
Quoting apokrisis
Not a flat earther, but a perfect circle denier. The ancient astronomers who wanted to replace the flat earth principles with perfect circles were just as wrong as the flat earthers. They described the sun, planets and moon as orbiting the earth, in perfect circles. The true reality was apprehended only through the realization that the so-called circles were not really circles. Dropping the idea of circles forced them have to figure out what was really the case.
You latched on to a phrase in a way that shows you don't understand the physical argument. Relativity would model the gravitational curvature as perfectly spherical, yet the definition is still asymptotic - the approach to a limit.
So Kerr models the ideal final state in a way then allows the calculation of actual physical histories. We can start to talk about real black holes in terms of their more lumpy and haphazard story of getting crushed down in practice towards the simple ideal.
Just check out the variety of modelled "imperfections" that in practice would break the perfect symmetry the description of the absolute limit describes....
Well, we differ in opinion clearly, because I think you will necessarily get a mistaken result if you start from the premise of the perfect symmetry, and work backward away from this, to describe something which is not a perfect symmetry. It's like starting from a false premise.
So I believe that what you describe in the Kerr geometry is very useful for determining the ways in which the real black holes may differ from the perfect symmetry which is derived from the theory. But the real black holes will never be properly understood unless we can establish premises for the reasons why it does not conform to a perfect symmetry, then represent it with theory which starts from those premises, rather than the premise of perfect symmetry. The latter being only useful for determining how the real black hole differs from the perfect symmetry. To determine the true nature of the real black holes would require further speculation, not being accessible through the principles of GR.
I suppose on the same principle you object to rulers that pretend to be straight, and clocks that pretend to be regular.
It is physically impossible that they are, so we must simply throw all rulers and clocks away.
As I said, it's very useful for determining the different ways in which the thing being measured varies from the standard of measurement, but the straight ruler wont tell you why the thing you are trying to measure is crooked. Nor will you get an accurate measurement of the crooked thing using the straight ruler. That's why we must devise other means for measurement. But first we must figure out why the straight ruler is not giving an accurate measurement.
Quoting Metaphysician Undercover
So you don't think GR might help with that? Or do you accept the calculation of geodesics - only not in the vicinity of a black hole for some reason?
Quoting Metaphysician Undercover
Except GR is telling you why your (Newtonian) ruler has a limit to its crookedness. The metric might curve, but it it can't be more curved than the surface of a sphere. A sphere is absolutely crooked - crookedness gone to its equilibrium limit. Talk of things being rounder than a circle is unphysical craziness.
And GR also defines the opposing limit of non-Euclidean curvature in saying that rulers could be bent hyperbolically the other way. Kind of like a white hole. Or the "inside" of inflation. That again is a limit-based argument. You can't diverge any faster than at an exponential rate. Crookedness in both directions has its geometric limits.
So a straight ruler has to live in an actually flat world - perfectly poised for no particular reason between the hyperspheric and hyperbolic limits on curvature. Or else we accept it bends with its world due to the world's gravitational contents, but we have ways of factoring that energetic out of our measurements. We know how to make relativistic corrrections so we can treat the world as if it met our demands to just be flat ... and its material contents don't make a difference to that.
No, I don't. That's the point. GR is coming at the real existing phenomenon which is called a blalk hole, with the Schwartzchild principle, which assumes a perfect symmetry. This is the straight ruler. The real existing black hole is not a perfect symmetry, so it is something which cannot be measured with the straight ruler. The straight ruler (GR with Schwartzchild principle) might be able to help us determine how the real black hole differs from the theoretical black hole, in a somewhat unreliable, speculative way, but it will not be able to tell us why the real black hole differs from the theoretical one. Therefore won't tell us the true nature of the real black hole. We need another theory for that, something which gives us the appropriate ruler.
The straight ruler is your analogy. Don't you recognize it as your analogy?
Quoting apokrisis
My claim was that we cannot derive the true nature of a real black hole through the means of the Schwartzchild principle because it approaches with the concept of a perfect symmetry, when the real black hole is not a perfect symmetry. You replied with the above quote about using straight rulers. And so I explained that I would object to using a straight ruler to measure a crooked object. That is what applying the Schwartzchild GR principle to a real black hole is analogous to, trying to measure a crooked object with a straight ruler. As much as the Kerr formulation may be an adaptation of the perfect symmetry in an attempt to measure the black hole, which is not a perfect symmetry, it is not the best approach. The right approach is to formulate a new theory which starts from a description of what a black hole really is.
Verification is always provisional at best, and all it amounts to in this case is that the mathematics in question isn't clearly falsified by observation.
Is a crooked object one that is not straight in your view? If so, you have just defined it in contrast to straightness. You are claiming to have measured some degree of departure from the ideal.
But please, if you are measuring crookedness in some other fashion, explain away.
I haven't thrown away the ideal of the perfectly straight, I've determined that it is not useful in this situation. There are still many uses for those ideals. We use these ideals, such as geometrical principles, in construction and manufacturing, production. We build things according to these principles. But when we go to measure naturally existing things, we find that they do not naturlly exist according to these same ideals. We can artificially force naturally occurring elements to take the form of the ideal, as we do in manufacturing, but in their natural occurrence, they are not in the form of the ideal.
Well, as an example, I would take a string, and make it follow all the crooks of the crooked object, to get a better measurement.
That's the hard part. That's what we need a different theory for. I hold the string to the ruler, so I just convert it to that straight ruler scale, but this does not really measure the item. That's why we need to refer to other scales. We can measure the volume by putting it in water and seeing how much water is displaced. We can weigh it, and figure the density. All these are different ways of measuring the item. I don't know how you would measure for crookedness, it depends on how you would define that. But what's your point?
Or the alternative is to be able to imagine "idealised crookedness" as the other pole of being from which actual being can then be measured. So now you would be measuring a reciprocal lack of crookedness (and thus an approach to the opposite ideal of absolute straightness).
This is simply how measuring the world works. We have to find some believable ideal and then measure the degree of deviation in terms of that. Then those ideals turn out to believable because they are self-defining by dichotomous logic. We see that reality is in fact bounded by its ideal extremes - and the bit in the middle we want to measure is now a position between the two bounds.
So talking about measuring crookedness by creating a crooked bit of string is not measuring anything. It doesn't give a number that reflects a position on some natural idea of a spectrum that is anchored by "fixed" bounds - or extremum principles, ideal limits.
Sure, you can define crooked as not straight if you want. But there are all kinds of different ways that something can be crooked. It could be bent, twisted, curved, etc.. So "not-straight" tells us very little about the shape of the object, because "straight" is just one particular ideal which the object does not conform to. So we can proceed from the determination of not-straight, toward describing what the thing is really like, idea which it does conform to. Describing an object is saying what it is. And if necessary, we sometimes have to produce new idea which are based in the very existence of that object itself. Nevertheless, we describe an object by saying what it is, not what it is not. Proceeding toward understanding the object by saying what it is not, is very tedious, and it is much more efficient to describe what the object is.
Quoting apokrisis
There is a lot more to understanding the world than measuring it. If the object doesn't conform to a particular ideal, and cannot be measured according to that ideal, then we do not gain an understanding of the object by saying it is not-X. We need to describe it, say what it is, in order to understand it. Describing an object is completely different from measuring it. And, I think it is necessary to have an accurate description before it is even possible to measure an object. The description allows us to determine which of our ideals will be useful in measurement, and develop other ideals if necessary.
And so you change the subject yet again.
I thought I'd try to make some progress in this discussion. You seem to be bogged down in your infatuation with measurement.
So now you have all these other description of crooked - bent, twisted, curved, etc. If something is not bent, what is it? If something is not twisted, what is it? If something is not curved, what is it?
Do you object violently to the description of "straight" for some reason?
Yes, for "some reason" I hate untruth, it makes me get violent. If the thing is not straight, and it is described as straight, then I object violently to that description.
Quoting apokrisis
Right now, what it is unknown. That's what's necessary, to figure out what it is. As an example, consider that the Copernican model of the solar system could not be proven to be correct, because it still employed the faulty Aristotelian description of perfect circles, putting the circles around the sun instead of the earth. With the use of circles, the numbers derived from observation could not be resolved. It wasn't until Kepler introduced ellipses, that the mathematics could be resolved.
Just say the word. :)
I really don't see what point you're trying to make. You've totally lost me. Do you think that if I say something is not X, then I should know what it is? That's illogical. The premise that it is not x, produces no logical conclusion of what it is.
The rest of my argument follows of course, so no need to repeat it.
No, I don't agree. All those words have a particular meaning, referring to a particular shape. Each is different from one another. Despite the fact that each of these shapes is other than straight, I do not believe that any of them is opposite of straight, and that is what is required in order for one of them to be the antonym of straight. In fact, I think it is a misunderstanding of geometrical principles, to believe that any shape has an opposite shape, they are simply different. Do you think square is the antonym of circle? A direction has an opposite direction, but a shape doesn't have an opposite shape.
Quoting apokrisis
I don't recall your argument, but it should be clear to you now, that your argument follows from a false premise, so it's a rather useless argument. That's probably why I didn't bother to remember it.
Of course not. You would argue the toss even with a dictionary.
Quoting Metaphysician Undercover
Great. And what particular shape does each of those particular words refer to then?
Curved = ?
Bent = ?
Twisted = ?
I can't understand why this is so difficult for you apokrisis. The word refers to the shape, just like "square", "rectangle", "circle". What do you mean by what shape does each refer to? The shape is signified by the word! I could look into a dictionary to get definitions, just like I could get definitions of square and circle. Is that what you want? .
Curve = "...having a regular deviation from being straight or flat, as exemplified by the surface of a sphere or lens.". Bent = "curved or having an angle" Twist = "change the form by rotating one end but not the other, or both ends in opposite directions"
Each has a different definition. None is the opposite of straight. Are you starting to understand yet?
Yet all of them are defined in reference to the straight. That being the point.
That's the point. You finally got there.
In understanding any particular curve, what is important is understanding how it deviates from a straight line. That it deviates from a straight line is a given. This is quite consistent with what I said three days ago.
Quoting Metaphysician Undercover
I was there from the beginning. You've been arguing that "not straight" suffices as an understanding of any possible not straight thing. Are you starting to get it yet? Or have you really been in agreement with me all along, and are just being contrary as a matter of principle?
This is what then doesn't make sense. If the crooked is the not straight (in some degree), then only something straight could be used to measure the degree of that non-straightness.
I don't agree with this, because we are using straight, and not-straight, to refer to different categories, not opposing qualities within a category. We classify things by putting them into different categories according to qualities. The difference between crooked and straight is a qualitative difference, they are not opposites within one category, like hot and cold. We measure within the category such that we measure the degree of that quality defined by that category. There is a difference which separates one category from another, the qualitative difference, and we cannot use the measure from one of the categories, to measure that difference.
So for instance, weight and temperature are distinct categories. We cannot use the measurement we use for weight, to measure the difference between weight and temperature. Likewise, straight, round, and angled, are all different qualities, different categories. We cannot use the means by which we measure one of these, to measure the difference between one and the other.
The idea that all qualities are reducible to one measurement system is a detrimental form of reductionism. There is a demonstrable incompatibility between one dimension and another, which is evident from the irrational nature of pi, and the incommensurability of the sides of a square with the diagonal of the square. Because of this incommensurability, the means by which we measure one dimension (straight), cannot be used to give us the difference between one dimension and another.
And curves are measured using the reciprocal extremes of tangents and osculatory circles. Perfect lines or perfect circles.
2. My explorations have led me to believe it is possible. Think of different ways for universe organisms to see. On earth most of us use light differentiation, but not all. Bats and others see just fine with sonar and surely their brains translate this information into a mental "image" of their world. It turns out that blackholes have a gravitational force attraction that can stretch to the farthest reaches of the universe, edge to edge. Now consider that there are billions of black holes, probably more than one per galaxy. If this is a network, and you envision gravity as a "sense" instead of "attraction" or pull...but as a field in which all other objects and atoms and possibly subatomic particles have an attraction to and move within...how sensitive might their data acquisition be?
3. What makes "black hole omniscience network theory" more curious, is the fact that the matter of the black hole is inside the event horizon, and therefore is in a space of bent or distorted time. The only thing better than more processing "power", would be more processing "time."
In my opinion, the universe itself may possess sentience with an omniscient awareness of every particle within itself through a network a the most dense, most massive objects known which happen to be entirely made of superconductive material with a sense of gravitational field that interacts with every particle. We can only imagine the sensitivity of this "sight" and how much "time" is created to process.
Viewed this way each black hole is like a neuron in a giant mind we call the universe. An omniscient mind.