Big Bang: Discovering the Reasons Behind Its Occurrence

[FizixFreak]

for what reason did the big bang took place?

 

[mgb_phys]

Nobody knows - You can rationalize this as:

It's a quantum event - there is no need for a cause, it's just random.
Since time was created - there was no 'before' for any cause to happen in.
since it's fundamentally unknowable - it's not a valid question

 

[Delta2]

It took place because God wanted to create something :)

 

[mgb_phys]

It took place because God wanted to create something :)

I've always been partial to the software bug theory = it was a buffer overflow in Universe 1.0

 

[Delta2]

I don't see any bugs in the universe, universe does not appear to be perfect to the common human sense but it is in fact very perfect (For every flaw we observe in the universe if we carefully think it over we ll see that it is not a flaw but it exists to give more meaning and make it more interesting) and this perfection proves that it is the creation of a supreme being which is what we refer as God.

 

[Chalnoth]

I don't see any bugs in the universe, universe does not appear to be perfect to the common human sense but it is in fact very perfect (For every flaw we observe in the universe if we carefully think it over we ll see that it is not a flaw but it exists to give more meaning and make it more interesting) and this perfection proves that it is the creation of a supreme being which is what we refer as God.

What? That's absurd. Calling something a "flaw" is a subjective judgment. As is meaning and making things more interesting. Reality cannot conform to these subjective judgments. The only way you can think it's true is if you bend your subjective judgments to conform to reality.

For this reason, asking "for what reason" something takes place is usually, in science, a completely bogus question. It is reasonable to ask how the big bang started, how often such a thing might happen, and what sorts of universes are produced in your typical big bang. We don't know any of these answers yet, but they're still reasonable questions. Asking for the "purpose" of the big bang, however, is just an invalid question: there is none. It just is.

 

[Delta2]

What? That's absurd. Calling something a "flaw" is a subjective judgment. As is meaning and making things more interesting. Reality cannot conform to these subjective judgments. The only way you can think it's true is if you bend your subjective judgments to conform to reality.

Whats the problem with subjective judgements? Life is not only science we don't have to consider only facts and objective truth. Universe supports life and life supports subjective judgements.

For this reason, asking "for what reason" something takes place is usually, in science, a completely bogus question. It is reasonable to ask how the big bang started, how often such a thing might happen, and what sorts of universes are produced in your typical big bang. We don't know any of these answers yet, but they're still reasonable questions. Asking for the "purpose" of the big bang, however, is just an invalid question: there is none. It just is.

Again life is not only science. We don't have to see everything in a scientific context and how it relates to science and if it carries an objective truth. Ofcourse you might argue that this is a science forum so u imply that we may discuss something only if it relates to science but that's another subject.

Saying that the purpose (or the cause ) of the big bang is none might stand from a purely schientific point of view but from a subjective point of view we expect things to have a meaning thus they must have a cause and probably serve a purpose.

 

[jackmell]

for what reason did the big bang took place?

I believe we can know how it happened just not now. Think about the history of Astronomy: we thought the Earth was flat, that changed, that we were the center of the Universe, that changed, that the sun and moon "moved" around the earth, that changed, that all we could see in the sky (mostly) was all that there was. I mean it was less than 100 years ago that we believed the entire Universe was the Milky Way. I believe our understanding is still incomplete and we do not at present have adequate tools to understand origins.

However I am comforted in reaching my own personal conclusion based on the "discontinuous" nature of phenomena in the Universe, that the reason it emerged was due to some larger system reaching a critical point like when a supersaturated solution of sugar is slowly cooled, it reaches such a critical point rapidly precipitating the sugar out of solution. In the same way, I suspect this larger system reached a critical point, and our Universe "precipitated" into existence.

 

[DaveC426913]

Saying that the purpose (or the cause ) of the big bang is none might stand from a purely schientific point of view but from a subjective point of view we expect things to have a meaning thus they must have a cause and probably serve a purpose.

Except that, since it's subjective, there are as many valid interpretations as there are people on the planet. Since everyone has an opinion, and none are wrong, you end up with a difference with no distinction. In other words, an utterly useless concept. I'm not saying there's anything wrong with the concept, just that it is of no use.


A useful concept, on the other hand, is one where there is enough internal logic that others - who may not have originally shared the same idea - are convinced it is sound.

 

[DaveC426913]

I believe we can know how it happened just not now. Think about the history of Astronomy: we thought the Earth was flat, that changed, that we were the center of the Universe, that changed, that the sun and moon "moved" around the earth, that changed, that all we could see in the sky (mostly) was all that there was. I mean it was less than 100 years ago that we believed the entire Universe was the Milky Way. I believe our understanding is still incomplete and we do not at present have adequate tools to understand origins.

However I am comforted in reaching my own personal conclusion based on the "discontinuous" nature of phenomena in the Universe, that the reason it emerged was due to some larger system reaching a critical point like when a supersaturated solution of sugar is slowly cooled, it reaches such a critical point rapidly precipitating the sugar out of solution. In the same way, I suspect this larger system reached a critical point, and our Universe "precipitated" into existence.

Ah, but all you've done then is push back the point of creation. OK, so the BB is simply an effect of a larger cause.

To borrow the OP's words, for what reason did the larger cause took place?

 

[jackmell]

Ah, but all you've done then is push back the point of creation. OK, so the BB is simply an effect of a larger cause.

To borrow the OP's words, for what reason did the larger cause took place?

Yeah, that's true but for now, I'm content with just trying to come to terms with the Big Bang. And keep in mind such (endless) regression may involve singularities which when pushed pass these points, concepts on one side of the singularity cannot be applied to explain phenomena on the other side of the singularity.

Take the sugar-crystal beings in the supersaturated solution. They may ask, "how could a sugar crystal emerge from "nothing" (something not a sugar crystal)? The answer of course is it did not emerge from sugar crystals but from something qualitatively different than a crystal: ions in solution. Applying that logic to origins, perhaps "cause an effect" we now observe in the Universe could emerge from something not cause and effect.

My main working hypothesis is the phase-transition that a system undergoes when it passes through a critical point and the realization that often qualitatively different concepts are needed to describe the system on either side of the critical point. My belief is the Big Bang was one such critical point.

 

[Chalnoth]

Whats the problem with subjective judgements? Life is not only science we don't have to consider only facts and objective truth. Universe supports life and life supports subjective judgements.

I'm not saying that subjective judgments are bad, merely that they should be used properly. Subjective judgments cannot be statements about the nature of reality. Instead, subjective judgments are statements about the person making the judgment.

Thus questions of "meaning", "purpose", or "interest" are questions about us, or about whoever (or whatever) else is making these subjective judgments, not questions about the nature of reality.

Saying that the purpose (or the cause ) of the big bang is none might stand from a purely schientific point of view but from a subjective point of view we expect things to have a meaning thus they must have a cause and probably serve a purpose.

That is completely invalid reasoning. You're basically saying that reality must conform to your whims. Sorry, but it doesn't work that way.

 

[bapowell]

I don't see any bugs in the universe, universe does not appear to be perfect to the common human sense but it is in fact very perfect (For every flaw we observe in the universe if we carefully think it over we ll see that it is not a flaw but it exists to give more meaning and make it more interesting) and this perfection proves that it is the creation of a supreme being which is what we refer as God.

If it does not appear perfect to the common human sense, and assuming that you are, in fact, a human yourself, how do you know that it "is in fact very perfect?" Do you talk to God?

I am also assuming that you recognize the extreme logical fallacy in concluding that perfection universally proves the existence of God. This is a physics forum where people discuss science. Your assertion is non-empirical, objectively useless, and has no place here.

 

[DaveC426913]

This is a physics forum where people discuss science. Your assertion is non-empirical, objectively useless, and has no place here.

OK well, in his defense, we was the first person to acknowledge that:

Ofcourse you might argue that this is a science forum so u imply that we may discuss something only if it relates to science but that's another subject.

 

[bapowell]

OK well, in his defense, we was the first person to acknowledge that:

Whoops. I didn't have the will power to read the second post. Apologies. Although I am still interested in finding out if Delta^2 is a prophet.

 

[DaveC426913]

I don't see any bugs in the universe, universe does not appear to be perfect to the common human sense but it is in fact very perfect (For every flaw we observe in the universe if we carefully think it over we ll see that it is not a flaw but it exists to give more meaning and make it more interesting) and this perfection proves that it is the creation of a supreme being which is what we refer as God.

The other problem with this logic is that it is self-fulfilling. There is no possible way, even in principle, for it to be falsifiable. Any "flaw" will simply be rationalized as another element that makes it more "interesting and meaningful".

Since it can not, even in principle, be falsifiable, that means it contains no truth.

 

[George Jones]

Ofcourse you might argue that this is a science forum so u imply that we may discuss something only if it relates to science but that's another subject.

This is a physics forum where people discuss science. Your assertion is non-empirical, objectively useless, and has no place here.

Yes, so, as required by the Physics Forums Rules,

Overly Speculative Posts: One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums or in blogs, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion.

stick to mainstream physic, or this thread will be locked, and warnings or infractions given.

 

[FizixFreak]

why is it that before big bang TIME could not exist?

 

[Chalnoth]

why is it that before big bang TIME could not exist?

Well, that's more a statement about certain very specific models of the big bang, not necessarily a statement about reality.

Basically, in some models, such as in Stephen Hawkings' no boundary proposal, there simply isn't any time before the big bang. Asking "what came before the big bang" is analogous to asking "what lies north of the north pole." This is because in his no boundary proposal, the space-time manifold doesn't actually have any sort of edge, just like there is no end to the surface of the Earth (in the sense of people who thought the Earth was flat thought of an edge). It is, however, finite, wrapping back on itself in a very specific way. Thus what we see of as "time" has a beginning of sorts, but there is nothing "before" it (just as the Earth has a point that is furthest north, but with nothing north of that point).

 

[FizixFreak]

Well, that's more a statement about certain very specific models of the big bang, not necessarily a statement about reality.

Basically, in some models, such as in Stephen Hawkings' no boundary proposal, there simply isn't any time before the big bang. Asking "what came before the big bang" is analogous to asking "what lies north of the north pole." This is because in his no boundary proposal, the space-time manifold doesn't actually have any sort of edge, just like there is no end to the surface of the Earth (in the sense of people who thought the Earth was flat thought of an edge). It is, however, finite, wrapping back on itself in a very specific way. Thus what we see of as "time" has a beginning of sorts, but there is nothing "before" it (just as the Earth has a point that is furthest north, but with nothing north of that point).

so time was ''created'' after the big bang .
cant i say that the big bang actually triggered the creation of the ''things'' that could experience time rather than saying that big bang caused the creation of time (as before it there was nothing or none that could measure or evaluate time)??

 

[Chalnoth]

so time was ''created'' after the big bang .
cant i say that the big bang actually triggered the creation of the ''things'' that could experience time rather than saying that big bang caused the creation of time (as before it there was nothing or none that could measure or evaluate time)??

It depends upon the model. We don't yet know which model is an accurate description of reality.

 

[FizixFreak]

It depends upon the model. We don't yet know which model is an accurate description of reality.

if we say that time was ''created'' after big bang wouldn't that imply that time only has existence when there is some one or some thing that can feel it but relativity gives a different picture of time to us?

 

[Chalnoth]

if we say that time was ''created'' after big bang wouldn't that imply that time only has existence when there is some one or some thing that can feel it but relativity gives a different picture of time to us?

No, not at all. You don't need an observer to experience time. But space and time themselves exist on what is called a manifold. Without a manifold, you have no space, no time.

 

[FizixFreak]

No, not at all. You don't need an observer to experience time. But space and time themselves exist on what is called a manifold. Without a manifold, you have no space, no time.

so before the big bang that manifold existed the bang just expanded it right? (or that is what i understood when i did some research on string theory).

 

[Chalnoth]

so before the big bang that manifold existed the bang just expanded it right? (or that is what i understood when i did some research on string theory).

No. Time is a direction within the manifold. There is no "before" or "after" outside of it.

 

[FizixFreak]

No. Time is a direction within the manifold. There is no "before" or "after" outside of it.

time is a direction?
i didn't quite understood that.

 

[Chalnoth]

time is a direction?
i didn't quite understood that.

Yes. In the same way that up/down, east/west, and north/south are directions.

 

[FizixFreak]

Yes. In the same way that up/down, east/west, and north/south are directions.

but if you call time as direction it means it existed before the big bang?
and does the time represents all known direction or just one specific direction.

 

[Chalnoth]

but if you call time as direction it means it existed before the big bang?
and does the time represents all known direction or just one specific direction.

No, because the direction only has meaning within the manifold. It doesn't have meaning outside of the manifold.

 

[Chronos]

Science tries to avoid the 'God' hypothesis. Not because scientists hate 'God', but, because they wish to explain as much as possible about the universe without resorting to 'miracles' [which history has proven to be a bad idea]. I have no problem accomodating a 'God' in my universe, just understanding the role s/he plays.

 

[Passionflower]

To address a common misunderstanding: time is not an actual dimension on the manifold.

The confusion arises because often a coordinate chart is used where an observer's x₀ (or sometimes denoted as t) is identical to his proper time. For instance a rest frame in Minkowski spacetime using Cartesian coordinates or Fermi normal coordinates in curved spacetimes.

Curved spacetime is a four dimensional manifold but no single dimension is explicitly time.

So what is time? Well for any timelike observer time is the metric distance between two events on his worldline.

In GR worldlines can simply end (at a singularity), by time symmetry (and GR is time symmetric) that implies that worldlines can simply begin as well. Hence according to GR it is possible that for a given observer time can have a begin and an end.

 

[Chalnoth]

To address a common misunderstanding: time is not an actual dimension on the manifold.

The confusion arises because often a coordinate chart is used where an observer's x₀ (or sometimes denoted as t) is identical to his proper time. For instance a rest frame in Minkowski spacetime using Cartesian coordinates or Fermi normal coordinates in curved spacetimes.

Curved spacetime is a four dimensional manifold but no single dimension is explicitly time.

So what is time? Well for any timelike observer time is the metric distance between two events on his worldline.

In GR worldlines can simply end (at a singularity), by time symmetry (and GR is time symmetric) that implies that worldlines can simply begin as well. Hence according to GR it is possible that for a given observer time can have a begin and an end.

Well, obviously there's ambiguity as to which sort of direction on the manifold we can identify with time. There is no definitive direction that is associated with time, and different observers will see time as being different directions on the manifold. But then, this is the same with all other directions as well, so time isn't exactly special in regard to this ambiguity.

 

[FizixFreak]

Well, obviously there's ambiguity as to which sort of direction on the manifold we can identify with time. There is no definitive direction that is associated with time, and different observers will see time as being different directions on the manifold. But then, this is the same with all other directions as well, so time isn't exactly special in regard to this ambiguity.

so may i say that time is a direction but the answer of WHICH DIRECTION changes with observer?
or may be that time exists within the three dimensions of space occupying some part of all three dimensions?

 

[Chalnoth]

so may i say that time is a direction but the answer of WHICH DIRECTION changes with observer?
or may be that time exists within the three dimensions of space occupying some part of all three dimensions?

No, time is definitely separate from the three dimensions of space. Which direction in space-time you see as time depends upon things like your velocity and acceleration.

Mathematically, time is exactly the same as the other dimensions, except that the sign of a metric component associated with time is opposite from the spatial dimensions. For example, if the spatial dimensions have positive metric components, then time has a negative metric component. With this convention, if you find the metric distance between two different times for a particular observer, you get a negative number (a timelike distance...this is the actual time that the observer sees on their clock). If you find the metric distance between two simultaneous events, by contrast, you get a positive number (a spacelike distance: this is the distance you would measure between these events in a reference frame where they occur simultaneously).

Finally, if you find the metric distance between two points in the travel of a light ray (for example, from when a light ray is emitted to when it is absorbed), you always get zero. So light rays themselves act as a boundary between timelike distances and spacelike distances.

 

[Passionflower]

so may i say that time is a direction but the answer of WHICH DIRECTION changes with observer?
or may be that time exists within the three dimensions of space occupying some part of all three dimensions?

If you read what I wrote before:

"So what is time? Well for any timelike observer time is the metric distance between two events on his worldline."

You have the answer as to what time is for an observer. Time is observer dependent in GR.

Mathematically, time is exactly the same as the other dimensions, except that the sign of a metric component associated with time is opposite from the spatial dimensions. For example, if the spatial dimensions have positive metric components, then time has a negative metric component.

Again, time is the metric distance between two events on a worldline.

Now if you use for instance a Fermi normal coordinate chart in curved spacetime or simply a rest frame in Cartesian coordinates in flat space you can use time (which is then proper time) on one axis so it looks like it is a separate dimension. But just by using such a charts does not make it a dimension.

There is a distinction between the manifold and a choordinate chart and it is a mistake to assume that any of the dimensions of the manifold is time.

 

[Chalnoth]

Again, time is the metric distance between two events on a worldline.

Now if you use for instance a Fermi normal coordinate chart in curved spacetime or simply a rest frame in Cartesian coordinates in flat space you can use time (which is then proper time) on one axis so it looks like it is a separate dimension. But just by using such a charts does not make it a dimension.

There is a distinction between the manifold and a choordinate chart and it is a mistake to assume that any of the dimensions of the manifold is time.

I don't see how this distinction is any different from any of the other dimensions. After all, which dimension on a manifold is "forward/backward"?

 

[Passionflower]

I don't see how this distinction is any different from any of the other dimensions.

What do you mean by "any of the other dimensions"? The manifold is 4-dimensional, but no singe dimension is a spatial or temporal. Only a coordinate chart maps (a region of) this manifold, with or without off-diagonal components, onto 4 dimensions of which one is temporal and three are spatial.

 

[finiter]

Dimensions are strictly mathematical. It may or may not represent the physical reality. The real world is just three dimensional. However, to analyze it, we can use one-dimensional or four-dimensional frames.

An expanding system requires a four dimensional frame. As time moves forward, the three space dimensions increase. The spherical surface of the expanding system, or the Gauzian surface described by the three space dimensions, encloses the spacetime. The spacetime can be regarded as the volume at a given time; it is the product of a volume factor and a time factor, ie, it is four dimensional. When the system contracts, the time factor decreases. Mathematically it is time moving back. But in real terms, the direction of time does not change, but the directions of the space dimensions are reversed.

 

[Chalnoth]

What do you mean by "any of the other dimensions"? The manifold is 4-dimensional, but no singe dimension is a spatial or temporal. Only a coordinate chart maps (a region of) this manifold, with or without off-diagonal components, onto 4 dimensions of which one is temporal and three are spatial.

Right. But your point about time being the metric distance between two space-time points for an observer is important, because the choice of dimensions is not completely arbitrary: the motion of an observer picks out a specific set of them. This indicates, for instance, that while no particular direction on the manifold can be identified uniquely as time, one cannot pick any direction as being time: there are some directions on the manifold which no observer can traverse (because it would mean moving faster than the speed of light).

 

[Chalnoth]

Dimensions are strictly mathematical. It may or may not represent the physical reality. The real world is just three dimensional. However, to analyze it, we can use one-dimensional or four-dimensional frames.

While true, the empirical evidence for four dimensional space-time is exceedingly robust.

The spacetime can be regarded as the volume at a given time; it is the product of a volume factor and a time factor, ie, it is four dimensional. When the system contracts, the time factor decreases. Mathematically it is time moving back. But in real terms, the direction of time does not change, but the directions of the space dimensions are reversed.

That would merely indicate that you chose a poor proxy for "increasing time", as increasing time should always be identified with increasing entropy.

 

[AC130Nav]

While true, the empirical evidence for four dimensional space-time is exceedingly robust.

Is it really evidence for FOUR-dimensional space-time? I think quantum mechanics indicates time must have at least two dimensions. After it's absolute nonsense that the observer determines and outcome.

The original evidence for the Big Bang was a uniform background radiation and seeming uniform expansion in all directions. The first was seen as making the formation of galaxies impossible and quickly non-uniformity was found. The second is based on the part of the universe we can observe. Is the world really flat?

 

[Chalnoth]

Is it really evidence for FOUR-dimensional space-time?

Yes.

I think quantum mechanics indicates time must have at least two dimensions.

Huh? No, not at all. All of quantum mechanics is based around a single dimension of time. And when people try to add a second dimension of time, they end up with closed timelike loops, which many people consider to be contradictory.

After it's absolute nonsense that the observer determines and outcome.

Yes, but that doesn't require more than one dimension of time. Everett explained how this works back in the 50's.

The original evidence for the Big Bang was a uniform background radiation and seeming uniform expansion in all directions. The first was seen as making the formation of galaxies impossible and quickly non-uniformity was found. The second is based on the part of the universe we can observe. Is the world really flat?

Er, it wasn't that quickly. The non-uniformity of the CMB wasn't observed until the early 90's (with the COBE satellite), about 40 years after it was first observed. That isn't very fast in my book. But it was pretty obvious that such non-uniformity had to exist, it was just too small to detect until that time.

 

[finiter]

That would merely indicate that you chose a poor proxy for "increasing time", as increasing time should always be identified with increasing entropy.

I agree. In the case of universe that is the accepted opinion. But in the case of a theoretical system, is it not possible that entropy decreases with time? Here, I am tempted to question the concept of entropy itself. Is it not logical to take that the entropy of a contracting star decreases, while the entropy of the universe increases? Both are related and there would be symmetry. Matter contracts while universe expands and vice-versa, and expansion would thus be self limited. Of course, this would go against the existing concepts.

 

[Chalnoth]

I agree. In the case of universe that is the accepted opinion. But in the case of a theoretical system, is it not possible that entropy decreases with time?

The direction in which time increases is defined as the direction where entropy increases, so the answer is no. This is, by the way, the only way in which you have an arrow of time at all: if the entropy is constant (which would mean the system is at equilibrium), then there is no way to distinguish the past from the future, and there is no arrow of time.

Here, I am tempted to question the concept of entropy itself. Is it not logical to take that the entropy of a contracting star decreases, while the entropy of the universe increases? Both are related and there would be symmetry. Matter contracts while universe expands and vice-versa, and expansion would thus be self limited. Of course, this would go against the existing concepts.

Obviously one has to be careful when describing what one means by "entropy increasing". In general the direction of increasing time is the direction of increasing entropy only for a closed system. If it's an open system, we can still make the same identification, but it requires we take into account anything flowing into/out of the system, so the full statement becomes more complicated.

In general we actually have a rather poor understanding of exactly how entropy relates to gravitational systems, so we don't actually know how to write down the entropy of a contracting star. But we can write down the entropy of a diffuse gas, and we can write down the entropy of a black hole. The entropy of the black hole (which can be seen as a far extreme of the contraction of th star) vastly exceeds the entropy of the diffuse gas from which it came. From arguments like this we understand that the universe becoming more clumpy with time is a manifestation of increasing entropy. In fact, it is this fact, the clumpiness increasing with time, and not the expansion, that is the primary increase in entropy since the end of inflation.

If it were to be the case that our universe were to recollapse (which today seems manifestly unlikely), then we would still expect our universe to become more and more clumpy as it did so.

 

[finiter]

In general we actually have a rather poor understanding of exactly how entropy relates to gravitational systems, so we don't actually know how to write down the entropy of a contracting star. But we can write down the entropy of a diffuse gas, and we can write down the entropy of a black hole.

Is it not that the entropy of a black hole thus obtained is more speculative than factual?

 

[Chalnoth]

Is it not that the entropy of a black hole thus obtained is more speculative than factual?

No. Basically, a black hole is a much simpler system than, say, a star, and the entropy can be derived through a variety of independent methods, all arriving at the same result: the entropy of a black hole is proportional to the area of its horizon.

Ultimately, understanding the entropy of most systems where gravity is a significant factor (e.g. stars, galaxies) is likely to require knowledge of quantum gravity. But a black hole is just one of those special cases that is mathematically simple enough that we can be quite sure about its entropy already.

 

[finiter]

But a black hole is just one of those special cases that is mathematically simple enough that we can be quite sure about its entropy already.

Then, what about the black holes themselves? Are these not just a theortical stuff, that too more mathematical than physical?

One should be sceptical about mathematical models. Mathematics is a tool, in fact, an excellent tool, for analyzing. But of late, it has changed its role, it appears, and has become a shaping tool.

Coming back to black holes, does the scientific community accommodate the Doubting Toms even now, or do the Doubting Toms outnumber the others?

 

[Chalnoth]

Then, what about the black holes themselves? Are these not just a theortical stuff, that too more mathematical than physical?

There are different degrees of skepticism where black holes are concerned. Most today are largely convinced that they are the objects at the centers of galaxies, and also make up one member of certain binary systems. We have some observational tests in the works using extremely large baseline interferometry to actually observe the shape of the event horizon, so in any case we'll be quite sure whether or not these objects are black holes in a few years' time.

Coming back to black holes, does the scientific community accommodate the Doubting Toms even now, or do the Doubting Toms outnumber the others?

The scientific community doesn't kick anybody out. It's just that nobody listens to "Doubting Toms" that don't bring evidence to the table, or worse refuse to pay attention to the evidence we already have. This is the way it works in science: slowly more and more people become convinced of an idea as more and more evidence mounts in support of it. There typically remain some holdouts who continue to seek alternative explanations, and often even if we don't agree with them, the rest of the scientific community recognizes that they provide essential value to the scientific enterprise as a whole because there is always the possibility that we are wrong.

But at the moment my impression of people who do research in the area of black holes has been that the number of people who seriously doubt that black holes are real (or at least are not a very good approximation to reality) is vanishingly small.

 

[AC130Nav]

But at the moment my impression of people who do research in the area of black holes has been that the number of people who seriously doubt that black holes are real (or at least are not a very good approximation to reality) is vanishingly small.

I would expect most who spend time and money looking for black holes to believe in them. But how many have the earlier Hawking belief they are forever (might even be little universes), or adopt the Hawking revision which allows them to dissipate? Hopefully, there are yet other positions.

Obviously, something happens when too much mass gets in one place, ergo some kind of black hole. But math belongs in the experiment phase of the scientific method, not in theory.

 

[Chalnoth]

I would expect most who spend time and money looking for black holes to believe in them.

Well, no, this is a false characterization, because we're talking about people who are studying the most compact objects. Whether or not they are black holes is a crucial question that must be answered when studying these objects.

But how many have the earlier Hawking belief they are forever (might even be little universes), or adopt the Hawking revision which allows them to dissipate?

There is no question that black holes evaporate. If they don't evaporate, they're not black holes. It's intimately connected with the entropy calculation I mentioned above.

Hopefully, there are yet other positions.

There have not yet been any compelling alternatives to black holes presented.

Obviously, something happens when too much mass gets in one place, ergo some kind of black hole. But math belongs in the experiment phase of the scientific method, not in theory.

I hope you realize that this has been tested? That people haven't merely taken this on faith?