Questions about Big Bang Theory

[JGregory32]

Let me preface this with a a few comments:
First I am not a scientist by training, I am a historian. That said I have observed various arguments about Steady State vs Big Bang theory for a while now. While I do disagree with the ideas of steady state (a static universe is just stupid) I have noted holes, BIG holes in the Big Bang theory.
That being said I would like some help interpeting an article:
http://whatreallyhappened.com/WRHARTICL ... =bang.html
Once you get past the OMG The BIG BANG is religion disguised as science BS he does seem to make a few points.

Perhaps the biggest contradiction with the Big Bang Theory is the question of the singularity. The "primordial egg" had to be a super-massive black hole. Therefore no amount of "bang", no matter how big, is going to thrust the universe out into, well, the universe.

Cosmologists eager to promote the Big Bang Theory have hit upon the "explanation" that the laws of physics, gravity., etc. simply did not apply in those first few moments of the universe. The present Cosmology theory is that the universe enjoyed a period of "rulelessness" of about 3 seconds, after which the elements formed and the fundamental forces of the universe, gravity included, were functioning as we see them today.

Ah, but there is a problem. The singularity formed by the primordial egg turns out to be rather large.

Estimates of the total mass of the universe vary wildly, given that the ends of the universe have not yet been determined. One estimate is found at http://www.rostra.dk/louis/quant_11.html of 2.6*1060.

From the mass, you can calculate the diameter of the event horizon by finding the distance from a point mass that will have an escape velocity of c. Use sqrt(2GM/r) where M is the mass of the hole (the entire universe in this case) and r is the radius (classical), and G is the gravitational constant. Work it backward starting at c and you get c^2=2GM/r.

This works out to an event horizon light years across!

In short, at the moment in time when the Big Bang theorists claim the universe was functioning as it does today, complete with all fundamental forces, the entirety of the universe's mass was still well within the event horizon of its own gravity well. That the well was not the product of a true singularity is irrelevant, Newton's equation provides an equivalent gravity field for a singularity or a super dense mass in a localized region.

Therefore the Big Bang, as currently described, could not have produced the universe as we see it today. At three seconds, the time the theorists claim the universe started operating as we know it, it would have come under the influence of its own gravity and unable to reach an escape velocity exceeding that of light, collapsed back into itself.

This seems to be a legitate critism of big bang theory. Does anybody know any rebuttal to this point?
There is also this comment from his main page:

That light which is reaching us now from a galaxy 13.7 billion light years away started traveling towards us 13.7 billion years ago. So, what we see today is not where that galaxy is right now, but where it WAS ... 13.7 billion light years away ... just moments after the supposed Big Bang.

Anybody have proof of the 13.7 billion figure?
Any help with understanding the argument would be appreciated.

[Count Dooku]

Let me preface this by saying that I'm an upper division chemistry student, not a physics major.

Perhaps the biggest contradiction with the Big Bang Theory is the question of the singularity. The "primordial egg" had to be a super-massive black hole.

Why does it HAVE to be a super massive black hole? The person writing the 'article' doesn't give a reason. Has every other possibility been exhausted?

Therefore no amount of "bang", no matter how big, is going to thrust the universe out into, well, the universe.

There was no bang - it was merely a rapid expansion of space-time.

Cosmologists eager to promote the Big Bang Theory have hit upon the "explanation" that the laws of physics, gravity., etc. simply did not apply in those first few moments of the universe. The present Cosmology theory is that the universe enjoyed a period of "rulelessness" of about 3 seconds, after which the elements formed and the fundamental forces of the universe, gravity included, were functioning as we see them today.

The idea of a super force is under investigation, and since James Maxwell's unified two different things in physics (light and magnetism), it's possible that the four fundamental forces we know about could have been on super force. Gravity is really weak compared to the other three, and a super force that broke apart in the early universe might explain that.

Ah, but there is a problem. The singularity formed by the primordial egg turns out to be rather large.

Every actual physicist I've heard make a comment on the size of a supposed singularity says it's extraordinary small. . .

Estimates of the total mass of the universe vary wildly, given that the ends of the universe have not yet been determined. One estimate is found at http://www.rostra.dk/louis/quant_11.html of 2.6*1060.

Seems the author doesn't understand the nature of matter and energy. Matter IS energy. Rest mass attests to this. A shift in potential energy, no mass at all, could have been the only thing in existence at the instant of the big bang.

From the mass, you can calculate the diameter of the event horizon by finding the distance from a point mass that will have an escape velocity of c. Use sqrt(2GM/r) where M is the mass of the hole (the entire universe in this case) and r is the radius (classical), and G is the gravitational constant. Work it backward starting at c and you get c^2=2GM/r.

This works out to an event horizon light years across!

If the author had taken AP physics in high school, he'd have known why that's such a moronic statement.

In short, at the moment in time when the Big Bang theorists claim the universe was functioning as it does today, complete with all fundamental forces, the entirety of the universe's mass was still well within the event horizon of its own gravity well. That the well was not the product of a true singularity is irrelevant, Newton's equation provides an equivalent gravity field for a singularity or a super dense mass in a localized region.

Useless dribble.

Therefore the Big Bang, as currently described, could not have produced the universe as we see it today. At three seconds, the time the theorists claim the universe started operating as we know it, it would have come under the influence of its own gravity and unable to reach an escape velocity exceeding that of light, collapsed back into itself.

*facepalm*

[Covenant]

One of the first things you should do is go look up inflation and try to wrap your head around it. The big bang blob wasn't a mass of matter in the void that exploded, it was simply all there was with all the space wrapped around it, and when space got bigger, the density of the object decreased, and so forth, and so on. It didn't blow up. Space is just getting bigger.

[JGregory32]

Space got bigger? Through what mechanism? If the big bang blob was all the matter there was with all of space around it then doesn't this blob also contain all the energy as well? Would it not then require an injection of energy from outside to start this process of expansion?
I'm no scientist but even I understand that the universe is a closed loop energy system

[Count Dooku]

Space got bigger? Through what mechanism? If the big bang blob was all the matter there was with all of space around it then doesn't this blob also contain all the energy as well? Would it not then require an injection of energy from outside to start this process of expansion?
I'm no scientist but even I understand that the universe is a closed loop energy system

A shift in energy. Right now, it's apparent that the net energy of the universe is zero, if I recall. A shift could have caused the rapid expansion of space-time. The exact mechanism is still being debated, and the real mechanism may not be known. That does not mean that the observations astrophysicists have made are somehow wrong.

[JGregory32]

That does not mean that the observations astrophysicists have made are somehow wrong.

I have never said the observations were wrong. I think science has produced extremly good observations for quite a long time.
I do however quibble about the interpertation of those observations vis a vie big bang theory.
Please correct me if I'm wrong but does big bang theory not require the existance of so called "dark matter", followed by "dark energy" and now "dark flows".
http://www.space.com/scienceastronomy/0 ... flows.html
I do understand the essential point of theories, that they produce a testable hypothesis. No test I have heard of has produced any illumination on "Dark Matter" and if anybody knows of one please inform me. The lack of results from these tests should point to the possibilty that the theory is incorrect and needs to be revised. However we still hear about 'dark matter' and how it is an integral part of big bang theory.

Now if I interperete the findings on "Dark Flows" correctly it indicates the presence of matter outside of the universe, matter that was not a part of the initial expansion indicated by bigbang theory. Does this mean that multiple bigbangs have happened or does it mean that rather than the bigbang being the begining point of creation that it is a rather regular occurence in differering portions of the universe?

[Morilore]

Let me preface this with a a few comments:
First I am not a scientist by training, I am a historian. That said I have observed various arguments about Steady State vs Big Bang theory for a while now. While I do disagree with the ideas of steady state (a static universe is just stupid) I have noted holes, BIG holes in the Big Bang theory.

huh what
The Big Bang is a visual observation, dude. If you look at distant galaxies, they are all red-shifted, and the further away they are the more red-shifted they are. This is clear visual evidence that the galaxies in this universe are hurtling away from each other at high speed (see Doppler effect). An elementary logical step follows: if all matter in the universe is currently flying apart, then in the distant past all matter in the universe must have occupied a smaller space then it does know. Everything past that, all the "singularity physics" stuff, is the realm of theoretical physicists and I don't think anyone who has thus far posted in this thread is qualified to intelligently criticize current theory.

[Wicked Pilot]

The Big Bang is an observed phenomon. When you look out into the universe you are literally seeing an explosion in action. Whatever difficult mysteries we run into in our attempts to find and understand the circumstances behind how and when the explosion began is part of the nature of scientific discovery. With every answer you obtain you find ten new questions so you just have to keep going. And with every step out understanding increases.



Someone familiar with the history of the Big Bang vs Steady State debate should point out to the quoted author that back before good evidence declared a winner it was the theist scientist who where backing Big Bang due to a perceived point of creation, while it was the atheist scientist backing Steady State for the opposite reason. You could almost argue that the creationist got one right.

[Feil]

A general note: if a layman with no skills in the field under evaluation has found what he thinks are big problems with a well accepted theory, there is something wrong with the layman's understanding. You're being as foolish as people who think the theory of evolution by natural selection is false because they don't see monkeys giving birth to human babies.

If you want to learn, don't go looking for controversies. Find what the experts are saying, and educate yourself.

[JGregory32]

If you want to learn, don't go looking for controversies. Find what the experts are saying, and educate yourself.

Problem is those experts are either spouting information WAY above my knowledge level or claiming to be an expert who is rebutting other experts.
Need I remind anyone of the many experts who claim that human CO2 emissions are the engine for climate change?

[Kanastrous]

There are texts for laypeople that set out descriptions of the theories involved, without recourse to very much terrifying math.

Superforce by Paul Davies and The God Particle by Leon Lederman are super-basic but decent reads.

I'm sure that an actual physicist - or even physics undergrad - would snicker at both of those books, but if there are better ones available for laypeople, I'll read 'em.

[Kuroneko]

Cosmologists eager to promote the Big Bang Theory have hit upon the "explanation" that the laws of physics, gravity., etc. simply did not apply in those first few moments of the universe.

I'm not sure what the implicature of putting "explanation" in quotes is supposed to be, but most physicists do not expect GTR to be applicable in those regimes because it is incompatible with quantum mechanics, so if they're right in that regard, plainly the known laws of physics, especially gravity, do not apply very near the singularity. On the other hand, if they're wrong about expecting GTR to break down, then the picture painted by GTR--that all the classical conservation laws apply at all times and yet the universe existed for a finite length of time in the past--would be literal. I don't think that either fork of this dilemma is very palatable to those who have religious reasons to deny the Big Bang theory.

Ah, but there is a problem. The singularity formed by the primordial egg turns out to be rather large.

One would think if this meant what the poster thought it meant, it would've been noticed by now.

Estimates of the total mass of the universe vary wildly, given that the ends of the universe have not yet been determined. One estimate is found at http://www.rostra.dk/louis/quant_11.html of 2.6*1060.

It's probably not appropriate to base one's criticisms of the scientific mainstream on a pet fringe theory that's frankly borderline crank. The total mass of the visible universe is about a millionth of that, although his conclusion would still not follow even if it was that high. [1]

From the mass, you can calculate the diameter of the event horizon by finding the distance from a point mass that will have an escape velocity of c. Use sqrt(2GM/r) where M is the mass of the hole (the entire universe in this case) and r is the radius (classical), and G is the gravitational constant. Work it backward starting at c and you get c^2=2GM/r. This works out to an event horizon light years across!

The relevance of a parameter applicable only to the Schwarzschild spacetime to a (flat) universe with a metric that looks nothing like Schwarzschild's is dubious at best.

That the well was not the product of a true singularity is irrelevant, Newton's equation provides an equivalent gravity field for a singularity or a super dense mass in a localized region.

Twentieth century gravitation: Einstein field equations → Friedmann-Robertson Walker solutions → Friedmann equations.

The FRW family of spacetimes are mathematically derivable from general theory of relativity, forming a very general class of "Big Bang" scenarios and some other cases. In turn, the Friedmann equations describe the actual expansion of FRW family in terms of some observable parameters. If there is any error up to here, it's purely a mathematical one. The physics is in whether (1) GTR is the appropriate theory of gravitation (which it is, excepting the regime very close to the singularity), and (2) whether observations are compatible with the GTR in general or FRW in particular. There is nothing in the argument that challenges any of this.

That light which is reaching us now from a galaxy 13.7 billion light years away started traveling towards us 13.7 billion years ago. So, what we see today is not where that galaxy is right now, but where it WAS ... 13.7 billion light years away ... just moments after the supposed Big Bang.

We don't actually see galaxies that old, but close enough. What's missing is that the universe has expanded since the light was emitted. This means both that (1) light emitted 13.7Ga ago is showing us matter that's currently about 45Gly away, and that (2) when first emitted, the matter was much closer, probably on the order of an million light-years or so.

Anybody have proof of the 13.7 billion figure?

WMAP gave 13.72±0.12Ga as the age of the universe. See the reference in the footnote below.

---
[1] The standard ΛCMD model has the total density of the universe, including dark energy, Ω ≅ 1. Hence, ρ = 3ΩH²/(8πG) = 9.3e-27 kg/m³, using H₀ = 70.5 km/(sMpc) from WMAP [pdf]. From the same source, the densities are: baryonic Ωb = 0.0456, cold matter Ωc = 0.2280, and dark energy ΩΛ = 0.726, with the universe close to flat of observable diameter 2R = 14Gpc. This gives ρ = 2.6e-27kg/m³ without dark matter. Hence: M = 8.6e53kg without dark energy, M = 3.2e54kg with dark energy

[Ariphaos]

The easy answer is 'yes, there should have been a black hole.'

It's important to realize that the Big Bang functions as a time-reversed black hole of apparently infinite size. For example, just as a black hole's singularity is the inescapable future of anything trapped within it, so is the singularity of the Big Bang the ultimate past of anything within the Universe that can never be returned to.

That is to say, there was no black hole because the very nature of the Big Bang was the exact antithesis of a black hole - it may not, exactly, be a white hole (and probably isn't), but the mechanism is similar.

How can that be? Well, that's what we're honestly trying to figure out. I doubt we'll have a very clear picture until we can build a particle accelerator near Mercury's orbit to actually probe inflaton ranges.

[Ariphaos]

Okay, well I started my post without seeing Kuroneko's, so obviously the issue is a lot more well understood than I thought and implied in my post.

[Kuroneko]

There is actually an event horizon around us--the problem for the argument, however, is that the presence of the event horizon does not imply that the universe acts like a black hole except as an analogy. Xeriar is right in that one can think of Big Bang expansion as qualitatively similar to a time-reversed black hole, although there are differences, one of which is that the Big Bang singularity occurs everywhere. A time-reverse of stellar collapse to a black hole would be a singularity spewing forth a star into pre-existing space, which is something Big Bang expansion lacks.

[Johonebesus]

...Need I remind anyone of the many experts who claim that human CO2 emissions are the engine for climate change?

Forgive me for getting a bit off topic, but what's your point? Yes, there is a scientific consensus that human activity is effecting climate change. Are you disputing this? If so, then I think you need to do enough research to find out what exactly the scientific consensus is on various issues, and just accept that consensus. You're never going to have the expertise to instantly see the flaws in every piece of pseudoscience. What you should do is just accept that the scientific process works, and the scientific establishment is not going to fail due to conspiracy or blindness. There may be some new discoveries that overturn traditional theories, but they aren't going to come from internet rants or creationists or energy-industry\conservative "think-tanks". Think of scientists as physicians, and science as medicine. You accept that your doctor doesn't know everything, and that there are always going to be new discoveries and new treatments, but you trust that medical science is the best option out there. Suppose you read that Western Medicine is wrong about Germ Theory and that illness is actually caused by toxins, and so you should never wash your hands or worry about hygiene. You would reject it out of hand (I hope), not because you necessarily understand all the intricacies of how bacteria, viruses, and fungi can cause illness, but because you trust medical science more than stuff you get off the internet, and physicians more than laymen. Just take the same stance on all science vs. pseudoscience\creationism debates.

[Broomstick]

A general note: if a layman with no skills in the field under evaluation has found what he thinks are big problems with a well accepted theory, there is something wrong with the layman's understanding. You're being as foolish as people who think the theory of evolution by natural selection is false because they don't see monkeys giving birth to human babies.

No, he is not being foolish - foolish would be believing everything he hears without question. He IS asking questions in order to further his understanding and that is not foolish at all. We must all start off ignorant and build from there and we are all at different stages of the process.

[Ariphaos]

Please correct me if I'm wrong but does big bang theory not require the existance of so called "dark matter", followed by "dark energy" and now "dark flows".

The Big Bang theory is separate from the Dark Matter theory. To prove the Big Bang, all that needs to be shown is that, as a general rule, nearly every galaxy in the Universe is receding from nearly every other galaxy - this was done decades ago.

More specifically, the expanding Universe is an observed fact. It's currently expanding at a rate of ~70.5 kilometers per second per megaparsec. This means that something ~13.7 billion light-years away is now receding from us at the speed of light.

And thus, 13.7 billion years ago, that something shared the same location that our primordial quark soup did.

Dark matter is an explanation for the unobserved mass in galactic rotation curves. The type of dark matter required has not been observed directly, but it has been indirectly detected via gravitational lensing observations.

What Dark Matter may have to do with the Big Bang is irrelevant to your current argument. Dark Energy is a bit more important, if it is the cosmological constant anyway.

http://www.space.com/scienceastronomy/0 ... flows.html

This is pretty nifty looking, if only for the possible promise that we may actually be able to analyze the structure of the Universe on a previously unheard-of scale. This appears to have to do with inflation and basically a significant part of the Universe that was attracted to something else before it got pulled out of our light-cone during inflation, or at least that's how I read it.

Then again, more precise measurements will be desirable, and more people looking at it.

I do understand the essential point of theories, that they produce a testable hypothesis. No test I have heard of has produced any illumination on "Dark Matter" and if anybody knows of one please inform me. The lack of results from these tests should point to the possibilty that the theory is incorrect and needs to be revised. However we still hear about 'dark matter' and how it is an integral part of big bang theory.

Dark Matter factors into the overall equations of the Universe on a large scale - galaxies and above. It has been shown to be very likely to exist via lensing, though there are other attempts to search for it.

Now if I interperete the findings on "Dark Flows" correctly it indicates the presence of matter outside of the universe, matter that was not a part of the initial expansion indicated by bigbang theory. Does this mean that multiple bigbangs have happened or does it mean that rather than the bigbang being the begining point of creation that it is a rather regular occurence in differering portions of the universe?

Neither.

If true, this means either inflation was not as homogenizing as we originally thought (not exactly a big deal, I would imagine it would remove a fair bit of fine tuning from the equation), or we are in an odd region of the overall 'multiverse' - that is, the Universe beyond our Hubble sphere.

[JGregory32]

Thanks Kanastrous turns out the library at SFU has Superforce so I can give that a good read.
I just want to thank everone for their help in explaining what seems to be a very complicated theory.
BTW Broomstick? Great post.

[Oskuro]

As has been explained already, there's much confusion about what does the expansion of space mean, since people often imagine it working like a regular explosion.

A very simple example I recall from a High-School book, has us picture a muffin with chocolate chips. As the muffin expands when cooked, the chips move appart, but the muffin is the very same.

The universe is pretty much the same, with space-time being the muffin, and matter being the chocolate chips inside. Now the question is why is it expanding, and what'll happen if we stay too long in the oven.

[Ryan Thunder]

[...] How can that be? Well, that's what we're honestly trying to figure out. I doubt we'll have a very clear picture until we can build a particle accelerator near Mercury's orbit to actually probe inflaton ranges.

Forgive my supreme ignorance, but why Mercury?

[Covenant]

He means the size of mercury's orbit, not physically near the path of mercury. It takes increasingly large particle accelerators to achieve the kinds of event power to peer back into the kind of fine mish-mash of energy at those times.

[Ender]

He means the size of mercury's orbit, not physically near the path of mercury. It takes increasingly large particle accelerators to achieve the kinds of event power to peer back into the kind of fine mish-mash of energy at those times.

It also takes more and more power, so putting it closer to mercury would be helpful in that regard as well.

[NoXion]

Xeriar is right in that one can think of Big Bang expansion as qualitatively similar to a time-reversed black hole, although there are differences, one of which is that the Big Bang singularity occurs everywhere.

I don't quite understand this. How can a point object like a singularity be everywhere? Did it stop being a singularity the moment space became greater than zero size, or was it "smeared-out" in some fashion by quantum effects? Or something else?

[starslayer]

This seems to be a legitate critism of big bang theory. Does anybody know any rebuttal to this point?

I have one: he's full of shit.

Perhaps the biggest contradiction with the Big Bang Theory is the question of the singularity. The "primordial egg" had to be a super-massive black hole. Therefore no amount of "bang", no matter how big, is going to thrust the universe out into, well, the universe.

No, it didn't. We actually have no idea what the hell it was, besides a singularity. However, it most certainly was not a black hole, and would not have behaved like a black hole. He doesn't get what TBB theory and it's partner, inflation, actually deal with; they don't give a fuck about the singularity, they only describe what happened afterwards.

Cosmologists eager to promote the Big Bang Theory have hit upon the "explanation" that the laws of physics, gravity., etc. simply did not apply in those first few moments of the universe. The present Cosmology theory is that the universe enjoyed a period of "rulelessness" of about 3 seconds, after which the elements formed and the fundamental forces of the universe, gravity included, were functioning as we see them today.

For all we know, they didn't. Kuroneko covered this, but I'll just add a digression: Physics has for the most part been coming up with low-energy approximations and then, as the energy gets higher, or the velocity gets closer to c, or whatever, we see new things that can't happen with the old, low-energy theory. Thus, we get SR and GR, QM, etc. Simply put, we don't know what happened; we have only speculation. However, we have informed speculation, using extrapolation from know natural principles. From this, and our particle accelerator experiments, we get the picture we do have.

Ah, but there is a problem. The singularity formed by the primordial egg turns out to be rather large.

Estimates of the total mass of the universe vary wildly, given that the ends of the universe have not yet been determined. One estimate is found at http://www.rostra.dk/louis/quant_11.html of 2.6*1060.

This makes no sense whatsoever. A singularity, by definition, is a single, infinitely dense point. Beyond that, we really don't have any idea of singularity dynamics or statics, as everything goes to infinity, and the theory breaks down.

From the mass, you can calculate the diameter of the event horizon by finding the distance from a point mass that will have an escape velocity of c. Use sqrt(2GM/r) where M is the mass of the hole (the entire universe in this case) and r is the radius (classical), and G is the gravitational constant. Work it backward starting at c and you get c^2=2GM/r.

This works out to an event horizon light years across!

One, it's not a black hole in a “normal” metric, so this argument is invalid. Two, the universe wasn't even this big for several hours to days after the beginning, IIRC. So what if a black hole of this mass would be light-years across? You can't be somewhere where space literally does not exist!

In short, at the moment in time when the Big Bang theorists claim the universe was functioning as it does today, complete with all fundamental forces, the entirety of the universe's mass was still well within the event horizon of its own gravity well. That the well was not the product of a true singularity is irrelevant, Newton's equation provides an equivalent gravity field for a singularity or a super dense mass in a localized region.

Yeah? Space itself was (and is) expanding at an incredible rate. Inflation theory holds that the universe went from being smaller than an atomic nucleus to the size of a soccer ball in less than one second! Of course, once hot BBT takes over, this rate slows considerably, but it is still very large. Oh, and at this stage in the game, it was really only photons, which don't have mass. Oops. And another thing: quantum effects absolutely dominated at that stage in the game; gravity didn't have a chance.

Therefore the Big Bang, as currently described, could not have produced the universe as we see it today. At three seconds, the time the theorists claim the universe started operating as we know it, it would have come under the influence of its own gravity and unable to reach an escape velocity exceeding that of light, collapsed back into itself.

No, sorry, you're completely wrong. You do not have a valid criticism of the BBT or inflation.

Anybody have proof of the 13.7 billion figure?

Kuroneko covered this.

Space got bigger? Through what mechanism?

Unknown. The leading candidate is dark energy, the characteristics of which are still being debated.

If the big bang blob was all the matter there was with all of space around it then doesn't this blob also contain all the energy as well? Would it not then require an injection of energy from outside to start this process of expansion?

Not as we understand it. No “injection of energy” occurred, to our knowledge; but for whatever reason, the dark energy term has begun to dominate, resulting in the accelerating rate of expansion we see today.

Please correct me if I'm wrong but does big bang theory not require the existance of so called "dark matter", followed by "dark energy" and now "dark flows".
http://www.space.com/scienceastronomy/0 ... flows.html
I do understand the essential point of theories, that they produce a testable hypothesis. No test I have heard of has produced any illumination on "Dark Matter" and if anybody knows of one please inform me. The lack of results from these tests should point to the possibilty that the theory is incorrect and needs to be revised. However we still hear about 'dark matter' and how it is an integral part of big bang theory.

The BBT requires no such thing. Dark matter came about due to observations of how fast stars revolved around galaxy centers; the stars at the outskirts were going far too fast for the observable mass present; hidden mass that is not electromagnetically coupled explained the observations perfectly. Thus the name, “dark matter.” As has been pointed out, the BBT is a direct result of observation.