Question about the Big Bang Theory?

Question

Now, I understand that scientists think the universe was once a singularity that began to expand rapidly. Black holes are also another object with a large amounts of mass within a very small space. Is the singularity during the initial moments of the Big Bang like a singularity of a black hole? And if so, what prevented this super black hole from sucking back the matter we know rapidly expanded?

I'm not trying to disprove the big bang. I want to know why it initial singularity is different than that of a black hole. I am sure I'm missing some essential information! :D

Answer 1

While Mark S's answer is quite good, it really seems to be the expansion of space, not an explosion, that makes it all happen, and not just collapse on itself.

An interview with Brian Greene, currently up on Radiolab will give you some of the current cutting edge ideas on expansion.

Also, check out Alex Filippenko's talk on the second link.  Really, all of these talks are great.

While the current known laws of physics do break down in the first fraction of a second of the Big Bang (which should be called the Extreme Expand), it doesn't mean that weird things happened, just that we don't know exactly what happened.  These same laws break down in the center of a black hole.  That doesn't mean they don't exist, we just don't know what's happening in any detail.  All this stems from our best theory of gravity - General Relativity, and our best theory of everything else - Quantum Mechanics.  GR doesn't deal with hyper dense things, and Quantum Mechanics doesn't deal with big things.  So if you have a massive small thing, you're stuck.

Finally, check out this Scientific American article.

Answer 2

Until it fulls, then it'll stop, preventing black hole, or worm hole is like remove a vacuum in your house...thought about it... all kinds of dusk will burry you.

Answer 3

Ok. Well, as my understanding goes, the laws of physics do not actually apply to the universal "pre" bang universe. Physicists are pretty clear that they can see from the universe around us what happened and can explain the last 15-17 billion years except for the first 10E-23seconds - a fraction of a second.

From that point forward some billions of years later, everything makes sense.

That said, the force of the explosion and the nature of the space means that the universe was expanding between each individual point, rather like an expanding balloon with dots on it, each dot becomes farther separated from each other dot. In the same way, there was no collapse into a black hole, because of this evenly spread out universe, so gravity - as such - couldn't really have the effect it did upon our universe.

Today, black holes suck up all matter within the area of space they travel in, as it happens, most galaxies have - at their core, a super-massive black hole, which does in fact eat everything around it.

But being REALLY massive means odd things happen, the larger the black hole, the more "gentle" it is, in so far as if you were to travel towards the center of the Milky Way's event-horizon, you wouldn't notice much of anything at all. By contrast, a smaller black hole formed from a collapsing super-nova is both extraordinarily dangerous and unpleasant, since vast amounts of radiation would be near the event-horizon - depending upon how much stuff the small black hole had recently captured. Furthermore, due to the severe changes in gravity, everything would be getting ripped apart at the molecular level.

Dr. Tyson over at the American Museum of Natural History calls this spagettification, and it is generally regarded as being unpleasant.

Answer 4

One of the hardest things to comprehend and reconcile in cosmology is the 'free lunch' factor - how it comes to pass that the universe can get something for nothing; how it can go from not existing, to existing; how matter or energy can come into being from it's former non-existing state. To be fair though, cosmology is not the only worldview suffering from this dilemma. Any account of supernatural creation, also leaves the existence of it's creator unexplained. Even then, it has resorted to the assumption that supernatural powers exist and natural laws are subject to inexplicable violations.

For any sensible secular attempt to explain the origins of the cosmos, we must proceed from what is known and seek to explain what is unknown without ceding to assumptions or contradictions. A good starting point is to observe that the universe does indeed exist. If it didn't we wouldn't be here contemplating it. It then follows that something had to begin existing or else we must assume that something existed for an eternity into the past. [The assumption that there can be no physical reality extending into the indefinite past may be a human bias based in our innately illogical wiring.]

The eternity idea, when applied to cosmological science, seems to be irreconcilable with direct evidence. The universe does appear to have a finite beginning in the past. This so called 'Big Bang' is much more subtle than our intuitive imaginations tend to picture it. It is not simply matter exploding into a preexisting void.

The big bang was actually predicted by Einstein's theory of relativity, in which time and space are aspects of the same thing 'spacetime'. The implications of this are less intuitive than most people realize. To have an appreciation of cause and effect, so that we can say "this was caused by that" we also rely on a concept of linear time, because each effect must be preceded by a previous cause. The perfectly sensible question of "but what caused that?", ultimately leading to the current question regarding the cause of all the matter in the universe, relies on the assumption that time existed before that matter. OK, it did, but the matter is only a manifestation of energy (again according with relativity), but that just pushes the question back to "where did the energy come from?" What is needed is a primal cause of all causes. Unless time itself breaks down and the concepts of 'before' and 'after' become meaningless.

When cosmologists say that the universe is expanding, they do not mean that the galaxies are rushing into a preexisting void. What they mean is that spacetime itself is expanding and increasing the relative distance between galaxies like raisins in an expanding raisin loaf. The implications of relativity for the big bang, is that time and space are properties of the universe that themselves began with the big bang. In conceptual thought and natural language this is hard to intuitively describe and comprehend, but in the language of mathematics, it seems the natural and inevitable consequence of the known evidence.

If the universe is expanding this way, then by running the clock backwards and inquiring into past epochs, we must conclude that the universe becomes smaller and smaller as we look further and further into the past. This is not hard to do in cosmology incidentally, because light travels at a finite speed and what we see from distant objects is delayed by the traveling time for light (approx. 300,000 km/sec).

The further away the object, the more ancient the light is that we are presently receiving from it. We are actually looking back through time as we look out through space.

Traversing the eons back through 13.7 billion years we come to a point where time and space cease to exist. Running the clock forward again we pass through a moment at the beginning of time where the universe is no bigger than an atom. At this point in history or prior, time and space become indistinct and it gets worse. Below the Plank constants, the entire universe is subject to quantum fluctuation. Quantum mechanics is another area that is full of counter intuitive but mathematically beautiful ideas.

So where did matter come from? It came from a free exchange with energy for particles. But as for the ultimate cause of all causes, we must assume that something was permitted to begin existing without cause, otherwise nothing could begin existing in the first place and at the first time. In this view, causality itself, was also born in the big bang. Without spacetime it is meaningless to speak about prior causes, because without spacetime, no linear progression of time from the past into the future is possible. It may be desirable to explain where this matter manifesting energy came from, but the question assumes that it is sensible and meaningful to ask a question about causality, in a situation where no prior causes are possible.

A relatavistic metaphor for this, honoring spacetime, is that below a certain size, the universe has no space for a past. Its entire volume was consumed at first by that primordial present moment. The only reason it found room for a future, is by expanding rapidly and dragging the present moment away from the past. The energy required to fund this expansion and the subsequent formation of matter is not justified by causality. because it existed at the birth of the universe, before which there was no time or causal relationships. On the other hand, the "free energy" can not be prohibited by causality either, as, by the same token, there were no causal relationships to prevent the "free energy" either.

Intuitively, we expect to find a cause for everything, but if we think about it carefully we must realize that this can not apply to absolutely everything. Something must initially exist without cause. There is no logical contradiction, or violation of natural law, if there is no natural law which prevents the spontaneous appearance of something. In our day to day lives at the human scale of existence, it would seem ludicrous for a chair to spontaneously pop into existence before our eyes. A chair is certainly the kind of object that must be made of other materials, by way of cause and effect relationships orchestrated by human minds. But what about a rock? again rocks are formed by geological processes, that have natural cause and effect relationships which in turn obey the laws of nature. We must then ask, how the rock manifested itself, bypassing the known laws of physics which create rocks.

Energy is much more nebulous and plastic. It is easily transformed from one state into another. We may use light to create electricity for instance, or heat to produce kinetic energy etc etc.. But ultimately we know that no energy is destroyed or created. it is just transformed from one form to another. This is called the principle of energy conservation. We know there are natural laws which make this principal inviolate. It is no coincidence of nature that energy can neither be destroyed or created. But those laws depend for their meaning an inviolability on cause and effect relationships within spacetime. No law was broken in the big bang, because no extra energy suddenly appeared in the universe, the energy appeared with the universe.

We might like to know why the universe began at all. According to the modern understandings, it was neither compulsory or impossible, but how probable was it? This is also a moot point, because there may be multitudes of such universes. Given that spacetime is born into the universe, these universes would exist outside of our space and time coordinate system, so there would also be no meaning to whether they exist before, after, or simultaneously with ours. Remember this when you are tempted to think that our own existence is unfathomably improbable. However improbable anything in our universe may seem, given a potentially infinite number of possible universes some of them (perhaps scores of them), may quite easily have the quirky improbable characteristics we find in our own Universe.

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As alluded to above, there was no matter as we know it in the time leading up to the big bang, but there was a concentration of energy that began to expand at some point. After thinning and cooling, particles began to condense. The rest is history.

It is interesting that people usually have no problem accepting the possibility of time unfolding into an endless future, but have a huge difficulty going in the other direction. The problem may be that the idea of things existing into an endless past is beyond our intelligence, wit and imagination. This difficulty might arise because 'anthropomorphizing' cosmology is simply irresistable to us. We have a beginning, and many of us are sure that we will enjoy existence for endless future ages [alternately, we have difficulty accepting that our existence could somehow completely end], and so logic notwithstanding we conclude that the cosmos must be the same. In reality, our concept of an endless future is every bit as dim and unsupportable by observation as is our conviction that an endless past is utterly impossibe.

Some theorists are considering the possibility that our universe began at the collision of two nearby universes, mathematically constructed as 'membranes' [an offshoot of superstring theory]. There may be countless other universes, many or all of which overlapping with our own. They may simply exist within the folded dimensions locked in the quantum world of the tiny. Of course, this might not be the case, but there are mathematical models that support the possibility. It goes without saying that such models offer hope that we might speculate about conditions prior to the big bang, and that we might one day shed the taboo of the forever indefinite past.

Answer 5

Actually you're not wrong it is quite similar.  The main difference is the this singularity contained all the matter and energy of the entire universe where as a black hole contains only a very small fraction.

Two reason why all matter didn't collapse back into itself:

1. It was propelled outward with so much force that it would have taken billions or years for the attractive force of gravity to overcome it.

2.  The reason this still hasn't happened is because of the presence of a mysterious force scientists call Dark Energy which acts exactly  opposite of gravity.  It repels matter away from each other and there is much more dark energy in the universe than there is matter (and thus gravity) to attract itself.  

Answer 6

The initial singularity is different than a black hole, because no mass was involved. All, there was was E, E as in mc^2, i.e., just energy.

When the Big Bang took place some 14 bill years ago, E was transformed into mass and speed of light velocities.

Answer 7

Hello Kitty, We are in the process of getting sucked back in.  It's just that in earth times, we haven't arrived there yet.  Ex:  12 minutes for light to get here from our sun.  We're in the interval, but it just hasn't touched us yet.  Like a boom-a-rang, going out, coming back in.

Hope this helps.

Answer 8

Mark S - Awesome answer!

Answer 9

To understand how the initial state of the universe and black holes differ, it might be best to try to visualize just what the universe looked like in the period immediately following the big bang. When the universe was very young it was very homogenous, meaning that any point in the universe was pretty much exactly like any other point. So if you were in a hypothetical space ship in the early universe you wouldn't feel the force of gravity at all. The pull of gravity would be exactly the same from all directions. Even though the universe was compressed into this really small space, the pull of gravity was imperceptible, because it was absolutely the same from all directions. In the midst of all this energy and mass you could basically float around weightless.

For some reason that scientists still don't know,  tiny, minute variations in the distribution of matter in the universe began to appear. Which meant that some points in the universe began to have a slightly stronger gravitational influence than other points.  But by this time the universe was large enough that the matter was not being pulled back to one common point, but rather each area of stronger gravity was pulling the matter around it into nebulae, galaxies and stars.

In our current universe we have a huge variation in the distribution of mass. We have empty space where the force of gravity seems nonexistent, and we have black holes, where the force of gravity is so strong that it overpowers everything else. It is this variation in the distribution of mass that gives gravity its strength.

A useful analogy might be to picture yourself in a ship flying in space. You're floating around weightless, and you don't feel any restrictions on your movements at all. But suddenly a small meteor punctures the ship, and you, along with all the air in your ship are sucked rapidly out into space. As long as the pressure was equal on all sides, you didn't feel the pressure of the air, but as soon as there was an imbalance you felt the pull caused by the imbalance. This analogy isn't perfect, but it's the best that I could come up with at the moment.

So in the early universe you wouldn't notice the force of gravity because it would be exactly the same at all points. It is the differences in the distribution of matter that gives gravity its strength, and that took time. Time enough for the universe to expand beyond the point where gravity could pull it back.

At least that's what I see when I try to visualize the early universe.

I hope that helps.