Social Question

ETpro's avatar

Big Bang Theory -- How can you divide infinity into a single finite whole?

Asked by ETpro (34461points) September 23rd, 2010

If you project the math of General Relativity backwards, we find a Universe that must have occupied Zero time-space and had infinite mass about 13.7 billion years ago. We call that the Singularity, because at that point, all known laws of physics break down. Far from being mostly flat, space-time at that point would have had infinite curvature. Immediately after the Big Bang, the math would suggest a Universe of infinite temperature. But if infinity divided by two is still infinity, how could expansion result in a Universe of finite mass and temperature? What could extract entropy from infinity?

Observing members: 0 Composing members: 0

41 Answers

dkranzberg's avatar

Honestly, the Singularity doesn’t make any sense (something of infinite mass that takes up no space). If something exists, it has mass…and if it has mass it takes us space—however small.

dkranzberg's avatar

If all the mass of the extant universe could somehow be contracted to a single point, and that point has no mass…then there is no possible way to measure the imperceptible except to base it on the finite mass that is known to us from this point. Math cannot account for the imperceptible, except in the imaginary world. In the end, it is kind of like saying that math can measure the concept of another product of the imagination: God.

Winters's avatar

Mankind cannot answer this question currently. This question’s answer is one that no one can answer simply because our equations fall apart when trying to describe time 0. Until we find a way to describe what was going on at time 0, we can only speculate.

Trillian's avatar

To see the world in a grain of sand
And Heaven in a wild flower,
Hold infinity in the palm of your hand,
And eternity in an hour.

(Blake, W)

iamthemob's avatar

@Winters has described the problem in my opinion. It seems impossible because once we collapse the physical universe into the singularity, relativity isn’t applicable. Hell, quantum mechanics isn’t applicable. It literally becomes unobservable – observation as we understand it requires the observer be somehow conceivably discrete from the observed – and in the singularity universe that’s impossible.

And also…Dark Matter (which is made of unicorns)

gasman's avatar

The singularity itself—the point of “zero time” and “zero size”—is a mathematical absurdity in theories—that why it’s called a singularity: It’s a single point at which equations have no solution. Hence the origin (time=0) of the big bang remains a deep mystery to even world-renowned theoretical physicists.

Yet physical evidence for big bang cosmology is incontrovertible: So far everything checks out with the so-called Standard Model, which goes hand-in-hand with explaining Big Bang physics. Theory agrees well with observation & makes many important and verifiable predictions, such as Hubble’s Law, the cosmic background microwave radiation, the relative abundances of hydrogen & helium, etc. Like any fundamental scientific theory, it rests on mountains of evidence. That’s why the big bang is such a big deal.

With high-energy machines like LHC in Switzerland, we can study how particles behave at energies ever closer to zero time (presently I think it’s around 10^ -20 seconds, give or take a few orders of magnitude). New observations at higher energies will impose additional constraints on theory and (hopefully) filter out wrong mathematical ideas that fail to correspond to observed reality.

It seems that scientists are highly confident that the big bang happened and that events unfolded afterward, as described by theory, to explain today’s universe. But the central mystery of all those pesky infiities at t=0 remains. Only time will how (or if) it resolves.

dkranzberg's avatar

Once upon a time there was a research scientist who devised a rat trap. The trap was made with the latest technology available in the 15th century. He went into a particularly rat infested London neighborhood and found a large, uninhabited building in which to conduct his experiment.

He had a theory about the size of rats corresponding to the rate of rabidity, so he set out dozens of rat traps over a 6 month period. Each rat trap was 3 inches wide by 12 inches in length.

After the experiment was over, he published his findings, concluding that only small rats under 12 inches in length have rabies, and larger rats don’t.

How does this apply to the question, above?

Consider the trap. It is analogous to any scientific tool we use to measure. Our conclusions are limited by the tools we use. Heck, the researcher might have also concluded that, since he didn’t catch any rats over 12 inches in length, that no rats greater than 12 inches in length exist.

@gasman is correct in everything he has written with the exception of the word “incontrovertible.” There can be no such thing in science.

iamthemob's avatar

@gasman

Yet physical evidence for big bang cosmology is incontrovertible: So far everything checks out with the so-called Standard Model, which goes hand-in-hand with explaining Big Bang physics.

What about the acceleration of galaxies away from each other?

gasman's avatar

@dkranzberg Ok, a fine pedantic point about “incontrovertible”. Agreed that “proof” and “truth” have no place in science and that in principle any theory is subject to being overturned by the very next observation. Can we agree on: A very high degree of statistical confidence in the correctness of the Standard Model to the exclusion of other cosmological theories?

It would be great if the next Newton or Einstein formulated a “theory of everything” in one tidy package—with or without Planck-scale evidence—but I’m not holding my breath. Meanwhile, look how far we’ve come in just the past century!!

Big bang cosmology was highly speculatsive and in rivalry with Steady State cosmology until the discovery of cmbr in mid-1960s and the co-development of high energy particle physics around that time.

To use @dkranzberg‘s analogy, they learned to build bigger cages & indeed found bigger rats (higher energy particles). This enabled them to refine the theory of rat anatomy.

@iamthemob: Good point—another fly in the ointment discovered in 1998. “Curiouser and curiouser.” This—once again—doesn’t alter the basic fact of the big bang.

iamthemob's avatar

@gasman

I don’t think it’s pedantic to point out that it’s not incontrovertible. I think it’s important. I also don’t understand how the observation doesn’t have the potential to completely undermine the basic [theory] of the big bang, as the big bang would predict the exact opposite result.

dkranzberg's avatar

Sorry @gasman if I came of as pedantic.

gasman's avatar

@iamthemob No more pendantic than I am—like its a bad thing… ~

What I meant by incontrovertible (though I tried to distance it from concepts like proof or truth—the cornerstones of dogmatic belief systems) was very high confidence in correctness. As opposed to absolute certainty, which is outside empirical science. In principle all theories are tentative and subject to revision or even rejection, in accordance with the scientific method.

Philosophers of science, however, demand extraordinary evidence to successfully challenge & topple an established theory, especially one as successful as the Standard Model of physics.

Everybody quibbles about esoteric details—that’s the cutting edge. Nobody denies the basic fact (another loaded word?) of the big bang, subject to various-size holes in understanding. The discovery of accelerating expansion is another mystery associated with so-called dark energy, which may drastically affect the universe’s future fate, but I don’t think this poses a problem for the basic big bang model to explain the past 14 billion years, validated by lines of evidence I mentioned earlier.

It appears that big bang cosmology is robust in the same sense that Newtons theory of universal gravitation (which fairly accurately explains the solar system) was never really invalidated or overthrown by Einstein’s relativity. Relativity was an add-on to existing theory, important only at certain scales. In this view Einstein did not “completely undermine” Newton, even though Newton’s laws sometimes give completely wrong answers where relativity gives the right ones. Whatever the “final theory” turns out to be, there is no reason to expect it will contradict the big bang.

iamthemob's avatar

@gasman

The problem is that if the big bang is true, then our theory of gravity is not. If our theory of gravity is true, then the big bang is not. I do not really accept on the face that scientists claim it all makes sense if the universe is made up of 80% dark matter, then it seems to make sense.

It seems disingenuous to say that both theories are robust when, in attempting to predict movement through the universe, they claim opposite outcomes.

You see what I mean? I’m open to have it explained. However, when scientists say “It we make up this thing the math makes sense” I am reasonably suspicious that our understanding should be phrased as anything but hypothetical. To use rhetoric to make it sound more reasonable isn’t a scientific argument…it’s politics.

Zyx's avatar

I like to think the big bang and crunch repeat and when all the matter is in a single place some law of nature causes entropy to be undone and the universe to be reinfused with energy. People have suggested this in science fiction often enough and it seems reasonable since this is the only pattern we have seen so far. In fact assuming the universe dies out at all is almost ridiculous. It’s never happened before.

And everyone is right in that you can’t know, pure speculation.

FireMadeFlesh's avatar

@iamthemob “The problem is that if the big bang is true, then our theory of gravity is not. If our theory of gravity is true, then the big bang is not.”
That is not quite correct. The advancing perihelion of Mercury doesn’t mean Newton was wrong, it just means he did not have the full picture. It is highly unlikely that General Relativity is the final word on gravity, but it is probably an approximation to the actual laws that govern gravity. There is a huge difference between something being wrong and it just being a part of the picture.

@Zyx The ever increasing rate of expansion of the universe has fairly conclusively ruled out the possibility of a Big Crunch. It seems that the universe will die a cold death, approaching ever closer to infinite entropy, with small islands of matter with their own event horizons created by the expansion over long distances being too great for light to traverse.

iamthemob's avatar

@FireMadeFlesh

You’re splitting hairs there, and misrepresenting the argument a little. Newton’s theory of gravity has been replaced by our current concept of what gravity really is. In this sense, it was wrong – it conceived of gravity as being something, acting in some way, and predicting behaviors in a way that turned out to be inaccurate. It is wrong in the same sense that the previous theory that the atom was the smallest unit of matter was wrong, and that matter and energy were different from each other was wrong.

Regardless, that doesn’t really contradict my statement.

FireMadeFlesh's avatar

@iamthemob I don’t believe I am. Both General Relativity and the Big Bang are probably true to a high degree of accuracy, but neither are likely to be entirely correct in the way we currently understand them. Newton’s theory was not as accurate as Einstein’s, but that does not make it wrong, it just makes it an approximation. Even the Ptolemaic model has some truth in it, and as such is not entirely wrong. Take a look at The Relativity of Wrong by Isaac Asimov.

gasman's avatar

It’s widely agreed that quantum mechanics and general relativity don’t really come together mathematically in any unified way, leaving a queasy feeling of incompleteness & lack of a bigger picture.

Higher-dimensional string theories are of great interest as potential candidate explanations, but they operate at the minuscule Planck scale, which is far beyond the reach of 21st century human technology to make actual observations that could test these theories. We’re lucky to be doing the LHC research “just” at several TeV.

So speculations fill the vacuum where theory is missing—big crunch, big bounce, and many other imaginative if plausible scenarios with no physical corroboration to back them up.

At least that’s how I understand it. I am not a physicist, nor am I involved in physics research. My undergrad degree in physics is a little moldy. But I read books by authors like Brian Greene and Stephen Hawking (though not the latest), follow news about astrophysical research, read skeptical literature, and see science headlines. Those are my reality checks by which I assert that big bang cosmology has not been discarded in light of new discoveries. And that’s as far as I can defend my comments for accuracy. Any theoretical physicists out there in Flutherland?
——————
I think the question of whether Einstein replaced versus refined Newton seems pointless. The relationship speaks for itself. Obviously classical physics is the foundation over which relativity and quantum mechanics are laid, and that’s still how it’s taught to students of physics.

ETpro's avatar

@Winters & @iamthemob I don’t think the question posed is an imponderable. It may be true that the supposition of an infinite mass occuppying zero space is imponderable, but it we accept that, then the question of how dividing or expanding it would result in a finite entity isn’t imponderable. It’s math dealing with the division of infinity. Infinity divided by any finite number is infinity. No? And @iamthemob We were trying to keep this a secret, but dark matter is actually unicorn poop.

@Trillian GA! Thanks

@dkranzberg I get the message of the example. But again, I am not really asking about T=0 in the question, but how an infinity became a finite thing,

@gasman I have been waiting for someone to say “Thank you.” in response to being called a pedant. :-)

@Zyx Accelerating expansion seems to rule out a Big Crunch type of cyclic Universe, as @FireMadeFlesh pointed out. @FireMadeFlesh, Here is my own SWAG. We have not yet fully understood the true geometry of space-time. When we do, we will find that expansion eventually turns in on itself, because infinite entropy would also be infinite, perfect organization. So it isn’t a Big Crunch but a Big Chill that makes an apparent infinite nothingness suddenly explode into Life, the Universe and Everything.

FireMadeFlesh's avatar

On the origin of the universe, and the cause of the Big Bang, you might find Sean Carroll’s ideas interesting. He envisages countless universes forming out of space time isolating itself from a parent universe, and the new universe has zero entropy.

ETpro's avatar

@FireMadeFlesh Thanks for the great link. I like that idea. At my age, I could really use a furlough to a Zero Entropy Universe.

iamthemob's avatar

@gasman

That’s basically where I am as well. I get frustrated with claims that these have been proven rather than are the most generally accepted theories about how our observations seem possible. Especially when, in order to make the big bang work right now, scientists need to “theorize” a brand new substance we haven’t discovered to make the math work…;-)

To me, it seems more and more that when observations run contrary to a theory, or are neutral, they are interpreted somehow to still fit the theory. It’s like they just can’t admit they may be barking up the wrong tree.

Of course, I don’t suggest (as I admittedly have an informed, but not deep at all, understanding of the theories) that they be abandoned…I just don’t know why there isn’t popularized news about research into alternate theories.

FireMadeFlesh's avatar

@ETpro It would be nice, if you wouldn’t be fried in the superheated quark-gluon plasma!

ETpro's avatar

OK in my readings I ran across the answer. Good Theories should not produce singularities. They happen when a theory leads to a mathematical projection that yields a divide-by-zero error AKA singularity. As I understand it, cosmologists think that there must be al little something wrong with the General Relativity Theory of Gravity and also with Quantum Mechanics, causing the two not to mesh perfectly, and also leading to General Relativity’s Singularity at T=0. It is hoped that the Grand Unification Theory, when and if it is discovered will eliminate this Singularity and merge Relativistic Gravity on the macro scale with Quantum Mechanics on the micro scale.

@FireMadeFlesh Sounds about as useful as stopping the march of time by diving into a black hole. You won’t age anymore, but you won’t live anymore either.

gasman's avatar

Yes, there’s definitely something wrong with theory, but right now nobody knows how to fix it.They had a similar problem with quantum mechanics until Feynman et al figured out renormalization in the 1960s. And don’t forget that the “flatness problem” (previously another cosmic mystery) was explained with inflationary theory by Guth only 3 decades ago, still accepted by most theorists today. So it goes in the history of physics…

(@ETpro) Thus I am optimistic that the mathematical absurdities you ask about will eventually be tamed. Hopefully, however, we’ll never reach The End of Science

ETpro's avatar

@gasman If the 2nd Law of Thermodynamics applies to science at all, I am confident we are nowhere near the Big Chill just yet. You and I probably are no more in threat of seeing that day than of seeing it happen to this Universe.

FireMadeFlesh's avatar

@ETpro I think it is about 3 trillion years till the event horizon forms around our local group of galaxies, and it will be quite a while after that till our local group cools to the point where it cannot sustain life.

iamthemob's avatar

Unless Jesus.

Winters's avatar

@FireMadeFlesh the event horizon is the point of no escape of black holes.

FireMadeFlesh's avatar

@Winters That is one example of an event horizon, but they exist whenever there is a barrier that light cannot cross, because that isolates a region in time.

kess's avatar

Infinity is One just as One is infinite.
The universe is infinite.

iamthemob's avatar

The universe is smaller than me…

…I am the infinite.

kess's avatar

You are indeed infinite just the universe is infinite, and the universe exist in you and you exist within the universe.

Zyx's avatar

And none of it is useful in real life.
Please tell me I’m not the only one who’s high.

iamthemob's avatar

You are high
And she is high
And we are high

And the universe is all together.

ETpro's avatar

High guys—I’m sleepy. Bye guys. :-)

Response moderated
Zyx's avatar

I can only say:

Too long, didn’t read.
Sounds paranoid and accurate though.

ETpro's avatar

@Zyx I have to agree. This person just signed up to post this here. I imagine it’s being posted on any sites that will allow such postings. I have to wonder if the Attribution at the bottom of it renders it spam. Will ask a mod’s opinion.

Caroline290's avatar

The energy is mostly converted to dark matter and dark energy, with a finite amount of matter and regular energy. The infinite dark energy causes the accelerating expansion of the universe seen today, though it gradually comes into effect, not all at once.

Answer this question

Login

or

Join

to answer.
Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
or
Knowledge Networking @ Fluther