Where is the center of the universe?

[JediSouth]

I have a question. I have been watching a lot of docs about cosmology and the origin of the universe, and seems that most agree that it began with inflation. I believe this, but what gets me is this. Where is the center of the beginning of this inflation? And, if the universe is expanding exponetionly, then how do we know that when we look far out in the sky, that we are looking in the right direction? If everything is moving away from everything else, then there has to be a point at which it all started...which would be the center of creation. Everything would have expanded away from that point.
That makes sense to me. The only thing I am asking is this. If we look in one direction, and supposely what we see, is what is at that vast distance, because of the time it took for that light to get here, would mean we are looking at the beginning of existence. But, what if we look in the opposite direction? Of course, things would always be moving away from each other, but what i can't figure out is this. We are lookiing at at those vast distances,and they show the beginning of creation, because of the distance it takes for that light to reach us, but how, the beginning of creation should only be seen by looking in the direction of the origin of creation, which would mean we would have to be looking towards some center of where it all started. How do we know that we are looking at the beginning of time when what are are analising at those millions of light years away is what has traveled AWAY from some center. It's a paradox to me. Why, just because the light we see took billions of years to get here, that that is the beginning of time, wouldn't the beging of time only be visible by lookin in the direction of the origin of it? There must be a center right? from which inflation began.
I don't know. I am not a physics prof but I am absolutely fascinated by these things and i understand the conceptual theories, just not the math. That gives me a disadvantage. But it defeinatly intrigues me
If anyone has a theory of this, I'd like to hear it please
thanks

New guy with lots of thoughts...lol

 

[russ_watters]

Welcome to PF. Imagine sitting on a high mountain. Turn around in every direction - in every direction, the Earth looks roughly the same. This is a good 2d analogy for the 3d space.

Everywhere we look in space, it looks about the same. This implies rather strongly that there is no center to the universe. And expansion need not require one: replace the Earth with a giant balloon, expanding, and the analogy still holds.

 

[Chronos]

The CMB [cosmic microwave background] intensity is virtually identical in all directions as viewed from earth. This would not be possible unless Earth happens to be very near the 'center' of the universe. Given Earth is not the center of the solar system, is vastly distant from the center of our galaxy, and not even close to the center of the local group of galaxies, the proposition appears hugely improbable. See, for example, http://www.astro.ucla.edu/~wright/cosmo_01.htm

 

[IanTBlack]

I'm going to have to agree with JediSouth. The implications are strong that there is not really a center of the universe. Imagine you are on a lake and if you look around you don't see any shore. How is it possible to know if you are in the center?

Also, when something is spinning, that doesn't mean that the object is spinning on its center axis. The point where the object is spinning is the spin center, but not the object center. What I'm trying to say is that you can't decipher an objects center through its spin.

Yet if we go with the Big Bang Theory and assume that during the moment when everything was at a single point and then it exploded, that the single point would have been the center of the universe and would still be. Although the expansion of the universe would beg to differ. Some parts probably expand faster than others. Therefore, the universe is more of and amoeba and does not have a center.

Just some thoughts.

 

[HallsofIvy]

I have a question. I have been watching a lot of docs about cosmology and the origin of the universe, and seems that most agree that it began with inflation. I believe this, but what gets me is this. Where is the center of the beginning of this inflation? And, if the universe is expanding exponetionly, then how do we know that when we look far out in the sky, that we are looking in the right direction? If everything is moving away from everything else, then there has to be a point at which it all started...which would be the center of creation. Everything would have expanded away from that point.

This argument is not correct. If every object in the universe got farther away from its nearest neighbot, that would be "expanding"- but there would not be, and there does not have to be a "center" of expansion.

Yet if we go with the Big Bang Theory and assume that during the moment when everything was at a single point and then it exploded, that the single point would have been the center of the universe and would still be. Although the expansion of the universe would beg to differ. Some parts probably expand faster than others. Therefore, the universe is more of and amoeba and does not have a center.

Just some thoughts.

As far as your "amoeba" analogy is concerned, I agree. But you are incorrect that the Big Bang occurred at a single point. There was no space before the big bang. It is correct to say, rather, that every point in the current universe was the point where the big bang occured.

 

[IanTBlack]

So what you are saying is that every point is the center?

 

[Lok]

So what you are saying is that every point is the center?

Space does not need to have been created at the big bang, and we will never know. So this concept of every point being a center is a theory.

Just one of many theories that may or may not hold water. All try to explain a few unexplained things about or universe, mainly to this thread is the average matter density of our observable universe which is rather constant anywhere we look, and the accelerated expansion ( with mystical dark matter & energy theories).

 

[Nickelodeon]

Welcome to PF. Imagine sitting on a high mountain. Turn around in every direction - in every direction, the Earth looks roughly the same. This is a good 2d analogy for the 3d space.

Everywhere we look in space, it looks about the same. This implies rather strongly that there is no center to the universe. And expansion need not require one: replace the Earth with a giant balloon, expanding, and the analogy still holds.

I never feel comfortable with the expanding balloon analogy because in this case the centre of the balloon would be the origin of expansion.
Also, the thought occurs that more than likely we are not be able to see the entire universe (Hubble horizon??) and so are not in a position to determine if the receeding acceleration and direction (edit .. of the distant galaxies) points to a preferred area.

 

[russ_watters]

I never feel comfortable with the expanding balloon analogy because in this case the centre of the balloon would be the origin of expansion.

That's a misreading of the analogy: the center of the balloon is not a point on the surface of the balloon.

Also, the thought occurs that more than likely we are not be able to see the entire universe (Hubble horizon??) and so are not in a position to determine if the receeding acceleration and direction (edit .. of the distant galaxies) points to a preferred area.

The other galaxies we see and the CMB provide such a dreference.

 

[JediSouth]

This argument is not correct. If every object in the universe got farther away from its nearest neighbot, that would be "expanding"- but there would not be, and there does not have to be a "center" of expansion.


As far as your "amoeba" analogy is concerned, I agree. But you are incorrect that the Big Bang occurred at a single point. There was no space before the big bang. It is correct to say, rather, that every point in the current universe was the point where the big bang occured.

Yeah, but how would that be possible? if every point was a center than that would mean we are in multiverses. maybe like a fabric of some kind resembling the way the physics of atoms work only in a larger scale.

 

[JediSouth]

This argument is not correct. If every object in the universe got farther away from its nearest neighbot, that would be "expanding"- but there would not be, and there does not have to be a "center" of expansion.


As far as your "amoeba" analogy is concerned, I agree. But you are incorrect that the Big Bang occurred at a single point. There was no space before the big bang. It is correct to say, rather, that every point in the current universe was the point where the big bang occured.

I never feel comfortable with the expanding balloon analogy because in this case the centre of the balloon would be the origin of expansion.
Also, the thought occurs that more than likely we are not be able to see the entire universe (Hubble horizon??) and so are not in a position to determine if the receeding acceleration and direction (edit .. of the distant galaxies) points to a preferred area.

Exactly! There would have to be a center of that ballooon.

 

[russ_watters]

Exactly! There would have to be a center of that ballooon.

No.

Ignoring the meaning of the analogy does not make it go away. You must deal with the analogy as it is actually worded/defined. Otherwise, you're just arguing against a point that doesn't exist.

 

[CosmicCrunch]

idk i i think when people use the balloon analogy there stating that the universe is stretching, not expanding

 

[IanTBlack]

The balloon analogy also makes it seem as if the universe is expanding at roughly the same rate. It isn't. Some parts go faster than others.

 

[Fredrik]

Jedi, Ian, Nick...There must be hundreds of these threads already. If you do a search, you will find hundreds of answers to your questions. Some of them bad, but the ones given by people with science advisor or mentor status are almost always good.

Lok...You have the wrong idea about what a "theory" is. It's not a guess that may or may not be true. A theory is just a set of statements that can be used to make predictions about results of experiments. So it doesn't make much sense to say that something is "just" a theory.

 

[Chronos]

So what you are saying is that every point is the center?

Yes, that is what Halls of Ivy is saying, and I agree.

 

[russ_watters]

The balloon analogy also makes it seem as if the universe is expanding at roughly the same rate. It isn't. Some parts go faster than others.

Incorrect: it is expanding at the same rate everywhere.

 

[seto6]

think space as a balloon. before "big bang" think if the balloon has no air then blow it up then find the center...you can't find the center. if it has cent it would contradict infinite universe

 

[IanTBlack]

Why is it expanding at the same rate everywhere?

 

[Lok]

Why is it expanding at the same rate everywhere?

Because the overall density of the whole bigbang matter is thinning, and a relativistic view of this means time is accelerating and space is expanding. It is a twofold thing that results in acelerated expansion.

 

[Fredrik]

Why is it expanding at the same rate everywhere?

Because matter is distributed approximately the same everywhere. This is actually only true on large scales, but the same can also be said about the expansion. The solar system and the galaxy isn't expanding, at least not at the same rate as the cosmological expansion.

 

[Mikeral]

What my impression of the discussion of the location of the center of the universe, would be look at it from another point of view. As a man on balloon looks around him, all he sees is a 2 dimensional plane with no possible to center to it. But when we take a look from outside the system, in a 3 dimensional point of view it is easy to find the center. Now since the human mind, like the balloon man has the concept of 2 dimensions, knows of only the concept of 3 dimensions, it would take an extra dimension to comprehend the shape of the world he lives in, the universe in our case. So in order to find the center of the universe we would have to expand our concept of 3 dimensions to include time and that the universe has a physical location but only at a specific time in existence, by that i mean, when all dimensions are at 0, like the center of the Cartesian plane, x,y and z are zero and time must be zero, therefore, the center of the universe exists at the big bang and disappears afterward.

 

[Chronos]

This is a phishing expediton, imo. Either [A] Earth is at the center of the universe, or there is no center. Choose sides. Hint - [A] is indefensible.

 

[Fredrik]

...therefore, the center of the universe exists at the big bang and disappears afterward.

The original big bang theory is just the claim that the properties of "space" changes with "time" as described by a FLRW solution. In those solutions, the phrase "at the big bang" doesn't make sense. These solutions only talk about times t>0, and at every value of the time coordinate t, the universe is homogeneous and isotropic. The big bang is the limit t→0.

There are more complicated "big bang theories" than the original, but as far as I know, none of them suggest that there was a center.

 

[Donkeylip]

First time posting here. I'm by no means an authority on the subject, and my knowledge of physics is all in layman's terms, but here is my take on the question of a center of the universe.

First I think Mikeral was using the balloon metaphor correctly. I think it is more intended too explain the limitations of how we perceive the universe, not to explain how the universe actually works.

A better metaphor is a loaf of bread. Imagine you're baking a loaf of raisin bread. As you bake the bread the dough expands. The bread is the universe, and each raisin inside it is a galaxy/galaxy cluster. Now as the dough expands and the loaf gets bigger, every raisin would see all the other raisins moving away from it. It doesn't matter where the raisin is located, the effect is universal. This is why we see the universe expanding away from us, our cosmic loaf is expanding.

Now imagine that our loaf of bread started as an infinitely small ball of dough, just like the universe. If something is infinitely small then everything is at the center. This is the core of why it will be very hard to determine the physical center of the universe.

Because of the speed of light, the farther away from Earth we look, the farther back in time we are looking. We cannot look out into the present, we can only look out into the past. If the universe started as an infinitely small point where all of the matter in our universe was technically at the center, then if we look far enough away in ANY direction we will eventually see the "center" of the universe because 13+ billion years ago everything was at the center.

Assuming the universe is finite, we will never be able to see the "edge" of it because we can only look out into the past, not the present. Thus we will never be able to determine where the current physical center is. Since matter in the universe is spread out fairly evenly, my guess is that even if we could find the current center of the universe, there probably wouldn't be anything out of the ordinary going on there.

Sorry for the long post :)

 

[Chronos]

Reminds me of one of my favorites - we are the most ancient object in the observable universe - which means we must be at the very edge. Still, everything looks pretty much the same in every direction, just younger. This is true no matter where [or when] you are in the universe. Every observer is forced to conclude they are both at the edge and the center of the universe - and neither conclusion is logical or valid.

 

[Nickelodeon]

This is a phishing expediton, imo. Either [A] Earth is at the center of the universe, or there is no center. Choose sides. Hint - [A] is indefensible.

What about [C]?

[C] could be that the red shift is caused by something other than a distance galaxy speed of recession

 

[IanTBlack]

I suppose that on a larger scale it would make sense.

 

[Greylorn]

Welcome to PF. Imagine sitting on a high mountain. Turn around in every direction - in every direction, the Earth looks roughly the same. This is a good 2d analogy for the 3d space.

Everywhere we look in space, it looks about the same. This implies rather strongly that there is no center to the universe. And expansion need not require one: replace the Earth with a giant balloon, expanding, and the analogy still holds.

I do not believe that either the mountaintop or balloon analogy is applicable to the problem. Would not the analogy of an explosion be more appropriate, since the Big Bang was an explosion?

Explosions have centers of origin. They can be located after the fact.

 

[russ_watters]

I do not believe that either the mountaintop or balloon analogy is applicable to the problem. Would not the analogy of an explosion be more appropriate, since the Big Bang was an explosion?

No. The explosion analogy is not appropriate precisely because the Big Bang was not an explosion. That's a pop-media misconception.

 

[Greylorn]

No. The explosion analogy is not appropriate precisely because the Big Bang was not an explosion. That's a pop-media misconception.

Russ,
Thank you for your reply. I confess to having active subscriptions to pop-sci magazines, and nonetheless hope that you will readdress this issue,

Between 1965 and 1979 I did pioneering work in applying computer to technology, beginning with instrumentation and pointing control for the first space telescope and first ground based totally computer controlled instrument. My degree is simply a B.S. in physics, but I do have a minor paper on variable stars, co-authored of course. I read, learn, and argue, and during this time was seriously interested in the then-unresolved conflict between Hoyle's and LeMaitre's theories. (I have a yellowed paperback copy of Gamow's Creation of the Universe, deep in storage because I regarded most of it as unsupportable, illogical bunk.)

I never found either the steady-state or big-bang theory sufficiently logical to adopt, and never felt that it was necessary to choose between two opposing fallacies. I've kept track of the evolution of Big Bang theory as it rose to ascendancy. Until around the turn of the century, its precursor was regarded as very tiny "particle" containing all the mass/energy of the current universe.

That was an absurd and unprovable notion from the outset, and I angered many a righteous astronomer explaining why. But sure enough, eventually cosmologists figured out the same thing, and solved the problem by renaming their cosmic micro-pea (which, back then, had acccording to theory, blown up), a physical singularity.

Now since I've written pointing code for telescopes, I know what a mathematical singularity is. But a physical singularity is, in my not very humble opinion, invented nonsense. Its parallel in human thought is the omnipotent infinite God concept.

Of course you are correct, that the Big Bang could not have been an explosion, because a "physical singularity" cannot do anything, much less explode.

But, if the "singularity" did not explode, what have you renamed what it actually did? Inflated? Really?

Best I can tell, the expansion velocities of post-bang matter are sufficient to make a thermonuclear bomb analogous, by comparison, to the result of a drunken college student igniting his fart.

Most of us would call a really awesome explosion, at the very least, a "Big Explosion." Few would dub it inflation. I've inflated rubber boats, kiddie pools, and truck tires. I've set off firecrackers and tickled some dry nitrogen tri-iodide. I know the difference. When did Orwellian linguistics creep into astrophysics? More importantly, why?

Can we have a real discussion about this? Can anyone out there consider the possibility that current Big Bang theory is on a level with religious dogma, and that there must be a better explanation?

 

[Heisenberg.]

Best I can tell, the expansion velocities of post-bang matter are sufficient to make a thermonuclear bomb analogous, by comparison, to the result of a drunken college student igniting his fart.

hmm I have a quick question - if we make the big bang analogous to a huge explosion, then would that not that contradict the uniformity of the universe? A popular example of showing how the universe is a little different from the common definition of "explosion" is dropping a balloon full of paint - it splatters everywhere - with random blobs of paint clumped together, not a uniform filled in circle of the paint. From what I have heard the reason why the difference is imperative is our universe would be a very different picture if it was in fact an "explosion", for it would contradict evidence such as wmap, no?.. pardon my ineptness if my comments are incorrect or if I have misunderstood your post.

 

[Greylorn]

hmm I have a quick question - if we make the big bang analogous to a huge explosion, then would that not that contradict the uniformity of the universe? A popular example of showing how the universe is a little different from the common definition of "explosion" is dropping a balloon full of paint - it splatters everywhere - with random blobs of paint clumped together, not a uniform filled in circle of the paint. From what I have heard the reason why the difference is imperative is our universe would be a very different picture if it was in fact an "explosion", for it would contradict evidence such as wmap, no?.. pardon my ineptness if my comments are incorrect or if I have misunderstood your post.

The paint balloon analogy does not seem to fit. When the balloon hits the ground, it is subject to asymmetrical forces. The bottom will likely break while the top is intact. The paint will be emerging from a non-spherical container which flexes in process. Shards of rubber block the flow of paint.

A more approximate analogy might be a perfect sphere of paint sitting in deep space, with a tiny symmetrical explosive charge placed at its center that releases its energy in about 10exp-40 second. I suspect that this would produce an evenly distributed pattern of paint.

As for the WMAP images, I've looked at them again and again and keep wondering why astrophysicists insist that they show a symmetrical energy distribution. There are blobs and lumps all over the place. I make it a point to keep in practice recognizing such things by studying a centerfold image monthly. Haven't lost my skills. The WMAP images look to me like the result of a sloppy, asymmetrical paint balloon explosion.

Thanks for your reply. Please don't worry about sharing your thoughts with me. I don't treat PF like a physics class where the answers are in the professor's private supplementary text. The PF is a place where awesome ideas could be formed if people share their honest thoughts and best ideas, post interesting questions and expect a variety of answers.

 

[Chronos]

Science relies on observational evidence to formulate theory. The big bang concept is supported by a vast body of observational evidence. Liking the evidence is optional. The burden is on dissenters to formulate a theory that more cleanly fits observation.

 

[Ich]

I make it a point to keep in practice recognizing such things by studying a centerfold image monthly.

Which kind of journal, if I may ask? And which kind of practice?

Haven't lost my skills. The WMAP images look to me like the result of a sloppy, asymmetrical paint balloon explosion.

Yeah, great. Maybe sometimes you'll find the scale of these false color pictures. Try http://www.astro.ucla.edu/~wright/CMB-DT.html" for a start..

 

[Greylorn]

Yeah, great. Maybe sometimes you'll find the scale of these false color pictures. Try http://www.astro.ucla.edu/~wright/CMB-DT.html" for a start..

Awesome link! Thank you! There is obviously more I can learn there before coming back on this issue. So, I will be getting back to studying.

Back in '75 when we were developing the imaging technology, we called it pseudo-color. "False color" is upfront and honest.

It never occurred to me to check the scale, which was stupid. (Of me, not the scale.) A difference of 0.018% seems downright negligible.

One curiosity, which I did not find answered on the page--- Is the low effect of galactic emission the result of a limited instrumentation bandwidth?

I appreciate your assistance and sense of humor, equally welcome.

 

[Greylorn]

Science relies on observational evidence to formulate theory. The big bang concept is supported by a vast body of observational evidence. Liking the evidence is optional. The burden is on dissenters to formulate a theory that more cleanly fits observation.

Actually, I had thought that BB theory was derived from observational evidence, more a half vast body, but good evidence nonetheless.

I find the theoretical basis for the BB an issue. I do not believe in physical singularities or omnipotent gods. What caused the "singularity" to become a universe? Did it suddenly "decide" to become unstable?

Physics works as an effective combination of observation and theory. In the instance of the origin of the universe, I find good reasons to seek a theory which does not include a mystery hypothesis. Religion does that quite well already.

 

[Ich]

One curiosity, which I did not find answered on the page--- Is the low effect of galactic emission the result of a limited instrumentation bandwidth?

Yes, they're measuring in the microwave region only. You get a relatively undisturbed signal there.

I appreciate your assistance and sense of humor, equally welcome.

Thanks, my humor is normally lost in translation, so I'm happy I could get through with it for once.

I find the theoretical basis for the BB an issue. I do not believe in physical singularities or omnipotent gods. What caused the "singularity" to become a universe?

You know, BB theory works backwards. We see the evidence now, obviously, and trace back the history. And there was definitely something hot and dense. This knowledge is independent of musings about the origin.
You could also start from the beginning with the exact moment we know nothing about. But that's not science, that's philosophy or religion.

 

[Greylorn]

Thanks, my humor is normally lost in translation, so I'm happy I could get through with it for once.

Me too! I suspect that your style of humor will generally be lost on those who take themselves seriously.

You know, BB theory works backwards. We see the evidence now, obviously, and trace back the history. And there was definitely something hot and dense. This knowledge is independent of musings about the origin.

I find the method by which we've derived BB theory fully plausible. But, where it gets us does not feel right. I don't mean feeling in the emotional sense, but in the logical sense.
It seems to me that if we got there from here, we should be able to get here from there. That does not appear to be the case. This makes BB theory logically asymmetrical.

Then there is the persistent observation that we live in a cause-effect universe; where then is the Big Bang's cause?

50 years ago I gave up my belief in God for several reasons, one in particular being the absurd motivations attributed to this entity for the creation of mankind. BB theory seems to me to suffer from the equivalent failing--- lack of plausible cause.

You could also start from the beginning with the exact moment we know nothing about. But that's not science, that's philosophy or religion.

Wherever we start can be fairly regarded as an hypothesis. Whether an hypothesis becomes the core of effective physical understanding, or the basic dogma of another religion, depends upon what we do with it.

If we can derive it mathematically from a bit of observational evidence, and test it empirically, then it's usually science. If it predicts something we'd otherwise not have known, then it is almost certainly science.

But if we insist that an hypothesis came inscribed on golden tablets, since removed to heaven, and cannot possibly test it, then it's religion.

If we wake up some morning suddenly knowing the secrets pf the universe, and wrap a bunch of coherent polysyllabic words around our notions but never bother to test any assumptions or trouble ourselves with predictions, we've got another philosophy.

IMO BB theory is in the neverland of what I'd call, physical theology. While derived by scientists, it lacks some properties which we normally associate with sound science. Moreover, the Big Bang's mysterious precursor shares more characteristics with the God of Christianity than with any known physical phenomenon. (Mysterious or non-existent origin, containing/creating all matter and energy, yet doing so without credible cause or purpose.)

Something's not right with BB theory.

 

[Chronos]

Actually, I had thought that BB theory was derived from observational evidence, more a half vast body, but good evidence nonetheless.

I find the theoretical basis for the BB an issue. I do not believe in physical singularities or omnipotent gods. What caused the "singularity" to become a universe? Did it suddenly "decide" to become unstable?

The singularity part is still conjecture. A number of prominent physicists currently suggest alternatives. Given that [according to most physicists] time [in this universe] originated with the BB, your causal complaint is irrelevant.

Physics works as an effective combination of observation and theory. In the instance of the origin of the universe, I find good reasons to seek a theory which does not include a mystery hypothesis. Religion does that quite well already.

Feel free to submit your alternative explanation that fits the body of evidence.

 

[Fredrik]

Actually, I had thought that BB theory was derived from observational evidence, more a half vast body, but good evidence nonetheless.

I find the theoretical basis for the BB an issue. I do not believe in physical singularities or omnipotent gods. What caused the "singularity" to become a universe? Did it suddenly "decide" to become unstable?

The original big bang theory is just the claim that the large-scale behavior of the universe is described by a member of a particular class of solutions to Einstein's equation. The theory that's built up around that equation (general relativity) describes an enormous range of phenomena including but not limited to: objects falling to the ground, the orbits of planets, the decay rates of fast-moving elementary particles, the fact that two clocks on different floors of the same building are ticking at different rates, redshift of distant galaxies (given that matter is distributed homogeneously and isotropically across the universe), the rate by which the frequency of a pulsar is changing (due to emission of gravitational waves). It makes predictions about all those things, predictions that are almost absurdly accurate. And you think the theoretical basis isn't sound!? That's very naive. This is the best theory in all of science, except possibly for quantum mechanics.

In the instance of the origin of the universe, I find good reasons to seek a theory which does not include a mystery hypothesis. Religion does that quite well already.

It's not a hypothesis. It's what the theory (general relativity) says must be the case if matter is distributed homogeneously and isotropically. (And according to the singularity theorems, if matter is distributed in any way that resembles what we see through a telescope). The comment about religion is just silly. You should probably refrain from making condescending remarks until you have some idea what the various big bang theories are saying.

I find the method by which we've derived BB theory fully plausible. But, where it gets us does not feel right. I don't mean feeling in the emotional sense, but in the logical sense.
It seems to me that if we got there from here, we should be able to get here from there. That does not appear to be the case. This makes BB theory logically asymmetrical.

That's clearly an emotional argument, not a logical one.

Then there is the persistent observation that we live in a cause-effect universe; where then is the Big Bang's cause?

Even if all events have a cause, that principle doesn't apply to the big bang (in the original big bang theory) since the big bang isn't an event. There's no first event in the big bang theory.

IMO BB theory is in the neverland of what I'd call, physical theology. While derived by scientists, it lacks some properties which we normally associate with sound science.

That's absolutely false. No one who understands the big bang theories or knows what science is would make a claim like that.

 

[Nickelodeon]

... Even if all events have a cause, that principle doesn't apply to the big bang (in the original big bang theory) since the big bang isn't an event.


That's absolutely false. No one who understands the big bang theories or knows what science is would make a claim like that.

If it isn't an event could you tell us what it is?

 

[Greylorn]

The singularity part is still conjecture. A number of prominent physicists currently suggest alternatives. Given that [according to most physicists] time [in this universe] originated with the BB, your causal complaint is irrelevant.

You may well be correct, but would you kindly explain why the non-existence of time eliminates the need for a cause--- specifically some force which rendered the micropea or singularity unstable?

Feel free to submit your alternative explanation that fits the body of evidence.

Good plan. I came up with a few strange ideas a few days ago while being kicked around by Darwinists on a statistical thread, and they seem promising. (The ideas, not the Darwinists.) It will take a few months to work them out and put them on paper, and getting them published if they do work out seems an uphill struggle, but I will definitely follow your suggestion. Thank you!

 

[blank.black]

but the History Channel said there is a center point from where the Big Bang occurred and they had various scientists on there as well...is the History Channel wrong? are the scientists on there wrong? must i not watch History Channel? :(

 

[Greylorn]

The original big bang theory is just the claim that the large-scale behavior of the universe is described by a member of a particular class of solutions to Einstein's equation. The theory that's built up around that equation (general relativity) describes an enormous range of phenomena including but not limited to: objects falling to the ground, the orbits of planets, the decay rates of fast-moving elementary particles, the fact that two clocks on different floors of the same building are ticking at different rates, redshift of distant galaxies (given that matter is distributed homogeneously and isotropically across the universe), the rate by which the frequency of a pulsar is changing (due to emission of gravitational waves). It makes predictions about all those things, predictions that are almost absurdly accurate. And you think the theoretical basis isn't sound!? That's very naive. This is the best theory in all of science, except possibly for quantum mechanics.

I'm here to learn, and appreciate your sharing your understanding with me. I'll do my best to honor that with honest questions, which by my standard, are those which I think are important, and to which I do not have the answers. It has been a long time since I learned what I could about general relativity, and my math skills were not up to the job of understanding either its full derivation or its implications. I am aware of most of the effects you mention, and like you, I've marveled at their powerful predictive value. (That's real science!) But isn't time dilation, the most notably accurate of Einsteinian predictions, described by special rather than general relativity?

I'd not known about the pulsar frequency changes. Nor was I aware that gravitational waves have been experimentally detected. I imagine that this would not be essential to pulsar theory, but have noted that all too often, things which cannot be detected turn out not to exist.

Perhaps more relevant, I thought that general relativity can be interpreted as leading to the possibility of a Big Bang, not that it necessarily does so. Moreover, it cannot solve the initial condition problems. Envisioning a collapse of the universe if we run time backwards, it seems clear that time is greatly affected by the concentration of mass-energy in a tiny space. I'd expect the general relativity equations to collapse well before the universe became (running time backwards) the size of a golf ball, and to become absurd afterward.

Also, the concentration of all mass-energy in a tiny space will produce the great grandmother of all black holes, a black hole without an event horizon, and the absence of time would preclude quantum effects at the event horizon from evaporating the hole.

Do you know if these issues have been dealt with theoretically, and where I might locate the papers?

It's not a hypothesis. It's what the theory (general relativity) says must be the case if matter is distributed homogeneously and isotropically. (And according to the singularity theorems, if matter is distributed in any way that resembles what we see through a telescope). The comment about religion is just silly. You should probably refrain from making condescending remarks until you have some idea what the various big bang theories are saying.

Clearly, the cosmological view of homogeneity differs from mine. I look into the universe and see subdivisions of lumps. If I poured out a bottle of homogenized milk with as many lumps as our solar system, or galaxy, I'd toss it as being spoiled.

That's clearly an emotional argument, not a logical one.

Perhaps I should clarify it. If we can determine theoretically that there must have been a Big Bang (getting there from here), then we should also be able to determine, theoretically, why the Big Bang occurred. (Getting here from there.) I honestly do not understand what is emotional, or non-logical about that proposal. Clarify, please.

Even if all events have a cause, that principle doesn't apply to the big bang (in the original big bang theory) since the big bang isn't an event. There's no first event in the big bang theory.

The "no event" notion smacks of religious beliefs in an omnipotent God who always existed without origin or cause, always knowing everything.

Nickelodion has replied to this more cogently, and I hope that you will answer him.

That's absolutely false. No one who understands the big bang theories or knows what science is would make a claim like that.

There, you are nearly correct. I will put my understanding of what science is, at both the ideal and practical levels, up against yours or anyone's. But I've been out of practice for a few decades, so lay no claim to actually being any kind of scientist, despite having done a fair amount of it.

You are correct in that I do not understand Big Bang theory. This could be because I am stupid, or could also be because Big Bang theory is not correct. I'm asking questions in hopes of correcting one or both of these issues.

 

[Greylorn]

but the History Channel said there is a center point from where the Big Bang occurred and they had various scientists on there as well...is the History Channel wrong? are the scientists on there wrong? must i not watch History Channel? :(

IMO the History Channel does a lot of what I'd call, "speculative science." They are more imaginative than NitGeo, and I appreciate their willingness to explore ideas openly.

I also think that there are many fields of inquiry which mankind has pursued since our beginning, which are now dominated by scientists instead of theologians and philosophers. This is a potentially good thing, but I am noticing that many science followers take the same dogmatic attitude to the currently approved theories that religionists apply to their own beliefs. This is not a good thing, because dogmatism always stifles creative thought.

So, if you truly believe that science has correctly answered all important questions about the beginning of the universe and the origin of life, Thou Shalt Not Watch the History Channel. Else, perhaps Thou Must Watch It.

 

[blank.black]

IMO the History Channel does a lot of what I'd call, "speculative science." They are more imaginative than NitGeo, and I appreciate their willingness to explore ideas openly.

I also think that there are many fields of inquiry which mankind has pursued since our beginning, which are now dominated by scientists instead of theologians and philosophers. This is a potentially good thing, but I am noticing that many science followers take the same dogmatic attitude to the currently approved theories that religionists apply to their own beliefs. This is not a good thing, because dogmatism always stifles creative thought.

So, if you truly believe that science has correctly answered all important questions about the beginning of the universe and the origin of life, Thou Shalt Not Watch the History Channel. Else, perhaps Thou Must Watch It.

but science has not answered all important questions about universe and life...just theories and possible explanations for mostly everything...that keep changing everyday due to new discoveries...hence making us buy new textbooks every semester

 

[Quantum-lept]

I did not take the time to read all posts, so someone may have pointed this out: If there is an edge to the universe, then there is a center. If there is no edge to the universe, then it is infinite, and there is no center.

But, would not expansion imply that there is an area outside of the universe to expand into? Or, if it is infinite, expansion is within and along the line of infinity?

I need to nap now, i overtaxed myself.

Having a center does not mean that it is a fixed point, as expansion may be uneven.

 

[Fredrik]

If there is no edge to the universe, then it is infinite, and there is no center.

It can be finite without having an edge. Think of the surface of a sphere for example.

But, would not expansion imply that there is an area outside of the universe to expand into?

No. Think e.g. of an infinite line with distance markings on it, and imagine the distance between the markings growing with time. The scale is changing, but the total size isn't.

If it isn't an event could you tell us what it is?

It's a mathematical property of a class of solutions of Einstein's equation. It can be characterized in many different ways. The most interesting detail is that the distance between two objects that stay at fixed coordinates in space goes to zero as the time coordinate goes to zero.

Each solution of Einstein's equation defines a spacetime. We're talking about a class of solutions, so we're also talking about a class of spacetimes. An event is a point in spacetime. A coordinate system is a function that assigns four coordinates (t,x,y,z) to each event. There's a specific coordinate system that's very convenient to use when we're dealing with these spacetimes. When I mention coordinates, that's the coordinate system I have in mind. If I e.g. mention "the time since the big bang", what I'm talking about is the t coordinate assigned by that coordinate system. (Everyone who understands this does the same thing. That phrase is defined to mean precisely that).

It's very important to understand that there is no event in any of these spacetimes that's assigned t=0 (or t<0) by this coordinate system.

but the History Channel said there is a center point from where the Big Bang occurred and they had various scientists on there as well...is the History Channel wrong? are the scientists on there wrong? must i not watch History Channel? :(

There are lots of garbage claims in documentaries about these things, but I doubt that they had astrophysicists on the show who said that. It's definitely wrong.

But isn't time dilation, the most notably accurate of Einsteinian predictions, described by special rather than general relativity?

Special relativity is one specific solution of Einstein's equation. There's time dilation in all of them.

I'd not known about the pulsar frequency changes. Nor was I aware that gravitational waves have been experimentally detected.

They haven't. GR predicts that the frequency will change because energy is lost in the form of gravitational waves, and that prediction has been verified to an absolutely ridiculous degree of accuracy, by measuring the frequency.

Perhaps more relevant, I thought that general relativity can be interpreted as leading to the possibility of a Big Bang, not that it necessarily does so.

All homogeneous and isotropic solutions have an initial singularity. That was known in the 1920's. The singularity theorems of Penrose and Hawking showed that a much larger class of solutions have initial singularities.

Moreover, it cannot solve the initial condition problems. Envisioning a collapse of the universe if we run time backwards, it seems clear that time is greatly affected by the concentration of mass-energy in a tiny space. I'd expect the general relativity equations to collapse well before the universe became (running time backwards) the size of a golf ball, and to become absurd afterward.

You're right that GR isn't expected to be accurate for very small values of t. But that's not a reason to think that your intuition about what things are like under those conditions are any better than GR. The theory that describes time in an intuitive way is Newtonian mechanics in Galilean spacetime. That fact that its predictions about results of experiments are much worse than the predictions of GR proves that our intuition is wrong about the properties of time.

Also, the concentration of all mass-energy in a tiny space will produce the great grandmother of all black holes, a black hole without an event horizon, and the absence of time would preclude quantum effects at the event horizon from evaporating the hole.

Do you know if these issues have been dealt with theoretically, and where I might locate the papers?

If you mean the issues at times when GR doesn't hold, then no. Those require a quantum theory of gravity. If you're saying that GR says that the early universe would have turned into a black hole, that's just wrong. The solutions that say that a large concentration of mass in a small region will form a black hole, are only telling you what would happen if the rest of the universe is empty. In the "big bang solutions", the density is the same everywhere. It's a very different scenario.

Clearly, the cosmological view of homogeneity differs from mine. I look into the universe and see subdivisions of lumps. If I poured out a bottle of homogenized milk with as many lumps as our solar system, or galaxy, I'd toss it as being spoiled.

It's approximately homogeneous and isotropic on large scales, but not on small scales. (Here "small" can mean millions of light-years). That's why the universe is expanding on large scales (distances to far away galaxies are increasing), but not on small scales (e.g. in the solar system).

Perhaps I should clarify it. If we can determine theoretically that there must have been a Big Bang (getting there from here), then we should also be able to determine, theoretically, why the Big Bang occurred. (Getting here from there.) I honestly do not understand what is emotional, or non-logical about that proposal. Clarify, please.

Do I really need to clarify why "it seems to me" isn't a logical argument?

GR describes the relationship between how matter is distributed in spacetime and how it must move. If you plug in the (approximate) current distribution of matter, the resulting description of its motion includes a big bang (which is a property of spacetime, but not an event in it). The singularity theorems prove that it's not an artifact of the approximation.

This theory is also the best theory of time that we have. Experiments have proved that our intuition about time is wrong (certainly much more wrong than how this theory describes time). So it makes absolutely no sense to argue that there must have been a time before the events that these solutions mention.

To ask "why" there was a big bang (of the sort described by this theory), is to ask why Einstein's equation is an accurate description of the relationship between the distribution and motion of matter. That's a perfectly valid question, but you have to understand that it can only be answered by another theory.

The "no event" notion smacks of religious beliefs in an omnipotent God who always existed without origin or cause, always knowing everything.

That's the kind of comment I would expect from a creationist who isn't at all interested in learning what this theory says or what a theory is. (Edit: I changed this comment a bit because it sounded too aggressive).

You are correct in that I do not understand Big Bang theory. This could be because I am stupid, or could also be because Big Bang theory is not correct. I'm asking questions in hopes of correcting one or both of these issues.

Those are not the only two options. And to prove a theory wrong, you have to perform experiments. Just asking questions isn't going to do it.

 

[Nickelodeon]

It's a mathematical property of a class of solutions of Einstein's equation. It can be characterized in many different ways. The most interesting detail is that the distance between two objects that stay at fixed coordinates in space goes to zero as the time coordinate goes to zero.

Thanks for your extensive replies. I have difficulty trying to picture the Big Bang as a property of a class of solutions of Einstein's equations. Sorry but my maths is not up to much - by 'class of solutions of' do you mean 'subset of formulas derived from'? If you can't assign the value t=0 to the formulas, presumably due to fear of infinities, but you can assign t=0 + a miniscule amount, then it still feels like an event to me.

Einstein is reported to have said 'Most of the fundamental ideas of science are essentially simple, and may, as a rule, be expressed in a language comprehensible to everyone'. I guess this example is the exception :-(.