Age of the Universe is Meaningless!!! (Reference frame questions)

As some of you might remember even before I was dissuaded of my anti-evolutionary position, I was never convinced that the earth or the universe had to be 6000 years old (our time) with a seven 24-hour day creation.I have two questions for this topic.The first seems straighforward, but maybe I'm wrong: To tell time, one must have a reference frame, right? How much time is passing depends on where you are and how fast you're moving or accelerating etc... So, the universe cannot be a reference frame for itself, right? That seems to be circular. Therefore it is meaningless to give the universe an age because the age is variable and determined by the observer within the universe itself. If you could get a photon from the background radiation to calm down and talk to you for a second, it would be convinced that it was only a second old even though it has been traveling a few billion years earth-time to get to us, right?My second question is to ask what frame of reference if any exists that gives a sort of average timescale of all observers in the universe and if it is possible to do this? Or would the average age of the universe be approaching 0 for all observers? How fast and far did our matter travel relative to all the rest of the matter in the universe to get to where it is now?Any thoughts or answers?{By edit note: Prior to moving topic, I have taken the liberty of adding the "(Reference frame questions)" part to the title. I hope this helps focus the topic. - Adminnemooseus}This message has been edited by Adminnemooseus, 12-10-2004 05:06 PM

Thread moved here from the Proposed New Topics forum.

I'm going to, yet again, guess about this. I think it is getting a bit to deep for my limited knowledge. But let's see.I would think that the choice of reference frame for dating is obvious. It is the earth's RF. Where else would be we be when measuring?I think that relativity would tell us that there is no average RF or timescale.Our matter hasn't traveled anywhere at all (well not compared to the size of the universe) we are somewhere "near" (if near is a few 100's of light years) from exactly where we started. This sounds odd only if you keep thinking that there was an explosion. An explosion, as we normally use the term, involves bits flying off from the point where the bomb went off. This is not what the big bang is.All galaxies where once very close to us. Now some are a couple of million light years away and some are billions of light years away. Yet none of them moved away from where they started! In an explosion the pieces move through a fixed space. In the big bang the "pieces" stay put and the space between them expands. There is "new" space where there wasn't as much before.I think that all observer's would see the universe at the same age unless they are moving at relativistic speeds separately from the expansion of space due to the big bang.This message has been edited by NosyNed, 12-10-2004 07:26 PM

Well, what got me started thinking about this was the photon. A photon from the background radiation is no older than the instant it was condensed a fraction of a second after the big bang. To us it seems like it is about 14 billion years old, but time does not pass for a photon. If matter was traveling near the speed of light right after the big bang, then time would pass slowly for it as well I assume. The simplistic model I have in my mind is that of a bomb exploding. Some bits go flying at terminal velocity while some smoke stays at the center. Could we use the center of the explosion as a reference frame for a bit that went flying off? If space is just empty space, then that should be the case, but if space is more like an ether that also expanded from the big bang in all dimensions at once, then I have a much harder time getting a grasp on how the explosion would work and an even much harder time accepting that all parts of the universe are the same age. So then the big bang was the expansion of space itself? What does this mean? And wouldn't this have some kind of effect on the dimensions and constants governing the universe?Also, if redshifts are interpreted as doppler shifts, we see galaxies racing away from us at near the speed of light. Is that not a "bit that went flying off?" If this galaxy has been flying away from us at near the speed of light since the big bang, then time must have passed very slowly for it. Or is it not really flying away from us, but rather the space between us has been expanding? If this is so then it seems that this would cause some kind of time dilation as well.

Time would pass slowly from our point of view, from our reference frame. Not "for it". "For it" our time is running slowly. As I understand this, that model is wrong and doesn't describe the big bang in anyway at all. I don't understand your difficulty here. Other than the obvious one of it being very hard to get ones head around. For that galaxy time is passing slowly for us, not it.

A much better analogy is to a balloon. Take an uninflated balloon. Take a marker. Draw two dots on the balloon that are right next to each other. Then inflate the balloon. See how the dots get farther away from each other? But nothing really goes "flying at terminal velocity" and where is the "center of the explosion"?Now this analogy fails because we don't see the fabric of space-time stretching (at least, over the distances in question here - the vastness outside our local group, obviously in strong gravitational fields you get frame dragging and such) but it is a good way to think of the effects of the "explosion".Usual disclaimers apply. IANAE.ChrisThis message has been edited by cmanteuf, 03-31-2005 04:04 PM

I'm having trouble with this too. The only difference I see between the balloon model and the explosion model is that the space-time stretches in the balloon model. If ours is not stretching, then why do people encourage the use of the balloon model? Why is it better than the explosion model?Ben

What I typed is wrong. What I was trying to type was that the stretching of space-time isn't really notable at the level of our local group, which as far as I know is true. But it is noticable beyond that, e.g. the red-shifts of more distant galaxies. Space-time is expanding, just the stretching is so small that it does not cause clusters to fall apart, just widens the space between clusters (because gravitational attraction is "stronger" than the stretching, basically).But an explosion is a bad model because, unless you assume that the earth is at the very center of the explosion you would see some distant galaxies 'coming along with us' on the journey away from the center of the explosion. Astronmers don't see that, they see everything (outside our local group) in every direction flowing away from us in an ever increasing manner. Assuming that we are not at the exact center of the universe (which seems unlikely since the Milky Way is clearly moving, as part of our local group, on a voyage to the Great Attractor among other reasons) then essentially we assume that any point in the universe would see the distant galaxies expanding away from it very rapidly. Hence the balloon model over the explosion model. The balloon model has limitations as well, of course, but it is closer to what astronmers see than an explosion model.Even more disclaimers apply. I am not an expert, I tend to write in a confusing manner, and I'm in a rush right now. If a real expert comes along and contradicts everything I've said, don't be that surprised. I was just a physics minor in college, that and some reading of popular books on cosmology is pretty much the extent of my knowledge.If this confuses you even more, I apologize and I'll try to fix it tomorrow.ChrisThis message has been edited by cmanteuf, 03-31-2005 04:05 PM

Hangdawg13 This is where the deviation from the actual occurs.Theses are concepts that it requires the mathematics to simplify keeping track of the "players" in the game.Spacetime tells matter how to move and matter tells spacetime how to curve.
A bomb uses high energy gases produces by chemical reaction to impart momentum to the shrapnel.In the big bang the expansion of spacetime draws out all the matter that was once "contained" as it progresses. Don't you hate it when nature won't make things dead simple?Space is not empty according to quantum mechanics.Virtual particle anti particle pairs pop into and out of existence continuously.They are capable of doing this because they do not exist long enough to reach a value greater than the uncertainty principle.From the Hyperphysics website It is apparent that the level of education we posses is far from complete enough to take in all the intricaies of the concepts involved but perhaps you are beginning to see that it is deeper than first glances might imply. This would take more space that would be practical to answer even with my limited understanding.I suggest that you perhaps follow your curiousity into the field of cosmology.This message has been edited by sidelined, 12-11-2004 01:49 PM

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A centipede was happy quite, until a toad in fun
Said, "Pray, which leg comes after which?'
This raised his doubts to such a pitch
He fell distracted in the ditch
Not knowing how to run.

Any amount of time may be between Genesis 1:1, and Genesis 1:2 .We know time had to pass, because God does not make anything "without form and void".The earth was Satan's domain (and still is, limited, for now) before. Possibly the earth was destroyed by Satan and his angel followers being cast back down to earth.Then at some point after this, God repaired the earth and made man where he would have the greatest struggles (against Satan) to build character, come to see evil for what it is, ect.

Hmm tough question at first glance, should we use the "center" of the big bang as our reference frame or earth as our reference frame?OH WAIT they are the same thing! Every point in the universe was the point where the big bang banged. Yeah it's easyer to think about it inflating or expanding. We often discribe it as an explosion because space expanded so very rapidly.This message has been edited by The Dread Dormammu, 12-15-2004 06:02 AM

This are my thoughts, I'm not sure if I've got it right:What do we measure the age of the universe in? We use years.What are years? They are the length of time it takes the earth to orbit the sun.Thus whatever frame of reference you are working in, your time measurement has already been calibrated to correct for it.

Ah yes, I keep forgetting this. So if space expanded, then all the galaxies we see redshifted are not racing away from us THROUGH space, but rather space is swiftly carrying them away (like the pennies on a ballon analogy). But the "expansion of space" implies change in this thing called space. If space is merely a construct of dimensions, energy, and probability, then how does that "expand". Does that mean the definition of a meter is changing? Of course if every dimension is changing at once, we wouldn't know the difference... BUT apparently there IS a difference since we were not always separated from those faraway galaxies by a lack of energy, and we are told that microseconds after the big bang energy began to condense into particles. Could we say instead that the width of the universe at this point exceeded the planck length or that the planck length shrank to less than the width of the universe? So if the definition of a meter is changing and the spacial dimensions are tied to the time dimensions, then the definition of time is also changing even though we cannot perceive this either.....I know I'm rambling, but I think we can all agree that the definition of time and space seems to be very stretchy since there is no absolute reference frame. Even our own subjective experience of time is dependant upon the processing speed of our brains. If our brains processed a million times faster, then one hour would seem like 2,500 years.

Yes, exactly.On the other hand, we can also move through space, and there is an absolute rest frame for measuring this motion, relativity notwithstanding.The microwave background radiation from the big bang fills the universe. Due to the expansion of space it has stretched and cooled, so that it is now at a temperature of 2.725 degrees Kelvin, with fluctuations in the order of 0.0002 degrees.This radiation has a rest frame. If you move in any direction, then the radiation approaching you from behind will be red shifted, and the radiation coming to you from ahead will be blue shifted. You are at rest with respect to the radiation when it comes to you from all corners of the sky at the same temperature.The Earth shows a velocity of about 600 m/s with respect to this background radiation. For comparison, our speed around the Sun is about 30 m/s. This velocity is large and unexplained. It is greater that the velocity of the Sun around the Milky Way, or of the Milky Way within our local group of galaxies, and this means that the whole local group of galaxies is moving rapidly through space.The COBE satellite, which found the ripples in the CMB radiation, also found our velocity with respect to the radiation as a side effect. Here is the temperature map of the CMB radiation seen by COBE: (This image from Astronomy Picture of the Day, Jume 27, 1999. Follow link for more information.)The ying/yang effect in the image is due to motion induced Doppler shifts. The small distortions across the middle are due to additional local radiation from our own Milky Way galaxy. When these are all removed, what is left is the CMB map I showed in Message 5.The CMBR thus defines a distinguished rest frame in which it makes sense to give an age of the universe in seconds. The time difference with the Earth's rest frame due to time dilation is only 0.0002%. Space is what stops everything hitting up against everything else. Space is room to move. Expanding space means that, over time, we find that there is more room to move than there used to be. Imagine a universe filled at every point with a dense gas. (This is indeed what the early universe was like.) There is no edge or boundary to this gas; it fills every point in the universe. However, as time passes, the gas becomes less dense. This is because there is more space available. The definition of a meter is not changing, and the definition of planck length is not changing. When we speak of the width of the universe, we really mean the width of the portion of the universe we can now see (the visible universe). We don't actually know how big the entire universe is, or even whether it is finite or infinite.Expansion of space is a difficult concept, but it is a real phenomenon; it really does mean you get more space over time, and it is not the same as defining different distance scales. We can perceive it, and we can measure it. Can't really agree, in fact. The definitions are not ambiguous. It is true that one can give different co-ordinate systems and different metrics, and map between them; and that time and distance are relative to an observation frame, but there are also invariants which apply in any frame. This has nothing to do with different subjective experience; the reference frames are objective and shared by all observers in that frame regardless of how quickly they can think. And there is a sensible distinguished rest frame for cosmology; being the frame of the cosmic background radiation.Cheers -- SylasFixed in edit: oops. recalculated the time dilation due to earth's motion in the CBMR rest frame. was calculating with kilometers not meters and got it badly wrong on first attempt.This message has been edited by Sylas, 12-18-2004 03:01 AM

Thanks for your reply and some new information. Ah...! CMBR is the ultimate reference frame. I should have thought of that. This makes sense, but I am still a bit skeptical. For one, isn't the CMBR much cooler than we expected for a 14 billion year old universe? And secondly, the egg apparently wasn't perfectly homogeneous right? I mean how could a homogeneous ball of energy evolve into our universe with dense clumps of galaxies separated by vast regions of empty space? If the original egg wasn't homogeneous then how can we assume that the variances in redshift correspond to doppler effects? Perhaps the effect is so large and distinct (I spose 600 m/s is significant) that there is no other obvious explanation. OR... is it possible that we are in between an older, cooler, and therefore redder part of space and a younger region of space? Is it a verified fact that every part of space is the center?Also, we are moving at 600 m/s now, but how fast was our matter moving right after the big bang? Isn't the current theory that the universe has experienced a major decceleration over time (and evntually a slight acceleration as well)? Can we extrapolate this back and figure out our velocity close to the big bang? I see exactly what you are saying, but isn't space tied to time? So as there is more room to move isn't there also more time in which to move? Instead of saying, "right after the big bang space expanded very rapidly," couldn't we say instead, "close to the big bang time flowed very quickly because space was small. As space expanded time slowed down."It's like time and space are two variables in a differential equation. When we talk about the big bang we always hold time at a constant rate and space expanding at an exponentially decreasing rate as a function of time, but couldn't we instead view them together as a dynamic system? I mean who said time flow must be constant?I don't think what I'm proposing is a paradigm shift in astrophysics only a different way of thinking about the age of the universe. We are so used to thinking of time as being constant that it carries over into our approximations of the dynamically changing space-time we live in. Maybe I'm wrong, I just don't see why time must be thought of as an unchanging dimension when space-time is said to have 'expanded'. But before energy condensed into matter, wasn't the egg essentially the same as the sea of zero-point-energy that we think exists below the planck length only much more energetic? We typically say that as space expanded energy condensed and cooled into matter. What exactly does this mean (I know it has nothing to do with the condensation of water vapor in a cloud)? Why does separating energy cool it down and condense it unless some property of its existence changes? Perhaps saying that H-bar got short enough for matter to condense is the same thing as saying space expanded enough for matter to cool? I understand that space is expanding, I just don't think we are realizing all that this means. It seems like scientists are saying one thing and thinking another. They say that the universe is more like the pennies on the balloon, but still go on approximating the situation with ideas of an explosion. The CMBR redshift and the galaxy redshifts all point to motion THROUGH space rather than expansion OF space, right? Wouldn't the expansion OF space produce other effects besides the movement of matter through space? (I think that the periodicity in redshifts MIGHT be one effect as they have yet to be disproven, but are still not accepted.)Anyway, I'm rambling again, thanks for your information.This message has been edited by Hangdawg13, 12-18-2004 02:01 PM