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Big bangs origin relative to the earth's location

  1. Apr 7, 2009 #1

    a^6

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    -Big bangs origin relative to the earth's location-




    i'm trying to comprehend this from the earths point of view.

    -If we have readings of an eliptical expansion (such as cobys imagery) how did we get that relative to the earths regional area in the universe? are we near said origin point? or did we mathematically find its origin based on measurements of surrounding multiple vectors from the earths core outward and differentiate accelerations and limits...

    thinking about the acceleration of expansion, I.E.- two points opposite from the earths core, do we somehow measure an acceleration being marginally faster at one, and the other marginally slower

    and we are able to depict from the earths relative perspective, the edges of the universe that are further then others from us- based on this space between objects?

    im just having trouble comprehending where we fit from the origin of this big bang, and how did we calculate where we are from this origin- because if we dont really know for sure where we stand in the expansion from this origin point wouldn't that obscure readings of the surface of expansion??

    these thoughts are where i currently am on trying to understand this lol, i may have it completely wrong and any help to this would greatly be appreciated

    prethankyou for any solutions to my confusion!!!
     
  2. jcsd
  3. Apr 7, 2009 #2
    the origin was everywhere not just at one point. And every point in the universe is the center. It all seems somehow holographic to me...
     
  4. Apr 7, 2009 #3

    marcus

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    Maybe that is a good way to look at it, Talon, but I suspect you are making it too complicated.

    The main trouble is the popular term Big Bang, which makes people get a completely wrong idea which was never intended---the silly idea OF AN EXPLOSION :rofl: at some point of origin in empty space!

    The big bang model was discovered in 1923 by Alex Friedman, and for him it was not an explosion picture of things flying out into empty space from some central point. It was never an explosion---that is a completely screwed up picture. Friedman did not call his model a "big bang". The name (which represents popular misunderstanding) came later.

    From the start, Friedman model has pictured that all space in a high density condition and, as it increased in volume, naturally the density declined.

    If you want a 2D analogy to 3D space, think of the 2D surface of a sphere with matter distributed approximately uniformly. All existence is concentrated on that 2D surface. No surrounding space. Then as the area of the surface increases the density will naturally go down.

    There is no point of origin.
    There is no edge.
    In the standard picture there simply was a brief period of time in the past when space was uniformly filled with matter at much much higher density than today.

    The name "big bang" is toxic waste: complete media garbage. It was a hostile epithet first used by an enemy of the theory, Fred Hoyle. He had a rival theory called steady state, and he resented the expansion picture which was winning out over his theory. It was reprehensible mischief on his part to call the picture he didn't like a "big bang" because it confused the public and misrepresented the theory. But journalists latched onto it and no way could you change how people talked.
     
    Last edited: Apr 7, 2009
  5. Apr 7, 2009 #4
    How can you have expansion, if you dont have an origin point, that is just totally absent of reason. Expanding from WHERE to WHERE?
    So what exactly filled the "space"? If the universe didnt have its original volume at the beginning, where did the room for everything to fill come from? Did it exist prior to the big bang? So we had this big empty space, and a singularity within it? What set up those initial conditions? I swear sometimes sciences cosmological explanations sound like a fairy tale.
    And if that circle increased in size, the origin of every force resulting in expansion, would point back to the center. No such thing exists in reality. If it did, I might not be so skeptical of certain assertions and assumptions that modern cosmologists seem to get hung up on. Heck, if we take the red shift information, and use that, Earth is the center ;-)
    And what filled the rest of it? If its uniformly filled, where did all the empty space for it to fill come from? If theres no point of origin, or "big bang center", than there is no big bang. If there is no edge, there is no "constantly expanding" universe, because it would require a place to move to, it cant just spread out, without getting farther from its "center", or encompassing an area BEYOND its edge.
     
  6. Apr 7, 2009 #5
    I'd say the "real" theory is far more "confusing" to the public than the term "big bang". Being that every time theres a hitch in it, they reinvent it with even more ambiguous concepts. It seems that many scientists find it "confusing" to the point where they believe IT is complete media garbage. Steady state makes more sense on every level.
     
  7. Apr 7, 2009 #6
    Hi Marcus.. Actually my 2 or 3 sentences essentially say the same thing that your paragraph says so I think my version is simpler. Well it makes sense to me anyway. Perhaps it was a bit too much of a poetic condensation. Yeah ok, your version explains it better. But anyway, this concept has been covered very well in this thread but there will always be those who can only envision things in terms of the normal everyday 3d world, rather than grasping a more abstract idea.


    reminds me of a famous quote
    " A .... knows not, and knows not that he knows not. A wise man knows not and knows that he knows not."
    I know not who originally said that.. :P
     
  8. Apr 7, 2009 #7
    I have no argument or problem with most of your answer, but it does touch on a question I raised in your sticky thread in this forum, which I still hope you'll respond to.

    I understand, specifically, that there is no edge. But as for there being no point of origin, is it not true that if the universe is finite (still an open question, right?), then there must be, if not a point of origin, at least a 'volume of origin'?

    Regarding your third point, about initially matter being at a much higher density than today, while from my (limited) reading I understand that this is the more popular theory, isn't the theory of an original singularity (which would comprise a finite volume of origin) still viewed as being a possibility?

    Beyond that, I'll wait (hopefully) for your response to my questions about the 'shape' of the universe in the first, stickied thread. Thank you.
     
  9. Apr 7, 2009 #8
    I would agree that if the universe is finite, then it's initial volume would have to be finite. perhaps plank volume? or as I read somewhere else, in the bounce model it would be something like 40% of plank density? We calculated that volume and density in another thread, don't recall which one.
    Of course even if it's finite and had a finite volume initially, that still doesn't mean it had a center. Continuing with the baloon analogy, we are imbedded on a 3 dimensional surface analgous to the 2d surface of the baloon and a surface doesn't have a center.
    Am I right? I'll defer to the brainier ones here...

    But as you say, we don't know 'yet' if it is finite or infinite...
     
  10. Apr 7, 2009 #9

    apeiron

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    You do seem to have two possible stories on the origin - either there was a singularity of some kind, or there was a phase transition which was everywhere at once, an infinite ground as Marcus (and many others) favours.

    The singularity approach would have to have been a big enough planck density point to produce the contents of our visible universe and some larger region beyond. So a finite volume story at least larger than just that needed to be "our point" of origin.

    Thus either way, it seems we are saying there was something larger, some context, within which our visible realm was once "a point". The universe would be the whole of this larger thing undergoing its phase transition. And that could be a finite or infinite volume. One presumably a closed hypersphere, the other a flat infinity.

    Yet then we have to consider another question I would suggest. What came before the point and its context?

    Three possibilities. Either it all popped into being out of nothing, or it always existed as it was, or it developed as a constraint on some greater state of potential.

    So say we take the scalar field of inflationary theory as a convenient reference. Either this dimensionally crisp field existed for all time. Or it popped into being out of nowhere and started spawning universes. Or its crisp dimensionality was a constraint, a reduction, of something much larger - like an infinite dimensionality for instance.

    On the whole, there is a lot of wiggle room in all this thinking.

    For example, if dark energy acceleration does create a finite distance event horizon for the visible universe (see recent sarfatti thread) then this would seem to be an edge of some actual kind to me.

    Every point of the big bang would have its edge, even if there are an infinity of such points and thus an infiinty of such edges.

    Points on one side of our universe, and points on the other, would have different such edges. Though they would overlap in the region that covers our own point and edge.

    So two versions of the origins issue? The universe started from some special place - a planck density. And this could have been a finite "volume" or an infinite one. Then every point of that place is the centre of its own visible realm and has an event horizon edge accordingly.

    So nowhere is special, yet everywhere is special. Nowhere is THE centre, yet everywhere is A centre.
     
  11. Apr 7, 2009 #10

    marcus

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    I don't know what phase transition or "infinite ground" you are talking about, Apeiron. I don't remember ever using the term "infinite ground". I doubt whatever you are talking about would bear any simple relation to the message I'm trying to get across. Simpler if you don't seem to put words in my mouth.

    Cosmologists as a rule are rather wise, then. What they have is a mathematical model, currently it is LCDM with parameters in certain ranges, that gives the best fit to the data. And there are literally millions of data points. Nobody claims to know the shape or expansion-history of the universe. Everybody expects new knowledge and improvements to the model. And the model clearly has interesting gaps to be filled in. It is just the best so far.

    LCDM is consistent with General Relativity, which is our best theory of gravity so far---tested accurate out to 5 or 6 decimal places. GR is a theory of dynamically changing geometry. The standard cosmo model is elegantly simple and also the best fit to data of any model consistent with GR. And it is agreed on, sometimes called consensus model or concordance model because it has been widely adopted by the professional astronomy community.

    My attitude is that our first job is to answer questions in terms of the standard LCDM model. So I hold back on my own private views if they differ, until it's clear that everybody understands what the standard cosmo model has to say.

    And nobody should confuse that with a statement of how Nature really is, or any such naive idea of Truth. It's an impressively successful model that has been tested against a lot of data and raises interesting questions for future research and observation. It dates back to 1998 and the field has been booming in the past 10 years. But it's a mathematical model and the usual thing is for those to evolve and change and develop. If I'm sure of nothing else, I'm sure the current professional consensus model will change. (and I'm eagerly looking forward to that!)
     
    Last edited: Apr 7, 2009
  12. Apr 7, 2009 #11

    russ_watters

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    Well which is worse?: having a theory that is confusing to laypeople but correct or having a theory that is clear to laypeople but wrong? Keep your eye on the ball!
     
  13. Apr 7, 2009 #12

    russ_watters

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    Consider the surface of a balloon. Where is the "edge" where you can move no further along the surface? Where is the center where the "edge" is equidistant in all directions? Can a balloon expand?
    No, space originated with the Big Bang.
    A circle most certainly exists in reality. As does a sphere. As does 3d space.
    And indeed it is.....but so is every other point in the universe. The spots on an expanding balloon analogy is an easy way to show how this can be true.
    That's basically all just gibberish - you are making claims that just plain aren't true because you don't understand the geometrical shape of space....despite having it explained to you in a straightforward way! Try accepting as provisional and then thinking through the explanations rather than rejecting them without any consideration. You may find you start to understand them.
     
  14. Apr 7, 2009 #13

    marcus

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    Please let's focus on the originally posted topic.
    The poster seems to think that the origin of expansion is a unique point that exists in today's space.
    He thinks that expansion is outwards from some unique location which we can point to, at the present time. We should be able to aim a vector from the earth in the direction of this unique place.

    How would you address this confusion?

    It sounds to me like instead of the dynamic changing geometry of General Relativity (where you can't expect distances and volumes to stay the same) he is imagining fixed geometry of empty space, and a big blast of material exploding outwards in this static geometry of empty space.

    So we have had General Relativity for almost 100 years. In 2015 there will be the centennial of it. Many people haven't absorbed the basic implications of spacetime being curved. Maybe we should start getting ready for the GR centennial. :biggrin:

    Any suggestions of what to say to the poster "a^6"?

    How about this:
    1. GR is by far the most accurate model of gravity we know.
    2. It says spacetime has a curved geometry. Geometry is dynamic and interacts with matter.
    3. Given that geometry is dynamic, you have no right to expect geometry not to expand. That's something it can easily do, given the right initial conditions, and is indeed likely to do. Friedman derived an expanding universe model as early as 1923. It is no longer appropriate to act surprised about this.
    4. What is unfortunately called "big bang cosmology" is essentially an overall pattern of mostly increasing distances. Including between galaxies which by the most reasonable criterion are sitting still. GR says we have no right to expect distances not to do this. Again, it is no longer appropriate to act surprised.

    Want to try your hand at saying the same thing in some nicer (hopefully more persuasive) way?
     
    Last edited: Apr 7, 2009
  15. Apr 7, 2009 #14
    It is what it is, just accept it, even if you don't understand it. Most laymen don't understand the math, myself included, so just accept the model at face value. That's my motto.. but then I'm comfortable with strange abstractions.
     
  16. Apr 7, 2009 #15

    apeiron

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    And you have to be looking for the gaps to see that they are there. This is the danger of your "stick to known models" approach. It sounds great as empiricist rhetoric. But it is not how minds actually function.
     
  17. Apr 7, 2009 #16
    Hi Marcus, thanks for the explanation, I have no trouble in your explanation of the expansion. What trouble me though is the concept of "beginning" of time then. I used to assume that it all started from a singularity, and then it would be meaningless to talk about "time" before the "beginning". But if it is just as you said, the universe was in a much higher (but finite) density with finite volume at the "beginning", it appears to me then it would be meaningful to ask about "time" before the "beginning", as the density and volume were always finite and well-defined. How then should one understand when physicists talk about the "big bang" happened some N years ago? Thanks.
     
  18. Apr 7, 2009 #17

    marcus

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    You are absolutely right, it is meaningful to ask about time before the beginning of expansion.

    In fact much current research is now being devoted to this. And a book on it with chapters by over a dozen top people is scheduled to come out this year.

    Roger Penrose pointed out the change in 2005 in a lecture he gave at Cambridge. It is online, tell me if you want the link. He said that until 2005 the prevailing view was that it was meaningless to talk about time before BB and that this had changed. And he was investigating the possibilities himself (along, of course, with many others.)

    This is one reason why, in cosmology, one should not trust writing from before 2005, it gives the wrong impression of the expert consensus. Have a look at the public outreach website of the Albert Einstein Institute---the link is in my signature at the end of the post, in small print. It is more up-to-date than some other wide-audience writing.
    http://www.einstein-online.info/en/spotlights/cosmology/index.html
    In particular, see their essay "A Tale of Two Big Bangs" (which clears up some common confusion caused by physicists using the term BB in two different senses):
    http://www.einstein-online.info/en/spotlights/big_bangs/index.html
    There is at present no scientific reason to suppose that time began at the start of expansion (estimated 13.7 billion years ago).

    There is a lot of pretty solid evidence that the current expansion began 13.7 billion years ago. One simply cannot say that there was a singularity, however, or that time began. There are now several types of physical model that go back further---for example ones showing a contraction leading up to a state of very high density (near Planck density, in fact.) The different types of model will be described in the book I mentioned. (Let me know if you want links to the Amazon page and the publisher catalog page for the book.)

    One can understand that as meaning just exactly that. The big bang (a high density state at the start of the current expansion) occurred about 13.7 billion (estimated) ago. I do not see any problem with that statement.

    Again, you might read the Einstein Online pages about this. Or if you want to sample the professional research literature you can use the Stanford research literature search tool called Spires and the keyword "quantum cosmology".
    http://www.slac.stanford.edu/spires...+DATE+>+2006&FORMAT=www&SEQUENCE=citecount(d)
     
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  19. Apr 8, 2009 #18
    So by your definition, our universe is the shape of the surface of a sphere? You analogy seems a bit flawed. I would imagine expansion to be more like this.https://www.youtube.com/watch?v=OHY9fFQhX68

    And if you had that marshmallow, hanging in space, it would expand outward uniformly, and you would get multiple directional forces associated with its expansion. This is what is claimed to be seen in the "red shift" in light viewed from distant galaxies. The idea that everything is uniformly expanding is quite unprovable. As would be the case if time was uniformly expanding, and even though a minute now, may be two later, it would be measured as one, and everything staying relative, noone would notice.
    I dont think you understood me there, so i'll ignore that.
    I dont see how it, in any way, shows that it can be true.
    And you are making assumptions that you cant explain, but you're sure are "true". You are talking about an expanding baloon, the balloon has an edge, and it has a center, when you inflate it, the edge moves further out into the space it didnt fill before. If there is no space to inflate the balloon into, it wont inflate.

    It would make more sense to think of the universe (atleast our little hunk of it) as a piece of matter, and the galaxies as atoms, and the bonds between galaxies as the different bonds between atoms to make compounds. And that heating that matter, would cause the molecules to spread out, and become closer to one another, and cooling it would cause them to contract, and be further apart. The whole trying to figure out the "age" of the universe is such a joke, and its based on the assumption of the expanding universe. We measured (and I'm still skeptical about the whole "red shift in distant galaxies is due to the doppler effect" spiel) the movement of distant galaxies AWAY from us, and assumed that its always been that way, and just kind of "rewind" till we get to everything being densely compressed into a singularity. That logic doesnt make sense. Its a very linear design, in a universe where nothings linear. Its a very human-relative thought. If it was true, we'd be getting more answers, than questions, and that doesnt seem to be the case.
     
  20. Apr 8, 2009 #19

    Chronos

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    Russ is asserting the modern scientific position [deductions based on observation]. It appears your assertions are classical, 19th century based logical fallacies. Can you cite any scientific papers affirming your position, yelram?
     
  21. Apr 8, 2009 #20

    a^6

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