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Thread: The start of everthing

  1. #1 The start of everthing 
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    Ive allways been interested in the universe and the great unknowns but lack the thought process to get my ideas out, so I went into art instead, one question I pose to you.

    To understand the begginnings of our universe we should surely point our most powerfull telescopes towards the centre of our universe if what im thinking is right, (that the big bang blew out 360 Deg and expanded into a spherical shape) to find the centre, you would have to find out where the galaxies are most clumped together and follow till it gets tighter and tighter. im guessing we just havent the technology yet.


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    This is a logical question and one that I have wondered myself. If there was a big bang from which everything expanded surely you should be able to pinpoint the point in space where it happened. It should be the dead centre of the universe. However if you ask this question to astronomers and cosmologists they will probably laugh at you or tell you your concept is flawed.


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    The short answer would say; The Standard BB Theory (most acceptable) claims there is no center point. What most people, including myself visualize a 'Singularity', which would have a center, that for some reason began to expand uniformly in all direction, what ever that center point was, should still exist.

    In other words, although the standard Big Bang models describe an expanding universe with no centre, and this is consistent with all observations, there is still a possibility that these models are not accurate on scales larger than we can observe. We still have no real answer to the question "Where is the centre of the universe?".
    http://math.ucr.edu/home/baez/physic...GR/centre.html


    Is there a center to the universe?
    No.
    If general relativity is correct, the answer is that there is no unique center to our universe anywhere within our 3-dimensional space. The center of a balloon is not located in the surface of the balloon, and the 'center' of our universe is by analogy not located in its 3-dimensional surface either. Still, every observer through out space will see the universe expand as though they are at the center of the expansion.
    Since, our observations from Earth, ALL would indicate the Earth or our galaxy was either the center or very close to it; The above site indicates that from any point in the Universe, those same observations would likely show the same. If Earth was a planet in the furthest seen light, suspected to now be a galaxy that galaxy would look very much like the Milky Way, today. If we made the same observations from there, what we see as that light 13 BLY away, would be observed looking back at Earth and the MW. Put another way, if there is a they, on that planet, they would observe us as part of the original Universe 13 BY ago.

    What I like to say, is there is no discernible center and likely one could never be determined. Then the U today is estimated to be around 250 BLY across/diameter (our known U 26-28 BLY), by some. If we are near an edge (so to speak) advanced technology could allow heat measurements (extreme heat should have existed in such a place 14-15 BLY away, near by already cooled) this would open up the possibility.

    As for a cluster of matter; Not necessarily, in fact it would likely be a void in space (pure opinion). As space expanded and matter formed, uniformity should be near consistent, relative to the U size. We do see what appear to be concentrated matter (more galaxy) at further distances, but are observing what WAS in that time frame, a much smaller Universe.
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    Awesome that makes sense, I also thought over red and blue shift to determine the origin point, wouldent we see the origin point as a tiny bubble of extreme heat then as we get further away that just expanding.
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    We are at the centre and so is everything else. That's what happens when you expand from a singularity. (The clue is in the word singularity.)
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    Quote Originally Posted by James_Leighton
    Awesome that makes sense, I also thought over red and blue shift to determine the origin point, wouldent we see the origin point as a tiny bubble of extreme heat then as we get further away that just expanding.
    As Ophiolite said, every point in space is the center. A similar way to think about it, is to try and find the center of the surface of a sphere. You can't.
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    James; If you could see the entire Universe, from a distance and in real time, every thing would look basically the same as we visualize today near by. Remember matter started forming in what was then a relatively smaller area and the hot spot would be that area. My imagination, can't figure a way we would ever see back in time to what was in those first seconds (light or energy-heat), but if ever done, yes the temperature should be very warm likely in all direction. That is the "tiny bubble" in real time, is what the entire Universe is today.

    Red and Blue shifts (Hubble's Law) is proportionate to the distance from us, caused from the expansion in the time frame we see the image, actual movement of the objects (galaxy) are likely no different than our own and near by galaxy, the space with in increasing. Opinion; What was going on under BBT, 3-5-10 or 13.7 Billion years ago (what we're seeing) may have nothing to do with what is going on today.

    http://en.wikipedia.org/wiki/Hubble's_law

    James/Kalster; In a three dimensional picture of the Universe today, under the assumption the U is finite our galaxy should have a position in the total, that's the reason some still argue or are unwilling to determine a center and I like the word 'indiscernible'. Common sense tells you there must be Galaxy nearer the edge than others and others near the center of the object (Universe).

    A similar way to think about it, is to try and find the center of the surface of a sphere. You can't.
    Would you deny, there is a center of the Moon, Earth or Sun, all spheres or objects?

    My opinions, anyway...
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    James/Kalster; In a three dimensional picture of the Universe today, under the assumption the U is finite our galaxy should have a position in the total, that's the reason some still argue or are unwilling to determine a center and I like the word 'indiscernible'. Common sense tells you there must be Galaxy nearer the edge than others and others near the center of the object (Universe).
    Quote:
    A similar way to think about it, is to try and find the center of the surface of a sphere. You can't.



    Would you deny, there is a center of the Moon, Earth or Sun, all spheres or objects?
    I think you are making a common mistake. If the big bang is the source of all matter, time and space and the universe is finite, then that means there cannot be a center of the universe like one would find in the middle of a sphere. For a center to exist, there must be an outside vantage point to the universe and there must be an edge. This is inescapable. Since the most common interpretation of the big bang theory purports that the big bang was the origin of all space, time and matter, this is not possible. There can't be an "outside" of the universe anymore than there is a seventh side to a standard die.

    As such, one of the most common analogies used to give an idea of how this works is the balloon analogy, which I am sure you have heard of before. The important thing to remember with the analogy is that it is only that, an analogy, and also that only the 2D surface of the sphere has to be considered and what the conditions of a 2D alien living on the surface would be like. A flatlander would start out walking in one direction, a perfectly straight one from his perspective, and eventually he would end up back where he started. Similarly, if a very fast ship were to take off from earth in a perfectly straight trajectory (and assuming the expansion stops) he would eventually end up back at earth. The same would happen if one were to take a similar journey from any point in the universe. What expansion would do is ad to the distance needed to be traveled for the someone to end up back where they started.

    So our galaxy's position in the universe can only be thought of as one relative to other bodies, not relative to a center, since everywhere would be the center, similar to how one would not be able to mark the center of the surface of a sphere.

    I hope that helps.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    The big bang could easily have been triggered from an external source (Multiverse Membranes colliding) then there could of been time and space before hand.
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    James; Fessing up, I don't buy into BBT or at best, am very skeptical. However explaining under BB, if space was released along with what formed our current matter, where would those other Universe have been, in another dimension or realm? Nor do I think space curves or that the U is two dimension, if anything many dimensional and we have no means to understand or measure.

    It could be, like so many things in science, we will be right back to where we started 500 years ago, looking for an answer to if the U started at all. Why couldn't the U or at least the matter, atoms or sub-atomic particles have always actually existed in some manner, even possibly much like the U we're seeing today. Recently mentioned, think this forum, the Hindu, 2000+ plus years ago felt the felt the Universe was a result of an old one that had collapsed, now considered as pulsating and I believe what's now called the Big Bounce.

    Keep looking for your own idea, study its potential, but don't expect an answer in your lifetime or even think the entire story will ever be known. Whatever the answer is, IMO something must have always been here, another U, whatever made up a singularity, those multi verse (String Theory) or maybe even we're just some experiment in a class room, and we are just a fungus on a rock, a few quadrillion quadrillions times in size, our entire U.
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    Any matter or energy in space-time warps it, that's what gravity is.


    It created the four fundemental forces, which only apply over the duration since Time=0. Beyond, or before this, there's nothing.

    We are trying to explain the weakling, Gravity, through the LHC. Edward Witten and Roger Penrose.
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    The trouble with that balloon analogy, KALSTER, is that we forget that the balloon is embedded within a higher dimensional space that is undetectable to our 2D friends. From our vantage point in 3D, outside of their universe, we can see the edge and calculate where the centre lies.
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    Quote Originally Posted by Zwirko
    The trouble with that balloon analogy, KALSTER, is that we forget that the balloon is embedded within a higher dimensional space that is undetectable to our 2D friends. From our vantage point in 3D, outside of their universe, we can see the edge and calculate where the centre lies.
    Nothing exists beyond the Universe.

    If you were outside of our Universe You wouldn't exist, you wouldn't be anywhere and there is no where.
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    Wouldn't our balloon-dwellers say something similar? I agree with what you say, and would probably say more or less the same thing to others when asked a similar question. However, I keep seeing cosmologists talking about things that would seem to suggest that there are other "places" that are not within our universe (by which I mean everything that was formed in the BB). Which would imply that there is an outside of sorts, no?

    For example, you've got things like the Many World Interpretation of quantum mechanics, brane theory, the idea that universe erupted from a black hole or that our universe is but one of many such space-time bubbles in a sea of such structures. Now, it doesn't really matter if any of these things are valid ideas supported by sound maths or, for that matter, if they are even testable or not; what's important (for the point I'm making) is that these ideas illustrate that cosmologists are capable of thinking about places that are not within our universe.
    It's in this sense (and maybe I'm just confused here) that I think that to say there is no outside is perhaps not quite true.
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    The trouble with that balloon analogy, KALSTER, is that we forget that the balloon is embedded within a higher dimensional space that is undetectable to our 2D friends. From our vantage point in 3D, outside of their universe, we can see the edge and calculate where the centre lies.
    Sure, but like I said, the analogy is only supposed to aid an intuitive understanding of how our 3D Minkowski space universe works, by thinking about how the 2D flatlanders would experience their universe. Looking at the analogy from a 3D perspective and inferring implications from it makes it invalid and destroys it. Our 3D equivalent of the flatlander's universe can be entirely described by using only 3 spatial dimensions.

    Wouldn't our balloon-dwellers say something similar? I agree with what you say, and would probably say more or less the same thing to others when asked a similar question. However, I keep seeing cosmologists talking about things that would seem to suggest that there are other "places" that are not within our universe (by which I mean everything that was formed in the BB). Which would imply that there is an outside of sorts, no?
    The meaning of no outside is similar to when I said it is the same as trying to think about the seventh side of a standard die. Anything that connects this universe to another implies a larger universe, rather than two or more separate ones to my mind. I have trouble thinking about other universes that are not connected to this one in some way, because they would be separated by a reality barrier of absolute nothingness (if that makes any kind of sense), which IMO does not even make them worthy of consideration. This is only an opinion though and I don't know how these things are treated mathematically or as hypotheticals in scientific circles.

    I think the main problem with trying to visualize our universe is that we almost inevitably try and look at it from an outside perspective and see things like spheres or two gobs connected by a bridge etc. , which ignores the fact that space is not simply the absence of matter or gravitational fields.
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    Defining what one means by the term "universe" is obviously important and I tend to use it to refer to the stuff that was formed in the BB. In that sense there is indeed perhaps an outside or an elsewhere. Again, I'd stress that it's just our ability to attempt to talk about such things that I'm looking at, and which would seem to make the "no outside" argument a little insecure.
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    As long as we can agree on what the extent of "absolute nothingness", then I don't have any issues with such an interpretation.

    One alternative I quite favour (though I am not sure about the scientific viability of it), is that there is in fact an outside infinite universe, but that our local corner of it is due to a big bang energy event that possibly causally isolated us from the rest due to curvature, similar to how a black hole is isolated from the rest of the universe. That would eliminate any "what happened before the big bang" type questions.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    I'm sure I've heard Roger Penrose (maybe it was somebody else though) talk about the BB as possibly just being an inflating patch of space-time and that universes such as ours may bud-off now and again.
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  20. #19 Re: The start of everthing 
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    Quote Originally Posted by James_Leighton
    Ive allways been interested in the universe and the great unknowns but lack the thought process to get my ideas out, so I went into art instead, one question I pose to you.

    To understand the begginnings of our universe we should surely point our most powerfull telescopes towards the centre of our universe if what im thinking is right, (that the big bang blew out 360 Deg and expanded into a spherical shape) to find the centre, you would have to find out where the galaxies are most clumped together and follow till it gets tighter and tighter. im guessing we just havent the technology yet.
    The idea of space expanding requires a hypersphere, as in a four physical dimensional sphere, expanding (think of a balloon, with the skin as our 3D universe).

    However while many are quick to point out that the universe has no centre, it does but it has been lost. If everything is moving apart and you had sufficient information and a good enough computer, then you could trace every movement of every body in space backwards and it would (in theory) be traced back to a single point.
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    The idea of space expanding requires a hypersphere, as in a four physical dimensional sphere, expanding (think of a balloon, with the skin as our 3D universe).
    Cyberia, no matter how many times you repeat this, it is not going to be true. Only three spatial dimensions are needed and saying more are needed is going against the people that actually worked this out. Just because you can't imagine it does not make it untrue. The fact remains that curvature can be fully described by only using 3 spatial dimensions.

    However while many are quick to point out that the universe has no centre, it does but it has been lost. If everything is moving apart and you had sufficient information and a good enough computer, then you could trace every movement of every body in space backwards and it would (in theory) be traced back to a single point.
    Again, no it wouldn't. The definition of a point center of the universe requires an outside perspective and a border, which cannot exist if the big bang was the origin of all space-time and energy.
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    Here's a little thought experiment I'm trying to visualise (without too much success): if the expansion of the universe was put in to reverse, what would we see regarding a boundary and a centre if we shrunk it down to 5 m in width? This is just a gedankenexperiment type thing, so I'm ignoring the fact that matter would not exist in a state that would allow observers etc.

    Without a great grasp of the mathematics of space-time geometry, I have this vision of there clearly being a centre to a 5 m wide universe. If that is indeed the case (not saying it is, just that I can't quite picture things) then it would imply that the universe of today still has a centre somewhere.

    What's the flaw in my conclusions of this thought experiment?
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  23. #22  
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    Quote Originally Posted by Zwirko
    Here's a little thought experiment I'm trying to visualise (without too much success): if the expansion of the universe was put in to reverse, what would we see regarding a boundary and a centre if we shrunk it down to 5 m in width? This is just a gedankenexperiment type thing, so I'm ignoring the fact that matter would not exist in a state that would allow observers etc.

    Without a great grasp of the mathematics of space-time geometry, I have this vision of there clearly being a centre to a 5 m wide universe. If that is indeed the case (not saying it is, just that I can't quite picture things) then it would imply that the universe of today still has a centre somewhere.

    What's the flaw in my conclusions of this thought experiment?
    That is exactly the type of question the balloon analogy is for. So imagine yourself as a 2D alien on the surface of the balloon and you'll get it. From your perspective the distance you'd have to travel to end up back where you started would decrease as deflation continues and you would still not be able to define a center, since you would be able to repeat the trip around the universe from anywhere within it.

    The balloon analogy provides the conceptual reference for us to imagine a 3D version of the flatlander's 2d universe. You won't be able to find the center on the surface of the 2D balloon, right?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
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    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
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  24. #23  
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    I do get it (sorta). As I said earlier, I even use the balloon surface analogy myself when the topic arises in conversation.

    It just gives me a headache...
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    Quote Originally Posted by Zwirko
    I do get it (sorta). As I said earlier, I even use the balloon surface analogy myself when the topic arises in conversation.

    It just gives me a headache...
    I hear ya. Wait until you have to try and imagine a saddle shaped or a toroidal shaped universe.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
    "All people know the same truth. Our lives consist of how we chose to distort it." - Harry Block
    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
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