The size of this universe

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Saint, Jan 14, 2014.

  1. brucep Valued Senior Member

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    Quit spouting bullshit wellwisher. Really, give it a break. Learn something instead.
     
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  3. paddoboy Valued Senior Member

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    GR and the laws of physics describe the Universe of which we inhabit. Itis also generally assumed that two independent observers, studying the same physical scenario, would eventually formulate identical laws of physics in order to account for their observations.




    Yes??? So????




    Not really.....DE for example only made itself obvious with the discovery that the Universe is now accelerating in its expansion rate.
    That was not always the case.
    Please elaborate more clearly in what you are trying to say.
    If you have evidence that SR/GR or any other cosmological theory is wrong, and you can falsify it, then do it.
    Don't beat around the bush.
     
    Last edited: Jan 29, 2014
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  5. brucep Valued Senior Member

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    It's a theoretical model. No theory can be proven to be absolutely correct. So why is that more debilitating for cosmology? Cosmology has been raised to the status of testable science. Leading to a empirically supported standard model of cosmology. That model is Lambda-CDM model. Good for the cosmologists getting this done.


    Wilkinson Microwave Anisotropy Probe
    http://map.gsfc.nasa.gov/
     
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  7. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    (cont.)
    Our Universe is all there is to us. We do not know if anything else exists or not, for all we know the Universe is all there is in some strange recycling nightmare or something. But even if you had a perfect rocket you would never find an edge, just more Universe. Einstein described it as finite in size but unbounded by edges. That means it is it's own container. This is really not possible for our monkey minds to understand or visualize. We try to model the concept at lower dimensions with Klien bottles and Mobius strips, but like the rubber sheet illustrates gravity in a two d form, but is not an accurate model of the three d reality, the three d Klein bottle does not accurately model the 4d hypersphere that is the Universe. The Klein bottle has two mobius strips, the one illustrated and a mirror image on the other side. A mobius strip is a two d object with just a single surface(IE one dimensional), the Klein jar is a three d object with two dimensions, the hypersphere(which cannot be illustrated well at all, though people try)is a four dimensional object with three spacial dimensions and one of time. Ergo something that contains itself. In the terms of our Universe, the three dimensions of space came out of the Big Bang, along with everything else, it created the space needed to contain itself. Now that's about as far as I got in Cosmological Topography, it takes a certain kind of crazy to go much further, and no, I don't understand it.

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    Also, the Event Horizon of a BH marks an edge to our Universe. I saw Hawking's arxiv article, but I'm not convinced. Few physicists do valid new science after 40, even Einstein had done the majority of his best work before that. Hawking just lost the bet with the Royal Astronomer(I forget his name)about information conservation in BHs, after all.

    Walter L. Wagner

    Correct, but it's 13.7 billion years, give or take a few hundred thousand. The thing is every point is space sees exactly the same thing, somewhat distorted by their different radial position. Every point sees itself in the exact center.

    !3 billion years of being tugged around by gravity is what gave us that real speed, everything started at relative rest but once the radiation pressure was no longer keeping matter apart the huge gas clouds and galaxies started collapsing and gathering in clusters. Falling toward a bigger galaxy or cluster over a few billion years builds up impressive speeds over time.

    Grumpy

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  8. paddoboy Valued Senior Member

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    It was Sir Martin Rees....I havn't heard of any retirement of late.
     
  9. Fraggle Rocker Staff Member

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    The names of the moderators of all the subforums pop up if you click View Forum Leaders on the title page. Alphanumeric is the Moderator of the Cosmology subforum, so if you have a complaint about the way it's being moderated, you should complain to him. I moderate Linguistics and Arts & Culture, so I avoid stepping into somebody else's territory unless it's something obvious like personal insults--and I have indeed bitched at a couple of people here for that exact violation. I'm hardly enough of an expert in cosmology to decide whether someone's assertion is bullshit or simply an interesting hypothesis in search of evidence.

    We're all unpaid volunteers so there's a limit to the time we can put into this "job." We disagree with one another as much as you do, so it's never easy to hammer out a policy for the entire website. In any case that's not even appropriate. I can easily tolerate digressions on the Linguistics board because it just doesn't get enough traffic to worry about. As for Arts & Culture, how the hell do you even define "trolling" in that milieu? "Debussy was the best composer who ever lived."-- "No he wasn't, it was Bruce Springsteen." I'm not going to try to settle that argument!

    Obviously, the hard science boards need a different standard.

    This academy has an entire wing devoted to poppycock and bullshit. I seldom go there so I'm not sure how rigorously it's moderated, but I'm fairly certain that people are free to discuss their own hare-brained schemes without being pestered by moderators invoking the scientific method. I would assume that the rules about personal insults, racism, not veering off topic, etc., are enforced.

    You misunderstood, sorry for not making myself clear. I was going back to the model of the cosmos that was generally accepted in my youth. In that model, our Hubble volume is not a singularity. It's just a tiny patch of the space-time continuum that happens to contain some matter and energy, and a few blobs of protoplasm who are trying to study it. In those days the space-time continuum was assumed to be infinite; the laws of nature were assumed to be universal throughout that continuum, as were arithmetic and logic. In that model, since the emergence of this Hubble volume is merely a spatially and temporally local reversal of entropy, there's no reason why other Hubble volumes can't also appear suddenly in other times and places.

    In other words, in those days our "universe" was not thought of as a singularity.

    I spend my days doing technical writing for a software house, and my evenings playing bass guitar. It's unlikely that I'll be the one to discover infinity.

    This is all speculation at best, and simply amusing exercises in logic at worst. It's okay to stretch your imagination. Even if the ideas that pop up can't possibly be true, proving that is a good way to exercise the old brain cells.

    And as I said, the cosmologists of 70 years ago were quite content with the notion that the space-time continuum is infinite. Who am I to argue with those guys, especially since their model of reality has not actually been disproven, merely fallen out of favor?
     
  10. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    Fraggle Rocker

    I was alive but just a tot when Hubble's work was published, but I remember Penzias' and Wilson's publishing from Popular Science or Scientific American, we learned a lot in the 60's that we are still trying to understand fully 50 years later. We are a long way from knowing everything about our Universe and some of the stuff we think we know now will eventually be shown to be in error. Even Einstein and Hawking got some things wrong or made assumptions that were not valid. For instance, I was taught that there had been an era of antimatter/matter at near parity, with the remnants of the slight imbalance toward matter being what we see in the Universe now. The latest hypotheses seem to be a bipolar multiverse where one Universe inflated with almost all matter, the other with almost all antimatter like two poles of a magnet, or a co-located, four lobed one(two of each)with each having roughly one quarter of the mass, but sharing the gravity between them, each Universe being one third of the Dark Matter in the other three. The Quantum guys say there are at least 11 dimensions, I have to take their word on that. Then there's strings and branes, nearly non-existent Planck lengths in time and space, quantum foam in empty space and entangled particles, "spooky action from a distance" indeed! Now we have the Higgs boson, quantum gravity may be giving up it's secrets and Hawking is saying Black Holes are not afraid of being hacked, they have no firewalls(or something). I may be getting too old to keep up!

    Grumpy:itold:
     
  11. brucep Valued Senior Member

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    It's called wisdom of knowledge. At least that's what I call it. It's that good thing that happens when you've reflected on knowledge for an extended period of time [like many old dudes and dudettes on this forum]. You have lots of it.
     
  12. brucep Valued Senior Member

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    AN is involved?. I've done my share of complaining about cranks and moderators. Doesn't help much. The science threads are dominated by poppycock and bullshit.
     
  13. paddoboy Valued Senior Member

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    Although I have crossed swords with Grumpy of late, [and still am undecided re our conflict] I do see him and yourself as two of the old shining lights around here.
    I'm also an oldie but don't shine as much but anyway.....speaking as a layman, I also see plenty of poppycock and bullshit floundering around in mainstream science where they shouldn't be anyway.
     
  14. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    paddoboy

    Many reputable scientists are sloppy in their rhetoric. Einstein said quite a few things that, if quoted out of context or in isolation, give rise to confusion. It is for that reason I have some of the phobias about the use of certain words or concepts. I do not know there are no infinities, but I do know too many otherwise good scientists use the term to mean other things(like "goes on forever" or "towards infinity", which is a direction, not a destination), too loosely and sometimes just to show off(Michio Kaku is really bad for this). At least Kaku explained that in physics an infinity often means "we don't know what happens then" or "there's something we're not understanding here". We've never seen one, we should therefore avoid adding this to our consideration unless and until.

    But the discussion we had was very passionate, but not rancorous. You ask good questions and you think about what you post. I am named grumpy for a good reason, so if I gave the impression of being irritated, that's my normal demeanor, nothing personal. I'm trying to work on that.

    Grumpy

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  15. paddoboy Valued Senior Member

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    I actually found you anything but grumpy....determined, to get your point across? enthusiastic? knowledgable? All certainly.
    Sometimes being an old bastard myself, and a layman to boot, I may not have a full grip on a situation, but I'm trying to get a better grip on the situation.
    I have worked out who's who in this zoo, and the ones to take notice of and the ones with the agenda.
    If I do have an agenda myself, it probably is to short circuit the wackos, that seem to want to oppose mainstream science, just for the sake of it, or to drag the science disciplines down to base level with nothing but criticism at every level.



    I had my disagreement with you, I have had one with brucep, and I'll probably continue to have them.
    I am about to venture [the next week or so] to get a good book on cosmology and SR/GR, so I'm open for a good recommendation.
    The last book I put down was Thorne's "Black Holes and Time Warps"before that Kaku's "Hyperspace" and Hawking's BHoT.
    Not too mathematical mind you...Just with the basic description of what is, what isn't and what's to be...The rest is faith on my part, but as I said to someone a week or so ago, far better to have faith without the Maths ability in recognised experts, then to put faith in the other side.
    As long as I'm aware of a model's observtional and experimental data that supports it.
     
  16. wellwisher Banned Banned

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    Here is an interesting tidbit of historical information about this topic. This is from Wiki.

     
  17. Grumpy Curmudgeon of Lucidity Valued Senior Member

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    wellwisher

    Lemaître's work has always been acknowledged, even by Hubble. Many Jesuits have always been at the leading edge of science. Being religious and being intelligent aren't two totally separate things everywhere, though it is prevalent among evangelicals and fundamentalists, especially here in the US, it seems.

    Grumpy

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  18. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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  19. paddoboy Valued Senior Member

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    I don't believe LeMaitre's theory about Universal expansion was misattributed to Hubble at all.
    It is documented as Lamaitre's proposal but it was Hubble who finally revealed the evidence supporting it...that is redshift of light from distant galaxies...
     
  20. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    "Both Friedmann and Lemaître proposed relativistic cosmologies featuring an expanding universe. However, Lemaître was the first to propose that the expansion explains the redshift of galaxies." http://en.wikipedia.org/wiki/Georges_Lemaître

    "Edwin Hubble, using the world’s largest telescope at Mt. Wilson in California, had shown that the distant galaxies all appeared to be receding from us at speeds proportional to their distances. It was at this point that Lemaître drew Eddington’s attention to his earlier work, in which he had derived and explained the relation between the distance and the recession velocity of galaxies." http://www.amnh.org/education/resources/rfl/web/essaybooks/cosmic/p_lemaitre.html

    "His findings were based on the achievements of Vesto Slipher, who – through the use of redshift – calculated recessional velocities and paired them with distances to the same galaxies as Hubble’s work. This led Hubble to demonstrate that the further away a galaxy was, the faster it would recede… the Hubble Constant. However, two years before Hubble published his work, a quiet man called Georges Lemaitre published the same conclusions based on Slipher’s same redshift data and Hubble’s calculated distances." http://www.universetoday.com/90862/the-expanding-universe-credit-to-hubble-or-lemaitre/

    "But while Einstein imagined an unknown force — a cosmological constant — which kept the world stable, Lemaitre decided that the universe was expanding. He came to this conclusion after observing the reddish glow, known as a red shift, surrounding objects outside of our galaxy. If interpreted as a Doppler effect, this shift in color meant that the galaxies were moving away from us. Lemaitre published his calculations and his reasoning in Annales de la Societe scientifique de Bruxelles in 1927." http://www.catholiceducation.org/articles/science/sc0022.html
     
    Last edited: Feb 3, 2014
  21. paddoboy Valued Senior Member

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    OK, accepted, I was wrong.....But as Grumpy pointed out, Hubble did acknowledge Lamaitre.....
    Hell, I used Lamaitre to illustrate the BB to my old school teacher and as an example of the overwhelming evidence for the BB.

    But then the question arises, with the general stuff posted by wellwisher [and others] that question and literally deride science uneccessarily and continually, presumably they appear to be trying to reinforce an agenda, not applicable to the debate or to show some aspect of science was wrong...or to show why [in their opinion] science is not to be trusted.

    Although in this case it did nothing, other than raise a possible misconception.
     
  22. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    Lamaitre's problem is that he initially wrote in French in a little-read journal, whereas Hubble wrote in English in the mainstream journal. French at that time was no longer the language of science. So Hubble got the recognition, and was good at publicizing the results. And yes, some of the posters here seem to have an anti-science agenda (without naming names).
     
  23. Fraggle Rocker Staff Member

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    Since this is a place of science (it says so in the name of the website!), no one is under any obligation to read or respond to their bullshit.

    If anti-science bullshit is inserted in a discussion of science, please notify the moderators. That is a textbook case of trolling, which is a violation of the website rules.

    We do occasionally treat a politely worded post that claims to invalidate science as a bona fide assertion and apply the scientific method to it, to demonstrate to our younger members how easily bullshit can be dismissed as bullshit.

    But in general we invoke the Rule of Laplace: "Extraordinary assertions must be supported by extraordinary evidence before anyone is obliged to treat them with respect." Since antiscience is, almost by definition, usually presented with no actual evidence, we are all allowed--even encouraged--to ignore it.
     

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