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Space Science

How Do We Know the Timeline of the Universe? 153

StartsWithABang writes The history of the Universe happened in a well-known order: inflation ends, matter wins out over antimatter, the electroweak symmetry breaks, antimatter annihilates away, atomic nuclei form, then neutral atoms, stars, galaxies, and eventually us. But scientists and science magazines often publish timelines of the Universe with incredibly precise times describing when these various events occur. Here's how we arrive at those values, along with the rarely-publicized uncertainties.
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How Do We Know the Timeline of the Universe?

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  • We don't (Score:4, Funny)

    by Anonymous Coward on Monday January 26, 2015 @03:10AM (#48902707)

    We pretend we do, but it was actually re-created yesterday after the reboot of God's Second Life server farm.

    • Re:We don't (Score:4, Interesting)

      by Z00L00K ( 682162 ) on Monday January 26, 2015 @05:54AM (#48903107) Homepage Journal

      Which is a theological way to define what Douglas Adams described on why the universe is so elusive to explain.

      Another aspect is also - how do we know that the Universe was created at Big Bang. What if it was an empty void that suffered a spontaneous mass appearance.

      Or do we live on the inside of a giant black hole?

      • Re:We don't (Score:5, Insightful)

        by disposable60 ( 735022 ) on Monday January 26, 2015 @08:31AM (#48903645) Journal

        What if it was an empty void that suffered a spontaneous mass appearance.

        And somehow that's not a big bang?

        • And somehow that's not a big bang?

          No...before the "Big Bang" there was no void. Before the "Big Bang" there was no time. I know it's hard for us to visualize, but that's what the theory describes.

    • by t_ban ( 875088 )

      We pretend we do, but it was actually re-created yesterday after the reboot of God's Second Life server farm.

      We should have a "-1, repetitive" mod option.

    • That explains the lag I had all weekend.

  • We Really Don't (Score:3, Insightful)

    by TrollstonButterbeans ( 2914995 ) on Monday January 26, 2015 @03:23AM (#48902739)
    "The history of the Universe happened in a well-known order: inflation ends, matter wins out over antimatter, the electroweak symmetry breaks, antimatter annihilates away, atomic nuclei form, then neutral atoms, stars, galaxies"

    This is the comic book version of what happened.

    We do not know that it happened in that manner. This is the popular version of what our current guesswork is and no more.

    It should not be taken as "canon" or "real" any more than 2001 The Space Odyssey intro with apes inventing the use of bones as tools.

    Because "science" --- the one with hypothesis, testing, reproduction of results is different than the speculation one --- which is very often quite wrong. If you want a recent example, there were many theories about the surface of Titan before we landed a probe there. They were quite wrong. So were a great many of the prevaling theories about Mars before we send probes there.

    Early Universe ideas? Not fact. Not "well-known". Guesses.

    Humans have made bad models from guesswork fit perfectly in the past, there were very orderly models of the geocentric model of the universe that accounted for the movement of Venus and Jupiter, etc quite well. http://en.wikipedia.org/wiki/G... [wikipedia.org]
    • This is the comic book version of what happened.

      Like all esoteric fields of study, we outsiders can't understand it because we don't have The Right Stuff.

      (Presumably that's something they smoke.)

      • Re:We Really Don't (Score:5, Informative)

        by Ken D ( 100098 ) on Monday January 26, 2015 @07:15AM (#48903313)

        You can understand it to the level of detail you are willing to spend on. So in this case "The Right Stuff" is mostly time.

        You want to spend 5 minutes understanding cosmology, you're going to understand it at the comic book level, same as any other field of study.

        • Sorry... I was going for the joke and didn't pitch it very well. My actual views are more like yours.

          As for the reality of the subject matter, I would borrow the concept of "probably approximately correct" from machine learning, and give it a 90-95% chance of being ~80% correct. (The 80% is lower to allow room for some more big discoveries like inflation.)

          Unfortunately, people will be (hopefully) studying this for thousands of years on top of the <100 we have so far, and none of us will live to see how

        • All the stuff is just hydrogen, helium and time. Not just the good stuff.

    • Re:We Really Don't (Score:4, Insightful)

      by jandersen ( 462034 ) on Monday January 26, 2015 @04:15AM (#48902873)

      This is the comic book version of what happened.

      Well, it seems to be simply a high-school essay with glossy graphics; what did you expect? It doesn't look like Stephen Hawking's style, or even Brian Cox' - it's just some guy that's mighty pleased with his ability to make his website look like an issue of the Hello magazine and who's out to attract traffic to his site, that's all.

      Because "science" --- the one with hypothesis, testing, reproduction of results is different than the speculation one --- which is very often quite wrong.

      Well, in a sense we know that science is ALWAYS wrong - we propose a theory, and if its predictions survive comprehensive testing, it is accepted as being not far off the mark, but we know that is it not the final truth. The scientific method has arisen on this background as a way to make the discrepancy between theory and reality ever smaller.

    • Re:We Really Don't (Score:5, Insightful)

      by stjobe ( 78285 ) on Monday January 26, 2015 @04:32AM (#48902921) Homepage

      Early Universe ideas? Not fact. Not "well-known". Guesses.

      That's... really selling science - and the scientific method - way short.

      It's not "guesses", it's hypotheses, which are by their nature our best explanations of something given our current understanding of how those things work.

      Calling these "guesses" reduces all the science that's actually going on and puts it on the same level as Joe Schmoe's wild-ass guessing on subjects he's not familiar with.

      There is a world of difference between Joe guessing what happened in the early days of the universe and a scientist that has devoted several years of his life studying the matter putting forth a hypothesis of what happened.

      Please don't paint these as the same thing, it's just doing the anti-science folk a service, and the rest of us a disservice.

      • Early Universe ideas? Not fact. Not "well-known". Guesses.

        That's... really selling science - and the scientific method - way short.

        So, the problem with his pointing out the lack of "testing, reproduction of results" in prehistoric history tales is ... that it isn't good sales?

        And that's your scientific objection? To his scientific objection?

        • by stjobe ( 78285 )

          So, the problem with his pointing out the lack of "testing, reproduction of results" in prehistoric history tales is ... that it isn't good sales?

          And that's your scientific objection? To his scientific objection?

          No, that's my non-scientific objection to his anti-science rant. A plea against ignorance and the wilful discrediting of a lot of hard-earned science, if you will.

          This guy [slashdot.org] put it a lot better than I ever could; in short, calling these hypotheses "guessing" is ignorant as well as insulting, both to the scientists in the field and to everyone's general level of intelligence.

      • Do we really need to establish a cult of science in which the gods are displeased if we don't use enough syllables in our word for "guess"? The words can be used interchangably. A "scientific hypothesis" does often catch more suggestion of testable, derived predictions, but it's also frequently used in a more general sense, just as "guess" can be used in a more noble sense.

        I am all about respecting the scientists who invest a lot of work, but the fact they've done a lot of work doesn't make them more likel

        • Re: (Score:3, Interesting)

          by Anonymous Coward

          We don't need to scheme and manipulate to make sure our presentation of science leaves them on the poorest footing to rebut us, because, unless they are using science, their rebuttal is irrelevant.

          As long as you think it is a priority for scientists to inform the public of their work, then it is necessary to some degree to address rebuttals regardless of the source of the claims. Such rebuttals become quite relevant in the minds of people who are not familiar enough with what is going on to tell the difference, especially with enough publicity. The only place it becomes completely irrelevant is if scientists should only communicate among their own spheres and journals and have no obligation to expl

        • Re:We Really Don't (Score:4, Interesting)

          by Jason Levine ( 196982 ) on Monday January 26, 2015 @09:00AM (#48903799) Homepage

          It might seem like nitpicking, but "guess" to me always implies taking a stab in the dark with little to no evidence and ending there. A scientific hypothesis, meanwhile, usually starts with some data, builds an argument that X should be true because of the initial data, and is subjected to testing to either confirm it or disprove it.

          To give an example, you are presented with a clear cube filled with gumballs. A guess would be glancing at it and saying "600?" A hypothesis would be measuring the sides, estimating the size of each gumball, figuring out that there should be 1,000 gumballs, and then opening up the cube and counting the gumballs.

          • My impression is that hypotheses can very well begin with guesses, and once the guy with the guess can come up with some solid reasons for it it turns into a hypothesis.

            • by Rich0 ( 548339 )

              My impression is that hypotheses can very well begin with guesses, and once the guy with the guess can come up with some solid reasons for it it turns into a hypothesis.

              More like once the guy with the guess can come up with an experiment that can demonstrate the falsehood (or lack thereof) of the guess it is a hypothesis.

              Obviously if the guess is already inconsistent with observations then there is no need to run the experiment since it is already falsified.

        • A "scientific hypothesis" does often catch more suggestion of testable, derived predictions, but it's also frequently used in a more general sense, just as "guess" can be used in a more noble sense.

          Calling theories that have been tested as much as relativity or quantum mechanics "guesses" is to deny the world in front of you. While they could be shown to be false in some manner tomorrow, the simple fact is that much of the modern world would simply not work if the words "hypothesis" and "guess" were equivalent. The computer you are typing on would not work if quantum mechanics was merely a guess. GPS could not function if relativity were merely a guess, regardless of how noble a sense you use it.

          • "Calling theories"... Hypothesis was used in the quote. In fact "theory" doesn't appear at all. So you're arguing against some other statement.

            "... the simple fact is that much of the modern world would simply not work if the words "hypothesis" and "guess" were equivalent." Incorrect. Reality doesn't give a crap how words are used. You apparently do and are taking umbrage. Fine, just don't act like what you're writing is fact. It isn't.

            "... rather than mysticism and magical thinking." Or hyp
            • The world would continue on, just as it did before people had a clue about quantum mechanics and general relativity. What wouldn't work is what would happen if we did certain things. GPS is an example; we made it work because what we know about relativity works in this case. Particle accelerators would not work if we were significantly wrong about special relativity or the speed of light. There's lots of electronics we use every day that works because what we understood of quantum mechanics was suffici

            • by sjbe ( 173966 )

              Hypothesis was used in the quote. In fact "theory" doesn't appear at all. So you're arguing against some other statement.

              Had you a clue about the scientific process you would know that the word "theory" as it relates to science simply means a well tested version of one or more hypothesis. The words are often used interchangeably though they are technically different mostly in the degree to which they have been substantiated.

              Reality doesn't give a crap how words are used.

              Engineers and scientists do give a crap how words are used because how they are used matters and affects their work.

              You apparently do and are taking umbrage.

              "Umbrage"? No. I'm just an engineer correcting someone who is stating something that is

    • You talk about ""science" --- the one with hypothesis, testing, reproduction of results". These things do kind of apply to cosmology. Hypothese are about things like the statistical distribution of galaxy sizes and redshifts, or the exact spectrum of the cosmic microwave background or the proportions of elements in the oldest stars or ... The speculators are working out these prediction so that the observational astronomers can test them with their next set of instruments. Or in some of the other areas, a

    • Re:We Really Don't (Score:4, Interesting)

      by AchilleTalon ( 540925 ) on Monday January 26, 2015 @04:37AM (#48902943) Homepage
      Well, the guy didn't claim at any point he is telling the Truth, with a capital T. He is telling what we know today with the knowledge we have and the understanding we have of the physical world. Of course, to a certain extent we have no facts about the early universe (first fraction of a second), however we know how matter behaves at temperatures near these fraction of a second. We know how the cooling affect the matter. We know the universe is cooling, we know about thermodynamics, etc. So, even if it is guesswork, it is pretty much on tracks. You cannot reverse the order like you seem to think, there is no way to link these events in another order.
    • Bullshit (Score:5, Informative)

      by Anonymous Coward on Monday January 26, 2015 @05:40AM (#48903075)

      Disclaimer: I work in a cosmology department. What you've just written is total bullshit.

      We make predictions, and they work. I could tear apart the nonsense you've written, but instead let me just point to the facts:

      http://xkcd.com/54/ [xkcd.com]

      http://sci.esa.int/planck/5155... [esa.int]

      http://www.astro.virginia.edu/... [virginia.edu]

      I could go on an on posting pretty pictures and graphs matching data, but let me just say that we work incredibly hard to make predictions from our models, we test those predictions against observations and test many of our systems to over 5 sigma. To say that what we're doing is just guessing is frankly insulting to a lot of incredibly hard working people. We /predicted/ the CMB then observed it. We predicted the power spectrum then observed it. We predict the population densities of stars at certain redshifts, point telescopes and damned well count the things and find them to match. We predict galactic rotations, lensing effects, (integrated) Sachs-Wolfe effects and a hundred
      other little things, and we damned well test them, lining up our models against observations. We certainly haven't got everything right yet - there's a lot of room for investigation as to what went on before inflation, say, or exactly what type of matter dark matter is (but before you say we know nothing about it, I suggest you educate yourself - we don't know what it comprises, but we have damned good bounds on certain properties like its ratio of pressure to density). We don't know why the cosmological constant takes the value it does, but a whole host of checks all come up with the same number.

      So no, we don't have "Guesses". We have repeatedly tested hypotheses from which we observe consistent data and find heavy statistical significance. What you've done is insult a lot of incredibly hard working, very smart people who are very serious about their work.

      • Damn! Where are mod points when you need 'em. +1
      • Considering that we will never know for sure how universe really started, I think that the point is not explaining the origin of the universe per se, but to create a model of that that fits with the present state of the universe, isn't it?
        • by Anonymous Coward

          Everything explained by science is a model that best fits observation, for every theory testing in a lab to in the sky. If you want "Truth" with a capital T, if you want to know what "really" happens behind something, go to the philosophy department. If you want a description of what we see with predictive power, then science can provide that. This isn't specific to cosmology.

      • Thank you for your hard work! We know more about our universe thanks to the hard work of scientists like you.
      • In my 61 years of asking for answers this is clear; who can say what a fact is except it always leads to other question(s) Kind of like nuclear reaction, only much slower. But don't let all of that genius mentality go to waste. You could look like 'ET' in a few thousand years with huge orbs!
    • by doug141 ( 863552 )

      oops... fixing a mis-clicked moderation. move along...

  • by Anonymous Coward

    on unreadable clickbait hipstersites.

  • Heard a radio discussion about which major piece of science would likely crack over the next fifty years. The answer came back as the Big Bang, with one of the participants saying [rather indiscreetly, IMHO] that it was Sir Martin Rees in a pers. comms. who suggested that it was full of holes and the area was ripe for a paradigm shift.

    I once saw Fred Hoyle lecture on his Steady State Theory. He was awaiting the red shift results from a twin maser in some distant galaxy somewhere and we were assured that it

  • Silly me, making the mistake of reading TFA on /. ( aside: what's the proper way to punctuate a sentence ending in /.?)
    You want to know how we 'know' all of those things with such great precision? It's all about the scale of temperature fluctuations in the cosmic microwave background. The CMB is a snapshot of the universe some 30k years after the big bang, during the time of first neutralization, when the pathlength of photons quickly (on cosmic scales) went form very short in the hot plasma (think neon l

    • by HiThere ( 15173 )

      Well....sort of. The CMB is modified by galaxies that are too faint to see, though I don't know by how much. It's filtered by intervening dust clouds moving WRT both us and the "origin of the signals". Etc. I normally assume that this is taken account of as best we can, but it's not unmodified signal. If you look at the raw (uncorrected) observations, I don't know how much noise is present, but clearly that are signals too weak to be recognized even though detected.

      OTOH, I am not a cosmologist. But I

  • Pretty much says same thing as these pictues or Degrasse's Cosmos calender, but with more snapy video.

"An idealist is one who, on noticing that a rose smells better than a cabbage, concludes that it will also make better soup." - H.L. Mencken

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