Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Space

What Happens To All the Universe's Hydrogen? 109

Posted by samzenpus from the here-today-gone-tomorrow dept.
StartsWithABang (3485481) writes "Just a second after the Big Bang, the Universe was a hot bath of radiation, with a small fraction of protons and neutrons in about equal numbers left over. By time it was four minutes old, it was 92% hydrogen (by number of atoms) and 8% helium. Yet the Universe has aged nearly 14 billion years since then, and have formed many generations of stars, all of which burn hydrogen into heavier elements. So how much hydrogen is left, and how much will be left far into the future? A lot more than you might think."
This discussion has been archived. No new comments can be posted.

What Happens To All the Universe's Hydrogen? More

What Happens To All the Universe's Hydrogen?

Comments Filter:

  • Survivalist (Score:4, Funny)

    by theshowmecanuck ( 703852 ) on Monday April 28, 2014 @01:55AM (#46856799) Journal
    I'm keeping a two year supply in my basement.

  • Given an infinite number of chemistry classes with an infinite number of science teachers holding an infinite number of matches to an infinite number of balloons filled with the universe's finite supply of hydrogen, I'd say we'd have 10 years left before the stuff's all gone and the universe is a giant swimming pool

  • And what about dark matter? (Score:5, Interesting)

    by 1 a bee ( 817783 ) on Monday April 28, 2014 @02:34AM (#46856895)

    I'm a bit skeptical of such cosmological estimates. If there is more dark matter in the universe than ordinary matter (by a factor of 4:1 they say), wouldn't you expect it to somehow figure in the "calculations" going back to the big bang? I saw no mention of it in the article. In fact, come to think of it, you seldom hear much about that big elephant dark matter in the room in the first minutes after the bing bag.

    Love reading about cosmology, but I think readers should be warned this is a very speculative field of study. Ideas and models in vogue today will likely not be in a few decades. I'm reminded of my physics professor of many years ago who claimed "Cosmology is as mature as botany was before Darwin."

    • Re: (Score:1)

      by Anonymous Coward

      I stopped watching the new cosmos after they stated the moon collision theory as if it was fact. They don't understand the ramifications of misleading people like that.

      • I'm pretty sure all sorts of people are self-selecting to not watch Cosmos because it goes counter to their personal sacred cows.

      • Re: (Score:2)

        by bberens ( 965711 )
        The beauty of science is that any of the "facts" we know today could be proven completely wrong tomorrow. I don't think there's anything special about the moon collision theory that should require extra qualifiers compared to anything else in that show as it's generally considered the prevailing theory of moon formation.

        • Re: (Score:3, Interesting)

          by meta-monkey ( 321000 )

          The problem with the new Cosmos is not all the "facts" they present are scientific. They also deal with history, and some of their "facts" are misleading or downright wrong, and we don't apply the scientific method to history.

          I get that Seth MacFarlane is an atheist and wants to push his creed (or lack thereof) on people. But in the first episode of Cosmos, the whole story about Bruno and his persecution was just wrong. Yes, Bruno did have an idea that the universe was infinite and that the sun was just ano

          • The bit went on for about 8 minutes of airtime, in a 40 minute show. They spent 20% of a science show talking about the persecution of a religious man for his religious views but making it out as if he were persecuted for his scientific practice, when he wasn't. It was purely a shot at religion in general and the Catholic Church in particular in order to push MacFarlane's world view. I thought they sacrificed their credibility by intentionally misleading people about historical facts.

            Well, they did say that Bruno's guess was a guess. The whole point of that segment was that religion was so opposed to views that challenged their world views. Whether his hypothesis or guess was that the sun was just another star, or that the "prophets" were just ordinary people (not divine), or that the Earth is older than 6000 years, really doesn't fucking matter. The issue is they burnt a guy at the stake for challenging their beliefs.

            Apparently, they should have devoted more than 8 minutes because yo

            • Why didn't they say that, then? They could have said "The Church was intolerant of dissenting views, and Bruno was burned at the stake because he challenged the Church's belief that Christ was the son of God." But they didn't. They presented that he was persecuted for stating that the universe was infinite and the sun was just another star. But the truth is, he wasn't. Nobody gave a crap about his views on astronomy.

              So why lie? That's the problem. They straight-up lied about about the persecution of Bruno.

          • Re: (Score:2)

            by Bengie ( 1121981 )

            we don't apply the scientific method to history

            Politicians apply scientific theory to history all the time, that's why it's so repeatable.

    • Doesn't physics have to come to terms with big issues like time and the fact that the laws of thermodynamics are statistical and show violations (fluctuation theorem, conservation of energy violated by dark energy and photons losing energy as they redshift)?

      • Re:And what about dark matter? (Score:5, Informative)

        by boristhespider ( 1678416 ) on Monday April 28, 2014 @03:45AM (#46857027)

        Time, yes. Not sure what you're referring to with thermodynamics - it's just a statistical theory that emerges when you deal with vast numbers of particles. (And if I did want to treat thermodynamics as inviolate, which it basically is for large enough systems of particles, there is no issue with conservation of energy with the loss of energy due to cosmological expansion. I'm not totally sure why you'd think there is: energy conservation is inherent in the system. There's nothing controversial about the idea that if you work in an expanding spacetime then photons that are not being pumped by an external source of energy will be stretched. Similarly if you work in a collapsing spacetime then photons not being drained with be blue-shifted. The Friedmann equation can ultimately be interpreted as an energy conservation equation if one is so minded, it just comes from the Hamiltonian constraint.)

        • Re: (Score:1)

          by Anonymous Coward

          energy conservation is inherent in the system.

          Come and see the conservation inherent in the system! Help! Help! I'm being conserved!

        • What's expanding the space, though? Where is that energy coming from?

          • That's just because $deity wants it to be so.

            But seriously, we don't know. To give it a name we call the force "dark energy" but it isn't clear what does it. Just that it happens (with reasonable certainty).
            Maybe future research will indicate the research that proved the universe was expanding was just a statistical fluke. Maybe we will find some force hidden in the equations that drives it. Maybe we'll never find out.
            Stay tuned to know more!

          • It's just how gravity works - if you fill a universe with not quite enough matter to make it collapse it will expand. Meaning if the universe was a bit denser it would collapse, but since it's not it's expanding. Then, as Neil Boekend says, due to something we're currently calling "dark energy" for want of a better term, with the amount of matter we've got we would expect the universe to be expanding but slowing whereas it's actually accelerating.

            Sorry I can't give a better answer but really no-one can -- j

            • Right, so my original motive for the first post in this thread, was to challenge the smugness of the guy who said his physics teacher described cosmology as being like biology before Darwin. My point was, physics has problems too. One of those problems being the supposedly sacrosanct law of conservation of energy.

              • Well, I wasn't a particular fan of that comment either... :) But your comments about the conservation of energy are basically wrong -- like I say, the expansion of the universe is governed basically by two equations:

                1) The Friedman equation, which is the "Hamiltonian constraint" and which can be interpreted as an energy constraint equation
                2) The matter continuity equations, which arise directly from conservation of equation of matter

                (Technically, and apologies for the ugly LaTeX notation here, matter is des

      • Doesn't physics have to come to terms with big issues like time and the fact that the laws of thermodynamics are statistical and show violations (fluctuation theorem, conservation of energy violated by dark energy and photons losing energy as they redshift)?

        I don't see why. Sure, any theory of everything would have to account for that, and also answer the question of whether sacred cows fart in a sacred manner.

        But we can do perfectly fine with multiple branches of physics that stay away from that problem, where each branch deals with only some aspects of reality. So long as we are mindful of the limitations of each mindset, and respect the ambiguous nature of the borders where one kind of physics butts up against some other kind, we have more than enough to

        • What happens when you get macroscopic objects displaying quantum effects, as in the experiments of Andrew Cleland and Aaron O'Connell [ucsb.edu]?

          Or Yves Couder [hekla.ipgp.fr] et al., who reproduce the two-slit experiment on a macroscopic scale - but it seems to require an ether if that's what's happening on the quantum level, which goes against physics dogma?

          • You handle these by stating the blatantly obvious, that these phenomena are currently outside the realms physics works with, and then you move on.

            Hell, physics cannot even handle ancient problems that are cracks in the bedrock of all western science. What is the reason that Pi is irrational (and don't just site one of the many different definitions of Pi as the reason: that is simply crippling your critical thinking ability with a blind belief in one or another tautology).

            We live in a universe that we not

            • So, the physics prof who said cosmology was like biology before Darwin (in the post I was originally responding to in this thread), was just projecting?

              • the physics prof who said cosmology was like biology before Darwin (in the post I was originally responding to in this thread), was just projecting?

                The original quote:

                "Cosmology is as mature as botany was before Darwin."

                I have no idea what was meant by that. My suspicion is that the professor provided enough context in his lecture that these nine words conveyed a distinct meaning, but we don't have that context here and I won't speculate on what the intended meaning might have been.

                To generalize my earlier statement: there are some things about the way the Universe is put together that are impossible to understand, and that has to be accepted. We can deal with this by recognizing that physics (and all s

                • Given no further context, the default assumption is that physics is in a much better state than cosmology. That was what I was reacting to.

    • Re:And what about dark matter? (Score:5, Informative)

      by boristhespider ( 1678416 ) on Monday April 28, 2014 @03:41AM (#46857021)

      Eh?

      "If there is more dark matter in the universe than ordinary matter (by a factor of 4:1 they say), wouldn't you expect it to somehow figure in the "calculations" going back to the big bang?"

      Yes. And yes, it does, it "figures" right from the start.

      "I saw no mention of it in the article."

      Who died and made this article God?

      "In fact, come to think of it, you seldom hear much about that big elephant dark matter in the room in the first minutes after the bing bag."

      That's chiefly becase in the first few minutes after the big bang the universe was radiation dominated, meaning that the density of photons (and neutrinos) was vastly greater than that of dark and normal matter. The transition between radiation and matter domination is governed by the density of dark matter just as much as baryons. Where on Earth are you getting this idea that dark matter is an "elephant in the room"? Here's an interesting fact for you - you know there are waves imprinted both on the CMB and on the large-scale structure of galaxies, right? If you "love reading about cosmology" you must, right? Those waves are the result of oscillations while the universe was radiation-dominated, caused by baryons tending to cluster together under gravity, and a restoring force introduced by radiation pressure, which set up ringing oscillations across the universe. Without dark matter to provide extra clustering under gravity those waves are at totally the wrong wavelength. From the CMB *alone* you can find how much dark matter there has to be relative to normal matter. How's that for an "elephant in the room"?

      "I think readers should be warned this is a very speculative field of study."

      As is all theory. However, I think readers should be warned that the fundamentals of cosmology are very far from speculative - even if the results might in principle be phenomenological, they will not change. Cosmology, particularly in the early universe but after the first microsecond, say, is based on well-understood science and is anything *but* speculative, and questions about whether dark matter or dark energy are physical quantities or are emergent in one way or another are not unique to cosmology but also arise on astrophysical scales. (And in some ways are irrelevant, since whatever dark matter and dark energy actually are, they have to work as cosmology describes them anyway. Small changes to the Lambda CDM model cause large disagreements with the data.)

      "I'm reminded of my physics professor of many years ago who claimed "Cosmology is as mature as botany was before Darwin." "

      Err, yeah. How many years ago? If he held the same opinion now I'd be surprised. If he held that opinion after the late 90s then he was ignorant of the field. That's OK, my Masters supervisor, in the early 2000s, is a brilliant physicist and held a similar opinion (although not stated quite so... badly, with a lousy analogy that could never work), and he was wrong too, increasingly so as the datasets grow ever huger and the tools with which to analyse them evermore sophisticated. This kind of view is untenable, and I say that as a man who has gone on record repeatedly with statements such as "cosmology is wrong. It is demonstrably wrong, it is wrong in its fundamentals and it is wrong in its principles" - because that's a statement I also surround with caveats. Cosmology is "wrong" in the same way that thermodynamics is "wrong", or that much of chemistry is "wrong", or much of biology is "wrong", in that it's at heart a descriptive, phenomenological theory. (Before chemists or biologists come to me to scream, those fields are typically phenomenological, although both contain subfields that are avowedly not so; but ultimately if you're not mapping up from the behaviour of the individual atoms you're dealing with phenomenology, and I'm well aware of how brutally difficult it is to do chemistry directly from the Schroedinger equation, which is what that implies. 'Phenomenology' is not a criticism, unless it's taken as so by people who mistakenly think they're dealing with the underlying science directly.)

      • Re: (Score:2)

        by 1 a bee ( 817783 )

        Who died and made this article God?

        Nobody. We're discussing the article here.

        As for the relatively recent evidence of dark matter showing its imprint in the CMB, well, again, doesn't this support my thesis that this is a rapidly evolving field? Cosmology textbooks have a short shelf life. Thirty years ago, for example, one of the big questions was whether the universe was open or closed. Now that we know it's open, and in fact expanding at an accelerating rate, we find that wasn't quite the right question. My physics textbooks, by contrast,

        • Re: (Score:1)

          by Anonymous Coward

          It is a "rapidly" evolving field, although maybe not as fast as you suggest. The idea that the universe is dark matter dominated was around in the 80s due to galaxy formation modelling, and the observation of the CMB in the early 90s confirmed that, narrowing down the proportions. Within a couple years dark energy was thrown into the mix, although not really contradicting the previous measurements that dark matter dominated normal matter, and for about 15-20 years now it has been shrinking error bars inst

      • "Cosmology, particularly in the early universe but after the first microsecond, say, is based on well-understood science and is anything *but* speculative"

        Come now. Applying what might be regarded as well understood math and physics to the first seconds of the universe isn't entirely speculative, it certainly requires some speculation to assume that this is what happened. Nobody knows for sure what conditions existed at that time.

        • Well, we can have a very good bash at it by taking the science we have at the minute, extrapolating back, noting every place where the story seems to get shaky and the edge cases that can arise, and see when things die. Surprisingly, the story of the last five billion years is a hell of a lot shakier than the story from, say, the fifth second up to the ten billionth year. Very early cosmology, yes, I totally agree -- it's speculation, and in particular (the slight overreaction to the BICEP2 results aside) I

      • Well said, sir. Repeatedly, even. Although (as a physicist also) I do have to say that DM/DE are a) one of several possible explanations or models that we have -- so far -- and while it has emerged as one of the most consistent that doesn't make it either unique or right. We may not have even hypothesized the right model yet (given the indirect nature of the data, that would hardly even be surprising, if true). b) One of the problems with having a huge amount of mass-energy out there, effectively decoup

        • I absolutely agree with your first paragraph. (Actually with pretty much your entire post.)

          For the record, my feeling on dark energy is that it's a mirage caused by analysing recent (highly inhomogeneous) cosmology through a model that at its base assumes homogeneity and isotropy, which a hunch would suggest is liable to cause odd effects, and which closer study through inhomogeneous models imply that at the least the effects of dark energy can be generated in pure dust (ie baryon + CDM) universes. My own r

          • Yeah, yeah. What you said. If DM/DE is an elephant in the room, it's an elephant that we know only in the sense of the blind men trying to describe the elephant by feel -- one says it is long and pliable, like a snake, another says that it is flat and massive, like a house, a third says that it is floppy and flat, like a large tree-leaf. We cannot yet see the whole elephant, and part of what we CAN see may turn out to be only the shadow of the elephant cast on the walls of Plato's Cave in some projection

            • That's like a description of high energy physics in general, and it's a very good one for M theory, particularly with the elephant's shadow given the AdS/CFT duality....

      • but ultimately if you're not mapping up from the behaviour of the individual atoms you're dealing with phenomenology...'Phenomenology' is not a criticism, unless it's taken as so by people who mistakenly think they're dealing with the underlying science directly.)

        Working with the theoretical (i.e., mental) constructs we call "particles" and "atoms" is no less and no more "phenomenology" [wikipedia.org] than is any other branch of science. Our observations about electrons and atoms are phenomena, not noumena [wikipedia.org].

        • Sure but you know what I'm meaning. In physics we have a very distinct hierarchy of descriptions. At the base are the "fundamental" theories, which are assumed to hold for point particles and fundamental forces (ie forces that don't reduce to different ways of viewing another force). These are the likes of the electroweak theory, the strong theory, and any random speculation about quantum gravity that you choose to believe (or not - I don't believe any of the theories of quantum gravity at the minute, thoug

    • Re: (Score:1)

      by Anonymous Coward

      There is no dark side of matter really. As a matter of fact it's all dark.

  • There doesn't seem to be any actual news here - just a link to someone's post about the hydrogen content of the universe.

  • 10E-10 levels of lithium and 10E-14 levels of beryllium are usually overlooked in discussions of Big Bang nucleosynthesis. But even minute proportions of Everything still results in rather large amounts of Something.

    • Wouldn't it actually be lithium hydride? The hydrogen atoms would instantly give up their electrons to form LiH. Free elemental lithium just doesn't happen in nature because it's only one electron away from a stable configuration.

  • Obvious conversion (Score:1)

    by Anonymous Coward

    It turned into stupidity.

  • And what happens to the world's helium?
    Since it is lighter than air, it moves to the top of the atmosphere, and cannot be mined anymore.

  • Man is that Medium.com Site buttugly. Giant Fonts, most parts of the page empty.

    Bleark.

  • So would that imply the universe was highly acidic in the beginning? What influence would that have on the creation of life?

  • One thing jumped out at me in the article in the third link... technetium's abundance looks way too high. It doesn't even exist on Earth, yet it's shown on the order of Molybdenum and Tin in the graph of relative abundance of elements in the universe.

    I'm not a cosmologist and Google's no help... anyone want to chime in?

  • the big bang model slipped and fell while walking down the runway. perhaps gravity can't be reverse engineered into this model of the universe because it's not exactly correct?

Slashdot Top Deals

He has not acquired a fortune; the fortune has acquired him. -- Bion

Close