Become a fan of Slashdot on Facebook


Forgot your password?

Why Are We Made of Matter? 393

StartsWithABang (3485481) writes "The Universe began with equal amounts of matter and antimatter after the Big Bang, and yet when we look out at today's Universe, we find that, even on the largest scales, it's made of at least 99.999%+ matter and not antimatter. The problem of how we went from a matter-antimatter-symmetric Universe to the matter-dominated one we have today is known as baryogenesis, and is one of the greatest unsolved problems in physics. Where are we on the quest to understand it as of April, 2014? A wonderful and comprehensive recap is here."
This discussion has been archived. No new comments can be posted.

Why Are We Made of Matter?

Comments Filter:
  • by Adam Colley ( 3026155 ) <mog&kupo,be> on Sunday April 06, 2014 @01:45PM (#46677409)

    God hid it.

    God is made of it.

    Okay, that's the god excuses out of the way... now on with the physics!

    • by Tablizer ( 95088 )

      Because God left the cap off the Matter toothpaste.

    • Re:Ah, antimatter (Score:4, Insightful)

      by Shakrai ( 717556 ) * on Sunday April 06, 2014 @02:22PM (#46677657) Journal

      Ah, the obligatory /. cheap shot at religion, always good for a cheap +5 funny. You failed to complete the cliche though, there should have been a slam aimed at the GOP in there somewhere.

      • Re:Ah, antimatter (Score:5, Insightful)

        by PopeRatzo ( 965947 ) on Sunday April 06, 2014 @04:03PM (#46678421) Journal

        there should have been a slam aimed at the GOP in there somewhere.

        Oh, if you insist: The GOP is using peoples' religion to encourage them to think of themselves as butthurt victims, creating divisiveness and the notion that in a nation where there's a church on every other streetcorner, religious people are somehow the oppressed, and they're doing it, not because they care about those religious beliefs or religious people, but in order to create a political climate where it's easier to redistribute wealth upwards.

        Oops, I'm sorry. You specifically requested a cheap shot and that wasn't one. I'll do better next time.

    • by Bengie ( 1121981 ) on Sunday April 06, 2014 @02:51PM (#46677897)
      Finally, news that matters.
      • Re: (Score:2, Insightful)

        by Anonymous Coward

        "News for WIMPs, stuff that's matter."

    • by Torodung ( 31985 )

      That brings to mind an idea: Maybe dark matter is antimatter, and the universe isn't as inscrutable as we think.

      • Re:Ah, antimatter (Score:5, Informative)

        by Immerman ( 2627577 ) on Sunday April 06, 2014 @04:24PM (#46678559)

        Nope. Antimatter is still basically "normal" matter, just with the opposite charge. We've created a fair bit of it in the lab, especially anti-hydrogen and various anti-subatomic particles The mass appears to be the same, and it interacts with light and other EM fields just as normal matter does. The only real difference is that when you bring a matter particle together with its antimatter twin they mutually annihilate.

        Dark matter on the other hand would have to interact only via gravity, no electromagnetism to promote "clumping" into atoms or larger structures, nor any absorption or emission of light or we would be able to see evidence of its existence in the spectrum and brightness of distant stars.

      • by rtb61 ( 674572 )

        Nope the simplest explanation is, it had to be either one or the other, complexity not altering the outcome. Take an coin toss a simple probability outcome, either heads or tails but the complexity of the event can be raised by many magnitudes of complexity and probability by not looking at whether the coin lands heads of tails, but at say how many calcium atoms will be scrapped from your thumb nail in the flipping action and be transferred to the surface where the coin lands. So both events occur simultan

    • God hid it.

      God is made of it.

      Okay, that's the god excuses out of the way... now on with the physics!

      Which is more scientific because ... look, strings! I mean, alternate universes! I mean ... squirrel!

    • by ras ( 84108 )

      We know where he hid it. He hid it in yesterday. Anti-matter is matter going backwards in time []*, so when when the big bang happened, all antimatter disappeared into yesterday while we headed off towards tomorrow.

      * For some definitions of time.

  • So what? (Score:3, Funny)

    by Anonymous Coward on Sunday April 06, 2014 @01:47PM (#46677425)

    What does it matter that we're made of matter? Were we made of anti-matter, would it anti-matter to anyone? Don't lose any energy on this matter, because it doesn't fucking matter.

  • Actually... (Score:5, Funny)

    by TubeSteak ( 669689 ) on Sunday April 06, 2014 @01:54PM (#46677457) Journal

    By mass, I'm currently ~70% water, ~29.5% matter, and 0.5% cookie dough

    Disclaimer: Do not eat raw cookie dough made with unpasteurized eggs.

  • The beginning probably had a spin one way or another that predisposed one type of matter VS the other.

    The effect was probably small, but over the vast space and energies involved that small difference made a giant outcome.

    Butterfly effect and all that.

    This would be my completely uneducated guess. Physics persons can freely rip on me as an idiot lol Please when ripping on me, tell me something in terms an idiot would understand though, I do enjoy learning some things. Especially the why of things! :)

    One of m

    • by PolygamousRanchKid ( 1290638 ) on Sunday April 06, 2014 @02:25PM (#46677677)

      tell me something in terms an idiot would understand

      Richard Feynman answered that question with something like:

      "I can't explain it in terms that you would understand, because I can't understand it, in terms that you would understand."

    • Usually the simplest explanations are correct. Also, my humble guess is that first we need to make sure that it should have the same amount of matter and antimatter in the universe, and then think about what happened to anti-matter.
    • by tomhath ( 637240 )
      I think what the article said. Matter and anti-matter were created in equal proportions but decayed into energy differently.
  • by kruach aum ( 1934852 ) on Sunday April 06, 2014 @02:11PM (#46677581)

    In spite of my better judgement I'm about to attempt an analogy, so bear with me here. The lowest number of moves to unscramble a maximally scrambled rubik's cube (a 3x3x3 one) is 20. That is, for every configuration of a rubik's cube, there is a sequence of 20 moves or less that will unscramble it. However, there is no algorithm to generate those solutions. They are unstructured; they're simply lists of moves. The algorithms used by human (and computer) rubik's cube solvers are far from move-optimal, but benefit from being executable by non-omniscient beings. They pick out some pattern that is applicable to the rubik's cube, and then direct you in manipulating it according to that pattern until it's solved.

    The way science understands the world is by comparing new data to what we already know. For example, we know penicillin kills bacteria; if we discover a new disease, and then discover that it is caused by bacteria, we can safely draw the conclusion that we'll probably be able to treat it with penicillin. We've used science to discover a pattern in the world ('penicillin kills bacteria'), then use deduction to determine where it is and isn't applicable, and form new categories based on what happens when we encounter new data (like bacteria not killed by penicillin being classified as anti-biotic resistant). Science is basically a collection of patterns like this, and because they're patterns (structures, structured rules, whatever you want to call them) we can understand them.

    Now, what I wonder about is this. What if the fact that we live in a matter universe now (rather than an anti-matter one) is like the set of move-optimal solutions to a rubik's cube? They both describe a certain state of affairs, but they also both completely lack (could lack) any kind of structure. And because they lack this structure, there is nothing for us to latch onto, nothing for us to understand, no pattern to detect. It is simply the case, and there is no further reason. There is no reason why there is no structure in the move-optimal solutions to a rubik's cube. There might not be a reason why there is a massive matter/anti-matter imbalance either.

    This is something I've been trying to work out for a while, so please excuse me if my explanation is unclear. I just think it would be a really interesting possibility, something which isn't often discussed, maybe because it simply gets overlooked.

    • by Viol8 ( 599362 )

      I'm sure there is a reason though perhaps I'm just too wedded to cause and effect. Anyway, whether that mooted reason occured in this universe after the big bang , or the seeds were sown "outside" in the multiverse - if there is one - we don't yet know. If its the latter then we'll probably never know what it was - as you say , its just the way it is. If this universe is part of a multiverse or some other larger structure and isn't completely self contained then physics may find itself up against a brick wa

    • by TheRealMindChild ( 743925 ) on Sunday April 06, 2014 @02:35PM (#46677747) Homepage Journal
      Occam's razor... the simplest answer is that the universe didn't start out with equal parts matter/antimatter
    • by TheLink ( 130905 )
      Here's another thing for you to work out while you're at it:

      Why are you even conscious? Couldn't a machine exist like you that did the exact same things you'd do but wasn't conscious at all?

      Note: I'm not talking about "free will". I'm talking about the subjective experience that I have (and I believe you have) of being aware. I don't think I'm the only conscious being in this universe.

      To me the two amazing things are:
      0) That there is anything at all in the first place.
      1) That there is this consciousness phe
    • by sjames ( 1099 )

      The question isn't why matter instead of anti-matter, the question is how did it not end up as a homogeneous 50/50 self-annihilating mixture?

    • I think the problem in this case is understanding the order of moves that got us to where we are. Maybe it would happen differently next time there is a 'big bang', but even if there is no consistency, there was still some pattern of moves that got us to where we are.
  • Why Are We Made of Matter? Why Am I Reading This Website?
  • we don't know we are made of matter. What if what we call matter is in fact anti-matter ? Or to put it differently, if the universe was made of "antimatter" wouldn't we think we were made of matter and the definition of antimatter (positron etc.) would be the opposite of what's now? Isn't it just a matter (no pun intended) of definition ?
    • by wjcofkc ( 964165 )
      Simple. If we and the Universe were as overwhelmingly made of anti-matter as it is instead matter, we would call anti-matter matter and matter anti-matter. It's just semantics. You reading into it way too much.
  • because we are almost surely living in simulation. [] and in that simulation, things just have to be so for us to be simulated.

    • by TheLink ( 130905 )
      Yeah we might be in a simulation (that's in another simulation and so on) but why do we experience this consciousness thing? Not talking about free will, but the experience of awareness itself.

      Are the rules of this universe such that no matter what as long as you have certain processes, consciousness will arise as an emergent phenomenon? And what would those certain processes be?

      Could it be extinguished and yet the person still continues on "living" and moving as before? For example say a person went to sle
  • by seyfarth ( 323827 ) on Sunday April 06, 2014 @02:21PM (#46677651) Homepage
    I wonder if it is possible that the Universe has some regions of matter and some of antimatter. In between there would be mixed regions and the resulting explosions could tend to keep the different regions separate. Initially asymmetry in the distribution would leave some small regions of each type. The m-am explosions could force separation and a certain portion of the matter regions would merge with other matter regions and the same for antimatter. This seems like a fairly obvious thought, so I assume that it has been considered and ruled out. Why or why not?
    • by JDeane ( 1402533 )

      I am not a physicist, but since light is a particle and a wave it would seem that light being matter would break down anti matter over time?

      Like I said it's just what I would think and I could be insanely stupid and wrong lol

      • I am not a physicist, but since light is a particle and a wave it would seem that light being matter would break down anti matter over time?

        Like I said it's just what I would think and I could be insanely stupid and wrong lol

        Nah, light isn't matter at all (a particle, yes, but not matter). More precisely: every particle has an equivalent antiparticle with exactly opposite charge (or other properties). For example, electrons are charged leptons with lepton number +1 and electric charge -1 (in units of electron-charge). The antielectron (positron) has lepton number -1, and electric charge +1. Conservation laws require that lepton number and charge be conserved, so the positron and electron can annihilate each other. The proton an

    • by Jaime2 ( 824950 ) on Sunday April 06, 2014 @03:01PM (#46677989)
      Read the article. It explains that if there were anti-matter regions, we should be able to detect gamma rays from the explosions. The number of gamma rays we detect are far too few for there to be large regions of antimatter.
    • by Bengie ( 1121981 )
      Matter of all kinds is just energy and in the beginning, the only thing that existed was energy. As matter and anti-matter was created from this abundance of energy, they would collide with each other and turn back into energy, then that energy would turn back into matter and anti-matter. This oscillation between energy and general matter would continue until the expansion of space would cause the density of energy to drop below the threshold to create matter.

      All of our current physics shows all matter ha
    • I've long wondered the same thing, but for that to be true, the antimatter would have to be outside our observational universe; otherwise, we would detect the matter-antimatter collisions.

  • In this universe we have this abundance of matter over anti-matter. Just over the quantum horizon in a parallel universe there is an abundance of antimatter. Together the baryon count would match and everything would be hunky dory. It happened this way because in the very early universe an matter+antimatter pair manifested themselves such a way that 99.9999%th of one matterparticle happened in this universe and 99.9999%th of its counterpart materialized over the quantum gap in the parallel universe.


    • by JDeane ( 1402533 )

      Just make sure to charge people to find out the "truth" take a page from l'ron hubbard.....

  • Because we travel the way we do through time.

    Antimatter travels through it in the other direction.

    And we when we and the antimatter get all the way from one end of Time to the other--BOOM! It's the end.

    .gninnigeb eht s'tI !MOOB--rehto eht ot emiT fo dne eno morf yaw eht lla teg rettamitna eht dna ew nehw ew dnA

  • Same reason why my martinis are 99.999% gin. I just rely on the probability cloud from the vermouth sitting on my bar shelf.
  • Prove it (Score:4, Insightful)

    by TomGreenhaw ( 929233 ) on Sunday April 06, 2014 @02:46PM (#46677849)
    That the universe started out with equal amounts of matter and anti-matter is an interesting hypothesis.
  • There are only two possible outcomes:
    - either matter and antimatter annihilate each other and the universe is mostly void
    - either one eventually wins over the other, leaving majorly one in the universe and pockets of the other

    Out of those two, one is clearly more likely to lead to intelligent life.

  • Maybe the anti-matter went backwards in time. Take a look at Paul Dirac's equations.

    Personally I don't like this idea because I perceive time as an emergent phenomenon of the expansion and disturbance of space and as such is not a dimension.

    Its more likely that the energy released by annihilation in the early universe reconstituted to form ordinary matter.
  • How do we know that there was a 50/50 distribution of matter and antimatter? Perhaps antimatter is rare, or more common in the anti universe in a parallel dimension?
  • ... Bacon [] is made out of matter. Had the universe evolved without bacon, we wouldn't be here to discuss the issue.

  • in the studies that i've been doing for the past four months the best explanation i've encountered is one where particles are actually photons obeying maxwell's equations *to the absolute* letter, on some form of circular (or knotted, or hubius helical) path, where the epicentre creates a synchtronic electro-magnetic field that it in symbiotic support of the epicentre. there is actually a lot of research recently into optics which shows that it *is* actually possible to create phased laser beams that will

  • and all the matter went to this universe and there is an alternate universe made with antimatter and there is an alternate of everything in this universe only made with antimatter, an antimatter version of me an antimatter version of you, an antimatter version of everybody in an antimatter world orbiting an antimatter sun that is in an antimatter milkway galaxy in an antimatter universe
  • by Kaenneth ( 82978 ) on Sunday April 06, 2014 @03:36PM (#46678233) Homepage Journal

    Is there any difference between a Black Hole/Singularity formed from Matter vs. Antimatter?

    Did galactic-sized magnetic fields push the antimatter into the supermassive black holes in their centers?

    If you're looking for something missing of the cosmic scale, black holes seem like a good place to look; although I suppose it'll also be the last place you look...

  • Antimatter is so derisory. Must we put such a polarizing label on something we do not fully understand? If people referred to me that way, I would not hang around, either.

    Of course it matters that we are made, and whatever we are made of quantum-wise, we should be proud, even if it destroys us when we come together.

    I vote for calling it 'matter-of-fact'.

    P.S. I appreciate StartsWithaBang renaming it from, "Why are we layered fatter?"
  • Maybe it all just dropped through to the other side.

  • ....contained energy and energy is what we all are, doods!
  • by genfail ( 777943 ) on Sunday April 06, 2014 @07:35PM (#46679601)
    I've always been suspicious of the Standard Model's insistence that the big bang consisted of nearly equal parts matter and antimatter. The assumptions made by observation of certain particle collisions need to be reevaluated. Much of this seems to because of a belief that time is single dimensional and that mass has no effect on the flow of time, although if you really look at relativity and quantum phenomenon it is obvious that neither of these is the case. Instead we invent the artifacts of dark matter and dark energy to explain away inconsistencies that these assumptions make.

"No, no, I don't mind being called the smartest man in the world. I just wish it wasn't this one." -- Adrian Veidt/Ozymandias, WATCHMEN