• Question: The elements that existed before the big bang, do each element still exist and do elements ever decompose, just become destroyed or ever become extinct?

    Asked by to Becky, Clara, Daniel, Simon, Thomas on 13 Mar 2014. This question was also asked by .
    • Photo: Simon Albright

      Simon Albright answered on 13 Mar 2014:

      We don’t know what was there before the big bang, or even if “before” has any meaning. It might be like asking what’s north of the north pole.

      We do know what happened the first instants after the big bang though. Initially there was just a seething mass of energy, and fundamental particles called quarks and gluons. After a little while the quarks and gluons came together to make up protons, then these combined with each other and electrons to make the first atoms, lots of hydrogen, some helium and a little lithium.

      It was only after a billion years that the first stars could form and these stars took that hydrogen etc and used it as their fuel. In the process they made all the heavier elements, the carbon, oxygen, iron, silicon and everything else we need to exist.

      Some of the elements the stars make are radioactive, this means they’re unstable and will decay into something a bit lighter. Eventually everything in the universe will either decay if it’s too heavy or get put together if it’s too light until there is nothing but Iron in the entire universe. Or that’s one option, but we don’t know for certain and sadly none of us will live long enough to find out (or maybe not sadly, slowly turning to Iron doesn’t sound fun).

    • Photo: Thomas Elias Cocolios

      Thomas Elias Cocolios answered on 13 Mar 2014:

      Lavoisier said (albeit about chemistry) that “nothing appears or disappears, but everything changes”. That concept applies to everything, even the Big Bang.

      Starting with energy, you eventually got a massive production of particles and anti-particles of all sorts in the very early universe. Those almost instantly annihilated each other and, technically, should have COMPLETELY annihilated each other. If matter and anti-matter were perfectly equal, the energy from the Big Bang should have gone back to energy. Thankfully, there is a slight asymmetry in the world that has resulted in more matter to be produced than anti-matter. What is left in the univers, however, represents only a very tiny fraction of what existed at the beginning. This happen in less than a heart beat!

      After that, the universe kept on expanding and cooling down to the point that randomly ‘deconfined’ particles got together to form protons (hydrogen nuclei) and other light particles. They slowly gathered together, attracted, pulled to one another and eventually formed galaxies. It probably took thousands of years, if not more before the first star ignited.

      And now in the stars, hydrogen “burns”: the fusion of two hydrogen atoms together results in the production of deuteron (1 proton, 1 neutron), which itself will make helium (2 protons, 2 neutrons). Once the hydrogen is burnt out, the helium starts to fuse. This time, it is 3 helium that gives you carbon (6 protons, 6 neutrons). And the story keeps on going until you reach iron. Beyond that, the star dies out and goes supernova! In the explosion, many more nuclear reactions happen giving rise to elements beyond and all the way up to uranium.

      Note however that, in all that process, protons and neutrons that were formed back in the days remain. They might change from one to the other through beta decay in the star process but they do not deconfine again.

      If a neutron is alone (we say ‘unbound’), it may in itself turn into a proton (which is more stable) within 10 minutes.

      Finally, the proton may itself break down. That has been speculated to take longer than the age of the universe, by a long shot!

    • Photo: Daniel Roach

      Daniel Roach answered on 14 Mar 2014:

      I think elements describe the state of matter of this universe, with the rules that apply to this universe. Before the big bang, the rules were obviously different, and so it’s unlikely that the word ‘elements’ had much meaning, there. Maybe there were other things that might have done the same (or different) jobs as our elements do. But this would be speculation – we can’t know.

    • Photo: Clara Nellist

      Clara Nellist answered on 21 Mar 2014:

      One of the interesting things about what existed just after the big bang is that we think the universe had equal amounts of matter (the stuff we’re made from) and antimatter! But matter and antimatter destroy each other when they come into contact (called annihilation) and leave just energy! There must have been a tiny amount more of matter than antimatter which was left to make us. But the strange thing is, we don’t know why! Scientists are trying to figure this out!

      There’s one theory that suggests that out in space there are whole anti-galaxies which are made up of only antimatter. Perhaps there are even anti-Earths with anti-Imascientists going on! But if the matter and antimatter galaxies collided in space there would be a huge amount of light from these annihilations, which we haven’t seen. Even if they didn’t collide though, we would still expect to see some anti-Heliums that have escaped the anti-galaxy. We have experiments, like AMS on the International Space Station, that are looking for anti-Helium nuclei. But so far, they’ve not seen anything.

      Another theory is that there is some small difference between the way matter and antimatter change into new particles, and maybe this would explain why slightly more matter than antimatter survived. Experiments like the LHCb detector at CERN where matter and antimatter are created in proton collisions, are searching for evidence of this difference. They’ve had some hints so far, but nothing that can account for the disappearance of a universe worth of antimatter!

      So we’re still looking and doing more experiments to try to find out.

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