So, about how much of the matter of which I am composed was created in the Big Bang? All of it? Or is matter being created all the time since then, allowing me to include some of this post-bang matter?
I guess it depends on how you look at the question, but I’d say all of it. It has, of course, been further refined in the hearts of various stars along the way (through fusion creating all of the other elements that weren’t created during the initial Big Bang, which from memory was mostly helium in various forms, as well as some other light elements), but the matter for the elements was created during the Big Bang…it simply took super massive stars to fuse that matter into heavier elements and then blow them out into the universe when they died.
That’s my Science Channel take on it at least.
Maybe the 9-10% of the human body that is hydrogen, though hydrogen began to form several minutes after the Big Bang.
Wait. I thought that the body is something like 75% water and that water is two-thirds hydrogen. So wouldn’t I be closer to 50% hydrogen?
Looks like you’re right. By mass, only about 10% of the body is H. There’s a lot of H atoms, but they have so little mass that it doesn’t add up to as much as I thought.
As if hydrogen can come to life spontaneously. :rolleyes:
Not to mention the rest of the elements, whose initial building blocks are nothing but hydrogen.
The best answer I can come up with is “almost all, but maybe not 100%.”
We have to distinguish between two types of matter here: baryons (which, for our purposes, means “protons and neutrons”) and leptons (which, for our purposes, means “elections and neutrinos”) In almost every process that has occurred since the big bang, “baryon number” and “lepton number” is conserved; this means that the total number of protons and neutrons is the same before and after each process, and the total number of electrons and neutrinos is the same before and after. When you do these sums, anti-particles count as negative; so if you have an electron and an anti-neutrino, the total lepton number is 0.
With this in mind, it’s conceivable that some small number of the particles in your body are not “primordial”, in the sense of having been around since the Big Bang. Electrons, and to a much lesser extent protons and neutrons, are created quite frequently in the upper atmosphere due to cosmic ray showers. Moreover, some nuclear fusion and fission processes (those mediated by the weak nuclear force, for the boffins) frequently produce spare electrons and neutrinos. These leptons and baryons are always produced with corresponding anti-leptons and anti-baryons, but those will run off and annihilate with other particles; once an electron (say) is created in this way, it’s just like any other electron.
I haven’t done the calculations, but if I had to hazard a guess, I’d say that it’s unlikely that any baryons in your body are non-primordial, but that there might be a few electrons in your body that are non-primordial. The creation of baryon/anti-baryon pairs is much rarer that that of electron/anti-electron pairs, simply because baryons tend to be much more massive and require more energy to create. (E = mc[sup]2[/sup] and all that.) But cosmic ray showers are common enough, and large enough numbers of electrons are created during them, that it wouldn’t surprise me at all if a few electrons in my body were created during one.
I don’t understand the response or the eyeroll here. It’s a valid answer to one interpretation of the question, and certainly didn’t imply hydrogen “can come to life spontaneously”.
:smack:
Scientists treat matter and energy the same. We learn that in middle school. If you accept the Big Bang theory, then all the existent energy has only one source, that is the Big Bang. All the matter we’re made of comes from the same source. Why are we talking about hydrogen when hydrogen itself consists of smaller particles, which themselves are composed of smaller things, which eventually boil down to pure energy? And why do we ignore the rest of the elements if they’re all built on hydrogen, which comes from the initial pure energy of the Big Bang?
The Hydrogen formed directly from the Big Bang. Elements like Carbon, Oxygen and Nitrogen formed later on in stars. They aren’t primordial. It’s a valid interpretation of the question. Just because it’s not the interpretation you would have made doesn’t mean it’s a stupid interpretation, so there’s no need for the snarky eyeroll.
How many posts before I can make a “your dad big-banged your mom” joke?
Of course, if you go down to that level, there’s really no meaning to speaking about the identity of elementary particles, i.e. saying this one is primordial, while that one is recent. In a reaction such as the one producing a proton p and an antiproton p’ due to a proton interacting with a nucleus A, i.e. p + A –> p + A + p + p’, you can’t point to one of the reaction products and say ‘this was the original proton that interacted with the nucleus’, and ‘that is the proton produced in the reaction’; so there’s really no good way to identify either particle as primordial or recent.
Seriously? :rolleyes: How?
Moderator Note
UY Scuti, we can do without the eye rolls. If you want to contribute to the thread, it would be better to offer explanations rather than snarking on the comments of others.
Colibri
General Questions Moderator
From here Warning PDF):
I promise to refrain myself.
My question referred to the fact that hydrogen is not the direct result of the Big Bang, according to the present theories. Your source bears me out.
Most of this is wrong. Although matter and energy are often taught as if they were the same, because that’s quite close enough for everyday explanations, the professional physicists here have shown us in many threads that there are differences that are meaningful in advanced physics. Hydrogen is composed of a proton and an electron. The electron is not composed of other particles; the proton is. But you can’t really say that the quarks that make up a proton are made up of pure energy. That’s a matter of much debate. And the Big Bang itself is a matter of debate. Depending on various interpretations, it can refer to the origin of our universe or the fractionally later inflation that grew the universe or it might not have happened at all. It’s a good simple way of talking about what happened in an ordinary conservation but the nuances here are all important.
The problem with the OPs question was identified in the very first response. It’s an ambiguous question. You could answer it by saying some, all, or none and still be right. Since by definition everything in our universe can be traced to the time just after the origin where physics starts making sense, then all of our particles must come from that same source. But the universe was in a super energetic state at that time, with none of the particles that we think of as matter existing, so you can equally well say that none of ours dates back that far. If you want to look at the makeup of our bodies by individual atoms, then some of our hydrogen atoms may be very, very old, but the few elements heavier than iron didn’t exist until supernovae made them. But since a hydrogen nucleus can be stripped of its electron and regain one what precise age can you put on the age of any hydrogen atom?
If you continue to participate in physics threads you’ll be hit over the head very quickly with the realization that everything you learn in school is at best not quite right and at worst wholly wrong.
[QUOTE=UY Scuti]
My question referred to the fact that hydrogen is not the direct result of the Big Bang, according to the present theories. Your source bears me out.
[/QUOTE]
Well, again, this depends on how you look at it and define your terms. I’d say that hydrogen WAS a ‘direct result of the Big Bang’, in that the conditions and properties of the Big Bang allowed the formation of hydrogen once the expanding universe started to cool enough to all for the formation. Same goes for all of the other elements…it was the conditions and properties of the Big Bang that eventually allowed for the formation of stars which pretty much made every other element possible. That it didn’t happen at the instance of the Big Bang is, to me, irrelevant…but, again, it’s all in how you look at the question. To me, what I posted there doesn’t bear you out, since I’m looking at it differently than you apparently are.
I don’t know if I’d say created so much as I’d say transmuted. If you take an atom of deuterium and an atom of tritium and fuse them, the resulting helium is “new” but it’s substance is that of the hydrogen isotopes that were fused, so I’d say that it was still created in the big bang.
It’s similar, albeit on a smaller scale to saying that isopropyl alcohol isn’t made from petroleum because it’s made from propene and water. However that propene is usually a byproduct of petroleum refining, so I think it’s fair to say that isopropyl alcohol is made from petroleum, at a step’s remove.
As has been pointed out, this depends on exactly what you mean by “The Big Bang.” Loosely speaking, the Big Bang can refer to not just the instant of origin itself but the immediate aftermath as well. Considered over a time span of 16 billion years, particles that originated within the first few seconds of the Universe’s existence might as well be considered primordial.
It’s fine if you wish to advance a different interpretation of the question. However, dismissive comments about other interpretations aren’t particularly helpful.
Well, assuming the mass of a human being (as well as the mass of anything else, really) is 99.9% protons and neutrons, I guess it comes down to agreeing if the formation of protons and neutrons is sufficiently close to the Big Bang and if so, what percentage might come from pair production that came well after the BB.