Ahm. Where? You mean the universe? Well – no, I don’t know. So let me try to work it out without consulting Dr Google.
1. Hydrogen (which would be a lot of H and then a lot of H2)
2. Helium
3. Probably some fusion product of those two, so, what would it be – lithium or beryllium. Except these are quite reactive so, err, what, carbon? As the element – on earth that’s “soot”. In space it’s spacedust.
You’ll notice that these aren’t very exciting yet. They are molecules in the sense that they are stable, atomic-sized things. Hydrogen (H2) is a molecule. Helium is an atom, but I’m including it because I think if I were helium I’d like to have a ticket into the Molecule Club. Hydrogen and helium are the things in stars, so are vastly more common than anything else. We don’t come into contact with them much down here on earth, but that’s because we live a very sheltered life. Putting helium in balloons is like putting your very own little bit of the big bang in a bag.
H2 and He are fusing the whole time, so I’m guessing that the next on the list is some product of these two. The way we work out what’s in stars is by the light that comes from them. Molecules/atoms absorb radiation, and they all do it differently. Whatever is between us and a light source will absorb light in a very individual way. So the stuff that’s missing from a star’s light tells us what’s in front of it. Very cool we can tell what the sun is made of without ever going there.
OK, so there are two to go. I’m going to forget about atoms and other small things now, since there’s probably a lot of other fusion-derived stuff in or near stars, but you get the idea. What about molecules not in stars?
Hmm. I know what you want me to say. You want me to say “water” but I doubt that’s right. We see a lot of water because we’re really watery things. But on the universal scale, it’s just not that big a deal.
This is a tough one. You know why? At the start of the universe, everything was pure energy. Not like in an energy DRINK, but actually energy. As the universe cooled, matter formed, and it was all hydrogen with a bit of helium. Stars formed. Fusion happened. More helium and, over time, heavier elements. Stuff like carbon, that we’re made of, came from stars exploding (which is amazing and we should totally talk about that) but it means that the heavier elements are rarer, and so are the molecules they’re in. I’d expect neon to be pretty common because it’s inert (doesn’t socialise with other atoms), but I don’t remember ever hearing that it’s all over the universe. I know that iron has a special place in the periodic table since it’s the element with the least to gain from fusion and fission, meaning that it tends to stick around a long time without undergoing any kind of nuclear change, but you need a lot of subatomic business to get to iron because it’s quite big and heavy.
But this is all atomic stuff. OK, back to molecules.
One last thing – it looks like the universe has a lot of “dark matter” in it. There’s a lot of stuff we can’t see. We know it’s there because you can kind of work it out from how things are moving – they’re responding to the gravity of something, but the thing is not visible. Putting that weirdness aside, there’s a lot of stuff there – maybe 70% of the mass of the universe. Something tells me that it’s not molecules, otherwise we’d be able to see them. So it’s unlikely to be a cloud of all the stuff we’ve ever lost down the back of our sofas. It’s likely to be other stuff.
Back to the question. I’m going to go for carbon monoxide, because I hear a lot about it. I seem to remember talking to an astrophysicist one time who had a picture of carbon monoxide on his T-shirt. We don’t see carbon monoxide a lot – it’s in car fumes and is bad for you – but it usually combines with oxygen to give carbon dioxide on earth. In space we don’t have a lot of oxygen, so CO stays as CO.
So that’s four. I’m breaking into a light sweat here. Let me have a coffee.
OK. I’m trying to decide between water (I know I said it wasn’t that) and nitrogen (N2). I’m thinking about all the rocky matter in the solar system, but I’m also thinking about the gassy giants like Jupiter, and what they’re made of. However, planets are pretty unimportant on the scale of the universe.
What I’m thinking now is: when comets and things come into the solar system from outside, they’re rocks covered with … water. That makes me think that outside the solar system there may be a lot of water. Water’s a pretty stable molecule. This could be embarrassing, but I’m going with that. So:
4. CO
5. H2O
If you’re talking about the 5 most common molecules we see as humans on the earth, then I’d say:
1. N2
2. O2
3. water
4. CO2
5. Dynamite!
Just kidding. 5 would be something like sand (polymer of SiO2) in Australia, right? 🙂
Ahm. Where? You mean the universe? Well – no, I don’t know. So let me try to work it out without consulting Dr Google.
1. Hydrogen (which would be a lot of H and then a lot of H2)
2. Helium
3. Probably some fusion product of those two, so, what would it be – lithium or beryllium. Except these are quite reactive so, err, what, carbon? As the element – on earth that’s “soot”. In space it’s spacedust.
You’ll notice that these aren’t very exciting yet. They are molecules in the sense that they are stable, atomic-sized things. Hydrogen (H2) is a molecule. Helium is an atom, but I’m including it because I think if I were helium I’d like to have a ticket into the Molecule Club. Hydrogen and helium are the things in stars, so are vastly more common than anything else. We don’t come into contact with them much down here on earth, but that’s because we live a very sheltered life. Putting helium in balloons is like putting your very own little bit of the big bang in a bag.
H2 and He are fusing the whole time, so I’m guessing that the next on the list is some product of these two. The way we work out what’s in stars is by the light that comes from them. Molecules/atoms absorb radiation, and they all do it differently. Whatever is between us and a light source will absorb light in a very individual way. So the stuff that’s missing from a star’s light tells us what’s in front of it. Very cool we can tell what the sun is made of without ever going there.
OK, so there are two to go. I’m going to forget about atoms and other small things now, since there’s probably a lot of other fusion-derived stuff in or near stars, but you get the idea. What about molecules not in stars?
Hmm. I know what you want me to say. You want me to say “water” but I doubt that’s right. We see a lot of water because we’re really watery things. But on the universal scale, it’s just not that big a deal.
This is a tough one. You know why? At the start of the universe, everything was pure energy. Not like in an energy DRINK, but actually energy. As the universe cooled, matter formed, and it was all hydrogen with a bit of helium. Stars formed. Fusion happened. More helium and, over time, heavier elements. Stuff like carbon, that we’re made of, came from stars exploding (which is amazing and we should totally talk about that) but it means that the heavier elements are rarer, and so are the molecules they’re in. I’d expect neon to be pretty common because it’s inert (doesn’t socialise with other atoms), but I don’t remember ever hearing that it’s all over the universe. I know that iron has a special place in the periodic table since it’s the element with the least to gain from fusion and fission, meaning that it tends to stick around a long time without undergoing any kind of nuclear change, but you need a lot of subatomic business to get to iron because it’s quite big and heavy.
But this is all atomic stuff. OK, back to molecules.
One last thing – it looks like the universe has a lot of “dark matter” in it. There’s a lot of stuff we can’t see. We know it’s there because you can kind of work it out from how things are moving – they’re responding to the gravity of something, but the thing is not visible. Putting that weirdness aside, there’s a lot of stuff there – maybe 70% of the mass of the universe. Something tells me that it’s not molecules, otherwise we’d be able to see them. So it’s unlikely to be a cloud of all the stuff we’ve ever lost down the back of our sofas. It’s likely to be other stuff.
Back to the question. I’m going to go for carbon monoxide, because I hear a lot about it. I seem to remember talking to an astrophysicist one time who had a picture of carbon monoxide on his T-shirt. We don’t see carbon monoxide a lot – it’s in car fumes and is bad for you – but it usually combines with oxygen to give carbon dioxide on earth. In space we don’t have a lot of oxygen, so CO stays as CO.
So that’s four. I’m breaking into a light sweat here. Let me have a coffee.
OK. I’m trying to decide between water (I know I said it wasn’t that) and nitrogen (N2). I’m thinking about all the rocky matter in the solar system, but I’m also thinking about the gassy giants like Jupiter, and what they’re made of. However, planets are pretty unimportant on the scale of the universe.
What I’m thinking now is: when comets and things come into the solar system from outside, they’re rocks covered with … water. That makes me think that outside the solar system there may be a lot of water. Water’s a pretty stable molecule. This could be embarrassing, but I’m going with that. So:
4. CO
5. H2O
If you’re talking about the 5 most common molecules we see as humans on the earth, then I’d say:
1. N2
2. O2
3. water
4. CO2
5. Dynamite!
Just kidding. 5 would be something like sand (polymer of SiO2) in Australia, right? 🙂
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