“How do we make water?”
That was the question I was asked on Wednesday morning, by the Younger Pawn (YP, nine on 5th November). Not, as you might expect, “where does water come from?” but specifically, “how do we make water”. The EP kept saying “from the sky”; by repeatedly answering the wrong question she’s either going to be a politician, or perhaps she’s just a product of the public school system (in Australia, ‘public’ is equivalent to our ‘state’).
So I thought about this, and said by the combustion of hydrogen-containing fuels, but immediately realized that this wasn’t going to cut it (yes, I could have said ‘respiration’ and talked about haem-Cu reductases and oxygen atmospheres but I want to riff off that for another blog entry. Besides, chemistry then biology, right?).
How can you understand that H + O 2 —> H 2 O if you don’t know what H or O are?
We started basic. Real basic. Back when the Universe formed, I said, all that there were was hydrogen atoms (I lied), and drew a little circle. I said that there’s more hydrogen than anything else in the universe and that hydrogen atoms are actually friendly little things and like to go around in pairs. I then said that if you squish hydrogen molecules together you can turn them into liquid, but if you do this even more they fuse and become ‘helium’. I said that hydrogen atoms weigh ‘one’ (‘one what?’ asked YP, incisively. Good girl), but that helium atoms are number ‘two’, weigh ‘four’, and are very unfriendly.
If you then squeeze helium together in the same way you can get beryllium, and then oxygen atoms, which like to be friends with two other atoms.
‘Oh,’ said EP, ‘the weight is twice the number?’
‘Up to a point, yes. But the weight gets bigger quicker, so chlorine—which we put in the pool, yes?—is number 17 but weighs 36, for example’ (I know, I know, shut up. It’s close enough).
If you could mix these first atoms together in the right way, in the middle of stars, I continued, you can get the other atoms, like carbon. And carbon, you see, is really friendly and likes to make friends with four other atoms, like hydrogen, and then you get methane. Sometimes it makes friends with other carbon atoms, and do you know what this is?
It’s what the lead in this pencil is made of. And if you organize the carbon atoms a bit differently so they stick out of the paper you get diamond.
“Coo-oool” chorussed the Pawns.
And the incredible thing is that all these atoms were made in stars right back at the beginning of the Universe, billions of years ago. And when a star dies —
‘That’s when the sun gets bigger than the solar system and then shrinks to nothing’ said YP.
Exactly. When a star dies, or goes ‘nova’, these new atoms are spread into space and form part of new stars, and planets, and you and me. We’re made from bits of old stars.
‘Wow.’
(And that piece of news was shared rapidly and enthusiastically at school on Wednesday).
So what happens, I said, drawing butane, is if you have a molecule like this with all carbons and hydrogens all friendly and happy, and add an oxygen molecule—which is what happens when you burn things—then because oxygen is friendly with just about every atom (including itself) it breaks all these other bonds, and you get carbon dioxide (because oxygen is such a good friend with carbon there only needs to be two) and…
water. Dihydrogen monoxide. H 2 O.
And that’s how we make it.
I said that we can also break water apart: if we stick an electric current through water it splits into hydrogen and oxygen gas. Their little eyes lit up and before they could ask if we might try that, I changed the subject.
I told them that the process by which we got our atoms of all sizes is called ‘fusion’, and asked them if they knew what ‘fission’ was. That’s when I drew a uranium atom.
‘OK, you’ve heard of nuclear weapons? Atomic bombs? No?’
I explained that if you had a lump of uranium about this size it would be warm, and it would give you radiation burns and cancer, because all the time it’s spitting out little things that are a bit like hydrogen atoms—they weigh ‘one’ and they’re travelling very fast. And when one of these neutrons hits another uranium atom, it will break it apart, and two or three more neutrons will come out, and they’ll hit two or three more uranium atoms and… they got the point of a chain reaction. Each time this happens, I said, you get an enormous amount of heat given off. And if you have two pieces of uranium, and bang them together very quickly like *this*, you’ll wipe out Sydney.
Seriously, I said. It’s so powerful, it would kill everyone within five miles.
‘Could you make one?’ they asked, horrified and fascinated. No, I explained, I couldn’t make one. You’d need a lot of money and machines and people.
‘I hope people never do it,’ said EP, fervently.
‘Sweetheart,’ I said, ‘it has been done.’ And I told them about Nagasaki and Hiroshima, about the hundred thousand people that were killed each time, about how certain people were worried because they think North Korea and Iran might be trying to make this sort of bomb instead of using uranium for power generation like they claim to be trying to do, and how the countries that do make these bombs are very scared to use them because they know how deadly they are.
But, I said, you can control this reaction and use it in powerstations. France makes most of its electricity this way. It’s clean, there’s no greenhouse gasses—
‘Why don’t we all do that then?’ demanded YP.
I said it’s a political issue. I said the Greenies were intellectually inconsistent. I said there had been accidents—Three Mile Island and Chernobyl—but the technology then wasn’t as good as it is now and people hadn’t followed safety procedures.
‘Well that was stupid, then,’ said YP.
Hell, if a nine year old can figure it out, it can’t be that difficult, can it?
And then I said, as powerful as fission is, fusion—the process in the middle of stars that makes them hot, the process that makes all the atoms that make you and me and the earth and everything in it, how we get the H and the O and the C and everything —is yet more powerful. Each time you fuse hydrogen, you get much more energy than you do from splitting uranium.
‘Oh,’ said EP, nonchalantly, ‘we’ve been told about fusion power. Why don’t we use it?’ and then I had to explain why they couldn’t come into the lab and try to fuse hydrogen or make liquid helium: except it was time for school and we were running late.
In the science fiction book I’m reading right now, all the scientists live in one place and the politicians have decided to bury the nuclear waster exclusively under their enclaves.
p.s. Thanks for the wonderful post. Their father has a good memory: not sure I could have pulled out all of that information without sneaking a peak at one of my old textbooks.
so chlorine—which we put in the pool, yes?
Life can’t be that hard, then, can it?
OK – Not bad but the stellar nucleosynthesis/nucleogenesis is a bit suspect… He –> C by the triple alpha process, as proposed by Fred Hoyle one of the great “never to win a Nobel” scientists.
Hell, if a nine year old can figure it out, it can’t be that difficult, can it?
Did you tell them about the half life of nuclear waste and compared it to the duration of the longest known stable civilization?
Brian—I was on the verge of suggesting they look up Fred, but we ran out of time, as I said.
Mark, no, I didn’t: it strikes me that it would have made my point even more strongly, though.
You’re too kind, Jenny.
Henry, the tramps in NSW have pools. Ours is 5,000 litres. Barely enough to get your chickens wet.
I had been under the impression you tried to teach that nuclear power was managable.
Anyway. Doesn’t matter. I think the children got stimulated and it can’t get better than that. Maybe it gives them the edge in the difficult process of learning the art of critical thought.
And I hope they got the message that there aren’t simple answers and science rocks!
Well done. I couldn’t have pulled it off.
I had been under the impression you tried to teach that nuclear power was managable.
It’s a shedload more manageable than ‘clean’ coal. The problems with nuclea power are political, not technical. The greenie weenies will not accept it.
Well done. I couldn’t have pulled it off.
Thank you.
When William was about 4 years old, he asked me why people on Australia didn’t fall off the Earth, if it was round. I gave a careful and considered explanation of gravity, to which he listened intently, nodding at the appropriate times. When I was finished he thought it over for some time.
“Plus, they wear sticky shoes, right, Daddy?”
“Yes. Right, William.”
HAHAHAHA!
Excellent. He’s right, you know Ian. We get issued with them at immigration.
(Yesterday evening of course they wanted to know ‘why we have gravity’. Try explaining the Higgs Boson and the LHC to children. I managed to segue it into a discussion of what science is and is not, actually, which was pretty cool.)
This was an exquisite post – lovely story, beautifully written. And your girls are obviously fabulous.
Thank you Katie. They are also somewhat scary… 😉
This reminds me of Friday Sprog Blogging over at Adventures in Ethics and Science (example ), except that Janet Stemwedel doesn’t teach her girls how to make an atomic bomb. Her sprogs are slightly younger than your pawns, but not much (I think her oldest is a bit older than your youngest).
Henry, the tramps in NSW have pools.
Yeah, right. I’ll bet that the cops have wooden legs, the bulldogs’ teeth are rubber, and the hens lay hard-boiled eggs.
Look Eva, if half of Australia disappears overnight,
it’s nothing to do with me.
bq. Yeah, right. I’ll bet that the cops have wooden legs, the bulldogs’ teeth are rubber, and the hens lay hard-boiled eggs.
I am seriously resisting the temptation to spoonerize the title of that song.
Ah. Temptation is the one thing I can’t resist, Big Cock Randy Mountain.
The problems with nuclea power are political, not technical. The greenie weenies will not accept it.
I wouldn’t call the problem of not being able to predict the future dynamics of waste management for the next 50.000 years a political one. You are not going to convince me that you can predict the next 50.000 years or more and what will happen to nuclear waste. Or what will happen to nuclear plants when the economy crashes. Are they going to be cleaned up after they reach the end of their life cycle if there is no money? Or are they going to be sunk like abandoned Soviet nuclear submarines?
The real problem is a moral one.
Are you going to donate your problems to the future or are you going to solve the problems now. I.e. are you going to take a good life now and let other people solve your problems. Or are you going to be responsible towards future generations.
Coal or nuclear are both not part of the ‘now’ solution.
The ‘now’ solution would involve major changes in our life style, and social and economical structure. Cut down drastically on energy use. Look for longterm solutions that may require investment and sacrifice.
And that is not going to happen since we all know about human nature.
So either way, coal or nuclear, it’s all the same. Both a stab in the back for future generations. It’s just a choice if you want to kill the future with global warming, or nuclear waste/economic bill.
It’s probably smartest to pick nuclear power since nuclear waste and accidents are probably not going to have a global catastrophic effect. Local hot spots. But then again, with the ever growing increase in the thirst for energy even nuclear power will contribute to effects such as global warming. It isn’t emission free after all.
Maybe the true enemy is the model of economic growth. As all biologist learn in their first year, any growing system will collapse because resources are finite. And more growth will just mean an earlier collapse.
As someone who works in the (US) nuclear industry, but isn’t in love with the technology, I have the following comments:
I appreciate the example of covering science with younger folk, where making things very simple is what must be done. But the interesting thing from my point of view is the description of having a lump of uranium and getting radiation burns and cancer. This is perhaps fine for the youngest of learners, but it also illustrates a perception that many, many adults have regarding the real-world dangers of radiation (and nuclear power and nuclear waste).
Radiation is not a nerve gas or a death ray. It takes a really huge amount of radiation exposure to cause even temporary damage to a human. (Congratulations, Chernobyl.) You won’t get there from holding uranium ore, and you’ll have a bit of a wait even if your hand is wrapped around the processed U-235 they put into bombs. (Swallow uranium, and the health effects do increase, both from internal radiation exposure and because it’s a heavy metal and mild carcinogen, like lead. And high level nuclear waste is just awful, however you’re exposed to it.)
The problem of perception with health effects, radiation and scale is the principal issue which makes general public discussion and decision-making on nuclear energy so problemmatic.
There are two other issues regarding energy and nuclear power where there are often accuracy problems that affect the quality of policy debate. First, the public perception of nuclear plants is driven by really, really bad TV and books that have all the physical accuracy of a Road Runner cartoon. (If you’d care to read how hard it is to put out accurate entertainment on the subject, see my LabLit essay, Lab Lit).
The second item is the scale of generation of various energy sources. Modern civilization uses a huge amount of power, 24/7, and its not a simple matter of replacing a nuclear reactor with a few windmills. Mr. Tummers’ comments on cutting down drastically on energy use via major societal changes are correct if you don’t wish to consider energy-dense options like nuclear and coal. The safest, cheapest energy is that which you don’t use.
Nuclear power isn’t perfectly safe, or cheap or the only solution to our energy woes. There are many other paths depending on what risks you wish to take, the lifestyle you want to lead, etc. Regarding the risks of nuclear, my novel Rad Decision takes a look at this from a U.S. perspective and I think provides a good overview. It covers Three Mile Island, Chernobyl, the technolgy, the politics and the people. It’s available free at RadDecision.blogspot.com and also in paperback via Amazon. (I get no royalties.) I think we’ll do a much better job of deciding on our energy future if we first understand our energy present. ( In Rad Decision, I tried to do it for nuclear in as gleeful and entertaining a way as possible – unlike this note.)
Dr. Tummer does ask some questions I can’t tackle because I don’t know the answers. I think my book gives some good insight into what it takes to run a nuclear plant now. I didn’t branch into speculation on nuclear power if economic conditions drastically changed. I also said very little about nuclear waste, because I’m not involved in that field – so I have nothing profound or new to offer. I read the same public reports as everyone else.
Here’s hoping energy discussions in the public sphere will be well informed and ready to look at the genuine pros and cons of all the alternatives. (I’m also counting on world peace in the near future).
And I’d like a pony.
Try explaining radioactivity to people who haven’t been taught physics or chemistry. And then try explaining the politics and technicalities of nuclear waste reprocessing.
(rant about energy wastefulness elided. Not the place and I don’t have the energy)
Henry, I should have known better than to call your bluff, shouldn’t I?
Okay, the atoms from which we are made were produced by stars that existed billions of years ago, but isn’t the whole stardust production process ongoing so that future supernovae will be spitting out new atoms that might create new entities elsewhere in the universe that might ponder such things (or not as the case may be)?
To paraphrase the big guy: it’s amazing what a few hydrogen atoms can do went left to their own devices, given a few billion years.
They’ll be new atoms, yes (from fusion): but there is a constant amount of baryonic matter being recycled. It’s fun to think about other intelligent life being made from us.