A personal history of ignorance - Anne Rooney

Formation of the Moon, giant impact hypothesis; image from NASA

"There are known knowns. There are things we know that we know. There are known unknowns. That is to say, there are things that we now know we don't know. But there are also unknown unknowns. There are things we do not know we don't know."
Donald Rumsfeld, US Secretary of State for Defence, 2002

Lockdown learning must have revealed a lot of known and unknown unknowns to beleagured parents. How we deal with the questions we can't immediately answer is important — perhaps more important than those we can answer.

When I was little, I knew that if I wanted to ask something like 'why does a magnet pick up metal but not leaves?' or 'why is there skin on custard?', I should ask my dad. I was lucky; he was a scientist. If I wanted to ask why I had to drink a cup of tea, I knew my mum's answer was going to be that I would be a social pariah if I didn't learn to drink tea. *wave to your local social pariah*. Some questions had no real answer 'Because I said so.' 'Because that's how things are.' And a few allowed some scope for experimentation. 'Why don't we eat ants like anteaters?' 'You are free to eat ants and find out.' (Even crystallised with sugar in a hot oven, British ants are not worth eating.)

To factual questions, the answer was sometimes 'I don't know.' We had a set of encylcopaedias in which many things could be looked up, but obviously only the things that encyclopaedists expected people to want to look up. I don't recall there being an entry on the untastiness of British ants. We had a library, but it was not close enough to go to without a car, so was a Saturdays-only venue for exploration. Unless the question arose on Saturday morning, it would have been forgotten by the time we got to the library. The library wasn't really an ignorance-sink until I was at secondary school and had a decent school library on hand.

Some questions don't have a definite answer. My mum believed in God; my father didn't. That quickly revealed that there are questions that even knowledgeable grown-ups disagree about. I didn't twig then that actually there is an answer but the answer can't be determined with objective certainty. The notion of grades of unanswerability lay ahead of me. But the existence of God fell into a group of questions where different people gave different answers. Then there are questions that no one could even suggest an answer for, such as 'why does 'cat' mean cat and not dog?' And then there were questions that people just refused to answer, such as 'why do we have to go to the family planning clinic? what happens there?' (I had to sit in the car with my father and brother during these visits; my mum couldn't drive and there was no other way to get there.)

On reflection, eating ants was a critical point. It showed that ignorance is an opportunity rather than a limitation. I could find out for myself. This wasn't the same as those experiments where you find out whether wood or stones float or sink. The person directing the enquiry knows the answer. You know they know the answer. What's more, they know why wood floats, and you know they aren't going to tell you. (That reminds me, I promised to show MB a floating stone. Must do that this morning.) You can't look up why we don't eat ants. And I'm sure in a famine people would eat ants. In case you are wondering, not only are they rather lacking in taste, you have to expend a great deal of effort to catch and cook enough ants to find out. There's probably an energy deficit in ant consumption here.

Despite all these obvious gaps in my knowledge, I grew up and went to university. The person who interviewed me said he had never seen such a bad entrance paper in two of the categories. This was a bit of a blow, as I still thought not knowing things was bad. School exams suggest that. But he said that he could see I had potential as I'd done very well in the one that he thought mattered, so I could come anyway. (I know, that wouldn't happen now. This was the early, uncoordinated, version of trying to address equality of opportunity. I do now wonder why they bothered even setting the papers that didn't matter. Perhaps views on which mattered varied.) Here, ignorance was not just the opportunity to eat ants but to find out stuff. A gap that could be filled, and there would be pleasure, discovery and achievement in the filling it. Another turning point came with my PhD supervisor, who once said, "You don't need to know everything. You need to know the people who do know things." You need to know who to ask. A PhD itself is an exercise in finding a gap in knowledge and filling it. The gap is the most important bit. We need ignorance or we can't do any original research.

By the time my children were growing up, things had moved on a bit. We could get to libraries and by the time they were at school there was Yahoo to look up answers to many things. But the idea that all questions are answerable with certainty is dangerous. (As we now see every day in the viciousness of twitter.) I encouraged them to think about questions that can't be easily answered. My older daughter's favourite book at six was the DK introduction to philosophy. I remember telling her in Waitrose I would buy biscuits if she could prove the biscuits existed. (She got biscuits; I wasn't very rigorous as long as she made a good attempt.)

Their primary school was excellent. It valued knowledge and ignorance. When the Iraq war was imminent, the older one went into school and asked about it. Not convinced she was getting a good answer, the next day she took in maps she had printed out and asked each teacher separately to show her where Iraq was. Few knew. Some teachers were annoyed; they didn't like their ignorance being found out. The good ones investigated with her (or actually knew where Iraq was).

And so to now. MB asks me where the Moon came from. I explain to her. We make an Earth and a Theia out of play-do and make them collide. We tear Theia and a chunk of Earth into pieces and then form the Moon out of the bits. She asks if Theia was hot or cold. I don't know. I ask a friend on Facebook with a PhD in astrophysics. We agree that as a rocky planet it should be cold. But as a very early planet it was probably geologically active and so should be hot. Hot or cold? The question heads off from a six-year-old in East Anglia to be asked around the astrophysics world. You don't need to know everything; you just need to know the people who do. Or you need to know the people who know who to ask. If I didn't know Helen, I could have asked on Twitter, with the right hashtags. Someone would know (though then we have the issue of assessing the reliability of the source, which is another matter). The point is not whether she will get an answer, but that the ignorance is productive itself. 

In the late 19th century, the professor of physics in Munich, Philipp von Jolly, told Max Planck not to become a physicist because all physics was known; there were no opportunities for discovery. Planck went on to reinvent physics with quantum theory. What could von Jolly's ignorant certainty have cost physics? Never underestimate the unknown unknowns. Any parents alarmed at the ignorance home learning has revealed — that ignorance is possibly the best bit. It's food for the enquiring mind. Children are excited by questions grown-ups can't answer. You should be excited by questions you can't answer.

Last night, less than ten hours after staging the formation of the Moon in play-do, MB had a message from school saying she had to attend a Teams class meeting and present some of her home learning. 'But I haven't done any!' she wailed. How do I answer that? I don't know.

Anne Rooney
Blog: The Shipwrecked Rhino: a wunderkammer
Latest book (as far as I know):
An Animal Park Keeper, HarperCollins, 2020