For the eminent professor of physics, it was yet another reminder never to underestimate the thought processes of children hell-bent on making sense of the world. And in his latest book, More Letters to Uncle Albert, Professor Stannard's answer to young Joseph is suitably humble.
"There can be some problem sitting right under everyone's nose (or in this case, sitting above their head), and no one even notices it is a problem. Then along comes some genius - like my hero Einstein - who becomes the first person to ask, 'Hey, what's going on here?' And then comes some big scientific discovery. Usually they are made by quite young scientists - those whose thinking is still lively and flexible, unlike us older scientists, whose thinking tends to get stuck in a groove. That's why you came up with your question and we didn't."
It's also why the 64-year-old father of four decided it would be a good idea to teach Einstein's theory of relativity and quantum theory to primary-age children. In doing
so, through his hugely popular series of Uncle Albert books, Professor Stannard realised an ambition nurtured since his student days, when he was first introduced to Einstein's physics at University College London.
He says: "It blew my mind. I thought it was the most remarkable thing imaginable. But I was also angry that it had never been taught to us at school. I thought, why wait until someone has decided to study physics at degree level before introducing them to this fascinating area of the subject?
"I wanted to tell everyone about it, although most adults didn't believe what I was telling them because it went against common sense. But Einstein said common sense consists of those layers of prejudice laid down in the mind before 18, and I realised you have to get in quick before those layers of prejudice become firmly fixed. Unfortunately, I did nothing about it for a long time."
In fact, a successful career involving international research into high-energy nuclear physics and 20 years as head of physics at the Open University put the idea of spreading the scientific gospel to the very young well to the back of his mind. But during the late 1980s, it resurfaced, made more urgent by the disturbing lack of students studying physics at degree level, and he set about putting it into practice in a highly systematic way.
First, he carried out extensive research into child psychology, to find out how children think and learn. He decided his theories would have to be expressed in a concrete, rather than a formal manner, so his young readers could relate to and understand them. He then investigated the types of books that most appeal to children and spent some enjoyable Saturdays at his local library in Leighton Buzzard, Bedfordshire, poring over those books with the most date stamps in the 9-to-13 section.
"The seats were too small, so I sat on the floor," he says. "The children thought this was a bit odd, but by the second visit, word had got round I was a professor and therefore a little strange, so that was all right. "
Professor Stannard noted that the most favoured titles included humour, fantasy, illustrations, short chapters and plenty of direct speech. Only when he had thoroughly researched his subject did he start to write The Time and Space of Uncle Albert.
Ever the scientist, he decided to test the water by inviting a random selection of 11-year-olds from two nearby primary schools to read the book and sit a short multiple-choice test. The results were positive. An average mark of 53 per cent showed most of the children could understand the complicated theories he was putting across. And 78 per cent said they found the book "interesting" or "very interesting".
After talking to the children and identifying the most problematic areas, he made revisions and was rewarded with even more positive feedback.
Unfortunately, the publishing community was less enthusiastic. Rejected by educational publishers for being "too entertaining", and knocked back by mainstream firms for being "too educational", he made a grim resolution.
"I had heard William Golding's Lord of the Flies was rejected 17 times before it was published. I thought that if the Nobel prize-
winner for literature was prepared to send his manuscript out so many times, I ought to do the same. Eventually, I received rejection letter number 17. Thoroughly depressed, I told Maggi, my wife, that if it was rejected one more time I was going to tear it up. She suggested sending it to Golding's publisher, Faber and Faber. I did - and they accepted it."
Published in 1989, the book sold out within three weeks and has continued to be a bestseller in 15 languages ever since. Hot on its heels came the equally-successful Black Holes and Uncle Albert and Uncle Albert and the Quantum Quest, which have made the theory of relativity and quantum theory accessible not only to thousands of children worldwide, but also to adults with little or no previous experience of physics.
Letters to Uncle Albert and More Letters to Uncle Albert take the learning process further, by answering some of the hundreds of questions about the universe and God that puzzle children and adults alike.
A strongly religious man - he has been a Reader in the Church of England since 1966 - Professor Stannard makes no apologies for bringing God into the scientific picture. Through his adult books, Doing Away With God? and Science and Wonders, his regular radio and television broadcasts, and his recent compelling series of Gifford Lectures at the University of Aberdeen, he manages to marry the theological with the physical in an entirely natural way. He believes this process is far more credible to free-thinking children than to their parents - and to those who compile the curriculum.
"It fascinates me that children don't compartmentalise their information. They may be writing to a scientist, but they're just as likely to ask 'Why does God allow bad things to happen?' as 'Why is the sky blue?' If a child thinks it's perfectly natural to ask about science and God in the same paragraph, why shouldn't religion be brought into subjects across the curriculum? It does seem as though schools need to offer a stronger line of guidance, not by telling children how they ought to behave, but getting them to think about the big moral questions and how these relate to the world around them."
You can't help but wonder
what Uncle Albert would make of that one.
More Letters To Uncle Albert
is published by Faber and