The University of the Third Age, U3A, was one of several positive discoveries made after I ‘retired’ as an academic and research scientist. It has, for instance, given me the opportunity finally to indulge in more creative writing – within a small group in which, comfortingly, I’m not the only person with a STEM* background. Some of the early-stage output from this endeavour is featured in a previous post (here). The other ongoing need in my life transcends the move from salaried employment to ‘going freelance’: trying to communicate science and my love for it to lay audiences. Although I’d been doing as much of this as I could fit in prior to retirement (e.g. see here or here or in umpteen other posts on this blog) and ad hoc invitations to do this have continued, I felt the need to go beyond one-off short talks. Again, the local branch of the U3A has provided a useful framework. And so it was that, last Autumn – my first year as a member – I opened my living room to a small group of brave souls who’d each paid £3 per session (to the U3A) in order to hear a complete stranger talk about glass. I had three two-hour sessions scheduled, so plenty of scope for peppering the science into a swathe of images and artefacts, art and history. The feedback was really positive, and word evidently spread that there’s more to glass than meets the eye (!) because my re-run of the course this coming autumn has far outgrown my living room and we are being moved to a larger venue in the city. This is hugely gratifying, but more importantly it helped to persuade me that my approach to presenting science in this context was broadly OK. However, talking about glass is, for me, an ‘easy’ thing – it can be harder to stop. I set myself a new challenge.
|The opening slide: ready to welcome my brave audience.|
The U3A run an annual series of ‘Summer Specials’: essentially taster sessions prior to members selecting what they might like to register for in the main programme, which starts each year in the Autumn. They also allow one to try out ideas for possible new courses, and this therefore provided an ideal vehicle for me. This is what I proposed:
In the event, I found I had more than enough material for an hour’s worth of my talking. This was a good thing in the sense that it allowed all the space required for what turned out to be a large number of challenging, high-quality questions that emerged as we went through. The downside is that we had less time for connected discussion at the end, but addressing the questions as they arose was definitely of more importance. Indeed, for me, getting good questions is one of the best forms of immediate feedback.
What did we cover in the end?
After introducing ourselves and grabbing a drink and a biscuit or two, we spent a few minutes on the 92 naturally occurring elements and their 1000+ isotopes, and in establishing the prevalence of radioactive isotopes in particular. Next, an overview of the principal forms of ionising radiation and how one might tell which is which; then, how they can be detected using a Geiger counter, and what sort of units we measure them in (the Becquerel, Bq, and the Seivert, Sv, in our case). The final bit of scientific background covered the meaning of the half-life as well as illustrating the concept of the decay chain. No equations saw the light of day – reflecting an important lesson I learned long ago. All-in-all, with questions, we spent about half our time on the basic science before moving on to consider the bad, the benign and the beneficial.
|I chose to reverse the order of the aspects of radiation drafted into my purposefully tantalising title: ‘bad’ is, in a very real sense, the easiest to cover – it is, well … bad.|
As I’ve said already, a constant theme was always to think in terms of perspective – the balance of risks. I wanted us to leave the session with an appreciation of what radiation is, where it originates, how much of it we encounter and what it does. My hope was/is that the group would thereby be better equipped – one might even say empowered – to engage with current and future debates. Reactions on the day exceeded all my expectations, and what people have kindly said in various emails since then has been truly humbling. One person made a very positive suggestion for improvement which I’ll definitely adopt. I doubt I shall ever forget the two people who, quite separately, said that had they been taught science like that when they were at school their later choices might have been very different. It doesn’t get much better than that.
|My parting slide, philosophically tongue-in-cheek, is shown here. We could have spent an entire session exploring these three points alone – and perhaps one day we shall – but we ended our two hours together with the suggestion that they be mulled over. As it turned out, I was motivated to post a brief reflection on the middle one in the week after my U3A talk: here, should you wish to read it.|
* STEM – Science, Technology, Engineering and Mathematics; sometimes an additional ‘M’ is added in order to include the Medical sciences.