Working with liquid nitrogen can be a daunting experience. It can suffocate in an ill-ventilated room, leave horrendous burns from seconds of skin exposure, and turn a banana into a deadly weapon…And yet it somehow pales in comparison to working with teenagers.
That is why I first reached out to David Williams to help out on ‘Physics in the freezer’. The MSc Science communication at UWE Bristol, more than anything, has taught me that while science is a subject that can be learnt, communication is a skill that must be lived and practised. And communication with young people is a skill unto itself.
David set up ‘Physics in the freezer’ to combine his two passions: teaching and conducting dangerous science experiments. He has created a set of shows featuring different demonstrations using magnets, liquid nitrogen, and superconductors. He takes these shows to primary schools around the South West to inspire kids into STEM. To his credit, David quickly realised that the most aspirational way of delivering this content is with young presenters. As such, we spent two days in Breacon Beacon High School, not just showing these demonstrations to sixth-form physics students, but teaching them how to deliver one.
It was an early start on Tuesday, as we arrived at the school and got everything set up in their science labs. I’d had a practice session with David and run the show for year 5 (9-10ys old) twice at this point, so while not new to the material, I was filled with equal parts excitement and apprehension. The aim of the first day was to run through a whole show ourselves and then have our sixth formers pick and practise which parts they wanted to do. We ended up with a class of 7 and got straight into a lengthy safety briefing. Above I outlined just a few of the dangers of working with liquid nitrogen, but in truth, like many things in life, a sensible approach and a healthy dose of fear significantly reduce the risks. It was then on to the demonstrations.
We always start with an introduction that covers the basics of the physics and the wonder that comes from seeing liquid nitrogen poured for the first time into a large glass dewar (a specialized container designed for storing and transporting cryogenic liquids). Smoke (or rather water vapour) billows down the sides, whilst the surface fizzes, pops and dances like quiet fireworks. The children at the shows love it, and even these teenagers seem somewhat impressed. Next, we proceed to pour liquid nitrogen into a steam kettle and listen to it whistle. I was in charge of this one, and while I’m used to getting ‘ohhs’ and ‘ahhs’ from a Year 5 audience, the sixth formers were less than impressed. Fine, and very understandable, but unsettling, nonetheless. Good thing we had bigger and better things up our sleeves. The following few demonstrations involve freezing, shrinking and bursting balloons, smashing frozen bananas and producing smoke-filled bubbles.
Sixth formers then separated themselves into groups and got to work learning the script and practising the demos. I had a group of three demoing a whistling kettle and smashing bananas. Teenagers, once you get talking to them, are not nearly as scary as they seem, even if they did constantly quote memes at me that I’m apparently too old to understand (I’m 25, that seems unfair). They were about as enthused by the material as you can hope for from people who have willingly chosen physics but less so willingly come to school.
After 4 hours of hard work and participation, we rewarded them with a more advanced show on superconductors and magnets, which was a perfect end to a long day, especially for me, who hadn’t yet had the chance to see some of these demonstrations. It’s a real bonding experience to realise that students, teachers and demonstrators alike are all kicking their feet and giggling overshooting frozen magnets 5 feet in the air.
On Day 2, we were putting our prodigies to the test; they were to give three shows back-to-back to local Year 5 students visiting the school. When David had first told me about this timeframe, it seemed to me to be a trial by fire, but having now done it, I understand just how valuable ‘just getting to do it’ is for learning. And they were terrific. They read from scripts, of course, no one wants to spend a hot June evening practising lines, but every one of them came out of their shell and, show on show, improved vastly. By the end it felt damn near professional. I took over a few of the demos for students who had to leave early and had a blast getting to improve my presenting skills further and go off script with a newfound confidence.
The idea of throwing yourself into an unknown field with a dangerous substance and plenty of public speaking might make you squirm. I would argue it should. But I never once felt unsupported or overwhelmed. David made sure of that. My biggest takeaway from this experience is to put trust in yourself when you are the learner, and trust in others when you are the teacher. Participating in physics in the freezer gave me the opportunity to be both of those things, and I cannot recommend it enough to others who want to grow their communication skills. Also, child, teenager, adult: who wouldn’t want to smash a frozen banana?
By Alice Thomson, MSc Science Communication student, UWE Bristol