Chemistry explosions are all bang and no buck

I am a chemist and I am heavily involved in science outreach, especially in chemistry. I have built a library of demonstrations that I can pull out to show scientific principles. I also have an array of demonstrations that will result in explosions, not something to brag about when needing to board a flight. The explosions and flames are my least-called-upon demonstrations. I loathe these demonstrations and use them sparingly. Chemistry is so much more than pyrotechnics so it is a tragedy that this is what it has become, and not just to people outside of science but also within science. As a chemist of 10 years, I have not once used an explosion in any of my work.

Well-meaning science communicators and chemists have used explosions to grab the attention and awe from audiences in chemistry talks and demonstrations for who knows how long. I have seen too many to count in many guises and for a range of audiences, and all with the intention of telling people about the chemistry of matter — the bits that make up stuff around us and the chemical reactions of the bits. This mode of chemistry out-reach is a dismal failure at representing chemistry and inspiring future scientists. I say this because the vast majority of people whose only exposure to chemistry through these demonstrations sum up chemistry with one word: “explosions”. Students, even before they have stepped into a chemistry class, will say this and then lament about the lack of classroom explosions.

Chemistry isn’t a study of pyrotechnics. I may know the chemical components of what is needed to make fireworks and the chemical compounds in a number of explosives but I don’t know the first thing about firing them safely. I’m not a pyrotechnician. There needs to be an overhaul of chemistry demonstrations that are trotted out on stage. Let’s face it, people who turn up at science shows are already interested so they’re not a hostile audience. It’s time they got more than a scaled-down fireworks display.

Instead of trying to design a show that encompasses the whole of chemistry, shows should focus on aspects of chemistry. This would mean a greater variety of demonstrations — we’ve got the equipment so let’s flaunt it — and a better representation of what chemistry is and more importantly how pervasive it is throughout science and everyday life. Let’s see more chemistry shows with themes and targeted messages beyond, “Chemistry is awesome and exciting!”

Demonstrations involving dry ice can be shown beyond placing it in a bottle or an old 35mm film canister and waiting for a big bang. Yes, gases expand and this is an excellent demonstration but given that CO2 is now a much-talked-about gas, there is opportunity to show people some of its other properties. You could collect CO2 and pour it over a flame to demonstrate the fluidity of gases. It also shows that it doesn’t support combustion and the principle behind CO2 fire extinguishers. Get an empty aquarium, throw in pellets of CO2 and blow soap bubbles into it and voila, floating bubbles.

Then of course there is the visual demonstration of bubbling CO2 through a solution to change the pH of a solution. The acidification of oceans has entered mainstream media reporting so why not get a sample of ocean water and experiment before a live audience? And with the advent of cheap webcams and live streaming, leave a shell in acidified ocean water for the audience to monitor over time after the show to see what happens. Chemistry isn’t confined to laboratories and shows so why not encourage ongoing discussion?

Why not bring in some analytical instruments to analyse samples? With so many handheld devices now available, if you have access to them, show them off in action. I attended an open day at a chemical analytical lab and the most popular and busy stalls had working handheld devices. Bring a piece of equipment and analyse something live in front of an audience in a themed show. Ask the audience for an everyday object they have on them to incorporate into the show.

One of the most awe inspiring demonstrations I have seen did not have a single explosion. It was a colour show showing off chemiluminescence accompanied by an informative talk. You know that CSI trick of spraying a bottle in a crime scene and then shining a UV light and suddenly the blood splatter can be seen? The chemists behind this talk took that right out of CSI, put it in front of the audience, and showed just how bright luminol can get —and with more colour. It no longer remained in the domain of television magic. The speakers did finish off with an explosion but afterwards it was the much more complicated chemical reactions behind chemiluminescence that everyone was talking about.

This kind of discussion comes only if the chemistry has content beyond the flashes of light and colour. Content is king. Chemists are not magicians or performers in white lab coats. Every chemist I talk to has a story of intrigue and mystery about their work — and not just the forensic chemists. Each one of us has a mystery to solve and who doesn’t love a good detective story? Why don’t these stories get shared, and in doing so shed the snap, crackle and pop impression of chemistry? After all, it’s not the study of a breakfast cereal.

I am not saying do away with explosions entirely but if the rest of the chemistry show can’t stand alone without them, then what is the point? Demonstrations should highlight the content and show off the chemistry. No smoke, no mirrors, just the revealing of chemistry in everyday life, which in itself is magical. Give people a real story of chemistry to walk away with instead of memories of a big bang and no buck.

This is taken from Philosophically Disturbed, a blog created and maintained by Magdeline Lum.