Why I hate liquid nitrogen

Jamie Gallagher, Mar 12

I love the science communication game. I do as many activities as often as I can. Everyone seems to have caught on to the importance of the topic. Across the country over the past few years many scientists have been taking tentative steps out of the lab to proffer their wares to a wider audience- especially since “impact factors” became a part of grant applications. I applaud their attempts, often with a slow steady sarcastic clap- but it is better than nothing. Some will say it is excellent that they are doing this; to a point- it is. However I see many science communication activities as a swing and a miss and here in contains my rant or “why I hate liquid nitrogen”.


My university, like almost all, has an Open day- indeed we have several. We open our lab doors to prospective students, their families and the curious. Staff and students of the department pull together to put on events. They give a flavour (generally vanilla or banana if you can see where this is going) of what chemistry is like. They watch us freeze flowers in liquid nitrogen; they watch us deflate a balloon in liquid nitrogen; they watch us fill ping pong balls with liquid nitrogen. Finally they are sent away clutching a liquid nitrogen made ice cream and filled with a deep understanding of what a chemist does.  


This type of science communication should have gone out the same day we stopped playing with mercury because this is little less toxic. What impression do they hope to give? I died a little inside as a final year PhD student held a partially deflated balloon fresh from a dewar aloft and announced to the crowd “look, liquid air” She was of course referring to the water that had condensed at the bottom due to her blowing it up herself. This type of demonstration is the “demo for demo’s sake” it is almost never backed up with any kind of explanation and is simply aiming for shock and awe. If any of our students are swayed into choosing chemistry after seeing a flower frozen- I pity them. It will be a long hard four years.


The reason these poor quality demonstrations are so prevalent is that they do interest people. Few people find a bubbling vat of ‘smoking’ liquid anything other than fascinating. Scientists often mistake an interest in the prop for an interest in the subject. The scientist forms a crowd, sees the awe inspired reaction and rests easy that they are a successful communicator. They fail to ask themselves the all important question “what has my audience learnt?”


Science communication is not easy; it is not necessarily something that comes natural to all. It needs work, it needs practise. A truly excellent communicator will be able to make almost any topic fascinating. Demos defiantly have their place. They can be a vital tool for explanation- giving a clearer picture of the science than words alone ever could. They can, also, in an hour long show be a welcome wake-up call to the audience adding variety and adding break points that will help to keep momentum. There is however a correct way to go about them. Ideally take a topic then use a demo to explain- never start with a demo and work science around it.


On open day I do have a stall, I also use liquid nitrogen. I use it to cool my super conductor and levitate a magnet. For this I go on to explain a little about magnets and what we can use this phenomena for in the real world. Audiences seem no less impressed or bored by the inclusion of real science and I hope that they leave with a slightly better impression of what I would work on day to day.


Science communication in its current form is still a new phenomena. It is continually growing, learning and developing.  There are many schools of thought. There are many styles of presenters. There are many types of audience. These are the strengths. I hope it continues on its current path, inspiring people, making science truly accessible to all. However let’s move past pointless demos and get a bit of science into our science communication. If however you are of a different school of though feeling that you are truly engaging people with these demos I will respect that. I would however ask that you wear a tuxedo/ sparkly dress and follow your hydrogen explosion with the words “That’s Magic”.