While the internet was wringing its collective mouse cords over the spectacularly badly thought out http://gizmodo.com/5954522/how-to-use-basic-chemistry-to-scare-the-hell-out-of-your-neighbors this Hallow’een, we were out doing some fairly decent and safe science to impress local families. We had three experiments on the go: flame tests, alien blood and enzyme catalysed decomp of hydrogen peroxide. The flame tests were given a wonderfully spooky twist by naming the salt solutions ‘Vampire blood’, ‘Dead Sea Salt’ etc, and the visitors to the event tested each by way of a soaked wooden splint in a portable Bunsen burner. Our visitors were from all ages and backgrounds but the response to the beautiful blue green of copper was generally the same wide eyed wonder.
Alien blood required slightly more improvisation as one of our chemicals wasn’t quite working properly. We settled on coloured acetone dissolving polystyrene packing materials along with a liberal sprinkling of fictitious aliens using their blood to get at your Christmas presents. The thing that impressed me was the ability of young children to separate the fiction back story that made the experiment kind of fun, and the science – many were able to comprehend both and wanted to know what the alien blood ‘really was’.
The peroxide decomp…well…that was incredibly surprising in the response we got. As it was Hallow’een, we’d decided that using bits of different organs and comparing the relative rate of hydrogen peroxide decomposition was the way forward. Rates that can be measured in terms of how much green bubbly foam (add washing up liquid and green food dye to the peroxide) are pretty easy to do. I was expecting some bits of heart, lungs and liver, I wasn’t expecting 3 full sheep’s plucks (heart, lung, liver all still attached to one another and the windpipe).
We started out in ‘a bit too gross triage mode’ and decided that keeping the bulk of the organs out of site from all bar the most interested and robust visitors would be appropriate. How wrong we were. The vast majority of visitors were fascinated by the organs, and we were able to demonstrate the lungs inflating by blowing into the windpipe. The peroxide worked fairly well although we weren’t able to get a glowing splint to relight most of the time. The liver was far superior in decomposing the hydrogen peroxide, logical really, having the greater concentration of enzymes of all organs tested.
Other displays at the event, run at Keele’s Sustainability Hub, included bats, lizards and snakes (I got to hold a python which made my week), dry ice, non-Newtonian fluids, making smoothies with the ultimate dynamo bicycle, face paints, pumpkin carving, the Make-it-Molecular crew were there and much more that I didn’t get a chance to see. It was a pretty amazing half-term event for families and good fun for all those who volunteered. Makes me look forward to the next outreach/science comms event in December…which reminds me, I need to order the chemicals!
With thanks to L Mills for the photographs.