The perks of physics
For two years, I was the social convener of PAIN, the physics club here at UQ. Despite being a lot of work (I originally wrote “little bit of work” but that’s an understatement…) it was a fabulous opportunity to both polish my presenting skills and explore some really cool physics. My job was basically to run an activity each week, on Fridays at 5pm, which had some relevance to physics but was a bit quirky and fun.
Pretty high on the list for me, as well as for many other such groups around the world, was making liquid nitrogen icecream. The basic idea is that you mix up your ice cream mixture (cream, milk, sugar + chocolate/berries/whatever), then freeze it using liquid nitrogen! Now, normally when you’re making ice cream you must stir it every 10-15 minutes as it’s freezing, because otherwise big ice crystals form and it doesn’t have that deliciously smooth and creamy texture. Nitrogen solves all those problems however - it freezes the ice cream so quickly that the big ice crystals don’t have time to form, and as it boils away it aerates the ice cream making it light and fluffy. It’s pretty much ready in 20-30 seconds! Delicious!!! PAIN’s running this activity again this afternoon - YUM!
The difference between us and other groups is that we let people make their ice cream in individual styrofoam cups, whereas other groups usually just do it in a giant pot. This is far more fun! And there are so many fun things you can do! A couple of years ago, our now-social convener Chris (I think it was him!) discovered that by alternately dipping strawberries in chocolate ice cream mixture and liquid nitrogen you would get a strawberry coated in light and fluffy chocolate ice cream. They’re so good!
And while everyone in the club got to play with this and eat ice cream, it was great being able to decide what flavours we’d have, what experiments we’d try (e.g., dripping ice cream in to make tiny “balls” of ice cream) and, of course, what we’d do with the left over liquid nitrogen! Favourites have always been pouring it down a flight of stairs (very Phantom of the Opera-ish) and pouring it into the fountain (ditto!) And of course this was just one activity - it was great to have the opportunity and budget to run pretty much any activity or experiment I found on the web and thought was interesting!