The inevitable Ice Bucket Challenge notification came along, courtesy of the Brothers Pag. Anyone who knows me knows that I can’t swim, so I wasn’t prepared to take the risk of attempting the challenge.
Also I didn’t have any ice in my lab, but I did have a Dewar of Liquid Nitrogen, so here is Balloon Matt nobly taking the challenge in aid of the DEC Syria crisis appeal.
**SAFETY NOTICE** Don’t do this at home. If you have liquid nitrogen at home, why on earth do you have liquid nitrogen at home? Whilst pouring and transporting liquid N2, heavy duty cold-proof gloves and a face visor must be worn. Do not touch parts of the balloon directly after they have been in liquid nitrogen. NEVER POUR LIQUID NITROGEN OVER YOUR OWN HEAD a million things can go wrong and you can lose eyes skin and hair: remember what happened to Boris. Do not cool an air filled balloon for prolonged periods due to risks of liquid oxygen condensation. **THANK YOU**
Anyway with that aside, and as mentioned in the video: the reason Balloon Matt shrinks is because of the combined gas law. As he gets colder, the gas inside him gets colder, and as the pressure of that gas remains the same, the volume it takes up shrinks. This means the pressure of the air outside makes the whole balloon shrink. As he warms back up again the volume of the gas increases and the balloon fills back up again. The reason the ink on Balloon Matt’s face starts to run is because the surface of the balloon dropped below 0°C which condensed water from the air onto the surface.
Over to you Andy.
Update: These guys at the Weizmann institute appear to have done it with a Liquid N2/water mixture.
Update 2: Some guys actually did it with liquid nitrogen and I really really don’t recommend it