6 March 2013
The $1 balloon
Sifting through old pictures of mine, I came across my homemade solar balloon created out of black trash bags. It’s no joke when I say I’m always bustling with crazy ideas, whether creating new games when I was a child, or carrying out personal business projects – a bit like an inventor in the making, except I usually only stay at that budding stage :-/.
So here are some pictures from exactly eight years ago (I looked much younger then, ouch) as I tested my balloon on a cold but sunny Winter’s day. It was poorly – but very patiently – made out of cheap garbage bags (it was my first – and only – prototype after all), cut and stuck together with tape, instead of melting the plastic which would have been better for seamless joints (tape on fragile plastic doesn’t stick well).
Anyhow, I was quite proud it could lift me up in the air and carry me across the street – just kidding, it could only carry just about 200 grams (a far cry from the first manned flight on a solar balloon across the English Channel in the 1970s). But I still felt a bit proud of having created my very own working balloon. So I guess it’s a nice DIY activity for kids – or for older kids, ahem.
PS. The way it works is pretty simple: the sun’s radiation heats up the air inside (it heats up more rapidly because of the black surface), thus decreasing the density of the air inside the balloon (just like a hot-air balloon)... and since the air is less dense than the outside colder air, the balloon lifts up. That’s also why it’s easier to test this out during Winter since the difference in air temperature and density is greater.