Candles in microgravity
Think about how hot air rises while cooler, denser air sinks. This all happens due to gravity here on earth, but what would happen without this force of nature? If the air isn’t rising or sinking around the flame, then how does the air mix to supply fresh oxygen to the candle to keep it burning?
UC San Diego student, Sam Avery is trying to understand this by taking his team aboard NASA’s Zero-G airplane. The flight follows a parabolic path and causes a dozen or so 30 second bursts of zero gravity. During this time Avery can ignite a flame in a special chamber to observe the effects of microgravity.
He led a team last year doing a similar experiment. During that time the flame was still able to burn, but at a much lower rate. It was able to get new oxygen to burn by a process known as molecular diffusion. So, why does it matter? By doing these tests, scientists can better understand a flame’s burn rate and possibly lead to developing more efficient biofuel engines.