Wednesday, June 22, 2016
So does tapping a can of fizzy pop REALLY stop it from exploding? Scientist finally reveals the truth - and the answer may surprise you
Have you gotten into the habit of tapping the top of your can of pop because someone told you it stopped it from exploding when you open it?
It's a bizarre ritual that many people just can't seem to shake off, but experts say there may well be method in the madness.
Indeed, scientist Christopher Arthur Edward Hamlett explains that tapping the top of the can may well reduce the bubbles.
In his essay for The Conversation he explained: 'Before the can is opened, microscopic gas bubbles attach to the inside of it (nucleation). When the can is opened, these bubbles increase in size, due to the decrease in the solubility of CO2.'
He goes on to explain that when these bubbles reach a certain size, buoyancy causes them to rapidly rise to the top of the can - where you open it - and displace liquid (the fizz) as they do so.
So what part could tapping the top of the can play in this process? He goes on: 'Bubbles in an unopened can nucleate at the walls, so tapping the can before opening could dislodge some of the bubbles, enabling them to float to the top of the liquid.'
He goes on to explain his theory in more depth, saying that when a can is opened, the bubbles expand with those deeper within the liquid travelling further than those near the surface, which can cause the explosion effect many fear.
'A "tapped" can will have fewer of these "deep" bubbles and so less liquid will be dislodged – and possibly sprayed out – than an "untapped" can,' he concluded.
So, next time someone questions your seemingly strange ritual, you can use science to back it up.