[ErinFromTexas (OP)]

I hope that the Naked Scientists can burst this bubble...  [:I]
 
I have heard that carbon dioxide bubbles cling to the sides of a soda can and that the release of pressure is what causes soda to fizz up when you pop the top... the carbon dioxide rushing to the lower pressure air outside.
So does tapping the lid of a soda can before you open it dislodge the bubbles and prevent it from foaming over? or is that simply a bunch of hot air?

Thanks!!!!

[Don_1]

How strange! I actually saw someone do this just the other day. He dropped his can of fizzy pop, stood it upright, gently tapped the ring-pull a few times with his finger nail and opened it. It actually worked! I stood back, expecting to be smothered in Dr Pepper, or whatever it was, but there was no gush of sticky liquid, just the usual PHSSST that would expect.

[AllenG]

I've heard of that ritual most of my life.
I don't know any of the science behind it.

[BenV]

Erin's got the theory right at least - care to test it?

The problem is that the bubbles expand underneath some drink, so if you can knock them all to the surface (by tapping the top) you should find that only gas escapes.

The problem is that cans are opaque, so you can never know how bubble-free the sides are until it's too late...

[Nizzle]

I've been doing this my whole life already

And the experiment works with a PET bottle of coke, which is transparent...