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Re: coke can tapping



I'm curious about this too. The "pressure increase" explanation is so
common, but I don't see a physical basis for it once the can/champagne
etc has achieved equilibrium. My own reasoning has been that the CO2
forms gas bubbles at a few nucleation sites normally, and these will
then be on the sides. Tapping the side can dislodge these and make them
join the top "bubble" where the pressure is instantaneously released on
opening. Shaking, on the other hand, breaks up bubbles into more small
bubbles which then have more surface area and will then tend to grow
faster than the large bubbles.

All this suggests one more thing, tapping will have little if any
benefit on a can that has been recently shaken.

Leon Leonardo wrote:

Greetings,

So what is the latest explanation as to why tapping
the side (or top) of a shaken coke can drastically
reduces the tendency for it to spray Coke everywhere
upon opening? In fact, just exactly what's happening
when the can is shaken? It doesn't seem doing so
should increase the gas pressure in the can. Perhaps
it forms bubbles on the inside walls which are
detached upon tapping? Ahh...I think I may see the
answer. If bubbles are formed on the wall upon
shaking, and then the can is opened, the bubbles will
suddenly expand...

Excuse my ramblings...any other thoughts?

LEon
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