Bill Pragnell wrote:
> How about the CO2 bubbles you see when you take the cap off a fizzy > drink bottle?
Ooh, been to a fairground recently? Got any helium balloons left
over...? Again, not directly observable but the effects are...
There's a good song about helium here:
http://www.weebls-stuff.com/toons/blimp/
:)
