Renormalization in Fluidodynamics

[random3f]

During a lecture about QFT (http://video.google.it/videoplay?docid=-8230150359736309141&ei=xFWDSNSiDITgjAKz46i3Bg&hl=it" ) Alain Connes said that Green (in1850) used a mass renormalization to calculate the acceleration of a ball in a liquid, because you can't directly calculate it just using Archimede's Law. I didn't understand It very well. So does anybody know a reference or where to find this kind of calculation?

Thank you.

 

[Zacku]

During a lecture about QFT (http://video.google.it/videoplay?docid=-8230150359736309141&ei=xFWDSNSiDITgjAKz46i3Bg&hl=it" ) Alain Connes said that Green (in1850) used a mass renormalization to calculate the acceleration of a ball in a liquid, because you can't directly calculate it just using Archimede's Law. I didn't understand It very well. So does anybody know a reference or where to find this kind of calculation?

Thank you.

Hello,

I don't know where to find such a calculation but I can explain the reason why it has to be done. Actually Connes talks about a ping pong ball that would be immerged into water because we are holding it for example and then we let it go. The archimede's law applies then and the ball feels a strength that repels it to the surface of water.
The fact is that when you try to compute the acceleration by applying Newton's law F=ma, you don't find the experimental result. The reason is that, when an object is moving in a fluid it induces hydrodynamics currents around itself which modify, in an effective way, the ball inertia in Newton's law. I will try to find a more quantitative reference in the next few days...

P.S : excuse me for my english