?? what happens to the piston system as the mass of the piston approaches zero ? ... ??? ....

p1 = h1/w12

p2 = h2/(1-w12)

w12'' = (p1-p2)/(piston mass)

h1' = -w12'*p1

h2' = w12'*p2

?? ....

?? pistons as giving interactions between chambers vs vice versa ... poincare duality ... ??? .... ??? property vs structure vs stuff here ?? ... ??? ... ?? "field" ... ?? ... ??? ....

?? constraint vs force vs field ??? ...... ???? ....

?? 1/r potential .... ??? .....