Hi Fran!
Thanks for the Refs! I was thinking that we might be able to get some of the ou hydrolysis researcher to try the Kr 81 and Raney thing! Scott Date: Mon, 22 Mar 2010 14:03:06 -0400 From: [email protected] To: [email protected] Subject: [Vo]:The Casimir force: background, experiments, and applications- Paper by Steven K Lamoreaux The Casimir force: background, experiments, and applications by Steven K Lamoreaux [Quote] The view that the Casimir force is simply the long-range (retarded) van der Waals interaction between material bodies is not accurate because the effect of the material boundaries must be considered in the calculation of the force. Furthermore, the van derWaals interactions between particles is non-additive, with the deviation increasing with density. Even in the case of three molecules, the van der Waals interaction is modified [10]. However, as shown in [5] (pp 249–51), a reasonable estimate of the Casimir force can be obtained by considering the pairwise interactions between the molecules contained in parallel plates with the polarizability 204 S K Lamoreaux determined from the dielectric constant, _, and the Clausius–Mosetti relation. In the limit of _→∞, a 1/d4 force law with magnitude about 80% of Casimir’s result is obtained. The lack of additivity is further addressed in [5], pp 254–8. As mentioned above, one manifestation of a Casimir effect has its origin in molecular (van derWaals or dispersion force) interactions; this is the force of attraction between dielectric bodies which, in the case of tenuous media, can be interpreted as arising from the retarded (1/r7) and short-range (1/r6) van der Waals potentials between the molecules that make up the bodies, as was first discussed by London [11]. When the bodies are sufficiently dense, it is no longer valid to consider molecule–molecule interactions alone, and one must take into account the boundary conditions for the electromagnetic fields at the material surfaces and intermolecular effects. Lifshitz [12]1 first developed in 1956 the theory for the attractive force between two plane surfaces made of a material with a generalized susceptibility. His work was motivated by experimental results from force measurements between dielectric bodies that were much smaller than expected due to van derWaals interactions alone [13, 14]. Remarkably, the Lifshitz result does not explicitly involve a body’s molecular properties; the attractive force is a function of only bulk material properties and the separation between the planes. The commentary in [14] indicates that before the Lifshitz analysis, it was expected that solid body force measurements would directly measure intermolecular forces, effectively amplified by the sheer number of participating pairs. The Lifshitz result indicates the importance of the boundaries, and in the limit of high density it is no longer possible to discuss the problem in terms of pair interactions. [/Quote] Regards Fran _________________________________________________________________ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/210850552/direct/01/
