The following paper just got posted on the arxiv:

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arXiv:0705.3612

Date: Thu, 24 May 2007 16:11:59 GMT (214kb)

Title: Swimming with a friend at low Reynolds number

Authors: C. M. Pooley, G. P. Alexander, and J. M. Yeomans

Categories: cond-mat.soft cond-mat.other

Comments: 6 pages, 4 figures

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We investigate the hydrodynamic interactions between microorganisms swimming

at low Reynolds number. By considering simple model swimmers, and combining

analytic and numerical approaches, we investigate the time-averaged flow field

around a swimmer. At short distances the swimmer behaves like a pump. At large

distances the velocity field depends on whether the swimming stroke is

invariant under a combined time-reversal and parity transformation. We then

consider two swimmers and find that the interaction between them consists of

two parts; a dead term, independent of the motion of the second swimmer, which

takes the expected dipolar form and a live term resulting from the simultaneous

swimming action of both swimmers which does not. We argue that, in general, the

latter dominates. The swimmer--swimmer interaction is a complicated function of

their relative displacement, orientation and phase, leading to motion that can

be attractive, repulsive or oscillatory.

\\ ( http://arxiv.org/abs/0705.3612 , 214kb)

Basically, I'm posting this because I really like the title. One thought it made me have was to wonder what boinking is like at low Reynolds number. (I doubt this arXiv blog entry will lead to an ego boost like the last one did.) Life at low Reynolds numbers, indeed! (This last sentence is alluding to a very famous article by Purcell. I haven't read it, but I really should. In fact, I've heard it's very readable, so I'll also recommend this to the rest of you.)