- scallop theorem
-
A theorem which states that to achieve propulsion at low Reynolds number in simple (i.e. Newtonian) fluids, a swimmer must deform in a way that is not invariant under time-reversal.
Wikipedia foundation.
Wikipedia foundation.
Commensalism — A titan triggerfish (Balistoides viridescens) creates feeding opportunities for smaller fish by moving large rocks too big for them to shift themselves. In ecology, commensalism is a class of relationship between two organisms where one organism… … Wikipedia
List of heraldic charges — This article does not cover those charges which derive their shape in part from that of the field; see Ordinary (heraldry). Subordinary chargesA few simple charges are traditionally, and arbitrarily, classified among the subordinaries. (All other … Wikipedia