.The Sand-dollar's appetite for magnetite reminds me that until recently, a dominant theory to explain the ability of several animals to orient with respect to the geo-magnetic fieldhad the presence of magnetite in certain nerve endings as the crucial transducer.I was interested to read in the last few days, of a "quantum" theory of geomagnetic field sensing, demonstrated in animal (and human) cell preparations.Passing a magnet near such a preparation demonstrated light band moving with the magnetic fieldvariation. This agrees to some extent with the suggestion that some migratory birds can directly senseultra-violet features in the sky associated with this field.However, experiments to demonstrate human sensing of the geo-magnetic field have generally been unsuccessful.Brian W
On Tuesday, January 19, 2021, 11:59:42 AM CST, bernard cleyet <email@example.com> wrote:
p.s. would harvesting magnetite from sand dollars be an efficient method of collecting the mineral?
Forum for Physics Educators