From Robert Matthews
Astronomers may have seen the effects of black holes being jostled by stars
(19 January, p 10),
but the Scottish naturalist Robert Brown never saw the
effects of pollen grains being jostled by atoms.
Contrary to what many textbooks state, Brown actually observed the motion of
much smaller particles inside fluid-filled voids within the pollen grains. This
no doubt sounds like tiresome nit-picking, but as Einstein’s analysis of
Brownian motion shows, the effect is far smaller for relatively huge pollen
grains than it is for the particles inside them.
Confusing the two has in the past led to accusations that Brown could not
possibly have seen the effect which bears his name. It would be a shame to rob
someone of his claim to fame simply because textbooks can’t be arsed to get the
facts straight.
Oxford
