Surfaces are where bodies touch, where heat flows, where chemicals react, and where things grow. Mass is the amount of "stuff" in an object. It's obvious (but only after you think about it, as Galileo did) that doubling the length, width, and depth of something multiplies its mass eightfold but only increases its surface area by a factor of four.
So the larger bodies get, the smaller their surface-to-mass ratio. Little creatures are "all skin" — so they can get away without the elaborate internal structures that big animals need to circulate oxygen and nutrients. A lump of coal isn't very reactive, but grind it into dust and the surface area becomes huge — now it can burn quickly, maybe even explode. A baby gets chilled or overheated much faster than an adult; the same holds for asteroids and planets and stars.
To make something change, think surface and think small; to preserve something, think mass and think big.
Saturday, November 20, 1999 at 08:04:25 (EST) = 1999-11-20
In physics II 'discussion' section, the teacher was talking about how the DC generator which had been described in the book (a loop of wire turning in a magnetic field, whose electrical contacts were two semicircles, so that voltage is reversed each half cycle) made sparks, and how that could be a big problem. He mentioned that in grain elevators, where there is so much dusty cellulose in the air that it is phyically impossible to breathe, the atmosphere is explosive, and so grain elevators blow up all the time.
RadRob - Nov. 14, 2002
Surface effects are a large contributor to achieving chemical reactions quickly and efficiently. Espicially true for explosions, which are mostly due to extremely rapid combustion – dust, aerosols, and so on, maximize contact between the fuel and oxygen. – Bo Leuf
(correlates: FinalLesson, IntellectualHeimlichManeuver, OnSolitude, ...)