Page 166 - Engineering in Nature

Engineering in Nature

things' power-creating engines are their muscles, capable of expand-
ing and contracting like backward and forward-moving levers.
One example of these engines can be seen in marine creatures,
most of whose movement takes place in a single plane. You can envis-

age that motion by imagining the way fish swim in water. The inter-
connected vertebrae in the fish's backbone constantly turns to right
and left, so that in order to swim, all a fish needs to do is to wave its
tail.
Under normal conditions, when the tail turns in one direction, the
fish's head should move in the opposite direction, propelled with the
same force. Yet that never happens, because fishes' bodies have been

Fish seem to have very simple physical structures, but the fact is, the systems and
mechanisms they employ to move in the water are the result of planning as sensitive
as that of the latest model car.

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