Page 60 - Biomimetics: Technology Imitates Nature

A jet engine takes in air from one
end and expels it from the other at
a much greater speed. The jet en-
gines in vertical take-off aircraft
like the Harrier have nozzles to di-
rect the exhaust down. Thanks to
this system, the Harrier can land
and take off vertically. After take-
off, the nozzles are pointed back-
wards, so that the aircraft flies for-
wards.

The squid use a form of propulsion
system similar to jet planes. A
squid's body contains two open
spaces like pockets. Water taken in
from them is drawn into a power-
ful elastic bag of contracting mus-
cles. In this bag is a backward-
pointing nozzle. The muscles con-
tract, expelling water out of that
nozzle at high speed. The animal
can reach speeds of up to 32 km (20
miles) an hour to flee predators,
sometimes even leaping out of the
water and onto the decks of ships.
(Phil Gates, Wild Technology, 38.)