Arthur C. Clarke – 8th April
The world lost one of its great inspirational influences in March this year.
Through his science fiction, Arthur C. Clarke was an inspiration to many 20th century
scientists and engineers. He was only an average practical physicist but one with
amazing vision and insight, which he communicated through word, film and by
example, through broadcasts from his extraordinary home in Sri Lanka.
There are two basic kinds of science fiction. One explores the human condition
through responses to imaginary situations, often with superpowers thrown in
(Superman, Star Trek). Despite attempts to put real science into this genre, its value
remains entertainment at best.
The other is different! It stretches known science into possible but unproven territory
and suggests goals of achievement. This was the world of Arthur C. Clarke.
Leaving aside “2001”, he was undoubtedly most famous for his invention of
communication satellites in geostationary orbits.
The understanding of the forces on a body, moving in a circle, is school level physics.
The effect everyone will know is when you swing a weight on a string around your
head and let go, the weight will fly off directly outwards. At global level, if the speed
is right (17,000 mph), the outward tendency is balanced by gravity and you have a
stable orbit in space, at an altitude of 150 miles.
What Clarke realised first (and lived to regret not patenting) was that, push the stable
orbit out to about 22,000 miles above the equator, the satellite will appear stationary
above the rotating earth below. It can then be used to relay messages and TV pictures
using high frequency radio waves. Those who watch Sky TV are using a satellite in
just such a “Clarke Orbit”. Indeed, geostationary space above the Atlantic and Pacific
oceans is getting a bit cluttered!
Clarke added ideas to this basic concept; cable lifts to geostationary space stations, so
one could travel efficiently without rockets. He knew the materials for such a strong
cable did not exist but he estimated them to be possible theoretically. He had the idea
of trained killer whales, monitored and controlled by satellite, herding tuna and
salmon in the oceans as a form of fish farming. Successes in nanotechnology, sea
mammal communication and satellite tracking might yet lead to such realities.
Yes, Arthur C. Clarke has left a legacy of ideas that will continue to inspire for years