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How would human civilisation differ if the sun, moon, stars and planets were always obscured by clouds? (Continued)
Alex McDowell
London, UK
Navigation at sea would have been difficult because, prior to the invention of radio beacons, inertial guidance, satellite navigation and more, sailors used celestial bodies to navigate. They would have needed to rely heavily on dead reckoning.
Some argue that, before the magnetic compass, Vikings used crystals called sunstones to locate the sun in overcast conditions. Archaeologists have made such devices using calcite and have been able to locate the sun to within a few degrees in cloudy conditions.
Sunstones are able to take advantage of the fact that light scattered through cloud vapour is polarised, but light straight from the sun is not.
The first clocks were sundials, but these would be useless if we were always under cloud cover. But sunstones could be used to find which direction the sun was in, and when. One could use sunstones together with magnetic compasses to work out the time.
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Until people could get above the clouds, there would have been a lot of speculation about what was in and above them
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Perhaps the difficulties mentioned above would have led to mechanical clocks being developed more quickly.
We might also have anchored lightships far out at sea to assist with navigation. Such ships could have periodically fired coloured flares into the air so that sailors could locate them from farther away; coastal installations could have done the same.
Astronomy would be delayed. Celestial bodies would be visible only if one could get above the clouds. If no mountain went above them, people would still be curious to know what was there, and this could lead to balloons and other aircraft being developed faster. Until people could get above the clouds, there would have been a lot of speculation about what was in and above them – and perhaps stories like Jack and the Beanstalk would have sounded credible!
Life would also have evolved differently. Plants may have developed a type of chlorophyll that uses more of the electromagnetic spectrum, absorbing even green light, and thus appearing black.
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