The early navigators

People have been using the sun, moon and stars to navigate by for a very, very long time.  And not just people but other animals too – like birds, butterflies, seals, and turtles – to name but a few.  This is a really exciting area of research and new discoveries keep piling in.  Maria Dacke and others have recently shown in an ingenious experiment that a dung beetle can roll its ball of poo back to its nest using the light of the Milky Way as a guide.  My guess is that our pre-human ancestors were pretty good at this kind of basic celestial navigation hundreds of thousands of years ago, though their purposes were probably a bit different!

What we do know is that the builders of Stonehenge and many other ancient monuments around the world are carefully aligned so as to highlight key celestial events like the summer and winter solstices – that mark the longest and shortest days of the year.  And the amazing Nebra Sky Disc – discovered in Germany in 1999 – shows that our Bronze Age ancestors understood the complicated relationship between the solar and lunar years.  It was made about 3,500 years ago.

And the Greeks knew a thing or two.  The amazing Antikythera Mechanism – discovered by sponge divers about 100 years ago – dates from around the end of the 2nd century B.C.  It  is the most sophisticated mechanism from the ancient world.  Nothing as complex is known for the next thousand years. The Antikythera Mechanism operates as a complex mechanical “computer” which tracks the cycles of the Solar System:

We know very little about how the Greeks and Romans navigated at sea, though they travelled widely and not just in the Mediterranean.  It’s always assumed that they didn’t use any specialised equipment.  But the Antikythera mechanism makes you wonder…  If they knew that much about the behaviour of the heavens, would they not have put their expertise to good navigational use?

On the other side of the world Polynesian navigators were already starting to venture out across the Pacific at least two thousand years ago.  In their outrigger canoes they could make accurate landfalls on tiny islands after travelling as much as two thousand miles across the ocean.  They didn’t use any instruments or even charts.  They relied only on their senses – and a lengthy apprenticeship that started when they were children.  When western sailors like Louis de Bougainville and James Cook first encountered these prodigies they were astonished and baffled.  Luckily we now know a lot about how these Polynesians navigated because researchers started asking the right questions before their skills died out.  At the heart of their technique was an encyclopaedic knowledge of the stars.  They knew exactly where on the horizon each bright star rose and set and could steer a steady course by reference to them.  They were also adept at estimating how fast they were going and could ‘read’ the changing patterns of waves and swells.  These remarkable skills are still being practised:

Experienced navigators everywhere used to pay very close attention to the world around them.  The colour of the water and its depth, the presence of birds and their behaviour, clouds on the horizon – these and many other signs could give early warning of the presence of land, often long before it could be seen.



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