When every action was being attributed to some unknown divine power and the clockwork nature of natural laws were not yet appreciated, Edmund Halley made a bold prediction the comet that he saw would come back after 76 years. Today, the comet is arguably the best known and it bears his name. Halley’s comet did come back after 76 years, as if fulfilling some mystical prophecy, but, as Halley pointed out, it was merely following the rigid laws of Nature. Today is the birthday of the British polymath, for he was an expert in astronomy, mathematics, geophysics and meteorology. Google honours him with a doodle.

The Doodle

For those who are opening Google’s page right now and being disappointed, Google’s doodle can be found on its UK page. The doodle is quite imaginative to say the least! It’s a brilliant piece of art.

Stars and planet cutouts are hung on some cosmic string, just like people thought they were in those days. Magically, all of these seem to spell out Google’, as always. A mouse-over reveals the reason for the doodle: Edmund Halley’s 335^th Birthday. A click goes to a page returning search results for Edmund Halley.

Edmund Halley. Painting by Thomas Murray (Courtesy: Wikimedia)

Halley: Comets and Craters

Halley has become a part of popular culture and has achieved as much popularity as an astronomer can possibly imagine. Comets were elevated from being the harbingers of evil and destruction to a spectacular feature of the Solar System, unrelated to human affairs. His name now decorates two craters one on the Moon and one on Mars. Both are called Halley crater’.

An Affair With Stonehenge

Later in life, Halley even attempted to accurately date the ruins at Stonehenge. He assumed that the monument had been laid out using a magnetic compass and had some directionality towards north. Then he attempted to calculate the deflection of the magnetic north at that time and thus get the age of the place. Since the magnetic north of the Earth changes in position, if you knew the position now and sometime earlier and assume smooth uniform transition in the intermediate stages, you can calculate the earlier time. He gave three times 920 AD, 220 AD and 460 BC – with the first one being the accepted one. Although a thousand years apart, the method used was revolutionary. It has been improved upon greatly in modern times.