We are in the year 1024, in the city of Gázni, the beautiful capital of the dynasty that governs Afghanistan. Sultan Mamude (971 – 1030), conqueror of Iran and Punjab, receives a delegation of Turks from the Volga. Visitors tell us that in the far polar regions to the north, at certain times of the year, the shadows are much greater than people and the sun does not set for days.
Deeply devout, the sultan is shocked and accuses them of heresy. In a country where there is no night, how could the faithful Muslim obey the Koran's mandate to pray 5 times a day? In the face of the monarch's wrath, Turkish ambassadors fear for their lives.
The court sage, Abu Raiane Albiruni (973-1048) spoke. Remembering that the Earth is curved, it makes Mamude understand the reason for the long days of the polar summer. Visitors' lives are saved. Albiruni is happy and proud. He managed once more to dispel the darkness of ignorance. But he knows that this war is never ending.
Born in the region close to the Aral Sea, Albiruni traveled for most of his life, at the mercy of the vicissitudes of wars and conquests. Mathematician, physicist, astronomer and philosopher, he wrote more than a hundred scientific works. Among them, a Treaty of Shadows where he criticizes "religious fanatics who feel nauseous when someone talks about shadows, trigonometric functions or altitudes, and for whom the mere mention of a calculation or a scientific instrument gives chills".
Eclipses of the Moon are caused by the shadow cast by the Earth on its satellite. Albiruni observed the lunar eclipse of May 24, 997 in his hometown of Kath and noted the time. He had previously arranged with a colleague in Baghdad to do the same.
From the difference between the hours of the event in the two locations, they determined the difference in longitude between the two cities. The method would be perfected more than half a millennium later, by none other than Galileo Galilei. But the practical solution to the longitude problem turned out to be another.
The American military man Robert Peary (1856 – 1920) was a daring explorer. He made several expeditions to reach the North Pole and, finally, he claimed to have succeeded on April 6, 1909. He even took a photo with his companions, in front of a flag stuck in place, to prove the feat. Upon returning to civilization, he learned that his countryman Frederick Cook claimed to have arrived at the pole almost a year earlier.
The controversy was in place, with supporters of the two vying for primacy. On March 3, 1911, the United States Congress resolved the matter, decreeing in favor of Peary. But his story never convinced the experts. There were too many clues that didn't match. One of the most striking is in the famous photo: the shadows are too short for this time of year at the polo …