Effects of the Earth's Rotation: Story of Ferdinand Magellan

This is the story of Ferdinand Magellan. Ferdinand Magellan, who was born sometime around 1481, commanded an expedition of the five ships that set out to sail to the East Indies via the West. In 1521, he was killed in the Philippines, but one of his ships reached Portugal in 1522 and therefore became the first to circumnavigate the world. When the ship arrived home, it found that it had lost a day. How could this happen? Imagine that you are on Magellan's ship that sailed west. Each day, the sun would rise a little later because you have moved west a little from Portugal, where you began. By the time you had traveled halfway around the world, sunrise would be 12 hours later than it was in Portugal. And by the time you reached Portugal again, your sunrise would be 24 hours later to you than that of Portugal. By traveling west, you have left the sun behind bit by bit. If you kept an accurate calendar, you would find that upon returning to Portugal, you have missed a whole day. The missing day is explained by this movement day by day, away from the sunrise, until one day, sunrise for you was a day later than you would have expected. Because your trip took so long, the change each day wasn't noticeable. Only when you got back to Portugal would you realize that something had happened. When you compare dates with the people in Portugal, you would find that they said it was Friday and everyone is sure of the date, while you thought it was Thursday. Somehow, you seem to have lost a day. If they say it is Friday, you have to work out why you think it is Thursday. You know it was Wednesday yesterday.