Science of a Second

The old definition of a second was based on the rotation of the Earth. As it takes the Sun one day to rise in the east, set in the west and rise again, a day was almost arbitrarily divided into 24 hours, the hour into 60 minutes, and the minute into 60 seconds. However, the Earth doesn’t rotate uniformly. In fact, it’s rotation decreases at a rate of about 20 millionths of a second every calendar year due to tidal friction caused by the Moon. Atomic time relies on the energy transition w...

 Fossils and the Age of the Earth

In the mountains of Parma and Piacenza, multitudes of shells and corals filled with worm-holes may be seen still adhering to the rocks, and when I was making the great horse at Milan a large sack of those which had been found in these parts was brought to my workshop by some peasants... The red stone of the mountains of Verona is found with shells all intermingled, which have become part of this stone... And if you should say that these shells have been and still constantly are being created ...