jan 1, 1846 - Lord Kelvin calculates the age of Earth (c. 1846)

Description:

One of Britain's most distinguished scientists proclaims that Earth is roughly 100 million years old. William Thomson, later known as Lord Kelvin, arrives at this estimate by assuming that Earth has cooled steadily since it first formed as a molten mass. Kelvin later broadens his estimate to 20-400 million years old. His scientific finding, unlike Bishop Ussher's 4004 B.C. date for the Creation, troubles Darwin. Is 20 million years enough time for the diversity of life on Earth to evolve?