"Hae" [Hay] Meaning: Have
...in 1846 Ulsterman William Thomson (Lord Kelvin) made the first scientific calculation of the age of the earth, thus challenging the bibical fundamentalists who claimed that ir begain 6,000 years ago.
Biologist Charles Darwin claimed that it was alomst infinitely old. Thomson calculated its age to be 100 million years based on the rate of cooling of the earth, assuming that at one time it had the same temperature as the sun. Before dying the discovery of radioactive elements in the earth's crust led to our modern estimate of over 4,000 million years!