On this date, the astronomer Edmund Halley was born on the eastern edge of London, England. Although he is chiefly remembered for the comet which bears his name, he also made a mark for himself in geology. In 1715, he lectured the Royal Society of London that the age of the Earth could be calculated by measuring the ocean’s salinity since ocean salts result from sediments carried by rivers and streams. Interestingly, he began his talk by rejecting a literal interpretation of Genesis for the Earth’s age:
Whereas we are there told that the formation of man was the last act of the creator, ’tis no where revealed in scripture how long the earth had existed before this last creation, nor how long those five days that proceeded it may be to be accounted; since we are elsewhere told, that in respect of the almighty a thousand years is as one day, being equally no part of eternity; nor can it well be conceived how those days should be to be understood of natural days, since they are mentioned as measures of time before the creation of the sun, which was not till the fourth day.
Halley had no doubt that the Earth had existed long before the accepted date of the Creation, 4004 B.C., the date arrived at by Archbishop Ussher in 1620 by counting back all the generations in the Bible. It has often been thought that Halley was concerned about demonstrating a very old age for the Earth by making his proposal to the Society. However, he was actually trying to provide a maximal estimate of the Earth’s age. Halley objected to the notion that the Earth is eternal, as he later stated in his talk:
….the foregoing argument, which is chiefly presented to refute the ancient notion, some have of late entertained, of the eternity of all things.
Needless to say, these views led him to be regarded as something of a heretic by the Church authorities.
- Edmund Halley, “A Short Account of the Cause of the Saltness of the Ocean, and of the Several Lakes That Emit no Rivers; With a Proposal, by Help Thereof, to Discover the Age of the World,” Philosophical Transactions of the Royal Society of London (1683-1775), Volume 29: 296-300.
- Stephen Jay Gould, Eight Little Piggies: Reflections in Natural History (New York, NY: W.W. Norton & Co., 1993) 168-180.