Old dating public service message mature dating ontario canada
In 1892, Thomson had been made Lord Kelvin in appreciation of his many scientific accomplishments.
Kelvin calculated the age of the Earth by using thermal gradients, and he arrived at an estimate of about 100 million years.
However, they assumed that the Sun was only glowing from the heat of its gravitational contraction.
The process of solar nuclear fusion was not yet known to science.
The physicist Hermann von Helmholtz (in 1856) and astronomer Simon Newcomb (in 1892) contributed their own calculations of 22 and 18 million years respectively to the debate: they independently calculated the amount of time it would take for the Sun to condense down to its current diameter and brightness from the nebula of gas and dust from which it was born.
Geologists such as Charles Lyell had trouble accepting such a short age for Earth.These had assumed that the original heat of the Earth and Sun had dissipated steadily into space, but radioactive decay meant that this heat had been continually replenished.George Darwin and John Joly were the first to point this out, in 1903.Studies of strata, the layering of rocks and earth, gave naturalists an appreciation that Earth may have been through many changes during its existence.
These layers often contained fossilized remains of unknown creatures, leading some to interpret a progression of organisms from layer to layer.material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.