In 1903 he collaborated with Frederick Soddy on the disintegration theory of radioactivity, showing that certain heavy atoms spontaneously decay into lighter atoms, and coining the term "half-life" for radioactive decay.
In 1905 Rutherford proposed a measure of the relative rate of decay of uranium atoms that would allow minerals to be accurately dated, a radioactive dating system that, when applied, greatly reduced the scientific estimate of the age of the Earth, and formed the basis of dating technology still used in geology.
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.
In the mid-18th century, the naturalist Mikhail Lomonosov suggested that Earth had been created separately from, and several hundred thousand years before, the rest of the universe. In 1779 the Comte du Buffon tried to obtain a value for the age of Earth using an experiment: He created a small globe that resembled Earth in composition and then measured its rate of cooling.
This led him to estimate that Earth was about 75,000 years old.
material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.
Thomson, and in 1896 he designed what was then the world's most sensitive electromagnetic wave detector, capable of identifying waves at a distance of several hundred meters.
giving an age for the Solar System and an upper limit for the age of Earth.
It is hypothesised that the accretion of Earth began soon after the formation of the calcium-aluminium-rich inclusions and the meteorites.
Ca-Al-rich inclusions (inclusions rich in calcium and aluminium) – the oldest known solid constituents within meteorites that are formed within the solar system – are 4.567 billion years old, giving an age for the solar system and an upper limit for the age of the Earth.
In 1899 he noted two distinct radiations, which he termed alpha rays and beta rays (high speed electrons), and in the same year discovered the radioactive gas radon.
Ca-Al-rich inclusions (inclusions rich in calcium and aluminium) – the oldest known solid constituents within meteorites which are formed within the solar system – are 4.567 billion years old, giving an age for the solar system and an upper limit for the age of the Earth.