Who uses radiometric dating
His calculations did not account for heat produced via radioactive decay (a process then unknown to science) or, more significantly, convection inside the Earth, which allows more heat to escape from the interior to warm rocks near the surface.Even more constraining were Kelvin's estimates of the age of the Sun, which were based on estimates of its thermal output and a theory that the Sun obtains its energy from gravitational collapse; Kelvin estimated that the Sun is about 20 million years old.
By measuring the concentration of the stable end product of the decay, coupled with knowledge of the half life and initial concentration of the decaying element, the age of the rock can be calculated.The process of solar nuclear fusion was not yet known to science.In 1895 John Perry challenged Kelvin's figure on the basis of his assumptions on conductivity, and Oliver Heaviside entered the dialogue, considering it "a vehicle to display the ability of his operator method to solve problems of astonishing complexity." Other scientists backed up Thomson's figures. Darwin, proposed that Earth and Moon had broken apart in their early days when they were both molten.Geologists such as Charles Lyell had trouble accepting such a short age for Earth.For biologists, even 100 million years seemed much too short to be plausible.In 1830, geologist Charles Lyell, developing ideas found in James Hutton's works, popularized the concept that the features of Earth were in perpetual change, eroding and reforming continuously, and the rate of this change was roughly constant.
This was a challenge to the traditional view, which saw the history of Earth as static, He assumed that Earth had formed as a completely molten object, and determined the amount of time it would take for the near-surface to cool to its present temperature.
It is also difficult to determine the exact age of the oldest rocks on Earth, exposed at the surface, as they are aggregates of minerals of possibly different ages.
Studies of strata, the layering of rocks and earth, gave naturalists an appreciation that Earth may have been through many changes during its existence.
Their values were consistent with Thomson's calculations.
However, they assumed that the Sun was only glowing from the heat of its gravitational contraction.
Kelvin calculated the age of the Earth by using thermal gradients, and he arrived at an estimate of about 100 million years.