3 assumptions of radiometric dating is dating a guy 10 years older bad
Other naturalists used these hypotheses to construct a history of Earth, though their timelines were inexact as they did not know how long it took to lay down stratigraphic layers.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.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.For biologists, even 100 million years seemed much too short to be plausible.In Darwin's theory of evolution, the process of random heritable variation with cumulative selection requires great durations of time.
The discovery of radioactivity introduced another factor in the calculation.His value of 56 million years added additional evidence that Thomson was on the right track.By their chemical nature, rock minerals contain certain elements and not others; but in rocks containing radioactive isotopes, the process of radioactive decay generates exotic elements over time.He did not realize that the Earth mantle was convecting, and this invalidated his estimate.
In 1895, John Perry produced an age-of-Earth estimate of 2 to 3 billion years using a model of a convective mantle and thin crust.
(According to modern biology, the total evolutionary history from the beginning of life to today has taken place since 3.5 to 3.8 billion years ago, the amount of time which passed since the last universal ancestor of all living organisms as shown by geological dating.) In a lecture in 1869, Darwin's great advocate, Thomas H.