Dating on earth subtitle download - How Old is the Earth: Radiometric Dating - TalkOrigins Archive


By the mid- to late 1800s, geologists, physicists, and chemists were searching for ways to quantify the age of the Earth. Lord Kelvin and Clarence King calculated the length of time required for the Earth to cool from a white-hot liquid state; they eventually settled on 24 million years. James Joly calculated that the Earth’s age was 89 million years on the basis of the time required for salt to accumulate in the oceans. There were other estimates but the calculations were hotly disputed because they all were obviously flawed by uncertainties in both the initial assumptions and the data.

Ages of millions of years are all calculated by assuming the rates of change of processes in the past were the same as we observe today—called the principle of uniformitarianism. If the age calculated from such assumptions disagrees with what they think the age should be, they conclude that their assumptions did not apply in this case, and adjust them accordingly. If the calculated result gives an acceptable age, the investigators publish it.


Dating on earth subtitle download

Dating on earth subtitle download