In 1862 Lord Kelvin used thermodynamic principles to calculate the Earth\'s rate
ID: 230193 • Letter: I
Question
In 1862 Lord Kelvin used thermodynamic principles to calculate the Earth's rate of heat loss into space. Assuming that the Earth went to a molten phase, Kelvin calculated that the Earth could only be a few million years old. Current scientific evidence indicated that the Earth is over 4 billion years old. Which of the following is the most likely reason for Kelvin's error?
A. Kelvin did not recognize that heat is constantly generated by the Earth's gravitational interaction with the sun, moon, and other planets
B. Kelvin's assumption that the Earth was largely molten at one point in its history was incorrect
C. Kelvin did not take into account the effect of Earth's atmosphere in trapping heat and slowing the loss of heat into space
D. Kelvin did not know that heat is constantly generated deep inside the Earth by radioactive decay
Explanation / Answer
D. Kelvin did not know that heat is constantly generated deep inside the Earth by radioactive decay