Geology and Astronomy are scientific fields of study that deal with different realms that are nonetheless highly related and relevant to one another. For a long time, students of both fields labored to try and understand and answer the puzzle of the seemingly vast discrepancy between the age of the earth and the age of the cosmos. Students of geology used techniques like the study of erosion and sedimentation rates. Astronomers and physicists grappled with the dichotomy using motion rates and energy consumption data. Yet, for a long time the data failed to make sense, always leaving scientists with the inevitable problem that the Earth seemed either too young or old to fit the picture. It was the discovery of radioactivity that finally broke some of the seemingly impassible barrier to bringing the age question into focus. Radioactive rock was proved to be significantly slowing the cooling of the Earth, proving that calculations made so far vastly underestimated the age of the Earth, finally bringing the numbers calculated for the earth and the cosmos closer together.

Key Takeaways:

- The study of radioactivity allowed scientists to calculate the age of rocks, minerals, and even the earth itself.
- Scientists discovered that radioactive decay (and, later, nuclear fusion) explains how stars can produce heat and light for long periods of time.
- Early geologists’ studies of erosion and sedimentation rates to determine the age of the earth resulted in a wide range of calculations.

“For a long time the apparent discrepancy between the age of earth and the age of the cosmos posed a great problem to geologists and astronomers alike.”

Read more: https://blogs.scientificamerican.com/history-of-geology/radioactivity-and-earth-180-s-age/