Geos 170A1 – Homework 1 – Age of the Earth
Due NO LATER than Monday, Jan 30, at 10:59 am, uploaded to the HW 1 folder under Assignments on d2l. It is worth 15 points total.
Instructions: You will need to refer to your notes from classes 1, 2, and 5, as well as the following articles, to complete this HW.
How Science Figured out the Age of the Earth by Paul S. Braterman, Scientific American, Oct 20, 2013.
How and archbishop calculated the Creation, Irish Times, Sep 25, 2003.
1. Based on your reading of the above articles, and what we discussed in class, briefly describe two ways that people came up with an age for the Earth that are NOT based on the scientific method. (2 pts each)
2. What did James Hutton observe that led him to believe the Earth was infinitely old, with “…no vestige of a beginning – no prospect of an end.” Explain in your own words what he thought was happening on Earth that meant it had to be old. (3 pts)
3. What does uniformitarianism mean? (2 pts)
4. In the mid-nineteenth century, Lord Kelvin estimated the age of the Earth based on the rate of heat loss from Earth and how long it would have taken to lose enough heat to form its solid rock and soil surface. He came up with an age that was way too young and not very precise (24 – 400 million years old). What was the big contributing factor/process going on in the Earth he did not consider when using only simple heat loss to calculate an age for Earth? (1 pt)
5. What is the accepted age of the Earth today, and what information/techniques did scientists use to get this number? (3)
___________________________________________ years old
6. Is the above age one that we can generally accept as true? Why or why not? (2 pts)
Bonus (one extra credit point): Explain in your own words how the factor Lord Kelvin neglected to account for would cause the age he calculated to be too young for the actual age of Earth.