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September 30.docx

Earth Sciences
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September 30
1. Early Calculations
- According to Usher the Earth now is about 6000 years old
- Wrote in Latin a book about that
- Controversy as to how old the Earth is (we learn about another major battle in
oEngland: 2nd half of the 19th century
- Charles Darwin: proposed brilliant idea of how mountains in the ocean form
oParents will give favourable traits to their children (ones that allow
them to adapt)
oProves that there would be enough time for evolution to work over a
long period of time (erosion of the Weald Dome..)
oInterested in the order of magnitude (it’s not 300,000 years its
300,000,000 years [as opposed to being 306, 662, 400 years]
therefore 300,000,000 years is the “lower bound” as it cannot be
younger but it can be older)
oAdmits that his calculations are inaccurate but at the time no one even
knew how many digits (thousands, millions or billions = order of
oTook geologic observations and was able to assign an age to it
- All estimates of the earths age are lower bound as they require something to
have happened before (i.e. some mountain must have formed for the water to
become satly)
oNone are super precise
2. cfhksdh
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