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Evidence for the Age of the
Earth
T412
Outline
• What does the Biblical account say about
the age of Earth? Very Little!
• Where else can we look for answers?
• How reliable are these answers?
Is the Earth……
• Several thousand or hundreds of millions
of years old?
• Interpretations of Genesis suggest that
Creation occurred 6-7000 ya
• Interpretations from science suggest that
Earth is 4.55 billion yo (4550000,000000ya)
The Earth is not Young!
• Oldest Living Tree
-
Tasmanian Huon pine trees are called the world's 'oldest known living
organism'.
Various methods estimate the age of the tree to 'more than 10,500 years
old'
•
Population growth rates
–
If the Earth is young and humans started having babies 6000ya
–
At the time the Israelites entered Canaan, for instance, we get a world human
population of 2024! We know the Israelites alone numbered 95,000.
•
Older civilisations!
-
There are some very old civilisations, i.e. Kerma in Sudan, Africa 3-5000BC
-
The oldest granary yet found dates back to 9500 BC and is located in Jordon
The Age of the Earth
• Prior to the 19th century, generally accepted age of the Earth was
based on religious beliefs
– ~6,000 years for Western culture (Biblical)
– Old beyond comprehension (Chinese/Hindu)
•
James Hutton, the “father of geology”, realized observable geologic
processes would require vast amounts of time to produce the mountains,
valleys, etc., we see on Earth today
•
Charles Lyell popularized Hutton’s work and concepts in his book, Principles
of Geology
“The present is the key to the past”
- sedimentation rates
- wind and water erosion
Evidence ~early developments
Geology & Geography
The Dynamic Earth
1. 1801-1858 Why do coastlines fit?
2. 1887-1932 Why are things the same?
- rock types
- marsupial fauna
- tree types
- fossil species
3. Continental Drift
- 1915 - Alfred Wegener
Land Bridge
Continental Drift
Not accepted until the 1960’s and
1970’s, when …….
• sea floor spreading was observed
• sonar was used to map the ocean
• past & present magnetism of rocks
observed
NOTE: Your Grandparents and Parents (maybe?) generation did
not have this taught to them in School
Evidence ~early developments
Biology
Early Intermediate form fossils lend weight to Theories of Evolution
FISH
AMPHIBIANS
Ichthyostega
- Fins and gill covers (FISH)
- Feet (AMPHIBIANS)
XXX
- After fish, before amphibians
(just where evolution predicts it
should be)
Evidence ~early developments
Obtaining the Age of the Universe from Astronomy
Big Bang Theory – The Universe was
created by a single event that caused a
small state to expand to a larger state
•
Extrapolate the current expansion rate of
the universe back to the Big Bang
– 10 to 20 billion years old
• Look for the oldest stars based on distance and
speed of light
- 11 to 18 billion years old
• Best current estimate is 13.4 ± 1.6 billion years
Star Cluster
Evidence ~early developments
Physics
The Age of the Earth
1862 - William Thompson - "Lord Kelvin"
- molten Earth - 7000º F
1896 - Henri Becquerel
- Fourier analysis of heat loss
- discovers
decay
of 100
Uranium
- Earth
was
million years old
1903 - Pierre and Marie Curie
- discover decay from new element - Radium
Evidence ~early developments
Physics
4. 1904 - Ernst Rutherford
The discovery of radioactivity allows an accurate
estimation of the age of the Earth and the results
suggest the Earth is very old
Summary 1
• Relative ages – placing geologic events in
their proper sequence, i.e. geology suggests
the Earth is old
• Estimated ages – the Big Bang theory, i.e.
astronomy says the Universe is 14 billion yo
• Absolute dates – define the actual numerical
age of a particular geologic event, i.e. physics
says the Earth is ?????
Radioisotope analysis
Measures “decay” of elements
CARBON 14
NITROGEN 12
5730 years
• measure the time taken for mass of element in
mineral or object to “decay” by half
•This period of time is called a half life
Jack Hills, Western Australia
Zircon Crystal
Radioisotope analysis
• Carbon Dating - Carbon changes to Nitrogen with a half-life of 5730 years
- can only be used to date younger objects up to 50,000years
• Uranium Dating – half-life of 710 million to 4.5 thousand million years.
• Potassium Dating – half-life of 1.3 thousand million years
• Rubidium Dating – half-life of 47 thousand million years
How old are the rocks?
Greenland 1983
3.7 billion years
North America
1983
Australia 1998
4.1 – 4.2 by
3.4 - 3.5 billion
years
South Africa 1983
3.4 billion years
Tasmania 2001
4.4 billion years
How old are other planets?
We don’t know…………but!
How old are other planets?
We don’t know…………but!
Meteorites aged to 4.6 billion years old
Rocks collected from Moon 4-3 - 4.6 byo
Final Summary
• Science has shown rocks on Earth, the
Moon and from meteorites are not
thousands but billions of years old
• This raises challenging questions about
Genesis