Lecture 5 Flashcards
1
Q
Cultural Views of time
A
- Greek and Hindu ancient philosophers rejected finite time
- proposed that time is cyclic with universe regenerated in cycles. Things that happen to day is part of the current cycle and one day in a new cycle the same things will happen again
- Europ thought time was linear and finite history was drawn from the bible. Provided the first such time frame for science
2
Q
Concept of human history
A
- dates to Herodotus 6.484 BC
- first attempt to research the past
- used a list of pharaohs to do so
3
Q
Biblical time line
A
CreationEnd of World
-importance was the production of a linear view with unique historical events on the finite time line
4
Q
James Ussher
A
- Bishop to Armagh in 1650
- calculated biblical chronologies
- calculated biblical record of births and deaths
- result was dating the creation making Earth 6000 years old
- Creation October 23, 4004 BC)
- first no qualms with scientists, fossils only then being recognized as former living creatures
- new explanation was that shells and bones found in rocks on mountains were from the flood
5
Q
New Sciences of Earth
A
- 18th Century
- study of past life-paleontology
- study of Earth physical nature and origin-geology and cosmology
- both quickly outgrow Biblical time scale
6
Q
Benoit de Maillet
A
- wrote about mythical philosopher Telliamed who claimed to be telling about what Eastern philosophers thought
- pointed out that places in sea level was going down
- Telliamed calculated how long it would have taken for the mountains to rise from the sea=2mry
7
Q
de Buffon
A
- mid 1700s astronomers begun to realize that the sun and its planets had condensed from a swirling mass of hot gas-how long would it take a planet to cool?
- Buffon tested with hot iron balls and extrapolated getting about 100,000 years
8
Q
Relative time
A
- time line that represents when something happened in relationship to something else
- measure by relative position, before, after, same time
9
Q
Absolute time
A
- real time dates
- how long ago something happened
- measured in time units like years
10
Q
Nicholas Steno
A
- helped with understanding relative time
- recognized and showed that fossils were remains of past life buried before mud became rock (tongue stones=shark teeth)
- came up with general theory of how sediments accumulated
11
Q
Principle of superposition
A
- gives relative age of rocks
- sediments accumulate on horizontal surface
- later different sediments deposited
- ultimately rocks form in layers going from oldest at the bottom and younger above
12
Q
Superposition applied to relative dating of rocks
A
- only a few kinds of sedimentary rocks
- sandstone, limestone, shale so it will occur in different ages
13
Q
How to tell ages of rocks
A
- take information from one location and fuse with information from another and come up with a rock section that you don’t see in any one place, but the order would be correct on earth
- confined to individual strata
- William Smith did this by carefully observing rocks and their fossils
14
Q
Superposition and strata correlation
A
- by use of index fossils in the 19th century used to map strata over wide regions of Europe and America
- also developed relative scale that’s still in use
15
Q
James Hutton
A
- figured out from key geological observation how ancient the world would have to be to account for observation
- saw tilted rock layers below and contact with overlying horizontal layers
- since all rocks are deposited horizontally the rocks were shifted to have new rocks deposited on top
- shifted rocks back to how they would be deposited and makes an order out of it showing oldest to youngest
- saw infinite amount of time
- eventually new horizontal segments will too be bent into mountains and cycle of erosion will begin again
