Our Place in the Universe

The Nebular hypothesis

A. solar nebula

B. contraction into rotating disk

C. Cooling causing condensing into tiny (dust sized) solid particles

D. Collisions between these form larger bodies

E. These accrete to form planets

I. The Earth is a system

A. Systems - a group of interacting and interdependent parts that form a complex whole

Feedback mechanisms

B. Hydrosphere
1. Global ocean

    a) 71% of the Earth’s surface

    b) 97% of its water

2. Cryosphere (Ice)
    a)most of your “fresh” water

C. Atmosphere
1. gaseous envelope - thin
a) the air you breath
b) protection
c) energy exchanger
D. Lithosphere
1. “solid” Earth
a) crust
b) mantle
c) core
2. Two principal divisions
a) ocean basins
(1). mid-ocean ridge system - 65 x 103km
(2). trenches - some >11x103 km
b) continents
(1) Continental shelf - 1/2 way
(2)this changes the % to 60/40
E. Biosphere
1. all life and the previous “spheres”
F. Interface - common boundary where different parts of a system come into contact and interact.
II. People and the Environment
A. Environment - everything that surrounds and influences an organism
1. biotic - living
2. abiotic - non living
a) also called the physical environment - this is Earth Science!
B. Environmental hazards - these are natural processes, people are the problem!!
III. Resources
A. renewable - replenished over a relatively short period of time
1. plants, animals (um um good!)
2. flowing water
3. wind
4. solar
B. nonrenewable - replenished beyond human time scale
1. coal
2. petroleum
3. metals
IV. What is SCIENCE?
A. Underlying assumption - the natural world behaves in a consistent and predictable manner.
B. FACTS - come from observation and measurement
1. standard measures
2. observer dependent
C. Hypothesis
1. explanations of facts
2. there can be more than one for the same set of facts
D. Theory
1. when only one hypothesis is left after lots of testing
2. high confidence - predictability
3. best testable explanation at that time
4. decided by scientists
E. Laws
1. describes what will happen
2. does NOT explain why
F. Scientific Methodology
1. There is NO one Scientific Method
a) collect facts
b) form hypothesis
c) construct experiments (test)
d) accept, modify or reject
2. Serendipity
G. General Guides for science

1. testable
2. Replicable
3. falsifiable
4. peer reviewed
5. changes with time (tentative)
6. product of culture


Images are from your T&L text - use low res if printing the pages out as notes