LECTURE 1
Geology = Study of Earth
Geology covers
Natural resources
Environmental issues
Natural disasters
Climate change
Engineering, construction & development
Science is a method to understand the world around us
Science uses facts
Facts can repeatedly demonstrate as true
Principles are the essential truths that the scientists agree are correct
Facts and principles lay the bedrock for science
Science isn’t the only way of viewing the world (Religion, theology, etc.)
Scientific Method
1. Observation- Observe things around you.
2. Questions- While observing things, you ask questions.
3. Hypothesis-
a. You answer questions by forming a hypothesis.
b. Hypothesis is an educated guess.
c. Must be testable & predictive.
d. Does it pass the “if-then” test?
e. You can make hypothesis based on past and future events.
Hypothesis Good or Bad:
1- Sunlight helps plants grow. Good b/c testable
2- Aliens can make flowers grow faster. Bad b/c we have no access to
aliens b/c they aren’t real.
,3- Dinosaurs went extinct because a giant asteroid hit the Earth 65 million
years ago. Good b/c based on past events
4- Halo is better than Call of Duty. Bad b/c opinion
5- Hippo herds help prevent wildfires. Good b/c testable
4. Collect Data- Test your hypothesis.
5. Evaluate your hypothesis based on your collected data.
When a hypothesis is wrong, you eliminated a thing, and you collected
data.
Science is all about trial and error, which is also why it takes time for
scientists to find new things. Every failure is 1 step closer (scientist
mentality).
Theory- Very strong idea with a lot of data backing it up.
Theory can become a law.
Law- A statement that describes an observable occurrence in nature that
appears to always be true.
Theories and laws are tested and revised too
You must have scientific data to challenge scientific ideas
Must use facts
Beliefs and opinions don’t invalidate a scientific hypothesis
Geology- Study of the Earth
Earlier approaches
6 catastrophes
James Hutton collected data on catastrophes and published his data in a
book called Theory of the Earth (1795)
Principle of Uniformitarianism (1800s)- The present is the key to the past.
,Actualism- a geological method that states that the same natural laws and
processes that are observed today were also present in the past
Meteorites enter the Earth’s atmosphere at up to 40 km/s ( miles per )
1 mile = 1.6 km
30 m (~100 ft) diameter meteorite @ 15 km/s impacts w/ energy – 4 million
tons of TNT
Study Hint
Billion years ago = bya or Ga
Million years ago = mya or ma
Thousand years ago = ka
Before 6 Ga: no solar system, just a nebula of H atoms.
Nebular Hypothesis: explains how our solar system forms.
Step A- gravity is still a force and it’s drawing all the hydrogen into the
center of the cloud.
Step B- Cloud collapses into Solar Disk Model
Step C- Protostar (6 Ga): prototype early stage of a star.
Step D- Fusion, which is the process of taking 2 atoms and fusing them
together to create 1 atom.
2 hydrogens make a helium
Step E- Planetary accretion, which is drawing things together (rapidly)
Key date = 4.5 Ga
Planetary accretion still happens.
Early Earth History
Theia Impact- 2 planets collide to create 1 planet
Theia Impact Aftermath
1- Lunar Formation
, 2- Molten Planet
3- Density stratification (if the Theia impact happened, earth layers
would have never happened)
Density- The mass of the object compared to its volume
LECTURE 2
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