Midterm #2 Geo 012

We can understand the past from the record that has been left behind via what methods?

Direct and indirect evidence of history

Direct evidence of history examples

Kings list, often something given sequence but not exact dates

Indirect evidence of history example

Antikythera mechanism; inferences about sequence and order made from record of objects or ideas

What is the antikythera mechanism

A Greek mechanical calculating device dates at the end of the second century BC. It is the most complex instrument known until 1000 years later.

What cycles does the Antikythera Mechanism demonstrate?

Metonic and Saros

Created/eternal

Plato vs Aristotle

Static vs changing

P+A vs Stoics and Epicurians

Cyclical/Linear

Stoics vs Epicureans

Epicurean View

Emphasized human agency, was attracted to the idea of a young earth with humans determining its destiny

Linear view of time in the Abrahamic religions

Key innovation wit respect to time is that history reflects a direct dialogue between humans and the will of god.

-Humans have agency and the earths history is the play of the human/God relationship was

Ozymandius Poem (Percy Bysshe Shelley) Main point

Achievements of most famous among us do not last forever

basis of induction

1. Very large # of observations

2. Observations repeated under variable conditions

3. No accepted observations conflict w/ the derived universal law

Deduction in action

1. All classes on what is science are boring

2. This is a class on what is science

3. This class is boring

-3 is a logical valid deduction if 1 & 2 are true

Eratosthenes believed that the earth was a sphere based on what observations?

-The moon and sun were round disks

-Earths Shadow appears round during eclipse

- Ships disappear over the horizon

The diameter of the shadow of earth at the moon is how many moons diameters smaller than earths actual diameter?

One

How much bigger is the earth shadow compared to the moons diameter

2.5

What did Aristarchus discover?

The earth is not the largest object in the solar system

Nearest star

Alpha Centauri

How do we know how far away distant objects are? (For relatively close objects)

Parallax method

Parallax method

A method for measuring the distances to nearby stars that relies on the fact that a star appears displaced relative to the background of distant stars when viewed from two different positions in space. Satellites orbit outside the Earth's atmosphere can measure distances up to almost 1000 pc in this way.

And for more distant objects where parallax is too small?

Cephid variables

Cephid Variable

Star with pulsation periods ranging from 1 to 100 days and luminosity that increases with the length of the pulsation period.

Types of galaxies

Elliptical, spiral, and spiral bar

Elliptical galaxies

Have stars that are cooler and therefore older. Now thought to result from the merger of spiral galaxies

Edwin Hubble did what

Measured red shift and used cephid variables to tell how far away these galaxies were from us

Expanding Universe

Plato

Steady state universe

Aristotle

Dark matter

Detected because galaxies are rotating faster than they should given known matter

Dark energy

Detected because the rate of expansion of the universe is higher than it should be for the calculated mass