Astronomy 1050 Summer 2013

What is Astronomy???

Do you think of Astrology???

The position of the sun, stars, moon and planets at the time of people's birth is said to shape their personality, affect their romantic relationships and predict their economic fortunes, among other divinations.

What is an specific prediction?

Fortune Cookies???

Are your fortunes accurate???

“You will run into money today”

• Did you literally run into a gold brick wall?

• Maybe you picked up a penny on the side walk…

• OR, maybe you picked up the penny because of your fortune

A specific prediction is rarely accurate while a vague one is rarely wrong.

Science makes specific Prediction:

• Can be quantitatively verified

Demonstration!

What happens when you drop an apple and a feather in a vacuum?

A. The ball will drop faster

B. The feather will drop faster

C. They will reach the bottom at the same time

D. Both will fly out into space!

Physics Predicts:

F=ma F=m𝐺𝑀

𝑟2

a = GM/r2

***Acceleration is independent of object

Astronomy

What is Astronomy???

Physics

• Study of matter and energy at all scales

• It is the fundamental science

all other sciences and technologies rely on the principles of physics.

Astronomy = Physics of the cosmos = Astrophysics

Basic Structure of the Universe

All figured out with quantitative predictions

The earth is a sphere

Structure of the solar system

Populations of other stars

Size of our galaxy

Populations of galaxies

Relative motions of galaxies

Earth is a Sphere

Curvature of the Earth

Diameter of the Earth

• Greeks 200 B.C.• Alexandria to Syene:

800km• Measured 7 degrees• circumference(360°):

42,000 km

• Actual Diameter• 40,000 km

• Google it!• close!!!

Little Things Go Around Big

Things

Galileo proved that not everything orbits the Earth.

Jupiter and its moons actually look like a miniature solar system

Newton & Gravity

Figured out that gravity is the reason planets go around the sun and why moons go around their planets!

Newton & Light

Emitting Sources

Hydro

gen 6

60 n

m

Helium

580 n

m

HR diagram

Measuring the properties of different stars, most stars have a relationship between the brightness and their color.

Color

Bri

ghtn

ess

Same Techniques on Whole Galaxies

• Hubble Tuning Fork

Other Galaxies

Hydro

gen

Helium

Red Shift and the Big Bang

All Galaxies Are Moving Away From Us

Red

Green

Sun

Big Bang

What happens if you rewind time???

Assessment Inquiry

I want to evaluate how well I am teaching

Take the rest of the class period