1. Vocabulary
15. Universal law of gravitation 16. Electromagnetic spectrum 17. Terrestrial planet 18. Planetesimals 19. Wavelength 20. Frequency 21. Doppler effect 22. Visible Light 23. Hersprung Russel (HR)
Diagram 24. Fusion 25. Universe 26. Spectroscopy
1. Solar system 2. Galaxy 3. Big bang theory 4. Sunspots 5. Nebular hypothesis 6. Protoplanet hypothesis 7. Rotation 8. Revolution 9. Geocentric 10. Heliocentric 11. Lunar eclipse 12. Solar eclipse 13. Ellipse 14. Newton

2. Basics of the Universe

3. Astronomy Cosmology the study of the universe
the branch of astronomy that deals with the origin, large-scale properties, and the evolution of the observable universe

4. The Universe
in simpler terms, all space, all the matter, all energy, and all time in it.
Big Bang – rapid expansion of matter from a state of extremely high density and temperature that marks the origin of the universe.
major components formed:
galaxies
solar systems
planets
everything

5. “Big Bang” Theory expansion of space, time, matter and energy
occurred about 13.7 billion years ago
expanded within a second from something the size of a spec of dust to the size of our solar system
Misconception Alert:
Describing this theory as
the “Big Bang” is a misnomer
because there really was not
an explosion, just a release of
energy

6. Early History of the Universe
Matter as we know it did not exist at the time of the Big Bang, only pure energy.
Within the first second, the 4 fundamental forces were created
gravity - the attraction of one body toward another
First explained by Isaac Newton
Universal Law of Gravity
electromagnetic force - binds atoms into molecules
strong nuclear force - binds protons and neutrons together in the nucleus
weak nuclear force - breaks down an atom’s nucleus, producing radioactive decay

7. Early History of the Universe
After 3 minutes, protons and neutrons began to fuse to form the nuclei of hydrogen and helium atoms
About 300,000 years later photons begin escaping from matter and light existed for the first time

8. Changing Composition of the Universe
200 million years later, with expansion still occurring, stars and galaxies began forming from leftover matter - hydrogen and helium
nuclear fusion in stars reduces Hydrogen to Helium
when a dying star explodes, the heavier elements (less that iron) created by fusion are blown into space to be recycled by newly forming stars
overall composition of the galaxies is gradually changing to the heavier elements

9. Energy of a Moving Object in Relativity: E = mc2
The Speed of Light
Energy of a Moving Object in Relativity: E = mc2
One consequence: as v approaches c, Energy goes to infinity

11. Astronomical Unit (AU)
unit of distance equal to the average spacing between the Earth and the Sun
equal to about 150 million kilometers (93 million miles)
light takes about eight minutes to cover this distance
The Earth animation is not rotating in the correct direction;
it should be rotating from west to east
150 million km
(93 million mi.)

12. Light Year
distance that light travels in one year in a vacuum, which is about 9.5 trillion kilometers (6 trillion miles)
The Milky Way Galaxy is about 100,000 light years in diameter
the speed at which light travels this distance is about 300,000 km/sec (186,000 mi/sec)
The second closest star to the Earth is a little over four light years away. How far away (in miles) is the star?

13. If one parsec equals 206, 265 AU, how many miles is it equal to?
unit of distance equal to about 3.26 light years (or 206,265 AU)
If one parsec equals 206, 265 AU, how many miles is it equal to?

14. Constellation a group of stars that form a pattern in the sky
stars of a constellation are often far apart from each other, but they appear grouped together when viewed from Earth

15. Why is it not possible to see all constellations at once?
88 constellations in the night sky
patterns of constellations are dynamic; therefore, the constellations of 100,000 years ago are quite different from today’s
a part of a constellation that forms its own pattern in the sky is known as an asterism (ex. – The Big Dipper)
Why is it not possible to see all constellations at once?

16. Edwin Hubble at Mt. Wilson
Hubble’s observations led him to the conclusion that the universe is expanding
Object’s recession velocity is proportional to its distance from the observer.
Objects farther away are moving away from us faster
Hubble guiding the Hooker
100 inch telescope in 1923.

17. Edwin Hubble
determined that other galaxies exist, besides the Milky Way
observed that galaxies were moving away from each other
based on Doppler Effect
Light is shifted toward red end of spectrum meaning its moving away from us
Hubble Law – the farther away a galaxy is, the faster it is moving away from us; supports the Big Bang Theory

18. Using the Doppler Effect to Measure Velocity
Redshift
Blueshift

19. Electromagnetic (EM) Radiation
Majority of astronomy looks at EM Radiation
EM Radiation – includes all radiation (light) from Radio to Gamma Rays
Humans only see small region
Visible light – 400 – 700nm (violet to red)

20. Hubble Space Telescope
reflecting telescope that was placed into orbit in 1990
sends images and measurements back to Earth electronically
Taken several long exposure images called “Deep field”
Image taken from:
What is one of the main
benefits of having the Hubble Space
Telescope in orbit, as opposed to
it being here on Earth?

21. Hubble Deep Field

22. Cosmic Background Radiation
Arno Penzias & Robert Wilson
accidentally detected faint radiation on a radio telescope in 1965
determined that the radiation was leftover thermal energy from the “big bang” about 300,000 years after it happened

23. Cosmic Background Radiation

24. Galaxy
a large assemblage of stars (and often gas and dust), typically containing millions to hundreds of billions of member stars
Star - a large hot ball of gas which generates energy in its core by nuclear reactions
estimated 100 billion galaxies in the universe each with billions of stars
held together by the gravitational attraction of all its member stars on one another
formed around 200 million years after the “Big Bang”
most large galaxies have super-massive black holes at their centers
sometimes contain very bright centers called quasars
3 major types:
Spiral
Elliptical
Irregular
What is the name
of the galaxy
we reside in?

25. 3 Types of Galaxies Elliptical
shaped like spheres or eggs; have almost no dust or gas between stars; contain old stars
Irregular
faint galaxies without a definite shape; smaller than the other types of galaxies; contain fewer stars
Spiral
have arms of stars, gas , and dust that curve away from the center of the galaxy in a spiral pattern
Ex. – Milky Way
The process of galaxies colliding to create a larger galaxy is known
as “galactic cannibalism.”

26. Our Solar System
Sun and all things orbiting around it, including the eight major planets, their satellites, and all the smaller pieces such as asteroids and comets
formed around 4.6 billion years ago
Formation called Nebular Hypothesis Theory
Solar system formed from massive rotating disk of gas (hydrogen and helium) and dusk
What is
incorrect
or misleading
about this
visual?

27. Satellite an object that orbits a more massive object (i.e. – moons)
probes we launch into orbit around the Earth are called “artificial satellites”
The Earth animation is not rotating in the correct direction;
it should be rotating from west to east

28. Universe Video (22 Minutes)
Latest Hubble Deep Field