Catalyst Pick up a note sheet. Pick up 1 piece of colored paper. Put “Unit 1 Astronomy” on the front of the colored paper. SIT SILENTLY IN YOUR SEAT.

AGENDA Notes – Astronomy and the Origin of the Universe Demo Independent Practice Exit Ticket

Astronomy the study of outer space (planets, moons, and stars) and the universe SCALE OF THE UNIVERSE VIDEO

The Origin of the Universe I can describe the origin of the universe and its organization.

Theory an idea or set of ideas that is intended to explain facts or events; some evidence an idea that is suggested or presented as possibly true but that is not known or proven to be true

Organization of the Universe Universe –Galaxies Solar systems »Stars, planets, moons, astroids, and comets Billions of galaxies; trillions of stars

EARTH WITHIN THE UNIVERSE

EARTH WITHIN THE SOLAR SYSTEM GeocentricHeliocentric

The Universe The Universe is everything we can touch, feel, sense, measure or detect. It includes living things, planets, stars, galaxies, dust clouds, light, and even time. Before the birth of the Universe, time, space and matter did not exist. The Universe contains billions of galaxies, each containing millions or billions of stars. The space between the stars and galaxies is largely empty. However, even places far from stars and planets contain scattered particles of dust or a few hydrogen atoms per cubic centimeter. Space is also filled with radiation (e.g. light and heat), magnetic fields and high energy particles (e.g. cosmic rays).

The Universe The Universe is incredibly huge. It would take a modern jet fighter more than a million years to reach the nearest star to the Sun. Travelling at the speed of light (300,000 km per second), it would take 100,000 years to cross our Milky Way galaxy alone. No one knows the exact size of the Universe, because we cannot see the edge – if there is one. All we do know is that the visible Universe is at least 93 billion light years across. (A light year is the distance light travels in one year – about 9 trillion km.)

The Universe The Universe has not always been the same size. Scientists believe it began in a Big Bang, which took place nearly 14 billion years ago. Since then, the Universe has been expanding outward at very high speed. So the area of space we now see is billions of times bigger than it was when the Universe was very young. The galaxies are also moving further apart as the space between them expands.

How did it all begin?? Theories according to scientists…

Doppler Effect When objects are moving towards you, the light they emit appears more blue because the waves are compressed. (“blue shift”) When objects are moving away from you, the light they emit appears more red because the waves are stretched out. (“red shift”)

Doppler Effect

Siren

Red shift Early 20 th century: Edwin Hubble discovered that light that reached Earth from distant galaxies in all directions was shifted toward the red end of the spectrum

Discuss When do we observe red shift? What does Hubble’s red shift tell us about the universe?

Conclusions… The Universe is expanding! If the Universe is expanding, how did it begin?

2 Theories Big Bang Theory Steady State Theory

Big Bang Theory Universe began as a dense, hot, single point 13.7 billion years ago, a rapid expansion occurred outwards in all directions All matter and energy was created at this point Matter cooled and formed atoms, gases, and stars Universe is still expanding outwards from that expansion

The Big Bang Theory

EXPANDING UNIVERSE!! The BIG BANG THEORY

Steady State Theory The universe looks the same as it has always been even though it is expanding New matter is constantly being created from empty space to maintain its density

The Steady State Theory

Death of the Universe How do you think the Universe will end? What are the possibilities?

DEATH OF THE UNIVERSE (2 THEORIES) Big Crunch Expansion forever

Big Crunch Eventually, the Universe’s gravitation will be strong enough to halt and reverse expansion The Universe will contract back into a single point or possible black hole …and then another Big Bang?

Expansion Forever The Universe will continue to expand and cool forever

Death of the Universe

AGENDA Notes – Astronomy and the Origin of the Universe Demo Independent Practice Exit Ticket

DEMO Answer the questions on your note sheet with your neighbor.

Independent Practice

Exit Ticket