ORIGINS OF THE UNIVERSE Expectations: D3.1, D3.2

Earth in the Universe

The Big Bang Universe began in an incredibly hot, dense expansion approximately 13.7 billion years ago A hot dense fireball spread outward quickly Universe cooled, energy began turning into matter  mainly hydrogen Over millions of years, matter formed clumps eventually forming stars and galaxies

Video (4min)

Galaxy Crash course Astronomy Galaxies #1 (12 min) https://www.youtube.com/watch?v=I82ADyJC7wE&list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL&index=38 Collections of millions to hundreds of billions of stars, planets, gas and dust, up to 100 000 ly across. Our galaxy – the Milky Way is a Spiral or spinning pinwheel galaxy

Expanding Universe All galaxies appear to be moving away from each other The farther the galaxy  the faster it moves away. Hubble made this discovery by studying the light emitted from galaxies. Each galaxy had its own spectrum of light. The light spectra was red shifted, meaning moving away.

Red Shift (see page 394)

Formation of the Solar System Expectations: D3.1, D3.2

Solar Nebula Theory: Solar system formed 5 billion years ago from a massive cloud of gas and dust (solar nebula) that began to contract. Nebula contracted, spun, leading to frequent collisions of material Grains stuck together to form larger objects pebbles/rocks/boulders One of these dense massive clumps became a protostar which contracted increasing the temperature and pressure at the core

The Protostar’s counterclockwise spin was amplified causing the cloud to collapse thus spinning faster increasing temp and pressure until nuclear fusion began A star is formed Bodies farther away from core became planets

Inner planets Outer planets It is believed: Blasted by radiation from sun & not much gravity to hold hot a atmosphere they became rocky. Outer planets Made of lighter gases (H & He) pushed away by solar wind Farther from intense heat they were able to keep their gas It is believed: Sun is 5 billion years old Planets 4.6 billion years old (proof: geological evidence of rocks age)

Evidence: planets orbit the sun in the same direction planets are all on the same plane with sun in center most planets rotate the same way, terrestrial planets are closer than gas planets

journey to the edge of the universe(Alex Baldwin) https://www.youtube.com/watch?v=bVQpwxgMQCg