ORIGINS OF THE ORIGINS OF THE UNIVERSEUNIVERSE

Expectations: D3.1, D3.2Expectations: D3.1, D3.2

Earth in the UniverseEarth in the Universe

The Big BangThe Big BangUniverse began in an incredibly hot, dense Universe began in an incredibly hot, dense expansion approximately 13.7 billion years agoexpansion approximately 13.7 billion years ago

A hot dense fireball spread outward quicklyA hot dense fireball spread outward quicklyUniverse cooled, energy began turning into Universe cooled, energy began turning into

matter matter mainly hydrogen mainly hydrogenOver millions of years, matter formed clumps Over millions of years, matter formed clumps

eventually forming stars and galaxieseventually forming stars and galaxies

Video Video (4min)(4min)

GalaxyGalaxyCrash course Astronomy Galaxies #1 (12 min) https://www.youtube.com/watch?Crash course Astronomy Galaxies #1 (12 min) https://www.youtube.com/watch?

v=I82ADyJC7wE&list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL&index=38 v=I82ADyJC7wE&list=PL8dPuuaLjXtPAJr1ysd5yGIyiSFuh0mIL&index=38 Collections of millions to hundreds of billions of stars, Collections of millions to hundreds of billions of stars, planets, gas and dust, up to 100 000 ly across.planets, gas and dust, up to 100 000 ly across.

Our galaxy – the Milky Way is a Spiral or spinning pinwheel Our galaxy – the Milky Way is a Spiral or spinning pinwheel

galaxygalaxy

Expanding UniverseExpanding UniverseAll galaxies appear to be moving away from All galaxies appear to be moving away from

each othereach otherThe farther the galaxy The farther the galaxy the faster it moves the faster it moves

away.away.

Hubble made this discovery by studying the Hubble made this discovery by studying the light emitted from galaxies.light emitted from galaxies.Each galaxy had its own spectrum of light.Each galaxy had its own spectrum of light.The light spectra was red shifted, meaning The light spectra was red shifted, meaning

moving away.moving away.

Red Shift (see page 394)Red Shift (see page 394)

Formation of the Solar Formation of the Solar SystemSystem

Expectations: D3.1, D3.2Expectations: D3.1, D3.2

Solar Nebula Theory:Solar Nebula Theory:Solar system formed 5 billion years ago from a Solar system formed 5 billion years ago from a

massive cloud of gas and dust (solar nebula) massive cloud of gas and dust (solar nebula) that began to contract.that began to contract.

Nebula contracted, spun, leading to frequent Nebula contracted, spun, leading to frequent collisions of materialcollisions of material

Grains stuck together to form larger objects Grains stuck together to form larger objects pebbles/rocks/boulderspebbles/rocks/boulders

One of these dense massive clumps became a One of these dense massive clumps became a protostar which contracted increasing the protostar which contracted increasing the temperature and pressure at the coretemperature and pressure at the core

The Protostar’s counterclockwise spin The Protostar’s counterclockwise spin was amplified causing the cloud to was amplified causing the cloud to collapse thus spinning faster increasing collapse thus spinning faster increasing temp and pressure until nuclear fusion temp and pressure until nuclear fusion began began

A star is formedA star is formed

Bodies farther away from core became Bodies farther away from core became planetsplanets

Inner planetsInner planets Blasted by radiation from sun & not much gravity to Blasted by radiation from sun & not much gravity to

hold hot a atmosphere they became rocky.hold hot a atmosphere they became rocky.Outer planetsOuter planets

Made of lighter gases (H & He) pushed away by Made of lighter gases (H & He) pushed away by solar wind solar wind

Farther from intense heat they were able to keep Farther from intense heat they were able to keep their gastheir gas

It is believed: It is believed: Sun is 5 billion years old Sun is 5 billion years old Planets 4.6 billion years old (proof: geological Planets 4.6 billion years old (proof: geological

evidence of rocks age)evidence of rocks age)

EvidenceEvidence::planets orbit the sun in the same planets orbit the sun in the same

directiondirectionplanets are all on the same plane planets are all on the same plane

with sun in centerwith sun in centermost planets rotate the same way, most planets rotate the same way, terrestrial planets are closer than terrestrial planets are closer than

gas planetsgas planets

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