Astronomy and Our Origins Where did we come

Astronomy and Our Origins

Where did we come from? • Scientists believe the entire universe began as a single, one dimensional speck that exploded into existence. • This idea is called the Big Bang Theory! • Do we know for sure…of course not…we could be right or wrong. We will never know. • But we do have a lot of evidence to support our hypothesis.

• That explosion caused everything in the universe to spread apart and speed away from each other. • This spreading apart is occurring today and can be measured. • If we wind the clock backwards, we believe the age of the universe to be 13. 7 billion years old.

• Doppler Effect = the change in frequency emitted from a moving object. • For moving sound sources (race cars, sirens, etc) the pitch (highness/lowness) changes. • For moving light sources (stars, galaxies, etc) the light color changes.

• Doppler Effect Things moving away shift to Redder colors = longer distances & longer wavelengths = red shift Things moving towards us shift to Bluer colors = shorter distances & shorter wavelengths = blue shift

• Countless stars formed, lived and exploded a violent death, spewing their guts into the universe.

• This is an actual star explosion that occurred in 1054

• Eventually gravity caused a section of all this left over star material to spin, clump together and form the sun, planets, and our whole solar system. • This process is called the nebular hypothesis. • Everything in space spins and moves in lots of different ways. • Earth’s motions include rotation, revolution, and precession, and others.

Formation of our solar system nebula

Nebula