Download Astronomy and Our Origins

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