Transcript In The Beginning

How did the Universe
form?
Astronomy
The study of the universe, stars,
planets and all celestial objects in
space.
The Big Bang Theory
15-20 Billion years ago all matter & energy
was squished into a tiny dot that
eventually exploded, forming the Universe.
Big bang animation
The Big Bang Theory
Huge clouds of hydrogen, helium and other
matter formed.
 Dust clouds formed the beginnings of
galaxies, stars, planets and other celestial
bodies.

COSMIC BACKGROUND RADIATION
Evidence for the
Big Bang
Long-wavelength background radiation
coming from all directions in the universe
 Electromagnetic Spectrum emitted by stars
 Almost all galaxies have a red shift;
indicating that the universe is expanding

Electromagnetic Spectrum
Doppler Effect

Change of wavelengths as an object
moves toward or away from us.
Doppler Effect
Objects moving away = red shift, wavelength
increases-stretches.
Objects moving towards = blue shift,
wavelength decreases.
Spectra:
Doppler Red Shift
‘Away’
Blue
Blue
Red
Red
Doppler Blue Shift
‘ to You ’
Blue
Red
Blue
Red
Hubble’s Law
 The
Universe is expanding
 Nearby spots are moving away
slowly while distant spots are
moving away more rapidly.
Light Year
 Distance
light travels in one
year (6 trillion miles) ! 1 light
year = 1 earth year.
Galaxies
What galaxy do we
live in?
Milky Way Galaxy
-Billions of stars !
Milky Way
Galaxy
-Sun is located
on one spiral
arm.
Irregular Galaxy
Elliptical Galaxy
Spiral Galaxy
Galaxies
 System
of billions of stars
 Classified according to their
shape
 Elliptical galaxies are most
common
Solar system
 Sun,
stars, planets, moons,
comets...
 Formed about 4.5 billion years
ago
SUN
A
star.
 Provides Earth with heat and light,
making life possible.
 Energy drives ocean currents and
weather.
 Composed of hydrogen and helium.
 5 billion years old.
SUN
 Temperatures
increases toward its
center-12million degrees Kelvin
 Galileo observed sunspots and
discovered Sun rotated.
 Rotates faster at equator than poles
(just like the earth)
CLOSURE
 Hw-UPCO
 Lab
p. 439-441
is Due by TOMORROW!!!