Transcript Big Bang Theory

Astronomy
Study of objects in space such as the Sun,
stars, planets, comets, gas, & galaxies.
*Also, the Earth’s place in the universe.
Universe = everything that exists
Disclaimer:
Astrology is NOT science !!!
There is currently no evidence that star positions affect human
behavior or your future.
Go ahead & read your
horoscope but remember
that it is just entertainment!
Geo-centric Helio-centric
Earth-centered
Sun-centered
view of universe
view of solar system
C. Ptolomy
N. Copernicus
90-168
1473-1543
modern view of the solar system:
“the Sun” is a star
planets orbit the Sun
Galaxies
= groups of billions of stars
there are more than 100
billion galaxies
they all have different
shapes
Spiral
Elliptical
Irregular
Cosmic Size
Universe
Galaxies
Star clusters & Constellations
The “Big Dipper”
constellation is a
pattern made of 7 stars
Solar systems
Stars
Planets,
moons
Asteroids,
meteors,
meteorites,
comets
watch this!
Powers of Ten Video
Apple in the Dark
Imagine you are sitting at a table with a red apple in front of you. Your
friend turns off all the lights. It is totally dark in the room. There are
no windows in the room or crack around the door. No light can enter
the room.
Write the statement you believe best describes how you would see the
apple in the dark & explain your answer in a short paragraph.
A. You will not see the red apple, regardless of how long you are in the
room.
B. You will see the red apple after your eyes have had time to adjust to
the darkness.
C. You will see the apple after your eyes have had time to adjust to the
darkness, but you will not see the red color.
D. You will only see the shadow of the apple after your eyes have had
time to adjust to the darkness.
E. You will see only a faint outline of the apple after your eyes have had
time to adjust to the darkness.
spectrum on:
p. 484 & 678
LIGHT:
ELECTROMAGNETIC SPECTRUM
& DOPPLER SHIFT
Learning from Light
What is white light?
Is there light we can’t see?
What is a prism?
What is ROY G. BIV?
Spectrum: light separated into
component wavelengths
spectrum on:
p. 484 & 678
Electromagnetic Energy
energy that travels in waves
spectrum on:
p. 484 & 678
DRAW YOUR WAVE:
1.
2.
3.
4.
5.
6.
7.
Gamma Rays
X – Rays
Ultraviolet
Visible Light
Infrared
Microwaves
Radio Waves
1 cm
2 cm
3 cm
4 cm
5 cm
6 cm
7 cm
spectrum on:
p. 484 & 678
The Electromagnetic Spectrum
Earth’s Seasons = caused by the tilted axis (23.5o)
Equinox = equal hours of daylight & darkness
Solstice = longest day & shortest day
Fall
Sep. 21
Dec. 21
SUN
Jun. 21
(shortest day)
(longest day)
Mar. 21
Spring
How we “see” the universe:
this is a
RADIO
TELESCOPE
we use this information
to study galaxies
Types of spectra
•Sunlight, light bulbs
•Sunlight that has
traveled through our
atmosphere
•Hot gas
Doppler Effect
wavelength changes if an object is moving toward or away from you
pitch gets higher
Whitney Houston !!!
BASS !!!
pitch gets lower
Doppler shifts from stars
Doppler Effect Song by Astrocapella
The Expanding Universe
 1929 – Edwin Hubble
found that the
universe is expanding
 Estimated distances,
relative brightness,
Doppler red shifts
Hubble’s Law: galaxies are moving
away from us (red-shift) at a speed that
is proportional to their distance
the more distant the galaxy, the
greater the velocity (moving away at
faster speeds)
 At one time, the universe was a hot, super
dense ball smaller than an atom.
 About 13.7 billion years ago, a rapid expansion
occurred sending material in all directions.
 This was the beginning of the universe.
 Eventually, matter cooled & condensed
into galaxies, stars, & planets.
Support for the Big Bang Theory
 Red shifts
 Cosmic background radiation (CBR)
 Signals coming from every direction in
space.
 Radio, microwave, infrared, & X-rays.
 Believed to be created by the big bang
expansion.
Video
Cosmic Background Radiation (CBR)
 The hypothesis that the universe has
always been expanding (since the “Big
Bang”) predicted (1948) that radiation
produced from the first moment of
expansion would permeate the universe.
 In 1965 this radiation was discovered
 In 2003 astronomers studying the CBR
determined the universe is 13.7 billion
years old
Incandescence: glowing from heat
Blue = hottest
Red=coolest
Nebula
A cloud of space dust or gas.
Nebular Hypothesis
A. nebula
B. accretion disk
C. cooling
A.
cloud of mostly hydrogen & helium
B.
Started rotating & collapsing toward
center because of gravity forming an
accretion disk , also the Sun forms
C.
rocky & metallic materials form as
nebula cools
D.
collisions of particles created asteroidsized objects (protoplanets or
planetesmals)
D. protoplanets
Sun = most dense object, nuclear fusion
Rock / Terrestrial planets = more
E. dense, heavy material, closer orbit
E. solar system
Gas / Jovian planets = least dense,
lighter material, farther orbit
Earth’s Motions
• Rotation
 spinning of Earth
from west to east
on an axis
 results in day / night
 Earth makes one
rotation in 24
hours
•Revolution
 Earth moves
around the sun
every 365¼ days
Earth’s Motions
•Precession
 The change in
direction of the
northern axis
 North star is different
• Nutation
 Slight wobble, or
change, in Earth’s axis
from 23.5°
 Very slow movement
due to the gravity of
the moon
Earth’s Motions
Winter – closest to the sun
Summer – farthest from the sun
Lunar Eclipses
 Occurs during full moon phases
 Do not see the moon because the Earth blocks light
 Sun, Earth, moon in a line
Solar Eclipses
 Occurs when sun is blocked by the moon
 Sun, moon, Earth
 If the moon is partially blocking the sun, a partial
solar eclipse will occur
Equatorial Bulge
 The Earth is not
completely round
 There is a bulge at the
equator because of
rotation
Video Link
Kepler’s Laws
 1st Law:
 orbital paths are ellipses (ovals)
 Sun is at one focal point
Animation of Laws
Kepler’s Laws
 2nd Law:
 a planet sweeps out equal areas in
equal times
Kepler’s Laws
 3rd Law:
 T 2 = d3
 T= time of orbit
 d = distance (avg) from the sun
Barycenter
 The point between two
objects where they
balance each other
 The actual center of
our solar system
 The sun orbits around
this point
Barycenter Video
Music :)
Energy
Nuclear Fusion
Nuclear Fission
 The fusion of two atoms to
 The splitting of an atom to
create energy
 Happens within stars
create energy
 Produced in nuclear
reactors
Cosmic Speed Limit
Speed of light = 300,000 km/s
Light-year = the distance light travels in one year
(9,500,000,000,000 km)
The 2nd nearest star is 4.3 light years away
(Alpha Centauri = triple-star system)