Download Slide 1

Beyond our Solar System
There are probably more than
170 billion (1.7 × 1011) galaxies in
the observable universe. Most
galaxies are 1,000 to
100,000 parsecs in diameter and
are usually separated by distances
on the order of millions of parsecs
(or megaparsecs).
Elliptical Galaxies
• 80% of galaxies are elliptical in shape
• X-ray technology has discovered black
holes and neutron stars in some elliptical
galaxies.
• Elliptical galaxies can be up to 2 trillion
light years across and can contain up to
10 trillion stars
Spiral Galaxy
Artist rendition of Milky Way
Barred Spiral Galaxy
• Consist of curved arms radiating from a
central, dense bulge
• Milky Way (our galaxy) is a spiral galaxy
• Our solar system lies on one arm (Orion
Arm)
Milky Way Galaxy
• Consists of over 200 billion stars
• 16,000 light years thick (central bulge)
• 100,000 light years across (long end to
end)
• The arm that our solar system is in (Orion
Arm) is about 30,000 light years long
Irregular Galaxy
• No true shape (irregular masses)
• Generally faint in luminosity
• Smaller and less massive than spiral
galaxies
Origin of the Universe
Singularity
According to the standard theory, our
universe sprang into existence as
"singularity" around 13.7 billion years ago.
Our universe is thought to have begun as an
infinitesimally small, infinitely hot, infinitely
dense, something - a singularity.
Big Bang Theory
There are many misconceptions surrounding
the Big Bang theory. For example, we tend
to imagine a giant explosion. Experts
however say that there was no explosion;
there was (and continues to be) an
expansion. Rather than imagining a
balloon popping and releasing its contents,
imagine a balloon expanding: an
infinitesimally small balloon expanding to
the size of our current universe.
Electromagnetic Spectrum
Visible Light
• Represents a fraction of the different forms
of energy on the electromagnetic
spectrum.
• The different wavelengths of visible light
are different colors:
–
–
–
–
–
–
–
Red = longest wavelength
Orange
Yellow
Green
Blue
Indigo
Violet = shortest wavelength
Emission Spectrum
• Series of unevenly spaced lines of
different colors and bright nesses.
• These lines are arranged in the ROY G
BIV sequence.
• Each gas has its own unique emission
spectrum (fingerprint).
Absorption Spectrum
• A continuous spectrum with dark lines
ommitted from it.
• Occurs when energy travels from a hotter
object (sun’s interior) through a cooler gas
(sun’s out layers).
Absorption and Emission
Spectrums
Doppler Effect
-- a perceived change in the frequency of a wave
as the distance between the source and the
observer changes.
http://www.seed.slb.com/labcontent.aspx?id=11082&terms=doppler
Fire Truck Sound.wav
The Big Bang and Expanding
Universe
#1. The diagram below illustrates three stages of a current theory of the
formation of the universe.
A major piece of scientific evidence supporting this theory is the fact
that wavelengths of light from galaxies moving away from Earth in
stage 3 are observed to be
1. shorter than
normal (a red shift)
2. shorter than
normal (a blue shift)
3. longer than
normal (a red shift)
4. longer than
normal (a blue shift)
#2. Which form of electromagnetic
radiation has a longer wavelength
than Microwaves?
(1) ultraviolet
(2) infrared
(3) radio waves
(4) microwaves
#3. Which form of electromagnetic
radiation has a wavelength of
1.0 × 10–3 centimeter?
(1) ultraviolet
(2) infrared
(3) radio waves
(4) microwaves
#4. At which location will the
highest altitude of the star Polaris
be observed?
1. Equator
2. Tropic of Cancer
3. Arctic Circle
4. central New York State
#5. Which star is cooler and many
times brighter than Earth’s Sun?
1) Barnard’s Star
2) Betelgeuse
3) Rigel
4) Sirius