Formation of the Universe - Student Notes
__________________________
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- groups of stars, dust, and gases held together by gravity.
The universe has hundreds of billions of galaxies
Galaxies are grouped in galactic clusters
Our galactic cluster is called the _____________________ Group and contains at least 28 galaxies
Our Galaxy
______________ _________
components.
1.
2.
3.
- our spiral galaxy consisting of over 400 billion stars, plus gas and dust arranged into three general
________________________ - a roughly spherical distribution which contains the oldest stars in the Galaxy.
Nuclear bulge and Galactic Center
______________________________-, which contains the majority of the stars, including the sun, and virtually all of the gas
and dust .
Our Solar System
But how did this all get here? The Beginning:
The Big Bang TheoryInitially, the entire universe was confined to a _______, ______, ______________ ______
About 13.7 billion years ago, a violent ________________ may have occurred, hurling this material in all directions.
_______________ and _________________ continues today
**This marks the beginning of the universe**
First stars and galaxies formed ____ ________________ years after big bang.
Solar system formed 4.6 billion years ago from a ________________________________________, according to the nebular theory.
Background for Big Bang
Most information about the universe comes from the ____________________________.
Electromagnetic radiation- different types of energy including ____________, _______________, ____________,
______________, _________________, __________________, and _________________________.
The narrow band of electromagnetic radiation we can see is ________________
___________________.
Electromagnetic Spectrum
Visible Light
________________ has shortest wavelength
________________ has longest wavelength
Red light has the longest wavelength which means that the object is moving _______ ______ _____ ____________.
Violet/blue light has the shortest wavelength which means that the object is moving ____________ _____ ___________.
Violet light has the ____________ energy (gamma rays) and red light has the __________ energy (radio waves)
The Big Bang Theory Evidence
Cosmic Background Radiation moves ___ _________ ___ our universe and is one piece of evidence supporting this theory
When viewing the sky with a radio telescope, the sky is not black, but has a faint glow (this is CBR)
Cosmic Background Radiation
The color differences are _______________________________________.
Evidence for the Big Bang Theory
___________ ______________- change in wavelength of a wave that is emitted from a source moving away or toward an object
Occurs for both ______________ and _______________ waves.
Astronomers are only concerned with the changes of light wavelengths, not sound.
It tells us whether an object is moving ________________ or ____________ from Earth
Large Doppler shifts indicate ______________speeds
Evidence for the Big Bang Theory
If the source moves _________________, the wave becomes stretched (longer wavelength)
If the source moves ________________ _______, the waves get closer (shorter wavelength)
The light from sources moving away appears _________
The light from sources moving closer appears _________
So…when an object moves towards Earth, the wavelength will be shortened and the color will be _________________________ and
when it moves away, the wavelength will get longer and the color will be _______.
Red Shift
“Red Shift” means that an object in space in moving __________________ from Earth
The Red Shift of distant galaxies tell us that the ____________________ ____ __________________________.
Greater red shifts in the color spectrum of distant galaxies indicate __________________ speeds.
Edwin Hubble- 1920s astronomer
Observed the light from distant galaxies and he noticed something amazing.
He saw that the light from these galaxy clusters was ____________________, which meant that they were all moving
______________________ from us.
The galaxy clusters that were farther away from us were moving at a _______________ rate, the farther they were away.
The universe seemed to be _______________________!
Hubble’s Law
According to this law, galaxies are moving _________ at a speed that is _____________________- to their distance.