Unit 1 Astro
The Big Bang evidence
-redshift of galaxies -abundance of elements (Hydrogen & Helium) -cosmic background radiation (heat left over)
Milky Way Galaxy size
100,000 light years
How long a message across Milky Way would take
100,000 years
Age of the Universe
13.7 billion years old (or about 14 billion)
Our solar system age
4.6 billion years old
The purpose of a control group in an experiment is to provide:
A basis for comparison.
Ptolemy supported a model of the Universe that puts the ...
Earth at the center of the universe.
How did we get heavy elements on Earth?
Heavy elements are formed by nuclear fusion reactions and supernovae in massive, ancient stars. Eventually gravity brings this stuff together and created our solar system.
Step 3: Nebular Hypthesis
Nuclear fusion begins and star is born; heavier elements stay closer to star while lighter ones are flung further out in the accretion disk
Step 2: Nebular Hypothesis
Protosun begins to spin and glows; accretion disk forms
The Copernican model of the universe puts the ...
Sun at the center of the universe.
protosun
a large mass that forms by contraction out of the gas of a nebula that will become the star
Radius of solar system
about 2 light-years
almost all galaxies
are redshifted
light spectra
are the specific wavelengths of light that any given element or compound give off; ex: Hydrogen shows only four lines while sunlight gives off a full rainbow.
red shifted stars are moving
away from Earth
supernova
death of a star; a star that explodes spreading elements across the Universe and becomes extremely luminous in the process; Fuses iron and other elements into larger elements;
nebula
extremely large cloud of gas and dust out in space that stars form from
Step 5: Nebular Hypothesis
fully formed solar system
nuclear fusion
fusing of atomic particles or elements to form larger elements
According to the Big Bang Theory, the Universe is expanding. What supports this?
galaxies are still moving away from each other today (redshift of galaxies)
accretion disk
gases and dust rotating around a star or protostar in a primitive solar system that planets eventually form from
Heavier elements than iron (like gold, lead, silver, copper, uranium) are created
in supernovae
a light-year
is the distance light travels in one year
If a galaxy is redshifted
it is moving away from our galaxy
Why does Mars not have life?
its atmosphere is too thin to hold on to heat and it has very little liquid water on the surface
Red colors have
long wavelengths
The elements on Earth
made up of star dust
star
mass of incandensent gas; a gigantic nuclear furnace where hydrogen is fused into helium at temperatures of millions of degrees
Nebular hypothesis evidence
observations of new stars how solar systems form (rocky inner/gaseous outer) rotation of planets asteroids all in same direction age of rocks and meteorites all same age
Step 4: Nebular Hypothesis
planets begin to form out of the accretion disk
Evidence for the age of the solar system
radioactive dating of Earth rocks and meteorites
Blue colors have
shorter wavelengths
The moons of Jupiter...
showed that not everything has to orbit the Earth.
A supermassive star will die in an explosion called?
supernova
Planets form out of
the accretion disk
When light waves are shifted (either red shift or blue shift)
the color of that light changes
The more massive a star...
the higher the temperature and pressure and heavier elements are produced
Step 1: Nebular Hypothesis
the nebula collapses
When a spectra's wavelengths are shifted a lot it means
the object is moving really fast
Why does Earth support life?
Magnetic field shields from solar winds and CMEs Atmosphere holds in heat Atmosphere ozone layer absorbs UV radiation Is located in the Habitable Zone Has liquid water on surface for biological functions
Copernicus and Galileo believed Earth orbited the sun. Their ideas were not accepted at the time because...
Their claims contradicted the most popular ideas at that time.
An explosive expansion from a tiny point
The beginning of the Universe -Big Bang Theory
Habitable zone (Goldilocks zone)
The distance from a star where temperatures are just right to allow liquid water on the surface of a planet. Earth and Mars both lie in this zone in our solar system;
redshift
The stretching of wavelengths toward longer wavelengths due to movement away from observer.
Controls
Used to keep a test with a little of variables possible; Controls between tests would be like keeping things at the same temperature or same amount of water
All electromagnetic radiation travels at
the speed of light (3.0 x 10^8 m/s)
Blue shift
the squishing of wavelengths to shorter wavelengths due to movement toward an observer; in visible light this causes the light to be more "blue"
Redshifted galaxies tell us that
the universe is still expanding today
Our eyes only detect which portion of the electromagnetic spectrum?
visible light
Types of electromagnetic spectrum
visible light radio waves microwaves x-rays gamma rays ultraviolet (UV) rays infrared
During the formation of the sun, gases
were thrown out farther than dust (rock material) because it had less mass.