McGruder Final Study guide
What is the basic structural unit of a substance that is not an element?
a molecule
The Big Bang
where the universe started
What is a Star?
-celestial= in the sky -hot -bright= luminous, produce its own light -ball→spherical -gaseous
(1826) Olber
-first application of physical law -calculated brightness of the night sky -the universe is infinite -the universe is infinitely old -the night time should be as bright as the day time based on calculations
(1915) Albert Einstein
-general theory of relativity (involving gravity) -Einstein's theory of gravitation
Apparent differences between the sun and stars
-the size -brighter -hotter -it appears to be different because it is closer
How many galaxies are there in the universe?
1.5X10^11
Average number of stars in the galaxy
10^10
size of the universe (radius)
13.8 billion light years
What is the number of stars in the universe?
15X10^20=1.5X10^21
Distance of Alpha Centauri from the sun
4.4X10^18
how far away is the moon?
400,000km
How many different stars can the naked eye see?(from earth's surface)
6000 different stars
distance of the sun from the earth?
93,000,000 miles
How does Scientific Notation work?
>When you multiply you add exponents (10000= 10^4) >When you divide you subtract exponents (0.0001=10^-4)
how are galaxies moving?
Galaxies are moving away from each other, expansion of the universe, Edwin Hubble
Celestial
Latin word for heavenly
3 Steps of The Scientific Method
Observation/Experiment Formation of theory/hypothesis to explain the observation/experiment Prediction of results from observation/experiment and checking to see if the prediction is correct
What is the nature of planetary light? (light from the planets)
Reflected sunlight, planets do not produce their own light. same for the moon
what do galaxies consist of? (normal matter)
Stars Gas Dust
order of clusters
Super Clusters → Galaxy Cluster→ Galaxies
What is the difference between the stars and the sun?
There is no difference, the stars are suns or the sun is a star
What is the difference between an Astronomer and a Astrophysicists?
There is really no difference, astrophysicists are more theoretical while astronomers are more observant
2 major characteristics of the universe
Vastness Emptiness
How do we know the temperature of the sun's surface?
We know this by the different elements seen on the sun
Cosmology
a branch of astronomy that concerns the universe as a whole
what is the difference between science and a scientist?
a scientist is restricted to only certain aspects of reality
Astronomer
a scientist who studies celestial bodies and the universe as a whole
What is the basic structural unit of a substance that is an element?
an atom
How many stars can you expect to see in a clear sky? (from where you are standing)
at any instant you should see 3000 stars because the horizon splits in half but you can really only see 2000 because the earth is surrounded by an atmosphere
what did the universe consist of at the time of the big bang?
at the time of the big bang the universe consisted of pure energy (light radiation, etc)
Alpha Centauri
closest star to earth other than the sun
Local Group
cluster that milky way belongs to
Super Clusters
clusters of galaxies forming an arch
Voids
completely empty space
What is the universe made of?
dark matter dark energy normal matter
Fred Hoyle
did not believe in the big bang called it the big orgasm
Clusters
galaxies come in families called clusters. The milky way is included in this family
What is the name of the unit (basic structural unit) of the universe?
galaxy
Aristotle
moon is the closest celestial body to earth
what do scientist do?
seek to understand certain aspects of reality
What does science do?
seeks to understand the universe and everything in it. seeks to understand reality
Astrology
seudo science; fake science; the formation of the stars determines human personality events and catastrophic events
(1905) Albert Einstein
special theory of relativity
why is there a restriction there for scientists?
there is so much out there that its impossible for a scientist to know everything so they restrict themselves to certain areas
Astronomy
the branch of science that deals with celestial objects, space and the physical universe as a whole
Which is greater, the suns surface or core?
the core of the sun is greater than the sun's surface in temperature (15,000,000 degrees)
Light Year
the distance that light travels in a year
Lunar Occulation
the moon
Nebula Hypothesis
the origin of the solar system (nebula in english means cloud)
after Darwin proved evolution who introduced it to astronomy?
the person who introduced evolution in astronomy was Immanuel Kant, nebula hypothesis
what must you use to be classified as a scientist?
the scientific method, their approach to science
What astronomical bodies does the naked eye see on a daily bases?
the sun the moon the earth the stars
What is the temperature of the earth's core?
the temperature of the earth's core is 6000 degrees
What is the temperature of the sun?
the temperature of the sun (surface) is 6000 degrees
how many professional astronomers are there?
there are 6000 astronomers
how do we know that dark matter and dark energy exists?
we cannot see dark matter or dark energy we only know it exists because of its gravitational effect/behavior
Occultation
when one celestial body moves in front of another.
Solar Eclipse
when the moon moves in front of the sun and you can see all of the stars
do galaxies possess ordered motion?
yes