What did the Principle of Occam's Razor state
In explaining natural phenomena, the simplest explanation consistent with the observations is to be preferred
What is not an advantage of the Hubble Space Telescope over ground-based
It is closer to the stars.
The sun's surface, as we see it with our eyes, is called?
Photosphere
Why are different stars seen in different seasons?
As Earth orbits the Sun, we see the sun in front of different constellations
Where was most of the material that makes up Earth and all life on Earth, including humans, forme?:
Inside stars that died before earth formed
What is the solar wind?
A stream of charged particles flowing outward from the surface of the sun
Light Pollution is?
is light from human sources that makes it difficult to see the other stars at night.
Why do stars twinkle?
Because of turbulence in the Earth's atmosphere
What is the sun's core temp?
15 million K
What is closest to a neutron star (size)?
a city
Why are different stars seen in different seasons?
as earth orbits the sun, we see the sun in front of different constellations
Why is the North Star, Polaris, special?
Appears very near the north celestial pole
Why do stars twinkle and jitter?
Turbulence in the Earth's atmosphere
Why are sunsets red?
More light at red wavelengths, than bluer.
Where is the Solar System located within the Milky Way Galaxy?
Roughly halfway between the center and edge of the visible disk of the galaxy
By what process does the sun generate energy?
Nuclear Fusion
What is the purpose of adaptive optics?
It reduces blurring caused by atmospheric turbulence for telescopes on the ground
When will the sun will exhaust its nuclear fuel?
5 billion years
Where does nuclear fusion occur in the sun?
in its core
What planet has the most substantial atmosphere?
Venus
What is a broad idea that has been repeatedly verified so as to give scientists great confidence that it represents reality?
Theory
What is closest to the sun's core temperature?
10 million K
What is the distance to the Alpha Centauri (the star nearest to the sun)?
About 4.5 light-years
What makes up the interstellar medium?
Gas and dust
What is the observable universe?
Everything out to a distance of 14 billion light-years from Earth
What is the diameter of the milky way?
100,000 light-years
About how hold is the Earth?
5 billion years
In a scale model solar system that used a grapefruit to represent the Sun, how far away should you put another grapefruit to represent Alpha Centauri, the nearst star?
2500 miles
On the scale of the cosmic calender, in which history of the Universe is compressed to 1 year, how long has human civilization existed?
a few seconds
Roughly how many exoplanets have been discovered and confirmed?
3900
If you could count the stars in the Milky Way Galaxy at a rate of one star per second, to count them all would take?
about 3000 years.
Our textbook discusses the cosmic calendar, a model of the history to a single year. The length of time represented by one month on this..Therefore?
About one billion years.
In a scale model solar system that used a grapefruit to represent the Sun, what would Earth be?
50 feet.
The first planets around other stars (exoplanets) were discovered when?
About 20 years ago.
What is the diameter of the Universe?
We do not know
Is NASA planning to launch a spacecraft that will leave for the Milky Way Galaxy to take a photograph of the galaxy from the outside?
No, not even a spacecraft that moved close to the speed of light would take thousands of years to get to a good vantage point
By studying distant galaxies in the 1920s, What did Hubble discovery that led us to conclude that the universe is expanding?
All galaxies outside the Local Group are moving away from us, and that they are, the faster they're going.
What is the correct order, starting from small to largest?
Planet, star, solar system, galaxy
When did the Big Bang occur?
About 14 billion years ago.
Why is Enceladus considered good candidates for the possible existence of life?
Strong evidence suggests that it has a deep, subsurface ocean of liquid water.
When we look at an object that is 1000 light-years away we see it______?
As it was 1,000 years ago.
What is the highest Mt.?
Mt. Everest.
What is the Tallest Mt.?
Mauna Kea
What mountain is closest to the sars?
Mt. Chimborazo
What are the 3 necessities for life?
Nutrient Source, Energy, Liquid Water
When did the earliest life form exist?
3.85 billion years ago
What evidence do we have of the earliest life forms?
Fossils and carbon isotopes.
What does life evolve through?
Time
What does Darwin's theory on Evolution tells how it occurs?
Through Natural selection
What happens during the DNA process?
Mutation
What does the earliest life on Earth resemble?
Bacteria near deep ocean volcanic vents.
What is the Miller-Urey Experiment?
Building blocks of life form easily and spontaneously under conditions of early Earth.
When did mars have liquid water?
Distant past.
Where does mars have lots of water?
Polar ice caps.
What is Saturn's moon?
Enceladus
What kind of signals is SETI looking for?
Deliberate
What are the three things of Fermi's Paradox
We are alone, Civilizations are common but interstellar travel is not, and interstellar travel is harder than we think
What is dark matter?
Undetected form of mass that emits little or no light but whose existence we infer from its gravitational influence.
What is dark energy?
Unknown from of energy that seems to be the source of a repulsive force causing the expansion of the universe to accelerate
What is the content of normal matter?
5%
What is the content of normal matter inside of stars?
0.7%
What is the content of normal matter outside of stars?
3.9%
What is the content of dark matter?
23%
What is the content of dark energy?
72%
What is a spiral galaxy?
Tend to have orbital velocities that remain constant at large radii, indication of large amounts of dark matter.
What evidence do we have for dark matter in clusters of galaxies?
Mass from galaxy motion in a cluster is about 50 times larger than the mass in stars, Clusters contain large amounts of x-ray emitting hot gas, and gravitational lensing.
What are the two basic options for dark matter?
Ordinary Matter (MACHOs) and Exotic Particles (WIMPS)
What is the fate of the Universe?
Eternal Expansion
What does the brightness of distant white dwarf supernovae tell us?
Much of the universe has expanded since they exploded.
Why does the sun shine?
Luminosity