Astro 101 final Questions And Answers 100% Pass
hypothesis - ✔✔✔-possible explanation
-a collection of ideas that seem to explain what is observed
-must always agree with existing observations and experiments (b/c difference with what is observed implies that the hypothesis is wrong)
theory - ✔✔✔-has been tested
-successful MANY times
-cannot ever be proven correct, BUT cannot be proven incorrect
-a body of related hypotheses pieced together into a self-consistent description of nature
ex. theory that planets are held in the their orbits around the sun by the sun's gravitational force
model - ✔✔✔-successful hypothesis
-has made correct predications
-hypotheses that have withstood observational and experimental tests
-tells us about properties and behaviors of some object or phenomenon
ex. model of an atom- electrons orbiting a central nucleus
-uses mathematics to make detailed predictions
good theories do what? - ✔✔✔-explain reality well
-can be used to explain new observations
important part of scientific theory? - ✔✔✔ability to make predictions that can be tested by other scientists
-an idea that cannot be tested by observation or experiment does not qualify as a scientific theory
units - ✔✔✔SI units/ MKS (meters, grams, seconds) units
AU
1 Astronomical unit (AU) - ✔✔✔distance from earth to the sun
light year - ✔✔✔distance light travels in a year
speed of light= C=3 x 10^8m/s
-we can see the earth from billions of years ago b/c thats how long it takes for it to get back to the earth
constellations - ✔✔✔-a group of bright stars
-not all the same distance from earth
,why are constellations not scientifically useful? - ✔✔✔because their only relationship is that their in the same direction in the sky- their not related
scientific method - ✔✔✔-approach used by scientists to explore physical reality differs from other forms of intellectual endeavor that is based on observation, logic
and skepticism
skepticism - ✔✔✔-the more radical the hypothesis, the more skepticism and critical evaluation it will receive
-extraordinary claims require extraordinary evidence
-why UFO claims aren't accepted- flawed evidence
describe space- big to small - ✔✔✔-universe (everything)
-clusters of galaxies
-galaxies (group of stars)
-stars
-planets
-moon/satellites
what makes our solar system? - ✔✔✔stars, planets, moons
planets in order - ✔✔✔-mercury
-mars
-earth
-venus
-jupiter
-saturn
-uranus
-neptune
steps of the scientific method - ✔✔✔-observation/data
-formulate question
-hypothesis
-prediction only
-test prediction- get dada
-repeat
why do the sun and moon move in a diurnal motion? - ✔✔✔due to the earth rotation
forms of light invisible to the human eye - ✔✔✔x rays, gamma rays, radio waves, microwaves, and ultra violet and infrared radiation
,meteorites - ✔✔✔-oldest objects found on earth
-bits of interplanetary debris that fall onto our surface
-have allowed us to see that our entire solar system is 4.56 billion years old
what is the nearest star to earth? - ✔✔✔the sun
how does the sun shine? - ✔✔✔-center of the sun is thermonuclear reactions (converting H to He at high tempts)
- releases a ton of energy, makes its way to the suns surface and escapes as light
-same way all stars shine at night
why can't all stars last forever? - ✔✔✔thermonuclear reactions- the way they shine- consumes material of which stars are made
nebulae - ✔✔✔huge clouds of interstellar gas found across the sky
ex. the orion nebula - stars are born from the material of the nebula itself
supernova - ✔✔✔star ends its life by blowing itself apart
where do we get carbon from? - ✔✔✔when stars die, they release gas into interstellar space- this gas has heavy elements like carbon
-intersteller space builds up all these heavy elements/gases
-sun and planets were formed from the interstellar material
- heavy elements like iron, nickel, carbon- make up earth, us and everything else
galaxies - ✔✔✔group of stars
quasars - ✔✔✔most distant and bright objects in the sky
-shines as bright as a hundred galaxies
-draw their energy from material falling into black holes
motion of distant galaxies explains what? - ✔✔✔the universe is expanding
-will continue and is expanding faster
angular measure - ✔✔✔size of an angle exactly
why do astronomers use angular measure? - ✔✔✔they use it to describe the apparent size of a celestial object- how wide it appears on the sky
why is the power-of-ten notation useful? - ✔✔✔-short hand system for writing numbers (for very large and very small numbers)
-more convenient
, who is AU unit convenient to use? - ✔✔✔for measuring large distances between planets and even larger distances between stars
advantage to using light year as a unit of distance - ✔✔✔-measures things very far from us
-measuring stars we can see how long it would take to get back to us in terms of distance
diurnal (daily) motion - ✔✔✔-daily motion of stars moving across the sky
-sun and moon too
diurnal motion of constellations - ✔✔✔-entire pattern of stars shift positions daily - you won't see the same constellations in the same place every day
-only after a year will the night sky appear the same as it did a year before
why does the sky go through diurnal motion? - ✔✔✔earth rotates from west to east, making one complete rotation every 24 hours- its why we have a daily cycle of
day and night
why do stars appear to rise in the east and set in the west? - ✔✔✔earth's rotation- 1 rotation every 24 hours
why do constellations visible at night change throughout the year? - ✔✔✔b/c earth orbits around the sun completely in a year
-night time side of earth turns towards different parts of space
celestial sphere - ✔✔✔-an imaginary sphere that rotates all the stars around the earth (everything in the universe moving around us)
-idea that this sphere rotated around the earth once a day from east to west- causing the diurnal motion of the sky
-not correct
celestial poles - ✔✔✔north/south poles- same position as on earth
-where earths axis of rotation (extended into space) intersects the celestial sphere
-north pole is always above the horizon
why is the celestial sphere a useful tool? - ✔✔✔easy to specify directions of objects in the sky and see the motion of them
celestial equator - ✔✔✔earth's equator projected into space- same position as equator on earth
-divides the sky into northern and southern hemispheres
-no circumpolar stars at the equator
zenith - ✔✔✔point directly above your head- straight overhead
horizon - ✔✔✔straight out in all directions
hypothesis - ✔✔✔-possible explanation
-a collection of ideas that seem to explain what is observed
-must always agree with existing observations and experiments (b/c difference with what is observed implies that the hypothesis is wrong)
theory - ✔✔✔-has been tested
-successful MANY times
-cannot ever be proven correct, BUT cannot be proven incorrect
-a body of related hypotheses pieced together into a self-consistent description of nature
ex. theory that planets are held in the their orbits around the sun by the sun's gravitational force
model - ✔✔✔-successful hypothesis
-has made correct predications
-hypotheses that have withstood observational and experimental tests
-tells us about properties and behaviors of some object or phenomenon
ex. model of an atom- electrons orbiting a central nucleus
-uses mathematics to make detailed predictions
good theories do what? - ✔✔✔-explain reality well
-can be used to explain new observations
important part of scientific theory? - ✔✔✔ability to make predictions that can be tested by other scientists
-an idea that cannot be tested by observation or experiment does not qualify as a scientific theory
units - ✔✔✔SI units/ MKS (meters, grams, seconds) units
AU
1 Astronomical unit (AU) - ✔✔✔distance from earth to the sun
light year - ✔✔✔distance light travels in a year
speed of light= C=3 x 10^8m/s
-we can see the earth from billions of years ago b/c thats how long it takes for it to get back to the earth
constellations - ✔✔✔-a group of bright stars
-not all the same distance from earth
,why are constellations not scientifically useful? - ✔✔✔because their only relationship is that their in the same direction in the sky- their not related
scientific method - ✔✔✔-approach used by scientists to explore physical reality differs from other forms of intellectual endeavor that is based on observation, logic
and skepticism
skepticism - ✔✔✔-the more radical the hypothesis, the more skepticism and critical evaluation it will receive
-extraordinary claims require extraordinary evidence
-why UFO claims aren't accepted- flawed evidence
describe space- big to small - ✔✔✔-universe (everything)
-clusters of galaxies
-galaxies (group of stars)
-stars
-planets
-moon/satellites
what makes our solar system? - ✔✔✔stars, planets, moons
planets in order - ✔✔✔-mercury
-mars
-earth
-venus
-jupiter
-saturn
-uranus
-neptune
steps of the scientific method - ✔✔✔-observation/data
-formulate question
-hypothesis
-prediction only
-test prediction- get dada
-repeat
why do the sun and moon move in a diurnal motion? - ✔✔✔due to the earth rotation
forms of light invisible to the human eye - ✔✔✔x rays, gamma rays, radio waves, microwaves, and ultra violet and infrared radiation
,meteorites - ✔✔✔-oldest objects found on earth
-bits of interplanetary debris that fall onto our surface
-have allowed us to see that our entire solar system is 4.56 billion years old
what is the nearest star to earth? - ✔✔✔the sun
how does the sun shine? - ✔✔✔-center of the sun is thermonuclear reactions (converting H to He at high tempts)
- releases a ton of energy, makes its way to the suns surface and escapes as light
-same way all stars shine at night
why can't all stars last forever? - ✔✔✔thermonuclear reactions- the way they shine- consumes material of which stars are made
nebulae - ✔✔✔huge clouds of interstellar gas found across the sky
ex. the orion nebula - stars are born from the material of the nebula itself
supernova - ✔✔✔star ends its life by blowing itself apart
where do we get carbon from? - ✔✔✔when stars die, they release gas into interstellar space- this gas has heavy elements like carbon
-intersteller space builds up all these heavy elements/gases
-sun and planets were formed from the interstellar material
- heavy elements like iron, nickel, carbon- make up earth, us and everything else
galaxies - ✔✔✔group of stars
quasars - ✔✔✔most distant and bright objects in the sky
-shines as bright as a hundred galaxies
-draw their energy from material falling into black holes
motion of distant galaxies explains what? - ✔✔✔the universe is expanding
-will continue and is expanding faster
angular measure - ✔✔✔size of an angle exactly
why do astronomers use angular measure? - ✔✔✔they use it to describe the apparent size of a celestial object- how wide it appears on the sky
why is the power-of-ten notation useful? - ✔✔✔-short hand system for writing numbers (for very large and very small numbers)
-more convenient
, who is AU unit convenient to use? - ✔✔✔for measuring large distances between planets and even larger distances between stars
advantage to using light year as a unit of distance - ✔✔✔-measures things very far from us
-measuring stars we can see how long it would take to get back to us in terms of distance
diurnal (daily) motion - ✔✔✔-daily motion of stars moving across the sky
-sun and moon too
diurnal motion of constellations - ✔✔✔-entire pattern of stars shift positions daily - you won't see the same constellations in the same place every day
-only after a year will the night sky appear the same as it did a year before
why does the sky go through diurnal motion? - ✔✔✔earth rotates from west to east, making one complete rotation every 24 hours- its why we have a daily cycle of
day and night
why do stars appear to rise in the east and set in the west? - ✔✔✔earth's rotation- 1 rotation every 24 hours
why do constellations visible at night change throughout the year? - ✔✔✔b/c earth orbits around the sun completely in a year
-night time side of earth turns towards different parts of space
celestial sphere - ✔✔✔-an imaginary sphere that rotates all the stars around the earth (everything in the universe moving around us)
-idea that this sphere rotated around the earth once a day from east to west- causing the diurnal motion of the sky
-not correct
celestial poles - ✔✔✔north/south poles- same position as on earth
-where earths axis of rotation (extended into space) intersects the celestial sphere
-north pole is always above the horizon
why is the celestial sphere a useful tool? - ✔✔✔easy to specify directions of objects in the sky and see the motion of them
celestial equator - ✔✔✔earth's equator projected into space- same position as equator on earth
-divides the sky into northern and southern hemispheres
-no circumpolar stars at the equator
zenith - ✔✔✔point directly above your head- straight overhead
horizon - ✔✔✔straight out in all directions
