astro 101 final ALREADY PASSED
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
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
