AY 101 002 CH 1 HW
if stars existed but galaxies did not:
we would not exist because we are made of material that required recycling in galaxies
3.5 x 10 ^0
3.5
the fact that nearly all galaxies are moving away from us, with more distant ones moving faster, helped us to conclude that:
the universe is expanding
rank the following items according to their size (diameter) from left to right, from largest to smallest : the milky way galaxy, our solar system, the sun, the local group, the universe, jupiter, earth, the local supercluster
the universe, the local supercluster, the local group, the milky way galaxy, our solar system, the sun, jupiter, earth
based on what you've learned from the raisin cake analogy, which two properties of distant galaxies do astronomers have to measure to show that we live in an expanding universe?
their distances and speeds
which of the following are real motions of our 'spaceship earth'?
- earth moves with the sun on an orbit around the center of the milky way galaxy - earth orbits the sun - earth and our solar system moves with the milky way galaxy relative to other galaxies in our local group
everyday observation statements
- james is wearing a yellow shirt - the defendant's DNA was found at the crime scene - the plastic melted when i held it near the light bulb - the defendant's calendar says he was at lunch when the crime occurred
everyday explanation statements
- james wears a yellow shirt when his other shirts are dirty - the defendant only intended to scare the victim - plastic melts when it reaches a temperature that breaks bonds that hold its structure intact
the following statements describe ways in which the analogy might apply to the real universe. which statements are correct?
- the average distance increases with time both between raisins in the cake and between galaxies in the universe. - the raisins stay roughly the same size as the cake expands, just as galaxies stay roughly the same size as the universe expands - an observer at any raisin sees more distant raisins moving away faster, just as an observer in any galaxy sees more distant galaxies moving away faster
rank the following items that describe distances from longest distances to shortest distance : the distance from the milky way galaxy to the andromeda galaxy, one light-year, the distance across our solar system (to neptune), the distance from earth to alpha centauri, the distance from the sun to the center of the milky way galaxy, the average distance from earth to the sun, one astronomical unit (AU)
- the distance from the milky way galaxy to the andromeda galaxy - the distance from the sun to the center of the milky way galaxy - the distance from earth to alpha centauri - one-light year - the distance across our solar system (to neptune) - the average distance from earth to the sun and one astronomical unit (AU)
consider the indicated events in the history of the universe that have helped make human life possible. rank the events based on when they occurred, from longest ago to most recent. to rank items are equivalent, overlap them.
- the universe begins to expand and the big bang - elements such as carbon and oxygen first exist - nuclear fusion begins in the sun - earliest life on earth - dinosaurs go extinct - earliest humans
(10 ^2 x 10 ^3) ^-2 =
0.0000000001
10 ^-4
0.0001
3.5 x 10^-4
0.00035
10 ^ -3
0.001
10 ^-2
0.01
3.5 x 10 ^-2
0.035
10 ^-1
0.1
3.5 x 10 ^-1
0.35
10 ^0
1
1 light-day in miles; express your answer using two significant figures
1 light - day = 1.6 x 10 ^10 mi
1 light-day in kilometers; express your answer using two significant figures
1 light - day = 2.6 x 10 ^10 km
1 light-hour in miles; express your answer using two significant figures
1 light - hour = 6.7 x 10 ^8 mi
1 light-minute in miles; express your answer using two significant figures
1 light - minute = 1.1 x 10 ^7 mi
1 light-minute in kilometers; express your answer using two significant figures
1 light - minute = 1.8 x 10 ^7 km
1 light-second in miles; express your answer using two significant figures
1 light - second = 1.9 x 10 ^5 mi
1 light-second in kilometers; express your answer using two significant figures
1 light - second = 3.0 x 10 ^5 km
1 light-hour in kilometers; express your answer using two significant figures
1 ligt - hour = 1.1 x 10 ^9 km
if you wanted to show the distance between earth and moon on the same scale, about how far apart would you need to place the two photos above?
1 meter (about the length of your arm)
10 ^10 is ________________ 10 ^1
1,000,000,000 times as large as
the speed of light is 3 x 10 ^8 meters per second, which means that light can travel 300 million meters in just one second. how far can light travel in one minute?
1.8 x 10 ^10
10 ^-2 is ________________ 10 ^-1
1/10 as large as
10 ^-4 is ____________ 10 ^-1
1/1000 as large as
10 ^1
10
10 ^3 x 10 ^-2 =
10
a typical galaxy contains about 100 billion stars, and there are approximately 100 billion galaxies in the observable universe. about how many stars are in the observable universe?
10 ^22
identify the equations that are true: 10 ^5 + 10 ^3 = 10 ^5+3 10 ^5 x 10 ^3 = 10 ^5x3 (10 ^5) ^3 = 10 ^5+3 10 ^5 / 10 ^-3 = 10 ^5-3 10 ^-5 / 10 ^-3 = 10 ^-5-3 10 ^5 x 10 ^3 = 10 ^5+3 10 ^5 / 10 ^3 = 10 ^5-3 (10 ^5)^3 = 10 ^5x3 10 ^5 / 10 ^3 = 10 ^5-3
10 ^5 x 10 ^3 = 10 ^5+3 10 ^5 / 10 ^3 = 10 ^5-3 (10 ^5)^3 = 10 ^5x3 10 ^5 / 10 ^3 = 10 ^5-3
rank the galaxies from left to right based on the amount of time it has taken their light to travel to earth, from the longest time to the shortest time.
10 billion light-years, 5 billion light-years, 2 billion light-years, 800 million light-years, 230 million light-years, and 70 million light-years
10 ^80 is ____________ 10 ^79
10 times as large as
10 ^2 is __________________ 10 ^-2
10,000 times as large as
10 ^2
100
10 ^5 is ______________ 10 ^3
100 times as large as
10 ^4 / 10 ^-1 =
100,000
10 ^8
100,000,000
(10 ^3 x 10^2) + 10 ^-3 =
100,000.001
10 ^-1 is ____________ 10 ^-4
1000 times as large as
2 x 10 ^7 / 8 x 10 ^5 =
2.5 x 10 ^1
suppose you wanted to show the sun on the same scale. about how big would it need to be?
3.5 meters in diameter (about 11 1/2 feet across)
3.5 x 10 ^1
35
3.5 x 10 ^5
350,000
3.5 x 10 ^3
3500
about how far away from earth would the sun be located on this scale?
375 meters (about the length of four football fields)
(7 x 10 ^2) x (6 x 10 ^3) =
4.2 x 10 ^6
(1.5 x 10 ^-7) x (3.6 x 10 ^15) / (1.2 x 10 ^-3) =
4.5 x 10 ^11
suppose you are asked to find 91, 321, 972 x 0.007004. doing a quick estimate by rounding the numbers in scientific notation, what value would you expect the answer to be close to?
63 x 10 ^4
consider again the galaxies you ranked in part a. this time, rank them from left to right based on the age of the universe at the time these galaxies emitted the light we recieve from them today, from oldest (closest to today) to youngest (furthest back in time).
70 million light-years, 230 million light-years, 800 million light-years, 2 billion light-years, 5 billion light-years, 10 billion light-years
classify each statement as either an observation, meaning something was have directly observed or measured, or an explanation, meaning something that we infer from observational or experimental evidence even though we cannot observe it directly.
OBSERVATIONS: - the andromeda galaxy is similar in structure to our own milky way - all planets orbit the sun in the same direction and nearly the same plane - more distant galaxies are moving away from us faster than nearby galaxies - stars can shine brightly for billions of years EXPLANATIONS - stars shine with energy generated by nuclear fusion in their cores - the andromeda and milky way galaxies formed in the same way - the orderly orbits of planets arose from their formation in a rotating gas cloud - the universe is expanding because it began with a big bang
according to current scientific estimates, when did the big bang occur?
about 14 billion years ago
the andormeda galaxy is faintly visible to the naked eye. when you look at the andromeda galaxy, the retina of you eye is absorbing light that has traveled through space for __________ to reach you
about 2 1/2 million years
suppose that someone in the andromeda galaxy has a super-telescope through which they were looking at earth right now. they would see earth _________.
as it was about 2 1/2 million years ago
the table in the video shows you the speeds of raisins 1,2, and 3 as measured from the local raisin. suppose instead that you measured speeds as seen from raisin 2. an observer at raisin 2 would measure _______________.
local raisin speed = 4.0 cm/hr; raisin 1 speed = 2.0 cm/hr; raisin 3 speed = 2.0 cm/hr
an astronomical unit is
earth's average distance from the sun
which of the following lies in the ecliptic plane?
earth's orbital path around the sun
which of the following correctly lists our 'cosmic address' from small to large?
earth, solar system, milky way galaxy, local group, local supercluster, universe
rank the following objects from largest to smallest : solar system, sun, galaxy, and earth
galaxy, solar system, sun, earth.
on the cosmic calendar, which compresses the history of the universe into a single year, about when did earth form?
in early september
on the cosmic calendar, which compresses the history of the universe into a single year, about when did life arise on earth?
in september
on the cosmic calendar, which compresses the history of the universe into a single year, about when did early humans first walk on earth?
just a few hours before midnight on december 31
regarding the history of the universe, which of the following is true?
key elements of which Earth and life are made, including carbon, oxygen, and iron, did not exist when the universe was born and were created later in stars.
could we see a galaxy that is 50 billion light-years away?
no, because it would be beyond the bounds of our observable universe
could you use the same scale to represent the distances to nearby stars? why or why not?
no, the nearest stars would not fit on earth with this scale
the age of our solar system is about:
one-third of the age of the universe
note that an observer located at the local raisin would see raisins 1,2, and 3 all move away from her during the video. what would an observer located at raisin 2 see?
raisin 1 and raisin 3 both move away from her
shown here are astronomical objects located at different distances from earth. rank the objects based on their distances from earth, from farthest to nearest.
star on far side of andromeda galaxy, star on near side of andromeda galaxy, star on far side of milky way galaxy, star near center of milky way galaxy, orion nebula, alpha centauri, pluto, and the sun
suppose each object emitted a burst of light right now. rank the objects from left to right based on the amount of time it would take this light to reach earth, from longest time to shortest time.
star on far side of andromeda galaxy, star on near side of andromeda galaxy, star on far side of milky way galaxy, star near center of milky way galaxy, orion nebula, alpha centauri, pluto, the sun
when we say the universe is expanding, we mean that:
the average distance between galaxies is growing with time
which of the following statements best describes what astronomers mean when they say that the universe is expanding?
the average distance between galaxies is increasing with time
the total number of stars in the observable universe is roughly equivalent to:
the number of grains of sand on all the beaches on earth
if we represent the solar system on a scale that allows us to walk from the sun to pluto in a few minutes, then _________.
the planets would all be marble size or smaller and the nearest stars would be thousands of miles away
in january, earth's rotation axis points in the direction of the star polaris. where does it point in july?
toward the star polaris
the star betelgeuse is about 600 light-years away. if it explodes tonight, __________________.
we won't know about it until 600 years from now
today, the evidence that we live in an expanding universe is extremely strong because astronomers have measured the motions of millions of galaxies. nevertheless, in science, we must always remain open to the possibility that some future observation could call even our most strongly supported theories into question. which of the following hypothetical observations would not be consistent with what we expect in an expanding universe?
you discover an extremely distant galaxy that is moving toward us
