WQ #29

The first satellite (spacecraft with instruments) to measure and confirm the cosmic microwave background was the: a. COBE (COsmic Background Explorer) b. Hubble Space Telescope c. Einstein d. Voyager 1 e. Chandra

a. COBE (COsmic Background Explorer)

When we determine the age of the universe using the Hubble Time, what important simplifying assumption goes into our calculations? a. that the expansion of the universe has been happening at the same rate - neither speeding up or slowing down b. that all the galaxies are moving away from us at exactly the same speed, no matter how far away they are c. that the cosmological principle doesn't hold: the universe is not isotropic and homogeneous d. that we have accounted correctly for the effects of dark energy e. that the universe is actually contracting instead of expanding

a. that the expansion of the universe has been happening at the same rate - neither speeding up or slowing down

Why did Einstein introduce the cosmological constant into the equations of his General Theory of Relativity when describing the universe? a. Einstein did not realize that black holes would exist at the centers of galaxies and pull everything into them b. Einstein's equations required the universe to expand or contract; he could not imagine or accept it doing either one, so he put a factor in to stop it from moving c. Einstein talked to Hubble and learned about Hubble's observations of the expanding universe, which made him so uncomfortable that he decided to change his equations d. Einstein had a hunch that the universe was accelerating (speeding up its expansion) back in 1918 and so introduced the constant into his equations to describe that e. Einstein liked cups of tea in the afternoon, and his constant was a comment on that habit

b. Einstein's equations required the universe to expand or contract; he could not imagine or accept it doing either one, so he put a factor in to stop it from moving

Today, we believe that only a small number of elements were actually formed during the Big Bang. Which of the following was NOT one of these: a. hydrogen b. carbon c. lithium d. helium e. you can't fool me, all of the above were definitely formed during the big bang

b. carbon

At first, right after the Big Bang, the universe was too hot for nuclei and electrons to combine into the kinds of neutral atoms that are familiar to us today. How soon after the beginning did it become cool enough for neutral atoms to form? a. 10-43 seconds b. 3 minutes c. a few hundred thousand years d. a billion years e. only last Thursday

c. a few hundred thousand years

Which of the following is the Earth not located in? a. the solar system b. the universe c. globular cluster M-13 d. the Milky Way Galaxy e. the Earth is located in all of the above

c. globular cluster M-13

When do astronomers now think that the "dark energy" began to accelerate the expansion of the universe? a. right after the Big Bang (after the first three minutes or so) b. a few million years after the Big Bang c. several billion years after the Big Bang d. about ten million years ago e. when the city of Bayonne, New Jersey was founded

c. several billion years after the Big Bang

The reciprocal of the Hubble constant (1/H) is a rough measure of the: a. the period of a typical Cepheid variable b. the distance to the last galaxies that formed c. the age of the universe d. the luminosity of a type I supernova explosion e. the cost of building a telescope in space

c. the age of the universe

After the Big Bang, in order for the universe to become transparent to light and other electro-magnetic radiation, what had to happen? a. stars and galaxies had to form b. the whole universe had to be hotter than the interior of a star c. the density of the universe had to decrease (to 1000 nuclei per cubic centimeter or less) d. the dark energy had to dominate over regular matter and energy e. telescopes had to be invented

c. the density of the universe had to decrease (to 1000 nuclei per cubic centimeter or less)

Some scientists speculate that our universe is not the only universe that exists, but the only one we can gather evidence about. This idea is called a. the Big Bang theory b. the cosmological principle c. the multiverse theory d. Hubble's Law e. the accretion disk hypothesis

c. the multiverse theory

One of the things that our current "standard model" of the Big Bang Theory doesn't explain is a. why the universe is expanding b. why there is a cosmic microwave background filling all of space c. why the temperature of the cosmic microwave background is so uniform throughout all of space d. why there is more helium in the universe than stars could have produced in 13.8 billion years e. why the galaxies show a red shift

c. why the temperature of the cosmic microwave background is so uniform throughout all of space

The two scientists who first discovered the cosmic microwave background radiation were: a. Hubble and Humason b. Einstein and Friedmann c. Gamow and Alpher d. Penzias and Wilson e. Kirk and Spock

d. Penzias and Wilson

The standard bulbs (standard candles) that made it possible for astronomers to discover the acceleration in the expansion of the universe were a. globular clusters b. Cepheid variable stars c. the brightest irregular galaxy in a rich cluster d. Type Ia supernovae e. the size of a galaxy dark matter halo

d. Type Ia supernovae

Factoring in everything we currently know about the history of the universe, our best estimate for the age of the universe is a. 4.6 billion years b. about 100 billion years c. roughly 2 million years d. about 13.8 billion years e. the age of the universe is infinite; there was no beginning

d. about 13.8 billion years

In the very distant future, given our best model of the accelerating universe, what will the universe look like? a. all the galaxies will start showing blue-shifts b. the universe will look pretty much the same as it does today c. the entire universe will become one huge black hole d. all the stars will die and the galaxies will be dark e. galaxies will shine even more brightly than today from all the dark energy

d. all the stars will die and the galaxies will be dark

According to the models of the universe we discussed in this course, why do the galaxies move apart (why do we have Hubble's law)? a. gravity is a repulsive force, once you get outside the Milky Way Galaxy b. each galaxy has net charge on it, and they repel by the laws of electricity c. supernova explosions happen more frequently on one side of each galaxy, giving the entire galaxy a push that moves it away from its neighbors d. as a result of the Big Bang, space itself is stretching, and this stretching carries the galaxies away from each other e. strong political and religious disagreements among the galaxies

d. as a result of the Big Bang, space itself is stretching, and this stretching carries the galaxies away from each other

Where in space did the expansion of the universe begin? a. at the center of the Milky Way Galaxy; that's why all the other galaxies are moving away from us b. near the center of the Virgo Supercluster of Galaxies c. at a point so far away that only our largest telescopes can show us glimpses of it d. everywhere at once e. nowhere at all; new observations show that the universe is not expanding after all

d. everywhere at once

In our modern view of the expansion of the universe, we understand that it is space that is stretching; individual galaxies don't speed away from each other as if they were rockets. In that case, why do galaxies show a red-shift? a. as galaxies age, they get redder and redder b. as space stretches, the waves of radiation in space also stretch and their wavelength increases c. as space stretches, the presence of dark matter slows down the light between galaxies d. as time goes on, waves in space encounter more and more dust, and get redder e. astronomers cannot think of any good explanation for the red-shift if it's space that expands/stretches

b. as space stretches, the waves of radiation in space also stretch and their wavelength increases

Astronomers have measured that there is more helium in the universe than can be explained by the fusion in stars over the last 13 billion years. How do they think the extra helium got into the universe? a. the extra helium was produced in the accretion disks of supermassive black holes b. the extra helium was made during the first few minutes of the Big Bang, when the entire universe was hot enough for fusion to occur briefly c. the extra helium was produced by the interaction of dark matter with the material at the edges of all galaxies d. the extra helium was produced recently during Type Ia supernova explosions e. the idea that there is extra helium has been shown to be in error; we were confused by the high red shifts of distant galaxies distorting their spectra

b. the extra helium was made during the first few minutes of the Big Bang, when the entire universe was hot enough for fusion to occur briefly

Recent observations indicate that the universe is expanding faster today than it was a few billion years ago (that, in other words, the expansion of the universe is accelerating.) What kind of observations have led astronomers to this surprising conclusion? a. the measurements of cepheid variables in the galaxies of the Local Group b. the measurement of galaxy distances using Type Ia supernovae c. the discovery of large amounts of dark matter in the halo of the Milky Way d. the measurements of the amount of deuterium in the universe e. the fact that galaxies today are getting a lot more speeding tickets than they used to

b. the measurement of galaxy distances using Type Ia supernovae

Scientists speculate that the properties (laws) of the universe must be the way they are because if they were significantly different, we would not be here to think about them. This idea is called a. the cosmological principle b. the Hubble law c. the narcissus conjecture d. the anthropic principle e. the inflationary self-image hypothesis

d. the anthropic principle

The model of the universe that involves an enormous increase of scale during a very short time in the early universe is called: a. the flat universe model b. the oscillating universe model c. the primeval atom model d. the inflationary universe model e. the cosmic burp model

d. the inflationary universe model

What is the strongest known force in the universe? a. gravity b. the electromagnetic force c. the weak nuclear force d. the strong nuclear force e. The Dallas Cowboys [put in your favorite local sports team here]

d. the strong nuclear force

The satellite that has given us the most precise measurements of the characteristics of the cosmic background radiation is: a. Planck b. Einstein c. the Hubble Space Telescope d. BeppoSAX e. Io

e. Io

If you want to check on what conditions were like in the universe a few hundred thousand years after the Big Bang, what sort of instrument would it be best to use: a. a gamma-ray or high-energy x-ray telescope in orbit b. a tank of chlorine deep inside the Earth c. a small refractor (which gathers visible light) on a college campus, but pointed in just the right direction d. an ultra-violet telescope in orbit around Jupiter e. a satellite with infrared and microwave telescopes on board

e. a satellite with infrared and microwave telescopes on board