Stars and Galaxies Chapter 24

Which of the following objects do many astronomers believe is a black hole?

Cygnus X-1

Einstein suggested that the regular change (advance) in the perihelion of the planet Mercury could be explained by:

a distortion in spacetime caused by the gravity of the Sun

According to the general theory of relativity, light and other radiation coming from a white dwarf or a neutron star should (and experiments show that it does) exhibit

a gravitational redshift

The first, indirect detection of gravitational waves in the 1970s involved

a pulsar that was in the same star system with a neutron star

From which of the following will a wave of light show the greatest gravitational redshift:

a white dwarf

When a light wave leaves a region of strong gravity, compared to the same wave leaving a spaceship in empty space, the wave in strong gravity will have

all of the above

Astronomers have concluded that growing supermassive black holes (which have millions of times the Sun's mass or more) is pretty unlikely at our location in the Milky Way Galaxy. Where do they think is the most likely place in the Milky Way for such a supermassive black hole?

at the center of the Milky Way Galaxy, where matter is more crowded

When Einstein proposed his General Theory of Relativity, he suggested some pretty strange ideas about space, time, and gravity. How did scientists in 1919 show that Einstein's theory described the behavior of the real world and wasn't just a crazy hypothesis?

by observing starlight coming close to the Sun during an eclipse

According to the general theory of relativity, the presence of mass

causes a curvature(or warping) of spacetime

If you are in a freely falling elevator near the top of a tall building, as the elevator falls, your weight would be:

equal to zero-you would be weightless

When one member of a binary star system is a black hole, and astronomers detect flickering x-rays coming from the system, where are these x-rays usually coming from?

from a disk of material around the black hole (material that has been pulled from the companion star and is falling toward the black hole

What is a key reason that gravitational waves are so much harder to detect than electro-magnetic (e-m) waves?

gravitational waves are much weaker than e-m waves, and therefore require very, very precise equipment to detect

Some years after college (and after you recover from your astronomy class,) you get married and exchange gold rings with your sweetheart. What connection is there between the gold in those rings and recent observations of gravitational waves?

our new understanding is that significant amounts of gold in the universe are produced in the mergers of neutron stars, which can be detected with gravitational waves

Far away from a black hole (at the distance of another star), which of the following is a possible way to detect it?

search for flickering x-rays being given off from an accretion disk around the black hole, as it "eats" part of a neighbor star

When astronauts aboard the International Space Station (ISS) in space let go of an orange, it just floats there. Why is that?

the ISS is falling around the Earth, and in free fall, things feel no weight

In 1959, Pound and Rebka did an experiment to test the prediction of Einstein's theory of general relativity about the relationship between the pace of time and the strength of gravity. When two identical atomic clocks, one on the ground floor and one on the top floor, were compared,

the clock on the ground floor ran a tiny bit slower

The equivalence principle (principle of equivalence) says that

the effects of gravity are equivalent to the effects of acceleration

In the first direct detection of gravitational waves by LIGO in 2015, the waves came from

the merger of two black holes

According to Einstein's general theory of relativity, the stronger a star's gravity,

the slower time runs near it

The first time that astronomers observed both gravitational waves and electro-magnetic waves from the same event, what they were observing was:

the spiraling toward each other of two neutron stars

Which of the following statements about the way the mass of a white dwarf affects spacetime is correct?

the white dwarf mass will curve spacetime; light has to follow that curvature