Homework on Chapter 24

What type of main sequence star is most likely to become a black hole?

an O-type star

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)

To predict whether a star will ultimately become a black hole, what is the key property of the star we should look at?

mass

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

the merger of two black holes

In the far future, a starship becomes trapped insidethe event horizon of a black hole. Although the crew discovers that their ship cannot out, they at least want to send a message to other ships in the area to stay away from the danger zone. If they send out a message in the form of a radio wave, what will be its fate?

the message will never emerge from the event horizon

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