Exam 14: Down the Rabbit Hole: Relativity and Black Holes

Two twins are separated at birth.One lives on a massive gas giant,while the other lives on a spaceship far from any stars.All other things being equal,which twin lives longer? Why?

An accretion disk around a black hole is threaded by magnetic fields.What is a likely result of this configuration?

In the late 19th century,how did scientists explain the wavelike properties of light?

What is the event horizon of a black hole?

What remnant will a star with an initial total mass of 100 M_sun leave at the end of its life?

The first experimental verification of the general theory of relativity was:

From the perspective of an observer near a black hole,which of the following appears to happen as he or she observes large distances from the black hole?

The figure below shows an observer and two light sources.How much faster does light from A appear to be moving for the observer than light from B?

Black hole A has a mass of 10³ MSᵤn,while black hole B has a mass equal to the Sun's.How large is the Schwarzschild radius of black hole A,relative to that of black hole B?

Most astronomers believe that stars that end their lives as black holes do not usually produce strong supernova explosions,unlike those that produce neutron stars.Why?

Why is the Schwarzschild radius significant?

Does gravitational lensing occur in Newton's formulation of gravity? Why or why not?

What are the three observable properties of black holes?

Imagine that a child is inside a car traveling at 8 m/s.The child throws a ball with a velocity of 1 m/s in the direction of the car's motion.How fast is the ball traveling relative to an observer at rest on the side of the road?

What produces the X-rays in an X-ray binary?

A disk of gas orbits a supermassive black hole.What can astronomers use to determine the mass of the black hole from the properties of this disk?

What is invariant between different frames of reference?

Astronomers discover a bright X-ray source in the Milky Way.They see no counterpart in the optical bands,but it has another star orbiting it,and they determine that the X-ray source has a mass of 10 MSᵤn.What is the most likely origin of the X-rays?

A muon is a type of subatomic particle.If a muon is at rest in the laboratory,it will decay into an electron after about 2 microseconds.Suppose an observer watches a muon travel through the atmosphere at 90 percent of the speed of light.How does the lifetime of the moving muon compare to the laboratory muon,for an observer at rest with respect to the lab?

According to the special theory of relativity,the duration between events depends upon the frame of reference in which those events are measured.In order to maintain a constant speed of light,what else must change between frames of reference?