Question 1

What is the difference between the singularity and the event horizon of a black hole?

Accepted Answer

The singularity is the very center of th

Question 2

What is the meaning of the Schwarzschild radius around a black hole?

Accepted Answer

A) It is the radius at which an orbiting object would show a precession. 
B) It is the radius at which gravitational redshift can be detected. 
C) It is the radius at which the black hole's spin equals the speed of light. 
D) It is the radius at which the escape velocity equals the speed of light. 
E) It is the radius at which a body falling onto the black hole would move at half the speed of light. 
A) It is the radius at which an orbiting object would show a precession. 
B) It is the radius at which gravitational redshift can be detected. 
C) It is the radius at which the black hole's spin equals the speed of light. 
D) It is the radius at which the escape velocity equals the speed of light. 
E) It is the radius at which a body falling onto the black hole would move at half the speed of light.

Question 3

Explain how Newtonian physics is an approximation to relativity.

Accepted Answer

Newtonian physics explains many phenomen

Question 4

A person would feel __________ as he approached the event horizon of a black hole.

Accepted Answer

A) extremely strong tidal forces 
B) intense heating 
C) strong Hawking radiation 
D) strong infrared radiation 
E) nothing 
A) extremely strong tidal forces 
B) intense heating 
C) strong Hawking radiation 
D) strong infrared radiation 
E) nothing

Question 5

Gravitational lensing occurs when __________ distorts the fabric of spacetime.

Accepted Answer

A) a star 
B) dark matter 
C) a black hole 
D) any massive object 
E) a white dwarf 
A) a star 
B) dark matter 
C) a black hole 
D) any massive object 
E) a white dwarf

Question 6

While traveling the galaxy in a spacecraft,you and a colleague set out to investigate the 106M⨀ black hole at the center of our galaxy.She hops aboard an escape pod and drops into a circular orbit around the black hole,maintaining a distance of 1 AU,while you remain much farther away in the spacecraft.After doing some experiments to measure the strength of gravity,your colleague signals her results back to you using a green laser.What would you see? Hint: you will need to calculate the location of the event horizon.

Accepted Answer

A) Her signals are shifted only slightly toward the red because she is orbiting well outside the event horizon of the black hole. 
B) You would see her signals shifted to a much redder wavelength because she is close to the event horizon. 
C) You would see nothing,because your colleague has crossed the event horizon around the black hole. 
D) You would see nothing,because no light can escape the gravitational pull of a black hole no matter how far she is from it. 
E) You would see her signals shifted to a much bluer wavelength because black holes can make highly energetic light. 
A) Her signals are shifted only slightly toward the red because she is orbiting well outside the event horizon of the black hole. 
B) You would see her signals shifted to a much redder wavelength because she is close to the event horizon. 
C) You would see nothing,because your colleague has crossed the event horizon around the black hole. 
D) You would see nothing,because no light can escape the gravitational pull of a black hole no matter how far she is from it. 
E) You would see her signals shifted to a much bluer wavelength because black holes can make highly energetic light.

Question 7

Name one verified prediction of general relativity.

Accepted Answer

A) Spacetime is flat except inside the Schwarzschild radius of the Sun. 
B) Relativity predicts Mercury has an orbital precession,but Newtonian physics does not. 
C) Starlight passing near the Sun should be bent away from the Sun by its gravity. 
D) Gravitational lensing should make Mercury brighter than it would otherwise be. 
E) Mercury's orbital precession is a little bigger than predicted by Newtonian physics. 
A) Spacetime is flat except inside the Schwarzschild radius of the Sun. 
B) Relativity predicts Mercury has an orbital precession,but Newtonian physics does not. 
C) Starlight passing near the Sun should be bent away from the Sun by its gravity. 
D) Gravitational lensing should make Mercury brighter than it would otherwise be. 
E) Mercury's orbital precession is a little bigger than predicted by Newtonian physics.

What is the difference between the singularity and the event horizon of a black hole?

What is the meaning of the Schwarzschild radius around a black hole?

Explain how Newtonian physics is an approximation to relativity.

A person would feel __________ as he approached the event horizon of a black hole.

Gravitational lensing occurs when __________ distorts the fabric of spacetime.

Name one verified prediction of general relativity.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

Exam 18: Relativity and Black Holes

What is the difference between the singularity and the event horizon of a black hole?

What is the meaning of the Schwarzschild radius around a black hole?

Explain how Newtonian physics is an approximation to relativity.

A person would feel __________ as he approached the event horizon of a black hole.

Gravitational lensing occurs when __________ distorts the fabric of spacetime.

Name one verified prediction of general relativity.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters