Test 3

Question 1

Which type of cluster is used to help find the center of a galaxy?

a. open cluster
b. galactic cluster
c. closed cluster
d. none of the above

Answer 1

d. none of the above

globular cluster

Question 2

What wavelength light is used to search for the galactic center?

a. radio waves
b. visible light
c. IR
d. UV

Answer 2

c. IR

Question 3

if two things are distinguishable then they are…

a. conserving entropy
b. symmetric
c. both a and b
d. neither a or b

Answer 3

d. neither a or b

Question 4

How many known forces are there in the universe today?

a. 1
b. 2
c. 3
d. 4

Answer 4

d. 4

Question 5

Which of the following is a Fermion?

a. photon
b. neutron
c. graviton
d. boson

Answer 5

a. photon

Question 6

Which of the following is true of force-carrying particles?

a. they are integer spin fermions
b. they are half-integer spin fermions
c. they are integer spin bosons
d. they are half-integer spin bosons

Answer 6

c. they are integer spin bosons

Question 7

How many types of rotation curves were discussed in class?

a. 1
b. 2
c. 3
d. 4

Answer 7

c. 3

Question 8

What type of rotation curve does our solar system have?

a. increasing
b. decreasing
c. open
d. closed

Answer 8

b. decreasing

Question 9

Which of the following is most responsible for multiple quasar images?

a. Doppler shift
b. gravitational lensing
c. both a and b
d. neither a or b

Answer 9

b. gravitational lensing

Question 10

Which of the following is not a type of neutrino?

a. electron
b. photon
c. muon
d. tau

Answer 10

b. photon

Question 11

Which of the following is dark matter?

a. moon
b. asteroid
c. comet
d. all of the above

Answer 11

d. all of the above

This is debatable and perhaps should be none of the above

Question 12

Energy used to create virtual particle pairs comes from…

a. event horizon
b. photon sphere
c. exit cone
d. none of the above

Answer 12

d. none of the above

curvature is where it comes from

Question 13

What type of particle will cross the even horizon during Hawking radiation and in which direction?

a. real particle moving toward the black hole
b. real particle moving away from the black hole
c. virtual particle moving toward the black hole
d. virtual particle moving away from the black hole

Answer 13

c. virtual particle moving toward the black hole

Question 14

Discuss the role of curvature in Hawking radiation?

Answer 14

• Hawking radiation is the result of curvature caused by gravitational field of SMBH
• virtual pairs created due to curvature, one is drawn into the black hole, the other is released
• this is a physical process, allowing for something (Hawking radiation) to be detected, pointing to location of SMBH

Question 15

Discuss the significance of the symmetry break in the electroweak force.

Answer 15

• At some point in the past, three forces at work.
• electroweak force had a symmetry break
• two separate forces resulted - EM and weak nuclear