Quiz: Gravity’s Warping Effect: Lensing and the Bending of Light

Question 1

When light from a distant star passes near a massive galaxy, how does the galaxy's gravitational field affect the light's path?

Accepted Answer

It bends the light, potentially creating multiple images of the star.

Answer

It absorbs some of the light, dimming the star's appearance.

Answer

It reflects the light, creating a mirror image of the star.

Answer

It speeds up the light, causing the star to appear bluish.

Question 2

What is the primary condition necessary for observing strong gravitational lensing?

Accepted Answer

The observer, the lensing mass, and the distant light source must be aligned in a straight line.

Answer

The lensing mass must be a black hole.

Answer

The distant light source must be a supernova.

Answer

The observer must be very close to the lensing mass.

Question 3

Gravitational lensing can be used to infer the presence of dark matter. Why is this possible?

Accepted Answer

The amount of bending observed often exceeds what can be explained by visible matter alone.

Answer

Dark matter emits its own light, which is bent more than visible light.

Answer

Dark matter reflects light from distant objects.

Answer

Dark matter creates its own gravitational waves that interfere with light.

Question 4

Which of the following phenomena is NOT a direct result of gravitational lensing?

Accepted Answer

The observed redshift of distant galaxies.

Answer

The formation of Einstein rings.

Answer

The creation of multiple images of a single distant quasar.

Answer

The magnification of distant supernovae.

Question 5

In gravitational lensing, what does the term "Einstein radius" refer to?

Accepted Answer

The distance from the lens at which the bending angle of light is greatest.

Answer

The radius of a black hole's event horizon.

Answer

The distance at which light from the source would orbit the lens in a perfect circle.

Answer

The radius of the observable universe.

Question 6

If a galaxy cluster acts as a gravitational lens and produces a ring-like image of a background galaxy, what is this ring called?

Accepted Answer

An Einstein ring.

Answer

A black hole shadow.

Answer

An Einstein cross.

Answer

A gravitational arc.

Question 7

Weak gravitational lensing refers to a subtle distortion of background galaxies. What is the main scientific advantage of studying weak lensing?

Accepted Answer

It allows astronomers to map the distribution of dark matter over large regions of the sky.

Answer

It can provide detailed images of individual distant galaxies.

Answer

It produces bright, magnified images of distant supernovae.

Answer

It is used to determine the exact mass of black holes.