Understanding Light and the Universe

What is the primary tool astronomers use to study the universe?

• Light

• Sound waves

• Magnetic fields

• Gravity

What happens to the wavelength of light when the source is moving away from the observer?

• It becomes longer

• It remains the same

• It fluctuates

• It becomes shorter

What is the term used to describe the change in wavelength as a light source moves toward or away from an observer?

• Redshift

• Blueshift

• Doppler effect

• Light year

If a galaxy appears red, what does it indicate about its movement?

• It is rotating

• It is moving toward us

• It is stationary

• It is moving away from us

What does the observation of redshift and blueshift in galaxies tell us about the universe?

• The universe is shrinking

• The universe is expanding

• The universe is static

• The universe is contracting

How long does it take for light from the sun to reach Earth?

• About 4 hours

• About 1 year

• About 1 day

• About 8 minutes

What is a light year a measure of?

• Brightness

• Time

• Speed

• Distance

When astronomers observe the Andromeda galaxy, how old is the light they are seeing?

• Ten billion years old

• A few years old

• A few thousand years old

• Two and a half million years old

What might astronomers be observing when they look at distant galaxies?

• A parallel universe

• An outdated version of the universe

• A future version of the universe

• The current state of the universe

What phenomenon allows astronomers to study the formation of stars and galaxies over time?

• The gravitational pull of black holes

• The observation of light from the past

• The expansion of the universe

• The speed of light