Space Physics: Red-shift

What is red-shift in the context of space physics?

• Red-shift is the result of galaxies moving closer together in space.

• Light from distant galaxies appears to be shifted towards longer (redder) wavelengths due to the expansion of the universe.

• Red-shift is caused by the absorption of light by interstellar dust.

• Red-shift refers to the change in color of stars due to their age.

Explain how the red-shift phenomenon supports the idea of an expanding universe.

• The red-shift phenomenon supports the idea of an expanding universe by showing that galaxies are moving away from each other.

• Red-shift is a result of galaxies staying stationary in space

• The red-shift phenomenon is caused by galaxies moving towards each other

• The red-shift phenomenon indicates galaxies are shrinking

Fill in the blank: Red-shift occurs when light from a distant galaxy is shifted towards the ______ end of the spectrum.

• invisible

• longer

• middle

• shorter

What is the relationship between the red-shift of a galaxy and its distance from Earth?

• Galaxies that are farther away from Earth tend to have a lower red-shift.

• Galaxies that are farther away from Earth tend to have a higher red-shift.

• Galaxies that are closer to Earth tend to have a higher red-shift.

• The red-shift of a galaxy is not related to its distance from Earth.

True or False: Red-shift is a result of galaxies moving closer to Earth.

• Partially true

• True

• Red-shift is a myth

• False

What is the Doppler effect, and how is it related to red-shift?

• The Doppler effect is the change in color of a wave in relation to an observer who is stationary.

• Red-shift refers to the decrease in wavelength of light from nearby stars.

• The Doppler effect is only applicable to sound waves, not light waves.

• The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Red-shift specifically refers to the increase in wavelength of light from distant galaxies, indicating they are moving away from us. This is related to the Doppler effect as the motion of galaxies causes the light they emit to shift towards longer wavelengths, appearing red.

Which scientist first observed the red-shift in the spectra of galaxies?

• Galileo Galilei

• Albert Einstein

• Edwin Hubble

• Isaac Newton

What is the difference between red-shift and blue-shift?

• Red-shift is related to sound waves, while blue-shift is related to light waves.

• Red-shift is the increase in wavelength of light indicating the source is moving away, while blue-shift is the decrease in wavelength indicating the source is moving towards the observer.

• Red-shift and blue-shift are the same phenomenon observed from different angles.

• Red-shift is the decrease in wavelength indicating the source is moving towards the observer, while blue-shift is the increase in wavelength indicating the source is moving away.

Explain how the Hubble Law is used to determine the distance of galaxies based on red-shift.

• The Hubble Law is used to determine the distance of galaxies based on red-shift by counting the number of stars in galaxies

• The Hubble Law is used to determine the distance of galaxies based on red-shift by measuring the brightness of galaxies

• The Hubble Law is used to determine the distance of galaxies based on red-shift by measuring the recessional velocity of galaxies and applying the Hubble Law equation v = H0 * d.

• The Hubble Law is used to determine the distance of galaxies based on red-shift by analyzing the color of galaxies

Fill in the blank: The greater the red-shift of a galaxy, the ______ its distance from Earth.

• same

• farther

• smaller

• closer