Red Shift and Blue Shift Flashcards
(15 cards)
Does the doppler effect impact light?
Yes
It impacts all waves.
As you move towards a light source, the wavelength of the light___________
decreases
We perceive a change in frequency in a sound wave as a change in ________, whereas we perceive a change in frequency in a light wave as a change in ________________
a) pitch
b) colour
As you move away from a light source, the wavelength of the light___________
increases
What does a change in frequency of a light wave look like to our eyes?
A change in COLOUR
Explain this diagram
The light moving towards the observer bunches into its own waves, shifting the colour towards blue. The observer watching the light move away will perceive the waves stretching, shifting the colour towards the red.
What is “redshift” of galaxies?
The lengthening of light waves from distant galaxies, similar to the Doppler effect. The redshift tells us that the universe is expanding away from us.
What does redshift reveal about the universe?
It reveals how the universe is expanding and allows astronomers to measure the distances and velocities of distant objects
How is redshift related to the Doppler effect?
It is the cosmological equivalent of the Doppler effect, where light waves from receding objects are stretched towards the red end of the spectrum
The Doppler effect is commonly known for sound waves, but it also applies to light waves.
What does a higher redshift indicate about a galaxy’s movement?
The galaxy is moving away from us faster
The more redshifted the light, the faster it is receding due to the expansion of space.
How does redshift help in determining distances to galaxies?
By comparing the redshifted light with light emitted from a nearby, similar object
This comparison allows astronomers to estimate distances based on the amount of redshift.
What is Hubble’s Law?
The relationship that states the farther a galaxy is, the faster it is receding from us
Hubble’s Law is fundamental in understanding the expansion of the universe.
How is cosmological redshift different from doppler effect for sound?
Cosmological redshift occurs because space itself is expanding. The doppler effect for sound occurs becasue the sound’s source itself is moving (like a firetruck).
Fill in the blank: Redshift is a powerful tool that allows astronomers to study the _______.
expansion of the universe
This tool also aids in measuring distances to galaxies and understanding the evolution of the universe.
True or False: Redshift can only be observed in nearby galaxies.
False
Redshift is primarily used to measure distances and velocities of distant galaxies.
