Understanding the Speed of Galaxies Through Wavelength Shifts

The video tutorial explains the relationship between the shift in wavelength of light emitted by galaxies and their velocity. It covers the concepts of redshift and blueshift, detailing how these phenomena occur when galaxies move relative to Earth. The tutorial introduces an equation that relates wavelength shift to galaxy velocity and demonstrates its application through examples. The first example calculates the shift in wavelength for a galaxy moving away from Earth, while the second example determines the speed of a galaxy using absorption spectra. The video concludes by emphasizing the significance of redshift and blueshift in understanding galaxy movement.

What happens to the wavelength of light when a galaxy moves away from us?

• It shifts to shorter wavelengths.

• It remains unchanged.

• It shifts to longer wavelengths.

• It becomes invisible.

Which of the following describes the observed light from a galaxy moving towards us?

• The light shifts to longer wavelengths.

• The light shifts to shorter wavelengths.

• The light's frequency decreases.

• The light becomes redder.

What is the term for the velocity of a galaxy moving away from Earth?

• Stationary velocity

• Approaching velocity

• Recessional velocity

• Orbital velocity

In the equation relating wavelength shift and velocity, what does 'C' represent?

• The speed of the galaxy

• The speed of light in a vacuum

• The speed of the observer

• The speed of sound

How is the shift in wavelength calculated for a galaxy moving away from Earth?

• By adding the observed and reference wavelengths

• By dividing the observed wavelength by the reference wavelength

• By multiplying the observed wavelength by the reference wavelength

• By subtracting the reference wavelength from the observed wavelength

What is the shift in wavelength for a galaxy moving away at 20 million meters per second?

• 0.066 nanometers

• 43.3 nanometers

• 20 nanometers

• 650 nanometers

What indicates that a galaxy is moving towards Earth when analyzing absorption spectra?

• The lines shift towards longer wavelengths.

• The lines remain unchanged.

• The lines shift towards shorter wavelengths.

• The lines disappear.