Doppler Effect and Red Shift in Astronomy

The video explains the concept of red shift, where a galaxy or star moving away from Earth causes a shift in the emitted wavelength towards the red end of the electromagnetic spectrum. This is due to the Doppler effect. The video introduces the reference wavelength and apparent wavelength, and explains how to calculate the velocity of a star using the Doppler shift equation. An example is provided where the velocity of a star is calculated based on observed wavelength changes. The video concludes with a call to subscribe for more physics content.

What happens to the wavelength of light from a star as it moves away from Earth?

• It becomes longer.

• It remains the same.

• It changes color.

• It becomes shorter.

What is the term used to describe the shift of light towards the red end of the spectrum?

• Yellowsift

• Greenshift

• Redshift

• Blueshift

What symbol is used to represent the reference wavelength?

• Lambda with subscript zero

• Delta lambda

• C

• V

In the Doppler shift equation, what does the symbol 'C' represent?

• The speed of the star

• The speed of the galaxy

• The speed of light

• The speed of sound

What does the Greek symbol 'delta lambda' represent in the Doppler shift equation?

• The speed of light

• The shift in wavelength

• The apparent wavelength

• The reference wavelength

What is the first step in solving for the velocity of a star using the Doppler shift equation?

• Convert units to meters

• Measure the apparent wavelength

• Rearrange the equation to solve for velocity

• Calculate the speed of light

How is the shift in wavelength calculated in the example provided?

• By adding the reference and apparent wavelengths

• By multiplying the reference wavelength by the apparent wavelength

• By dividing the reference wavelength by the apparent wavelength

• By subtracting the reference wavelength from the apparent wavelength

What is the observed wavelength of the star in the example?

• 482 nanometers

• 450 nanometers

• 500 nanometers

• 434 nanometers

What is the calculated velocity of the star in the example?

• 3.3 x 10^8 meters per second

• 3.3 x 10^7 meters per second

• 3.3 x 10^9 meters per second

• 3.3 x 10^6 meters per second

Why is no unit conversion needed in the example calculation?

• Because the equation is dimensionless

• Because both wavelengths are in nanometers

• Because the velocity is already in meters per second

• Because the speed of light is constant