Doppler effect

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/doppler-effect

1. Who discovered Doppler effect?
2. What is the discoverer?
3. What is the related topics?
4. Why does a siren sound higher when it comes toward us and lower when it goes away?
5. How do scientists use the Doppler effect to learn about stars?

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. Who discovered Doppler effect?1842
2. What is the discoverer?Christian Doppler
3. What is the related topics?Wave physics, electromagnetism, acoustics, relativity, signal processing, astrophysics
4. Why does a siren sound higher when it comes toward us and lower when it goes away?When the source moves toward us, the waves get squished together, so we hear a higher pitch. When it moves away, the waves stretch out and the pitch gets lower.
5. How do scientists use the Doppler effect to learn about stars?By measuring how much the light from a star is shifted, astronomers can tell if the star is moving toward or away from Earth and how fast.

Frequency: The rate at which wave oscillations occur, perceived as pitch in sound and color in light.
Wavelength: The spatial period of a wave, the distance over which the wave's shape repeats.
Redshift/Blueshift: The shift of light towards longer (red) or shorter (blue) wavelengths due to Doppler effect.