Question

part 2: star and the earth
click on the link: https://intelligentdesigneronline.com/drhoades/advanced/labs/emission_lab/emissionlab3.php?debug=1
click to drag the star towards earth

1. what happened to the wavelength while you were dragging the star towards the earth?
2. why do you think this is happening?

click to drag the star away from earth

1. what happened to the wavelength while you were dragging the star away from earth?
2. why do you think this is happening?

predict: what color might be associated with longer wavelengths? which color might be associated with shorter wavelengths? why?

Explanation:

1. When dragging the star towards Earth, the wavelength decreases (blue - shift occurs) due to the Doppler effect. As the source (star) moves closer to the observer (on Earth), the waves are compressed, resulting in shorter wavelengths.
2. The Doppler effect for light is responsible. When there is relative motion between the source of light (star) and the observer, the frequency and wavelength of the light change. In the case of approaching motion, the wavelength shortens.
3. When dragging the star away from Earth, the wavelength increases (red - shift occurs). As the source moves away, the waves are stretched out, leading to longer wavelengths.
4. Again, the Doppler effect is at play. For receding motion between the source and the observer, the light waves get stretched, causing an increase in wavelength.

For the prediction: Red is associated with longer wavelengths as it is at the long - wavelength end of the visible light spectrum. Violet is associated with shorter wavelengths as it is at the short - wavelength end of the visible light spectrum. This is based on the order of colors in the visible light spectrum from longest to shortest wavelengths: red, orange, yellow, green, blue, indigo, violet.

Answer:

1. The wavelength decreases (blue - shift).
2. Due to the Doppler effect; approaching source compresses light waves.
3. The wavelength increases (red - shift).
4. Due to the Doppler effect; receding source stretches light waves.

Prediction: Red for longer wavelengths; Violet for shorter wavelengths because of the order of colors in the visible light spectrum.