Question

A researcher studies the light emitted by a distant star. The researcher finds that the light received from the star falls slightly closer to the red end of the electromagnetic spectrum when compared to a similar source closer to Earth. The researcher claims that the star is moving away from Earth.Is the researcher correct?

A. No. All hot stars emit red-colored light
B. Yes. All moving objects emit red-colored light
C. No. The red-colored light emission is due to the composition of the star.
D. Yes. Light from any object moving away from Earth shifts to red-colored light.

Answer 1

When the light emitted by a distant star falls closer to the red end of the electromagnetic spectrum, it indicates that the star is moving away from Earth. This phenomenon is known as redshift.

Step-by-step explanation:

The researcher is correct. When the light emitted by a distant star falls closer to the red end of the electromagnetic spectrum, it indicates that the star is moving away from Earth. This phenomenon is known as redshift. Redshift occurs because light waves from a source that is moving away from an observer get stretched out, causing the wavelengths to become longer and shifting towards the red end of the spectrum. Conversely, if a star is moving towards Earth, its light waves would get compressed and shift towards the blue end of the spectrum, known as blueshift.

Answer 2

The researcher's claim that the star is moving away from Earth based on the redshifted light is correct, due to the Doppler Effect.

Step-by-step explanation:

The observation that the light received from a distant star is slightly shifted towards the red end of the spectrum when compared to a similar source closer to Earth is an example of the redshift. This phenomenon is due to the Doppler Effect, which affects the light from astronomical objects in motion relative to the observer. If a star or galaxy is moving away from Earth, its light appears redshifted—a shift to longer wavelengths. Conversely, objects moving towards Earth would exhibit a blueshift, where the light is shifted to shorter wavelengths. This redshift is a key piece of evidence for the expansion of the universe, especially in the context of objects that are millions of light-years away, indicating they are receding from us at high speeds.

Therefore, when the researcher concludes that the star is moving away from Earth based on its redshifted light, the correct answer is D. Light from any object moving away from Earth shifts to red-colored light, consistent with what is known as the Doppler Effect in cosmology.