GK
THE UNIVERSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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redshift and blueshift
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ultraviolet and infrared
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absorption and radiation
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absorption and emission
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Detailed explanation-1: -When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift. Astronomers use redshift and blueshift to deduce how far an object is away from Earth, the concept is key to charting the universe’s expansion.
Detailed explanation-2: -Astronomers can use redshift to determine the motion of the Milky Way. They do that by measuring the Doppler shift of objects in our galaxy. That information reveals how other stars and nebulae are moving in relation to Earth. They can also measure the motion of very distant galaxies-called “high redshift galaxies".
Detailed explanation-3: -Astronomers can look at the spectra created by different elements and compare these with the spectra of stars. If the absorption or emission lines they see in the star’s spectra are shifted, they know the object is moving either towards us or away from us.