MCQ Detailed View

In astronomy, the term Blue Shift refers to a phenomenon related to the Doppler effect of light waves. When an object emitting light, such as a star or galaxy, moves towards an observer, the wavelengths of light it emits become compressed. Shorter wavelengths correspond to the blue end of the visible light spectrum, so the object appears slightly bluer than it normally would. This effect is known as Blue Shift.

The opposite effect, called Red Shift, occurs when a celestial object is moving away from the observer, stretching the light waves to longer wavelengths, making the object appear redder. Both effects are important in astrophysics, as they help scientists measure the velocity and direction of motion of stars, galaxies, and other celestial bodies relative to Earth.

Let’s review the other options:

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  Turning a star from white to blue: The star’s color depends on its temperature, not motion. Motion only shifts the perceived wavelength slightly.

  
  


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  In future sun would become blue: The Sun’s color will change only as it evolves, not due to Blue Shift, since it is not moving toward us at high speed.

  
  


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  Black hole was blue at its start: Black holes do not emit visible light in this manner.

  
  


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  None of these: Incorrect, since option A explains the correct phenomenon.

  
  

Blue Shift provides crucial information about stellar dynamics, galaxy collisions, and cosmic expansion. Observing Blue and Red Shifts allows astronomers to map the movement of distant objects and understand the structure of our universe. This makes it a key concept in both astronomy and physics under the study of wave behavior and the Doppler effect.