GENERAL KNOWLEDGE

Detailed explanation-1: -What is ‘red shift’? ‘Red shift’ is a key concept for astronomers. The term can be understood literally-the wavelength of the light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum. Something similar happens to sound waves when a source of sound moves relative to an observer.

Detailed explanation-2: -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-3: -The fabric of space expands. This is the cause primarily responsible for the redshifting we see of distant galaxies. Light travels through the fabric of space, which is expanding as time progresses since the Big Bang, and that expanding space stretches the wavelength of the light that travels through it.

Detailed explanation-4: -Likewise, if a star is zooming away from you, any light it emits gets stretched. You see these stretched-out light waves as having a lower frequency. Since red is at the low-frequency end of the visible spectrum, we say that light from a receding star is shifted toward red, or redshifted.