EVERYDAY SCIENCE

Detailed explanation-1: -As an object moves away from us, the sound or light waves emitted by the object are stretched out, which makes them have a lower pitch and moves them towards the red end of the electromagnetic spectrum, where light has a longer wavelength. In the case of light waves, this is called redshift.

Detailed explanation-2: -In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in frequency and energy, is known as a negative redshift, or blueshift.

Detailed explanation-3: -’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-4: -Bottom line: A redshift reveals how an object in space (star/planet/galaxy) is moving compared to us. It lets astronomers measure a distance for the most distant (and therefore oldest) objects in our universe.

Detailed explanation-5: -Doppler shift This apparent change in wavelength can also be observed for the visible light emitted by stars or galaxies. So, if a star is moving towards Earth, it appears to emit light that is shorter in wavelength compared to a source of light that isn’t moving.