GK
THE UNIVERSE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
What does a red shift in light from distant galaxies indicate to a scientist on Earth?
|
|
The gravitational force on Earth changes.
|
|
|
The universe appears to be expanding.
|
|
|
The Jovian planets are aligned with the Sun.
|
|
|
Galaxies are becoming more numerous.
|
Explanation:
Detailed explanation-1: -Ever since 1929, when Edwin Hubble discovered that the Universe is expanding, we have known that most other galaxies are moving away from us. Light from these galaxies is shifted to longer (and this means redder) wavelengths-in other words, it is ‘red-shifted’.
Detailed explanation-2: -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.
There is 1 question to complete.