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What is the effect of the expansion of the universe on light?

Answer 1

It causes redshift.

The universe is expanding, like a pie with raisins in the oven. Over time, the pie grows and the raisins, or the galaxies, get farther apart. However, what is actually happening is that the pasta, or the space itself, is growing, not the galaxies. The galaxies are standing and getting farther apart; the space that separates them is expanding.

This kind of universe causes the redshift, which is also known as the cosmological redshift, because light travels through it at a wavelength that is getting longer just like any other distance.

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Answer 2

Levi Acosta

As the universe expands, light from far-off objects experiences redshift, or an increase in wavelength as it passes through expanding space; this causes the frequency and energy of the light to decrease.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.