If we add up all the light coming from galaxies (and the stars within them), and from all the clouds of gas and dust in the Universe, we’d end up with a colour very close to white, but actually a little bit ‘beige’. Averaged over the whole sky, however, this beige colour is diluted and appears almost, but not quite, black.
Given the immense size of the Universe, and the abundance of stars, it might be surprising that the sky isn’t bright white. This is because the Universe has a finite age, and the light from the furthest stars hasn’t had time to reach us yet.
- How far do we travel through space every day?
- What colour is the sky on an exoplanet?
- Is space a perfect vacuum?
- What determines the colour of an object?