Olber’s Paradox — Explained

Before I go into any detail about this fascinating mystery of the scientific world, we need to establish what a paradox is in the first place. So, a paradox (also known as an antimony) is a logically self-contradictory statement that runs in contrast to your expectation. It is a statement which gives credible reasoning for one side of it yet somehow reaches the completely opposite or logically unreasonable conclusion.

When the question of why the night sky is dark, the general answer from people is “because the sun has set” yes this is true yet think about it for 1 moment, if 1 star can light up the whole sky, then why can’t other stars light up the sky, exactly that other stars can, so then this raises the question, why is the night sky dark but not illuminated, here we are looking at something called Olbers paradox, named after the German astronomer Heinrich Wilhelm Olbers (1758–1840), the paradox was initially brought up by a Greek monk called Cosmas indicopleustes in the 6th century, when he stated in the Topographia Christina (one of the earliest essays of what we would have known about the scientific and geographic world at the time) where he stated: “The crystal-made sky sustains the heat of the Sun, the moon, and the infinite number of stars; otherwise, it would have been full of fire, and it could melt or set on fire.” Olbers states that our understanding of there being a night sky does not agree with the theory that our universe is static and infinitely old. This can be shown by the fact that if the universe was indeed static and eternal in life, then we would be looking at completely different night sky. Instead of there being darkness till the eye can see, we would be looking at very rich and intense bright light starting right back at us, the reason for this is because the universe is uniform on a massive scale and therefore has an infinite number of stars occupying its space, from this we can gather that at any angle we look at we should be blocked by a star, therefore if the theory the universe is stagnant, and everlasting has to be false. So, our next valid theory is one to do with the fact that our universe is expanding by the minute though it has a finite number of years to its life. Different people are claiming that the universe is expanding at different velocities, people are saying 67 kilometers per second per megaparsec (3.26 million light years) and some are going all the way up to 500 million kilometres per second per megaparsec. Though of course none of these can be truly proven with valid evidence but we can take for this that there is a possibility that by the time you finish reading this sentence the universe would have already expanded 7,500 km per megaparsec. the dynamic universe theory is the only logical one. This can be explained like this, when you look up at the night sky we see some stars, and maybe one next to another and if we look in between it we don’t see anything, from our understanding the universe is ever expanding, this shows us that the reason that we don’t see anything in between is because the light, simply, hasn’t reached our sight yet, we can see some stars as the light from those stars have reached our eyes already, but due to the fact that light has a certain speed to it, 300,000,000 m/s, it takes a certain amount of time for light to reach our eyes.

So, you may ask, why this is referred to as a paradox? Well this is a paradox because we are able to explain why this is. In Olbers time the universe was considered to be static and eternal in life, well this has been disproven by the big bang, a known origin of our universe, showing us that the universe had a beginning to it therefore making it impossible for it to be infinite, the big bang also disproves the theory of a static universe by showing is that it has a boundary and therefore is finite.

Now this paradox does not necessarily prove that the universe is still expanding and finite, yet it agrees with our understanding of the universe making it a reliable source. This was certainly a perplexing matter in the time of Olbers, though now we have an explanation to it, hence why it is known as Olbers Paradox.