How the Cosmic Horizon May Hide the Truth of Our Universe
What could lay beyond the edge of visible space?
I’ve always had difficulty wrapping my mind around just how big the Universe is. Sitting here on Earth, it can be easy to forget that our comfortable little planet is just a speck in the ocean that is space.
With that said, every ocean has a horizon and space is no different. The cosmic horizon is fascinating because planets, stars, and entire galaxies are constantly disappearing over the edge.
That horizon is estimated to be about 42 billion light-years away from us and beyond it? Well, who knows. It’s a mystery.
But it’s important to gain a sense of how the cosmic horizon works and why it actually exists. Our Universe has a finite age of about 13.7 billion years. Therefore, one may expect that the radius of the Universe would also be 13.7 billion light-years.
Yet, as mentioned, the cosmic horizon is about 42 billion light-years away. This is because the expansion of space is actually faster than the speed at which light can travel. To put it in perspective, the oldest light in the Universe is 13 billion years old but comes from a region that is over 40 billion light-years away.
