What's at the edge of the universe? The answer that leaves you speechless

Short answer: We don't know. However, we know what exists within the observable universe, and everything that exists within what is called the “cosmic horizon.”

It's one of the questions you ask us a lot in the comments Humanity has been asking itself practically since the beginning of time: What exists at the edge of the universe? Is there a wall that demarcates the border? The answer is that it is more complicated than that. If you traveled through space in a faster-than-light spacecraft, where would you go? It's so hard to imagine all that. On the other hand, an infinite universe is equally difficult for scientists to accept. After all, there has to be something that space expands into, right?

Cosmic horizon

Let us immediately assume that our universe has limits Relatednamed Cosmic horizon. Light emitted immediately after the Big Bang travels through space for 13.8 billion years. And we are so far. This means that We can only see the universe at a current distance corresponding to a light travel time of 13.8 billion years.

Space expansion

Thanks to the expansion of space, the so-called joint motion distance is approx 45 billion light yearsAnything beyond this limit is unobservable to us because not enough time has passed since the birth of the universe for light from these remote regions to reach our telescopes.

Like a sailor on a ship

Just like the horizon that sailors see on the ocean, this cosmic horizon is not a physical boundary TRUE. Just as the ocean extends beyond the sea horizon, so space extends beyond our visible universe. There is no reason why galaxies cannot exist at such great distances. They are simply invisible to us, no matter how powerful our telescopes are. But knowing that it extends beyond 45 billion light-years does not yet tell us whether it is finite or infinite.

The universe has no boundaries

One thing is certain: The universe has no edges. There are no physical boundaries: no wall, no fence around the universe. However, this does not necessarily mean that the universe is infinitely large. In principle, we can live in the universe I finishProvided that three-dimensional empty space is geometrically curved in a certain way, which is a distinct possibility according to Albert Einstein's theory of general relativity.

The shape of the universe

If the universe had what is called positive curvature, it would be like the surface of a balloon, but instead of a two-dimensional surface, it would be three-dimensional space. If you lived in this spherical version of the universe, you wouldn't need an endless supply of paint to cover everything. However, you will not have the same borders or edges on the same surface. In contrast, a negatively curved universe would resemble a potato chip (or saddle), curved upward along one axis and downward along the other, while a flat universe would resemble a handkerchief. Both versions will extend infinitely.

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