Whether the universe has a limit is one of science’s biggest controversies. Although scientists assume that the universe is constantly expanding, the universe we know is just what we can observe.
With the development of technology, astronomers have the opportunity to examine the events that occurred after the Big Bang in more depth. However, this does not mean that we have all the information about the universe. There are still so many mysteries in space that technology doesn’t allow us to study. We don’t even know if the universe has a limit.
In fact, there are three different ways to think about this question, and each has a different answer. We can go on an endless journey with a powerful rocket, combine everything discovered since the beginning of the Big Bang, or try to guess what is beyond what can be observed using imagination.
Is there a limit to the universe? Or are we in an immense universe?
We consider the universe as a 3D coordinate system in which the shortest distance between two points is a straight line and the distances do not change over time. But since spacetime is subject to curvature caused by the presence of matter and energy, the shortest distance between the two points naturally depends on the shape of the universe between these points.
Observationally, there is strong evidence that the universe is expanding. However, these findings have some complex consequences for objects separated by cosmic distances, including the widening of the distance between them. The most distant objects we can see today are only 30 billion light years away, although only 13.8 billion years have passed since the Big Bang.
Most people assume that the universe is 13.8 billion years old, and the limit we can go the farthest in the universe will be 13.8 billion light years. If the universe were stationary and not expanding, this assumption would be true, but unfortunately it is not. The rate of expansion is changing, and knowing what’s happening in the universe tells how fast the universe is expanding.
The boundaries of the universe represent the boundary of the universe we can see, not the boundary of space. Because the speed of light has been spreading for only 13.8 billion years since the Big Bang, no matter how wide the universe. Consequently, it has not yet been enough time for the light of objects at a distance of 30 billion light years to reach Earth.
Just because the universe is constantly expanding doesn’t mean it’s infinite. However, the limit shown by our observations does not prove that the universe has a limit. Therefore, it is not possible to say that the universe has a limit or not at the moment.