Is the universe truly infinite?

(Dan Tri Newspaper) - That is one of the most profound questions we can ask, and here is the short answer: We don't know.

Is the universe infinite or finite?

Despite significant progress in exploring the observable universe, scientists have yet to provide a definitive answer to the question of whether space is infinitely vast or takes on some strange shape.

Current theories are divided into two main camps: some argue that the universe is truly infinite, without boundaries, while others believe that the universe is finite but without "boundaries" in the conventional sense.

Researchers emphasize that the ultimate answer may remain beyond human reach, despite increasingly detailed observations and theoretical advances.

However, what we know about the observable part of the universe and the most distant galaxies can provide important clues.

A dense and highly active region of stars at the center of the Milky Way (image: Triff/Shutterstock).

What we know about the universe

The portion of the universe that we can observe is certainly finite. Because light travels at a finite speed and the universe is expanding (confirmed by black hole collisions), we can only see a certain "horizon".

The universe has been expanding since the Big Bang, causing galaxies to drift further and further apart. The greater the distance between two galaxies, the faster they separate.

This can be visualized by inflating a balloon with dots drawn on its surface; as the balloon inflates, the dots move apart, simulating the expansion of space.

However, the shape of the universe, as well as whether it has "edges" or stretches infinitely, remains a mystery. Current measurements of cosmic curvature suggest that the universe is spatially flat.

This doesn't mean the universe is a flat disk, but rather that if two laser beams shone parallel through space, they would never intersect or separate, even after billions of years.

The idea of ​​a flat universe opens up two clear possibilities: If the universe were as flat as an infinitely long sheet of paper, it would be infinite. But it could also be toroidal (shaped like a donut), in which case it would be finite but without boundaries.

The planar geometry we observe still allows for a finite but boundaryless global topological structure, and current observational accuracy is insufficient to clearly distinguish between these two cases.

Why can the truth remain a mystery forever?

Illustration of the multiverse theory. This theory suggests that beyond our observable universe, there may be countless other universes, sometimes called parallel universes or "bubble" universes (image: Vchal/Getty Images).

Despite remarkable advances in observation, the ability to determine whether the universe is truly infinite or merely vast still faces significant limitations.

Astrophysicists hold differing views, some leaning towards an infinite universe, others believing in a finite universe with a specific interconnected structure. The multiverse theory further complicates the issue, emphasizing the speculative nature of this question.

Because we only observe a portion of the universe, any conclusions about the entire universe require extrapolation that may never be verifiable.

We cannot "rewind" the universe or conduct controlled experiments on a cosmic scale. We are entirely dependent on passive observations. This means that questions about what lies beyond our observational horizon, how space is connected, whether there is a boundary, or whether time and space extend infinitely, may remain unanswered.

Ultimately, the universe may be so vast that even if it is finite, distinguishing it from the "infinite" may forever remain beyond our reach.

If it were infinite, we might never observe evidence of a boundary. In any case, this question may be beyond the reach of human empirical understanding.

Source: https://dantri.com.vn/khoa-hoc/vu-tru-co-thuc-su-vo-han-20251126015148568.htm