The Earth’s atmosphere, compared to the rest of the planet, consists of a relatively thin layer extending 80-100 km above the surface. It provides life, protects all living beings from cosmic radiation and solar ultraviolet light. Beyond the atmosphere opens up a vast Universe rich in planets, stars, galaxies and mysteries that mankind is only beginning to unravel. The basic question remains open to science: does the Universe have a limit or is it infinite?
Scale of space
Earth is part of the Solar System, a family of eight planets that orbit the Sun. Although it dominates our sky, it is actually an ordinary star – a yellow dwarf. The closest star to us outside the Solar System is 4.36 light-years away, the triple star system Alpha Centauri. However, even the fastest spacecraft would take thousands of years to travel that distance.
Stars form galaxies, and our Milky Way galaxy has about 100 billion stars. Almost all stars have planets, some of which are probably Earth-like. They may be homes to life that could also be looking for answers to cosmic mysteries.
Beyond the Milky Way are billions of other galaxies. In between is almost a void filled with the mysterious dark matter that forms the structure of the Universe. Telescopes reveal to us a multitude of galaxies flying endlessly in all directions, creating a spectacular cosmic landscape.
Expansion of the Universe
The Universe is constantly expanding, like an inflated balloon with dots (galaxies) moving away from each other. Over millions of years, this expansion creates new space. However, this raises important questions: will the expansion be infinite? Is the universe closed? And if there are boundaries, what is beyond them?
Science offers several hypotheses. Some believe that the Universe is infinite and contains countless galaxies. Others suggest that it is looped back on itself, like the surface of a sphere of a globe: traveling in a certain direction will bring you back to the starting point.
Observable Universe
However, despite advanced technology and modern telescopes, there is a limit to the observable cosmos, which is bounded by the speed of light and the age of the Universe itself, which is about 13.8 billion years. But given the fact that it has expanded considerably since its inception, the current radius of the observable Universe is about 46.5 billion light years. This means that the diameter of the observable Universe is about 93 billion light years. What lies beyond this boundary is still unknown to science.
What will happen to the Universe?
Various theories describe possible scenarios for the future:
Heat Death of the Universe. If the expansion continues indefinitely, the energy will be evenly distributed and any activity will cease.
Big Rip. Because of the acceleration of expansion, dark energy can even destroy atoms.
Big Crunch. Under the action of increasing gravity, the Universe may shrink back into a singularity.
Cosmic Rebirth. Expansion is probably constantly replaced by contraction in endlessly repeating cycles.
Search for answers
The question of whether the Universe has an end poses a challenge to both science and philosophy. If it is infinite, it raises the question of its origin. If it is closed, its scale is still beyond human comprehension.
Modern telescopes help us look deeper into time-space, unlocking new mysteries of the cosmos. While we may not find definitive answers, each discovery is a reminder that we are part of this limitless Universe.
When looking at the starry sky, it’s worth remembering that each star and galaxy is not only a source of inspiration, but also a reminder of our common journey to understanding the Universe. Future generations will continue this quest, driven by the same wonder that drives us today.
Earlier we covered how the Universe emerged.
According to TheBrighterSide
