The Universe is everything, without exceptions. Matter, energy, space and time, everything that exists is part of the Universe.
It is also called Cosmos . The sciences that study it are several, especially two: astronomy and cosmology.
The Universe is very large, but perhaps not infinite. If it were, there would be infinite matter in infinite stars, and it is not. On the contrary: as regards matter, it is, above all, empty space. Some even claim that the Universe we live in is not real, that it is a hologram .
The known Universe contains galaxies, galaxy clusters, and larger structures called superclusters, as well as intergalactic matter. We still do not know exactly its magnitude, despite the advanced technology available today.
Matter is not distributed uniformly, but is concentrated in specific places: galaxies, stars, planets … However, it is assumed that 90% of what exists is a dark mass, which we cannot observe. For every million hydrogen atoms the 10 most abundant elements are:
| Symbol | Chemical element | Atoms |
| H | Hydrogen | 1,000,000 |
| I have | Helium | 63,000 |
| OR | Oxygen | 690 |
| C | Carbon | 420 |
| N | Nitrogen | 87 |
| Yes | Silicon | Four. Five |
| Mg | Magnesium | 40 |
| Ne | Neon | 37 |
| Faith | Iron | 32 |
| S | Sulfur | 16 |
Chemical elements of the Universe
The Cosmos has at least four known dimensions: the three of space (length, height, width) and one of time. It is held together and in continuous motion thanks to a dominant force, gravity.
Our place in the universe
Our world, Earth, is tiny compared to the sky.
We are part of the Solar System , lost in an arm of the Milky Way, a galaxy that has 100,000 million stars, but is only one of the hundreds of billions of galaxies that make up the Universe.
The Big Bang Theory Explains How It Was Formed
He says that about 13.7 billion years ago matter had an infinite density and temperature. There was a violent explosion and, since then, the universe has been losing density and temperature.
The Big Bang is a singularity, an exception that the laws of physics cannot explain. We can know what happened from the first moment, but the moment and size zero still have no scientific explanation.
Until this mystery is unraveled, scientists will not be able to explain with complete certainty what the Universe is.
