Universe

What is the universe?

What is the universe?

He Universe It's everything, no 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 so. On the contrary: in terms of matter it is, above all, empty space. Some people even claim that the Universe we live in is not real, that it is a hologram.

The known Universe contains galaxies, clusters of galaxies and larger structures called superclusters, in addition to 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:

SymbolChemical elementAtoms
HHydrogen1.000.000
I haveHelium63.000
OROxygen690
CCarbon420
NNitrogen87
YesSilicon45
MgMagnesium40
NeNeon37
FaithIron32
SSulfur16
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 remains united and in continuous movement thanks to a dominant force, gravity.

Our place in the universe

Our world, the Earth, is tiny compared to the sky.

We are part of Solar system, lost in an arm of the Milky Way, a galaxy that has 100,000 million stars, but is only one among the hundreds of billions of galaxies that make up the Universe.

The Big Bang theory explains how it 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 is 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 unveiled, scientists will not be able to explain with total certainty what the Universe is.

Discover more:
• The four fundamental forces
• Edwin Hubble and the expansion of the Universe
• Articles and readings about the universe


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Basic UniverseObservation of the Cosmos