How did the universe form? What led to the formation of stars, planets, and galaxies? These are some of the questions that millions of people have asked throughout history. Specifically, scientists want to find an explanation for all the phenomena that exist. From here is born big Bang Theory. For those who do not know yet, it is the theory that explains the origin of our universe. It also collects the explanation of the existence of planets and galaxies.
If you are curious and want to know how our universe was formed, in this post we will tell you everything. Would you like to know in depth the big Bang Theory?
Characteristics of the Big Bang theory
It is also known as Big Bang theory. It is the one that maintains that our universe as we know it began billions of years ago in a great explosion. All the matter existing in the universe today was concentrated in just one point.
From the moment of the explosion, matter began to expand and is still doing so today. Scientists keep repeating that the universe is continually expanding. For this reason, the Big Bang theory includes the theory of the expanding universe. Matter stored at a single point not only began to expand, but also began to form more complex structures. We refer to the atoms and molecules that, little by little, were forming living organisms.
The date of the beginning of the Big Bang has been estimated by scientists. It had its origin approximately 13.810 million years ago. During this stage in which the universe was just created, it is called the primeval universe. In it, the particles are supposed to have enormous amounts of energy.
With this explosion, the first protons, neutrons, and electrons were formed. The protons and neutrons organized themselves into atomic nuclei. However, the electrons, due to their electrical charge, organized themselves around them. This is how matter originated. You can also read more about the origin of the universe in another related article.
Formation of stars and galaxies
Our solar system is within the galaxy known as the Milky Way. All the stars that we know today began to form long after the Big Bang.
The first stars are believed to have begun to form 13.250 billion years ago. They began to appear approximately 550 million years after the explosion. The oldest galaxies originated 13.200 billion years ago, which makes them also older. Our solar system, the Sun and the planets, formed 4.600 billion years ago. This star formation is fundamental to understanding the evolution of the universe and is related to the study of the star births in various regions of the cosmos.
Evidences of an expanding universe and the explosion
To prove that the Big Bang theory makes sense, evidence must be reported that the universe is expanding. These are the evidences in this regard:
- Olbers paradox: The darkness of the night sky.
- Hubble's Law: It can be verified by observing that the galaxies are moving away from each other.
- Homogeneity of the distribution of matter.
- Tolman Effector (variation in surface gloss).
- Distant supernovae: A temporal dilation is observed in its light curves.
After the moment of the explosion, each particle was expanding and moving away from each other. What happened here was something similar to what happens when we blow up a balloon. As more air we introduce, the air particles expand more and more until they reach the walls.
Theoretical physicists have managed to reconstruct this chronology of events starting at 1 / 100th of a second after the Big Bang. All the matter that was released was composed of the elementary particles that are known. Among them we find the electrons, positrons, mesons, baryons, neutrinos, and photons.
Some more recent calculations indicate that hydrogen and helium were primary products of the explosion. Heavier elements were formed later inside stars. As the universe expands, the residual radiation from the Big Bang continues to cool, reaching a temperature of 3 K (-270°C). The effects of this radiation reflect the profound legacy of the Big Bang and have been the subject of constant study, as have the technological advances of the James Webb telescope, which have allowed us to observe more about the universe.
One of the great doubts of scientists is to solve if the universe is going to expand indefinitely or if it will contract again. Dark matter It has great importance in this and is related to the structure of the universe, in addition to being a relevant aspect in the study of what lies beyond the observable universe, a fundamental theme when analyzing the Big Bang theory.
Discoverers and other theories
The theory that the universe is expanding was formulated in 1922 by Alexander Friedmann. He was based on Albert Einstein's (1915) theory of general relativity. Later, in 1927, the Belgian priest Georges Lemaître drew on the work of the scientists Einstein and De Sitter and reached the same conclusions as Friedmann.
Therefore, scientists do not come to another conclusion, only that the universe is expanding.
There are other theories about the creation of the universe that are not as important as this one. However, there are people in the world who believe and consider them to be true. We list them below.
- Big Crunch theory: This theory bases its foundation on the fact that the expansion of the universe is going to slow down slowly until it begins to retract. It is about the contraction of the universe. This contraction would end in a large implosion known as the Big Crunch. There is not much evidence to support this theory.
- Oscillating universe: It's about our universe oscillating in a constant Big Bang and Big Crunch.
- Steady state and continuous creation: It maintains that the universe is expanding and that its density remains constant because there is matter in continuous creation.
- Inflation theory: It is based on the same characteristics as the Big Bang but it says that there was an initial process. The process is called inflation and the expansion of the universe is faster.
Lastly, there are some people who think that the universe was created by God or some divine entity.
