What is the Big Bang?
The Big Bang is the theory that tries to give the answer to how the universe originated and how its later development took place until today.
The Big Bang – which literally means big bang – is the most widely accepted theory of the origin of the universe by scientists worldwide, and is therefore also known as’standard theory’.
This happened some 13.8 billion years ago. Theoretical physicists have managed to reconstruct this chronology of events from 1/100th of a second after the Big Bang.
After the explosion, at the same time that the Universe expanded (in the same way that when inflating a balloon it occupies more space), it cooled sufficiently and the first subatomic particles were formed: Electrons, Positrons, Mesons, Baryons, Neutrinos, Photons and a long etcetera up to more than 90 particles known today.
Scientists like Roger Penrose, George F. R. Ellis, and Stephen Hawking, on the other hand, started from the theory of general relativity that Albert Einstein postulated and added notions related to space and time.
These measurements allowed them to infer that time and space had a finite beginning, corresponding to the origin of energy and matter.
The current big bang theory, in short, combines the principles of the theory of general relativity with various observations on the position modifications of galaxies, enabling the conditions of the universe in time to be extrapolated.
Where the name Big Bang was born
The name Big Bang is due to the British astronomer Fred Hoyle and was the result of his intention to pejoratively name this theory, with which he did not agree at all. By the way, this astronomer was the author of the steady state theory.
Later atoms were formed. Meanwhile, due to gravity, matter was clumping together to form clouds of these primordial elements. Some grew so big that stars began to rise and form galaxies.
A tiny, warm start
Originally, the universe was made up of tiny, hot particles, mixed with light and energy. It was nothing like what we see now.
As all that expanded and took up more space, the universe began to cool.
The small particles clumped together. And they formed the atoms. Then those atoms grouped together. After a very long time, atoms came together to form stars and galaxies.
The first stars created larger atoms and groups of atoms called molecules. From there, more stars were born.
At the same time, galaxies collided and grouped together. As new stars were born and others died, things like asteroids, comets, planets and black holes formed.
What happened after the Big Bang?
The initial universe was completely disorganized, possessing no galaxies, no stars, no molecules, no atoms, no atoms, not even nuclei of atoms. It was just a broth of formless matter, at a temperature of billions of degrees.
When some 380,000 years had passed since the Big Bang, the Universe had experienced an expansion which, in turn, had produced a strong cooling.
When the temperature dropped to less than 3,000ºK the electromagnetic interaction was already able to get the electrons to bond with the protons.
Hydrogen and helium atoms were generated, the photons were able to escape and the universe became transparent to light.
At such a high initial temperature, the physical processes accelerated incredibly. More processes occurred in a second that occurred in millions of years in a colder world.
History of the Big Bang Theory
In 1948, the Russian physicist George Gamow, a naturalized American physicist, modified Lemaître’s theory of the primordial nucleus.
Gamow stated that the Universe was created in a gigantic explosion and that the various elements observed today were produced during the first minutes after the Big Bang.
When the extremely high temperature and density of the Universe fused subatomic particles into the chemical elements.
More recent calculations indicate that hydrogen and helium would have been the primary products of the Big Bang, and the heaviest elements were produced later, within the stars.
Gamow’s theory, although elementary and then rectified, provides a basis for understanding the early stages of the Universe and its subsequent evolution.
The matter that existed in the early moments of the Universe expanded rapidly. As they expanded, the helium and hydrogen cooled and condensed into stars and galaxies.
The Expansion of the Universe
This explains the expansion of the Universe and constitutes the physical basis of Hubble’s law.
As the Universe expanded, the residual radiation from the Big Bang continued to cool, reaching a temperature of about 3 °K (-270 °C).
These traces of microwave background radiation were detected by radio astronomers in 1964, providing what most astronomers consider to be the confirmation of the Big Bang theory.
Recent measurements of the redshift of supernovae, for the time being attributed to dark energy, indicate that the expansion of the universe, far from slowing down, is accelerating.
The study of black holes and the recent discovery of gravitational waves continue to provide more interesting data. It seems that the investigation into the Big Bang still has a long way to go.
Recently, scientists at Harvard University’s specialized center who are studying this topic found evidence of gravitational waves that would contribute to the Big Bang theory.
The Big Bang is the only theory?
The Big Bang theory is not the only theory of the origin of the universe, but rather the most popular.
One of the best known is the one created by physicist Robert Gentry, in which he explains his model based on the defects of the Big Bang theory.
On the other hand, it must be borne in mind that in cosmogony, science and God seem to meet: since creation was a supernatural event, it is worth asking if there is anything beyond the natural.
The Big Bang theory remains one of the most widely accepted, but several questions remain unanswered.
The Planck Space Telescope
The European Space Agency’s Planck space telescope has produced the most detailed map to date of the cosmic microwave background, the fossilized radiation of the Big Bang.
This new map was presented this morning and presents features that challenge the foundations of today’s cosmological models.
This first image is based on data collected during the first 15 and a half months of Planck’s observations and is his first full-sky map of the oldest light in the Universe, recorded in the sky when it was just 380,000 years old.
A great book I recommend is this.
- Christopher Lloyd
- Publisher: What on Earth Books
- Pasta dura: 352 pages