How did the universe begin?
This is a difficult problem that has been tackled by many physicists. The Big Bang theory, which states that the world began with a fireball, is famous, but there are still many things that are not fully understood.
The “inflation theory” was proposed. In this series, a world-famous authority on inflation theory explains its essence in an easy-to-understand manner. Introducing the wisdom of physics that approaches the secrets of the creation of the universe.
*This article is written by Katsuhiko Sato.Inflationary cosmology: What happened before the big bang?This is an excerpt and re-edited version of “ (Bluebacks).
–Did this universe we live in have a “beginning”? If there was a “beginning”, what was it like? —
These are questions that have been asked since the beginning of human history. In the past, it was thought that only religion and philosophy could answer these questions. The story was so far-fetched that it was thought that science could not compete with it.
However, we are now in an age where these questions can be answered using the “words of science.” This is because “cosmology,” the academic field that studies the birth, evolution, and structure of the universe, has made amazing progress over the past 100 years.
More than a hundred years ago, for humans, all that the universe meant was the Milky Way Galaxy, where we live. That was the extent of the universe that humans could observe. However, at the beginning of this century, thanks to explosive advances in observation technology, we realized that the universe has expanded to at least 40 billion light years and is home to countless galaxies, of which the Milky Way is just one. I know. We also learned that the universe began with a “ball of fire” called the Big Bang.
However, observations are not the only thing that has contributed to this expansion of knowledge about the universe. Rather, prior to observation, there were theories that predicted that the universe might be like this, and as these theories were proven through observation, cosmology developed.
The theory of Relativity:
The theory of relativity, which considers time and space, was created by Einstein in the early 20th century, and the quantum theory, which describes the microscopic world, was created around this same time by Bohr, Heisenberg, Schrödinger, and others. These are the two pillars that support modern physics, and with the establishment of these two theories, cosmology has also made dramatic advances.
As a physicist, I am very proud that the countless mysteries of the universe can now be explained through the use of physical theory.
The now famous Big Bang theory was built based on the theory of relativity and quantum theory, and the theory predicted a scenario for the birth of the universe 13.7 billion years ago, which was later proven by observational facts. I think it’s really amazing and wonderful.
However, as research progressed, it became clear that the Big Bang theory alone could not adequately explain the creation of the universe. For example, the Big Bang theory cannot answer why the universe began as a “ball of fire.” Furthermore, as we advance the Big Bang theory, we are forced to believe that the ultimate beginning of the universe was a “singularity”, a point where the laws of physics completely broke down. We have to admit that there is, so to speak, a “god’s realm” in the universe beyond the reach of physics, and as someone involved in physics, this is something that I cannot easily accept.
