Big Bang: The theory of the Big Bang – simply explained

The Big Bang forms the basis for our theoretical understanding of the origin of the cosmos and its evolution

The Big Bang – beginning of space and time

The idea of the Big Bang fascinates and confuses at the same time. It is the scientific theory that explains the beginning of space and time. But what exactly happened in the Big Bang and what does it mean for our understanding of the universe?

• The Big Bang is the instantaneous burst from which space and time exist. It is the starting point from which the universe expands.

• According to the current scientific assumption, there was neither space nor time before the Big Bang. What was “before” the Big Bang is therefore a question that cannot be answered with our usual understanding of time.

• The Big Bang did not lead to the explosion of an existing material into an empty space, but to the creation of space and time itself.

• According to the Big Bang theory, the universe was extremely hot and dense in the first moments. As it expanded, it cooled and matter formed.

• The radiation that was released shortly after the Big Bang is still detectable and is called cosmic background radiation.

• The Big Bang theory is supported by a variety of observations, including the so-called redshift of distant galaxies and the existence of the cosmic background radiation.

• Despite this, there are still unanswered questions and debates regarding details of the Big Bang theory and the behaviour of the universe in general.

The Big Bang and modern cosmology

After the Big Bang, an incredible cosmological process began that shaped our universe and laid the foundation for everything we know today. But how did the universe evolve from the state of the extremely hot, dense Big Bang to its present structure? And what physical concepts help us understand this evolution?

• After the Big Bang, the universe went through different epochs, including the inflationary phase, the Dark Era, the era of reionisation and the formation of structure.

• The inflationary phase theory states that the universe expanded exponentially shortly after the Big Bang. This would explain some of the mysteries of the universe, such as its impressive uniformity.

• The Dark Era is the period after the end of inflation when the universe did not have enough thermal energy to emit light.

• The era of reionisation marks the end of the Dark Era, when the first stars began to burn and illuminate the universe with their light.

• In the era of structure formation, the first stars and galaxies formed from the primordial matter clusters under the action of gravity.

• Modern theories of cosmology include concepts such as dark matter and dark energy, which help explain the expansion and structure of the universe.

• Astronomers use sophisticated tools like space telescopes and particle accelerators to unravel the mysteries of the universe and deepen our understanding of the Big Bang and its aftermath.

• Although the Big Bang theory is a fundamental foundation of our cosmology, the study of the universe is a dynamic and ever-evolving field with many exciting discoveries still waiting for us.