According to the prevailing scientific understanding, the Big Bang did not create energy or matter in the traditional sense. Instead, the Big Bang is considered the starting point of the expansion of the universe from an extremely hot and dense state.
In the earliest moments of the universe, often referred to as the Planck epoch, the conditions were incredibly intense and beyond our current understanding of physics. At this stage, the universe was compressed to a singularity, a point of infinite density and temperature. The laws of physics as we know them break down at this point, and a complete theory of quantum gravity is needed to accurately describe these conditions.
As the universe expanded and cooled down, various processes occurred that are believed to have led to the creation of energy and matter as we currently understand them. These processes include:
Inflation: Shortly after the initial singularity, the universe underwent a period of rapid expansion known as cosmic inflation. During inflation, the universe expanded exponentially, smoothing out irregularities and providing the seed for the structure we observe today. The energy for this inflationary expansion is thought to have been sourced from the gravitational field associated with the singularity.
Particle Production: As the universe cooled further, it entered an era where the energies were low enough for particles and antiparticles to be created and annihilate each other. During this period, known as the particle-antiparticle annihilation, particles and antiparticles could spontaneously appear from the available energy and then annihilate, effectively converting their mass into energy.
Quark-Gluon Plasma: As the universe continued to expand and cool, it reached a stage where the energy was no longer sufficient to create particle-antiparticle pairs. At this point, around 10 microseconds after the Big Bang, the universe was filled with a dense, hot soup of fundamental particles, primarily quarks and gluons. This state is referred to as the quark-gluon plasma and is considered the earliest phase of matter as we know it.
In summary, the Big Bang itself is not considered a creation event but rather the starting point of the expansion of the universe. The subsequent evolution of the universe involved the conversion of energy into matter and the creation of particles through various physical processes as the universe cooled down and expanded.