How did quantum fluctuations transform into cosmic objects

How did quantum fluctuations transform into cosmic objects

Scientists have created a simple model explaining the evolution of the universe since the Big Bang. In this model, the basic components are dark energy, cold dark matter, and normal matter.

In my previous article, we tried to understand what happened in the first second of the universe after the Big Bang. In that first second, the universe expanded extraordinarily, the expansion rate slowed towards the end of the first second, and as gravitational waves spread throughout the universe, forces separating from the superforce began to form subatomic particles. Immediately afterward, with the activation of the Higgs field, these particles gained mass.

At this stage, the universe was like a particle soup of matter and energy.

This cosmic soup contained a homogeneous mixture of quarks, electrons, and their antiparticles. Neutrinos, photons, and dark matter particles were also present in this soup.

As you know, dark matter particles are a type of massive particle that does not interact with photons and is therefore called dark; they do not emit light and their nature is not yet known.

The Matter-Antimatter War
0.0001 seconds after the Big Bang, less than a second later, a terrible war awaited matter. Because it had an opposite, antimatter. At this stage, while energy was transforming into matter, its opposite was simultaneously formed. We call it antimatter.

We know that when matter and antimatter come together, they collide and annihilate each other, leaving behind energy.

Therefore, after the collision of matter and antimatter, an enormous amount of energy fills the universe.

Matter wins this war by a narrow margin, and the remaining matter is enough to form the universe. Antimatter has disappeared.

Everything we witness today is the remnants of this war. The present-day universe is built with these remaining matter particles.

However, a multitude of questions remain. Why are there more matter particles than antimatter particles in a situation where the amount of matter and antimatter is expected to be equal?

There is no reasonable answer to this question yet.

100th Second and the Opaque Universe
As the first second passes, the universe continues to expand and cool. The universe’s width is 100 trillion km (10¹⁹ cm) and its temperature is around T=10¹⁰ K. The universe is still like a very hot soup of particles.

In this phase, quarks grouped together in sets of three to form protons and neutrons; these are the components of the atomic nuclei we know today.

The density and temperature of the particles are extremely high, and the particles are constantly colliding. Because of the high density, photons are trapped within matter particles such as electrons, protons, neutrons, and the atomic nuclei that had formed up to that point.

Therefore, this prevents photons from moving freely and also prevents any matter condensation that could occur under the influence of gravity.

Approximately 100 seconds after the Big Bang, protons and neutrons combined to form hydrogen and helium nuclei. This phase is called “nucleosynthesis.”

At this stage, the universe is opaque and will remain opaque for 380,000 years.