Our universe begins with the Big Bang theory; started with singularity; infinite density temperature and no stars a heat ball.

What Happened?

Then, an explosion occurred around 13.82 billion years ago. Due to the explosion, our universe started expanding and stretching, forming atoms- creating stars and galaxies. This theory was discovered by Edwin Hubble.

Evidence: Cosmic Inflation

Evidence of such an event was supported by red shifting an example of the Doppler effect. The universe is expanding/ travelling faster than the speed of light. Light wave lengths are too slow to keep up with the original length therefore getting stretched causing our universe to expand. Till today our universe is still continuously expanding!

Right after the Big Bang, it was too hot for the atomic nuclei to make atoms; instead universe was swarming with a sea of subatomic matter. The universe was a sea of electrons and quarks. However, 100-200 million years after the Big Bang the universe cooled down, forming stars.

What happened?

380,000 years after the Big Bang; atoms were created. During the time it was still extremely hot similar to the temperature of the core of a star. The extreme heat allowed nuclear fusion to occur. In the first few minutes, particles smashed together, forming deuterium (an isotope of Hydrogen), and lithium.

After the first billion years of the Big Bang, galaxies were formed. During the period the Universe was still hotter than a star's surface. As it is expanding and cooling; structures start to form as the gravity of matter can overcome the heat. Therefore, becoming the galaxies we see today.

Due to the absorbing effects of all those hydrogen atoms' absorption powers. The cosmos was black for the following 200 million years. No stars were present to shine. At this moment, the universe was made up entirely of hydrogen atoms, helium, and minuscule quantities of heavier elements.

At 380,000 years into the existence of the universe, elections were not confined due to the rapid movement of atomic nuclei. Each attempt was thwarted by the high temperatures, causing random photons to dislodge them once again. At this point, the universe was in an ionized state. However, after 380 millennia, the temperature had sufficiently decreased, allowing electrons to merge with protons and helium nuclei, forming stable neutral atoms for the first time. This moment is known as Recombination.

What is it about?

Reionization is a phase in the history around when the universe was 1 billion years old. When the first stars and galaxies formed. Their intense ultraviolet light stripped electrons from hydrogen atoms, turning neutral gas into ionized plasma. This process, called reionization, made the universe more transparent to light and influenced the formation of galaxies and cosmic structures.

What do we predict?

Scientists thought the universe's current expansion was slowing down; however, it is in fact the opposite. Our universe's cosmic expansion is speeding up. In 1998, astronomers made a discovery indicating that specific supernovae, which are intense stellar explosions, appeared less luminous than anticipated. They deduced that this discrepancy could only be explained if the supernovae had travelled to greater distances and at a swifter pace than initially predicted.

Our solar system was estimated to be created 9 billion years after the Big Bang. Scientists believe our solar system was formed from solar nebula (dust) and a huge rotating gas cloud. Nebula collapsed due to gravity, causing it to spin faster and flatten into a disk. Almost all the material was pulled toward the center forming the sun.