The Universe
The universe was born with a hundredth of billion of trillionth of a second in age. It experienced on incredible burst of expansion known as inflation, in which space itself expanded faster than the speed of light. During this period, the universe doubled in size at least 90 times. According to NASA , after inflation growth of the universe continued, but a slower rate.
Roughly, 380,000 years after the Big Bang, matter cooled enough for atoms, to form during the era of recombination, resulting in a transparent, electrically neutral gas, according to NASA. These set loose the initial flash of light created during the Big Bang, which detectable today as cosmic microwaved background radiation. However, after this point, the universe was plunged into darkness, since no stars or any other bright objects had formed yet.
Until about 30 years ago, astronomers thought that the universe was composed almost entirely ordinary atoms or 'baryonic matter' , according to NASA. It turns out that atoms only make up 4.6 percent of the universe. Of the reminder, 23 percent is made up of dark matter, which is likely composed of one or more species of subatomic particles. When it comes to the atoms we are familiar with, hydrogen make up about 75 percent while helium make up about 25 percent, with heavier elements making up only a tiny fraction of the universe atoms.
The shape and whether or not is finite or infinite in extend depends on the struggle between the rate its expansion and the pull of gravity. If the density of the universe exceeds of a specific critical value, then the universe is closed and positive curved like the surface of a sphere. If so, according to NASA, the universe is not infinite but has no end, just as the area on the surface of a sphere is not infinite but has not beginning or end to speak of.
After that, it was long thought the gravity of matter in the universe was certain to slow the expansion of the universe. The expansion of the universe was not slowing due to gravity, but instead inexplicably was accelerating. The name of unknown force diving this accelerating expansion is dark energy, and it remains one of the greatest mysteries in science.
-NURUL ADAWIYAH BINTI MOHD FAUZI-