@f_702h: Some of the earliest cosmological models of the universe were geocentric, placing Earth at the center. During the Scientific Revolution, astronomical observations led to a heliocentric model. Further observational improvements led to the realization that the Sun is one of a few hundred billion stars in the Milky Way, which is one of a few hundred billion galaxies in the observable universe. At the largest scale, galaxies are distributed uniformly and the same in all directions. At smaller scales, galaxies are distributed in clusters and superclusters, which form immense filaments and voids in space, creating a vast foam-like structure.[11] Discoveries in the early 20th century, including general relativity, led to the modern view of an expanding, isotropic, homogeneous universe. Evidence accumulated supporting the Big Bang theory: an initial hot fireball cooled and becoming less dense as the universe expanded, allowing the first subatomic particles and simple atoms to form. Giant clouds of hydrogen and helium were gradually drawn to the places where matter was most dense, forming the first galaxies, stars, and eventually, everything else. From studying the effects of gravity on both matter and light, it has been discovered that the universe contains much more matter than is accounted for by visible objects; stars, galaxies, nebulae and interstellar gas. This unseen matter is known as dark matter.[12] In the widely accepted ΛCDM cosmological model, dark matter accounts for about 25.8%±1.1% of the mass and energy in the universe while about 69.2%±1.2% is dark energy, a mysterious form of energy responsible for the acceleration of the expansion of the universe.[13] Ordinary ('baryonic') matter therefore composes only 4.84%±0.1% of the universe.[13] Stars, planets, and visible gas clouds only form about 6% of this ordinary matter.[14] There are many competing hypotheses about the ultimate fate of the universe and about what, if anything, preceded the Big Bang.#fyp #explore

ً

Open In TikTok:

Region: SA

Monday 27 July 2026 11:01:29 GMT