Physical science

• Physical Science is a branch of natural science that studies non-living systems
• Cosmology is the branch of astronomy that studies the evolution of the universe, which is approximately 98 billion light-years in diameter
• There are 2 trillion galaxies in the universe
• A galaxy is a huge collection of gas, dust, and billions of stars
• The Milky Way is our galaxy and contains approximately 3,916 stars
• The Solar System is a collection of planets and their moons orbiting around the sun
• There are 290 moons orbiting planets in our Solar System
• Physical cosmology explains the universe based on scientific evidence and experiments
• Nicolaus Copernicus proposed that the sun is the center of the universe (1473 - 1543)
• The Big Bang theory suggests that the universe originated from a single, hot, and dense point that began to expand and continues to expand
• Vesto M. Slipher and Carl Wilhelm Wirtz discovered that spiral nebulae (galaxies) were moving away from the earth, known as redshift (1910)
• George Lemaitre is known as the father of the Big Bang theory
• Edwin Hubble supported the Big Bang theory and proposed Hubble's law
• The Premival Atom theory by George Lemaitre is also known as singularity
• Redshift, proposed by Edwin Hubble, is considered evidence of the Big Bang
• Stars are giant balls mostly made up of hydrogen and helium
• Stellar Nucleosynthesis is the process by which elements are formed within stars
• Stellar Evolution is the process by which a star changes during its lifetime
• Formation of main sequence stars: any star that has a hot, dense core fuses hydrogen into helium to produce energy
• All stars are born from clouds of gas and dust called stellar nebulae or molecular clouds that collapsed due to gravity
• As a cloud collapses, it breaks into smaller fragments that contract to form a super hot stellar core called a protostar
• When the core temperature reaches about 10 million Kelvin, nuclear fusions and other nuclear reactions begin, leading to the formation of a main sequence star
• When the majority of the helium in the core has been converted to carbon, the star's fuel is depleted, and the outer material is blown off into space as a planetary nebula, leaving behind a hot and inert carbon core known as a white dwarf
• Isaac Newton who introduced the Law of Universal Gravitation
• Albert Einstein Theory of General Relativity
• (1931) George Lemaitre proposed that the universe began from a single, primeval atom theory which he called " singularity"
• Mythological cosmology this explains the universe and life based on religious beliefs of a specific tradition