Overview of the Universe - Lecture 1 Notes

Overview of the Universe - Lecture 1 Notes Beginning of Lecture: - It is quite an exciting thing to imagine the universe where mysteries are so many and still there are many that are left unsolved. - It involves all the objects that exist in the world comprising the microcosm as well as the macrocosm. - Knowing the universe consists of studying its structure as well as its subunits and the laws that regulate it. The scale of the universe is almost incomprehensible. Key points to consider: ● Molecules- Also in the intermediate category, and have parts which are even tinier than the atom which is unimaginably small. ● Atoms – particles consisting of protons, Neutrons, and electrons- the building blocks of matter making up the field of chemistry. ● Organisms - building blocks or subunits called cells that are in turn made up of molecules by the billions. ● Humans – made of trillions of cells that are each a whole world in itself. ● Planets – which are among them our planet, earth orbit stars and can exist life if the conditions are favorable. ● Stars – big spheres of hot gas that can give off light and even heat. ● Solar Systems – accumulation of planets in an individual solar system that revolves round the star. ● Galaxies – clusters of stars, planets and other celestial bodies contained within them and held together by gravity. ● The Universe- a system, structures, systems of planets, stars, and especially galaxies that make up the cosmos. Observable Universe and Beyond ● ● ● ● Observable Universe - stretches about 93 billion light-years in diameter. Hubble Deep Field - a small region of the sky revealing thousands of distant galaxies. Cosmic Microwave Background - radiation left over from the Big Bang, providing a snapshot of the early universe. Dark Matter - unseen matter that exerts gravitational forces, influencing the structure of ● ● the universe. Dark Energy - mysterious force driving the accelerated expansion of the universe. Multiverse Theory - the hypothesis that our universe may be one of many universes, each with different laws of physics.