Origin of Universe

#ORIGIN_OF_THE_UNIVERSE_তেংপান্বা_কারম্না_শেম্লকখিবগে!!!

The present universe began approximately 13.78 billion years ago with "Big Bang" as the Singularity Point. #The_BIG_BANG_created_the_Universe and formed space and time. The solar system was formed about 4.57 billion years ago.#The_Big_Bang_timeline which led to the formation & Evolution of the universe are the following:
1. #THE_BEGINNING_Time_Interval: (0-10^-43 sec); Temp (∞-10^32 K); Radius (<10^-52 m); Planck Epoch; Forces Unified:
Key Events – BIG BANG occurs; Universe Formed; radius of the Universe < 10^-50 cm; and energy in form of radiation. Four Fundamental Forces (Gravity, Strong Nuclear Force, Weak Nuclear Force, and Electromagnetism) all have same strength and are possibly unified into one Fundamental Force.
2. #Time_Interval: (10^-43 - 10^-36 sec); Temp (10^32-10^28 K); Radius (10^-52 - 10^-50 m); Grand Unification Epoch; Gravity Separates:
Key Events – Gravity separates from the other fundamental forces (which remain unified), and the earliest elementary particles (and antiparticles) begin to be created.
3. #Time_Interval: (10^-36 - 10^-32 sec); Temp (10^28-10^26 K); Radius (10^-50 m – 1 m); Inflationary Epoch:
Key Events – Separation of strong nuclear force initiates rapid exponential expansion whereby universe expands by a factor of 10^26 to 10 cm; universe filled with dense plasma of Quarks and Gluons.
4. #Time_Interval: (10^-36 - 10^-12 sec); Temp (10^28-10^16 K); Radius (10^-50 m – 12 light seconds (ls)); Electroweak Epoch; Strong nuclear force separates:
Key Events – Particle interactions create exotic particles of W,Z, and Higgs bosons. Higgs field slows particles and confers mass on them that allows a future universe made out of radiation to support particles that have mass.
5.#Time_Interval: (10^-12 - 10^-6 sec); Temp (10^16-10^13 K); Radius (12 ls – 3.3 lh); Quark Epoch; Weak and Electromagnetic forces separate:
Key Events – Four fundamentals forces now distinct and assume present form. Quarks, electrons, and neutrinos form in large numbers as the universe cools Quarks and Antiquarks annihilate each other upon contact, but surplus of quarks survives that will ultimately combine to form matter.
6.#Time_Interval: (10^-6 – 1 sec); Temp (10^13-10^10 K); Radius (3.3 lh – 137 ld); Hadron Epoch; Four forces distinct:
Key Events – Quarks combine to form Hadrons (protons and neutrinos) and Anti-hadrons; and electrons collide with protons to form neutrons and emit massless neutrinos.
7.#Time_Interval: (1 sec – 3 min); Temp (10^10-10^9 K); Radius (137 ld – 1.2 ly); Lepton Epoch; Four forces distinct:
Key Events – After most Hadrons and Anti-hadrons annihilate each other, Leptons (such as electrons) and Anti-leptons (such as positrons) dominate mass of universe. Electrons and Positrons annihilate each other releasing energy in the form of photons.
8.#Time_Interval: (3 min – 240,000 yr); Temp (109- 5x10^3 K); Photon Epoch; Four forces distinct:
Key Events – In first 20 min temperature decreases to where atomic nuclei of Hydrogen, Helium and Lithium form (NUCLEOSYNTHESIS). Afterwards universe is filled with plasma, a hot opaque soup of atomic nuclei and electrons. Energy in universe dominated by photons that interact with charged protons, electrons and nuclei.
9.#Time_Interval: (240,000 yr – 300,000 yr); Temp (5x10^3 - 3x10^3 K); Recombination/Decoupling; Four forces distinct:
Key Events – Density continues to decrease. Ionized hydrogen and helium are neutralized by captured electrons. Photons decouple from matter and are observed as the Cosmic Microwave Background Radiation (CMBR). At the end of this period, universe consists of a fog of 75 % hydrogen, 25 % helium and traces of lithium.
10.#Time_Interval: (300,000 yr – 1.5x10^8 yr); Temp (3x10^3 – 55 K); Dark Era; Four forces distinct:
Key Events –Period after formation of atoms and before formation of stars. Diffuse matter remains essentially inactive. Although photons exist, the universe at this time is literally dark, with no stars having formed to give off light.
11.#Time_Interval: (1.5x10^8 yr – 1 billion yr); Temp (55 – 17 K); Re-ionization; Four forces distinct:
Key Events – First Quasars form from gravitational collapse and emitted radiation re-ionizes the constituents to form plasma. From this point on, universe remains as ionized plasma.
12.#Time_Interval: (1 billion yr – 1.5 billion year); Temp (17 – 14 K); Star and Galaxy Formation; Four forces distinct:
Key Events – Gravity amplifies irregularities in density of primordial gas with small clouds increasing in density as universe continues to expand. Small, dense cloud of cosmic gas starts to collapse under their own gravity, becoming hot enough to trigger nuclear fusion reactions between hydrogen atoms creating first stars. First stars are short-lived supermassive stars that burn out quickly and explode in massive supernova events with remnants forming subsequent generations of stars. Large volume of matter collapse to form galaxies and gravitational attraction pulls galaxies towards each other to form groups, clusters, and superclusters.
13.#Time_Interval: (8.5 billion yr – 9.2 billion year); Temp (4.5 K); Solar System Formation; Four forces distinct:
Key Events – Sun is a late-generation star that incorporates debris from many generations of earlier stars. Solar System formed around Sun around 8.5 to 9 billion years after the Big Bang.
14.#THE_PRESENT_Time_Interval: (13.78 billion year); Temp (2.76 K); Radius (46.6 billion light year); Present; Four forces distinct:
Key Events – #EXPANSION_OF_THE_UNIVERSE_CONTINUES……!!!