Origin of the Universe: Big Bang Theory

• The universe encompasses space, time, and all its contents, including matter, galaxies, and energy.
• The universe is estimated to be about 13.8 billion years old.
• Its age was determined through observations of cosmic microwave background radiation and measurements of its expansion rate.

Big Bang Theory

• Scientists believe the universe began with a massive explosion called the Big Bang.
• Initially, the universe was in an extremely hot and dense state, and then it rapidly expanded.
• Since the Big Bang, the universe has been expanding and cooling.
• Over billions of years, matter clumped together, forming stars, galaxies, and eventually planets like Earth.
• Alexander Friedman & Georges Lamaitre proposed the Big Bang theory in 1920
• Alexander Friedman & Georges Lamaitre, the best-supported theory of our universe's origin.
• Arno Penzias and Robern Wilson discovered cosmic microwave background radiation.

Timeline of the Big Bang

Singularity (Planck Era)

• All matter was condensed on a single point of infinite density and extreme heat.
• This is known as the earliest known period of the Universe.
• It Exploded 13.7 billion years ago.

Inflation Epoch

• The universe expanded from the size of an atomic nucleus to 10^25 meters in width.
• Grand Unification Epoch: The Strong Nuclear Force split away from the remaining forces.
• Inflationary Epoch: Weak and Electromagnetic forces remained; the temperature was high, and the universe expanded rapidly.

Electroweak Epoch

• All forces split away from each other.
• The universe consisted of elementary particles: Quarks and Electrons.
• Quark Epoch: The universe's ingredients were still present, but the temperature was too hot for subatomic particles to form.
• Hadron Epoch: As the temperature started to cool down, Quarks bound together to form Protons and Neutrons.

Lepton and Nuclear Epoch:

• The temperature finally cooled down.
• Protons and Neutrons fused together, creating Helium (He).

Formation of the Universe

• fundamental particles and energy that made up the universe, consisting Quarks, Electrons, Protons, Neutrons.
• Protons and Neutrons joined to create hydrogen, known as basic elements
• The synthesis of helium nuclei is called Nucleosynthesis
• wavelengths composed the radiation era

Matter Domination:

• Matter began to dominate, electrons joined with hydrogen and helium to make small neutral atoms.
• Slightly irregular areas of gas clouds gravitationally attracted nearby matter and became denser, birthing Stars and Galaxies
• They Gained enough mass to ignite and produce light.

Epochs of radiation

• Planck Epoch: Universe's earliest phase, 13.7 billion years ago, following Singularity explosion, forming Gravity, Strong Nuclear, Weak, and Electromagnetic forces; Gravity later split.
• Grand Unification Epoch: Strong Nuclear Force separates from remaining forces.
• Inflationary Epoch: Forces left: Weak and Electromagnetic; rapid temperature increase; Universe expands like a grapefruit
• Electroweak Epoch: All forces separate; Universe comprises Quark and Electron particles.
• Quark Epoch: Universe contains all ingredients; temperature too high for subatomic particles to form.
• Hadron Epoch: Temperature cools down, binding Quarks into Protons and Neutrons.
• Lepton and Nuclear Epoch: Temperature cools; Protons and Neutrons fuse, forming Helium (He).
• Matter Era: Begins following Radiation Era.

Epoch duration & order

Atomic Epoch: Includes 3 Epochs

• all of the universe's ingredients were present at this point.
• The universe contained Nucleus, protons and Neutrons,
• Recombination occurred when the electrons were attached to the nucleus, creating hydrogen

Galactic Epoch:

-The temperature cooled down,

• helium (He) and hydrogen (H) populated/dotted universe, creating atomic clouds to form gas packets and allow atoms to collect
• clusters of atoms became the seedlings of galaxies, and then stars began to form.

Stellar Epoch:

• the continued formation of stars caused a ripple effect in the universe, and heat within the stars caused (H) and (He) to be converted into different elements.
• it led to elements started to form and would go onto become the building blocks of planets.

Evidence of the big bang

• Hubble Space Telescope: Earth-orbiting telescope, launched in 1990, captures distant object images.
• Ultra Deep Field: Sky patch with thousands of galaxies.
• Red Shifting (Doppler Shift): Indicates objects moving away, longer wavelengths.
• Blue Shifting: Indicates objects approaching, shorter wavelengths.
• Hubble's Law: Galaxies receding, distances increase over time.

Cosmic Microwave Background

• Arno Penzias and Robert Wilson, 1960 discovered the cosmic microwave
• Possible Fates of Universe
• Big Freeze/Chill (Heat Death): Perpetual expansion, cooling to emptiness.
• Big Crunch: Expansion halts, gravitational pull reverses it.

Alternate Theories

• Inflation Theory: Addresses flatness and horizon issues, monopoles undetected.
• Religious Cosmology: Mormon, Buddhist, Islamic, Hindu views on universe origins.
• Creationism: Belief divine creator formed universe/life in short time.
• Steady State Theory: Proposed in 1948, suggests perpetual universe, constant matter creation.
• String Theory: Universe's basic units are vibrating strings.
• M-Theory: Unifying theory with eleven dimensions, membranes.

Other Theories outside Bigbang

• Where matter is continuously created to maintain a constant density
• Steady State Theory was Challenged by the discovery of cosmic microwave background radiation
• Steady State Theory dictated that when an old star dies, a new star replaces; the universe always stays the same -String Theory proposes the fundamental constituents of the universe are tiny, one-dimensional vibrating strings and vibrating strings
• M Theory is an Extension of M Theory, incorporates five versions of string into a single comprehensive framework operates in dimensions
• M-Theory attempts to unify and work in eleven dimensions
• Branes are fundamental objects in M-theory membranes of various dimensione

Multiverse

• Parallel universes within exist with different physical rules, originated various forms and combinations of string theory
• The theory stipulates that could have originated from inflationary, quantum, or string theory
• Grand Unification Epoch: Strong Nuclear Force separates from remaining forces.

The Solar System

• Planets revolve counterclockwise from west to east relative to earth's north pole is on the