BBN & BBT

• Cosmology, the body of science that studies the universe's origin, evolution, and eventual fate, can answer these questions.
• Nicolaus Copernicus proposed that all systems in the universe, including our solar

  system, are heliocentric. In this model, the sun is the center of the universe, and planets

  revolve around it.
• After a decade, Isaac Newton refined the Copernicus model and

  introduced the law of universal gravitation, which extended the laws of classical physics in

  Earth to that of the universe.
• Albert Einstein said that the universe is dynamic and constantly changing.
• According to Big bang theory, the universe is very dynamic.
• The big bang theory is a cosmological model that describes how the universe started its

  expansion about 13.8 billion years ago.
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  The idea that the universe is dynamic was first observed by Vesto Slipher and Carl Wilhelm Wirtz in 1910 when they discovered that most spiral galaxies were moving away from Earth.
• Redshift is the phenomenon referred to the movement of most spiral galaxies away from Earth.
• Georges Lemaitre said that the galaxies were not moving, instead it is expanding.
• In 1965, Robert Wilson and Arno Penzias discovered a low, steady “hum” from their Holmdel horn antenna (an antenna built to support NASA’s Project Echo). They concluded that the noise was the cosmic microwave background radiation (CMBR), which spread out across space evenly. This radiation was believed to be energy remains.
• According to the theory, the universe began as a point called a singularity.
• The singularity is a hot, dense point containing all space, time, matter, and energy.
• There was “nothing” around the singularity, but in this nothingness, the singularity expanded rapidly in a process known as inflation.
• Space was believed to first expand at speeds faster than light during inflation.
• Energy started expanding after inflation and created matter and antimatter, although some of these pairs cancel each other out in a process known as annihilation, which brings back energy.
• As the universe expanded, it cooled down.
• Matter, in the form of protons, neutrons, electrons, and photons, scattered in a highly energetic soup called plasma soup.
• This soup was where nuclei of light atoms started to form via nucleosynthesis or nuclear fission between protons and neutrons.
• Later on, electrons started to mingle with these nuclei in a primordial chemical process known as recombination.
• These particles, which are now called atoms, continued moving in space until energy, in the form of gravity, acted on these particles and collapsed them to form celestial bodies such as stars and galaxies.
• Heavier nuclei and matter form from these cosmological units.
• The universe continues to expand until today.
• Space continues to travel faster than matter and energy, increasing the distance between galaxies and matter.
• According to the theory, the universe began as a point called a singularity. It is a hot, dense

  point containing all space, time, matter, and energy. There was “nothing” around the

  singularity, but in this nothingness, the singularity expanded rapidly in a process known as

  inflation. Space was believed to first expand at speeds faster than light. Energy started

  expanding after and created matter and antimatter, although some of these pairs cancel

  each other out in a process known as annihilation, which brings back energy.
• The universe expanded and cooled down.
• Matter in the form of protons, neutrons, electrons, and photons scattered in a highly energetic soup called plasma soup.
• Nuclei of light atoms started to form via nucleosynthesis or nuclear fission in the plasma soup.
• Electrons started to mingle with these nuclei in a primordial chemical process known as recombination.
• These particles, which are now called atoms, continued moving in space until energy, in the form of gravity, acted on these particles and collapsed them to form celestial bodies such as stars and galaxies.
• Heavier nuclei and matter form from these cosmological units.
• As the universe expanded, it cooled down. Matter, in the form of protons, neutrons,

  electrons, and photons, scattered in a highly energetic soup called plasma soup. This soup

  was where nuclei of light atoms started to form via nucleosynthesis or nuclear fission

  between protons and neutrons. Later on, electrons started to mingle with these nuclei in a

  primordial chemical process known as recombination.
• Big bang nucleosynthesis (BBN), also known as primordial nucleosynthesis, produces

  the light elements during the big bang expansion. The American cosmologist Ralph Alpher

  was able to prove BBN with his calculations.
• Deuterium (D), an isotope of hydrogen with one proton and one neutron, was first

  formed from the fusion of a proton and a neutron,
• Binding energy is the energy required to break down a nucleus into its components.
• Tritium (T), a radioactive isotope of hydrogen with one proton and two neutrons, was

  formed from the fusion of two deuterium nuclei, accompanied
• Helium-3, an isotope of helium with one neutron and two protons, was formed from the

  fusion of two deuterium nuclei and a release of a neutron.
• Helium-4, which has two neutrons and two protons, has a binding energy equivalent to

  28 MeV.
• Lithium-7, an unstable nucleus with three protons and four neutrons, was produced

  from the nuclear fusion of helium-4 and tritium.
• Beryllium-7, an unstable isotope of beryllium with four protons and three neutrons, was
• Ralph Alpher proved big bang nucleosynthesis