PHYSCIE

• The Big Bang Theory describes how the universe started its expansion about 13.8 billion years ago
• The universe began as a singularity, a point containing all space, time, matter, and energy, and expanded rapidly through a process called inflation
• During the Big Bang, a soup of matter formed, creating nuclei of light atoms through nucleosynthesis or nuclear fusion between protons and neutrons
• Evidence supporting the Big Bang Theory includes Vesto Slipher and Carl Wilhelm Wirtz's measurement of redshift in 1910, Edwin Hubble's calculation of distances between Earth and galaxies using redshift in 1929, and the discovery of cosmic microwave background radiation in 1965 by Robert Wilson and Arno Penzias
• Big Bang Nucleosynthesis (BBN) is the process of producing light elements during the Big Bang expansion, yielding stable isotopes of hydrogen, helium, lithium atoms, and beryllium isotopes
• In Big Bang Nucleosynthesis, a proton and a neutron may fuse to yield deuterium, which can further fuse to form tritium or helium-3, and helium-4 can be formed from three fusion reactions
• He-4, with a binding energy of 28 MeV, may undergo further fusion to yield lithium-7 or beryllium-7, and the correlation between predicted and observed cosmic abundances of hydrogen and helium is a major proof of the Big Bang Theory
• Cosmology is the body of science that studies the origin, evolution, and eventual fate of the universe.
• Physical cosmology explains the origin of universe based on scientific insights, studies, and experiments
• Religious or mythological cosmology explains the origin of universe and life based on the religious beliefs of a specific tradition
• Nicolaus Copernicus and the heliocentric
• the sun is the center of the universe
• Isaac Newton refined the Copernicus model and introduced the law of universal gravitation
• Albert Einstein published his final theory in general relativity.
• Albert Einstei suggested that the universe is dynamic and constantly changing
• Big Bang Theory is cosmological model that describes how the universe started
• inflation a rapid yet peaceful expansions
• nucleosynthesis or nuclear fusion is creation of nuclei of light atoms
• recombination

  • interaction of electrons with other nuclei to form primordial atoms
• Vesto Slipher and Carl Wilhelm Wirtz (1910)

  • Measurement of redshift
  • spiral galaxies were moving away from the earth
• Georges Lemaître (1927)

  • propose the idea of expanding universe
• Edwin Hubble (1929)

  • Calculated distances between the earth and several galaxies using redshift of light
• Robert Wilson and Arno Penzias (1965)

  • Discovered cosmic microwave background radiation (CMBR)
• Modern astronomy (2014)

  • Universe is estimated to be 13.8 billion years old with 5% as ordinary matter
• Big bang nucleosynthesis (BBN)

  • aka. primordial nucleosynthesis
  • process of producing the light elements
  • yields two stable isotopes of hydrogen
  • two isotopes of helium
  • lithium atoms, and beryllium isotopes
• John Dalton's contribution to the understanding of the concept of chemical elements:

  • Matter is composed of indivisible atoms
  • Atoms of the same elements have the same properties
  • Atoms cannot be created nor destroyed, only combined, separated, or rearranged
  • Atoms of the same or different elements may combine with each other in a fixed, whole number ratio
• Dalton's Atomic Theory:

  • Matter is composed of atoms
  • Atoms of the same elements generally have the same properties
  • Isotopes exist, which are atoms of the same element differing in the number of neutrons
• Modern Atomic Theory:

  • Atoms cannot be created nor destroyed, only combined, separated, or rearranged
  • Atoms of the same or different elements may combine with each other in a fixed, whole number ratio
• Elements:

  • Elements are composed of just one atom with different properties
  • Jöns Jacob Berzelius used symbols to represent elements
  • Dmitri Mendeleev arranged elements in the periodic table
• Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks

  • All atoms of an element were identical, while different elements had atoms of differing size and mass
• Isotopes:

  • Atoms differ in their masses within one element, called an isotope
  • Dalton's system of naming elements and compounds was replaced with chemical symbols and formulae by Jöns Berzelius
• Atomic Number:

  • The atomic number corresponds to the number of protons
  • The number of protons gives the identity of the atom
• Nuclear Transmutation Reactions:

  • Knowledge of the atomic number introduced nuclear reactions
  • Transformation of one element or isotope into another element
  • The reaction includes protons and neutrons
• Particle Accelerators:

  • To overcome the repulsion between the nucleus and alpha particles, particle accelerators were used
  • A cyclotron is a particle accelerator that uses alternating electric fields to accelerate particles in a spiral path in the presence of a magnetic field
• Transuranium Elements:

  • Elements with an atomic number greater than 92 are known as transuranium elements
  • Transuranium elements are synthesized using particle accelerators
• Henry Gwyn Jeffreys Moseley discovered that the periodic table of elements should be arranged based on its atomic number
• Identify:

  • It is a number that corresponds to the number of protons in the nucleus
  • He is an English physicist who demonstrated that the atomic number determines most of the properties of an element
  • It is a device that is used to speed up particles to overcome the repulsion between the particles and the target atomic nuclei by using magnetic and electrical fields