Notes on the Origins of the Universe and the Big Bang

Introduction to Cosmology

• Understanding the origins of the universe.
• Key concepts: White holes, Big Bang, Inflation, Matter, Light.

The Big Bang Theory

• The Big Bang marks the beginning of the universe.
• Concept of a white hole: theoretical opposites of black holes, expelling matter.

The Nature of the Universe Before the Big Bang

• No Time or Dimensions: Before the Big Bang, time and space as we know them did not exist.
• Space Creation: As the universe expands, it creates space; it does not expand into anything.
• Inflation: Rapid expansion of the universe immediately after the Big Bang, stretching electromagnetic waves (light waves).
• Evidence of Inflation: Cosmic Background Radiation (CBR) transitions from orange light to long radio waves.

Observations from the Milky Way

• Hubble's Law: Objects in the universe are moving away from us, with speed proportional to their distance:
  • v = H • r
  • Where v = velocity, H = Hubble constant, r = distance.
• Visualization: Compared to raisins in dough; the more space between them, the faster they move.

Evidence for Expansion

1. Moving Away: All galaxies are receding from each other.
2. Cosmic Background Radiation: Found everywhere in the universe, supporting the notion of a hot, early universe.

Understanding Light and its Evolution

• Initial State of Universe: Too hot for atoms to form; as it cooled, first atoms formed, emitting orange light.
• Redshift: As the universe expanded, the emitted light was stretched to longer wavelengths (redshift).

Element Formation in the Early Universe

• Primordial Nucleosynthesis: Formation of light elements within the first few minutes after the Big Bang.
• Hydrogen and Helium:
  • Examples:
  • Hydrogen (1 proton), Deuterium (1 proton + 1 neutron), Helium (2 protons + 2 neutrons).
• Predictions: Proportions of elements can be predicted based on conditions during the Big Bang.

Future Evidence through Neutrinos

• Neutrinos and Deuterium Correlation: Each deuterium formed could produce a neutrino.
• Future Measures: By measuring neutrinos, we can confirm the amount of deuterium produced in the universe.

Conclusion

• Validity of the Big Bang Theory: Supported by multiple lines of evidence, from cosmic radiation to elemental composition.
• Future Research: Ongoing studies aim to provide more insights into the early universe and test existing theories.