Origin of the Universe

Religious Cosmology

• Explains the universe’s origin, history, and evolution through creation mythologies involving a creator (single deity or pantheon).

Biblical / Christian Cosmology

• “Creation ex nihilo” (creation out of nothing).

• Six-day creation narrative in Genesis.

• Purpose-oriented: Life created to be holy and blameless.

Mormon Cosmology

• Human spirits = literal children of heavenly parents; premortal life.

• Spirits derive from an eternal “intelligence.”

• Earth organized from pre-existing matter, not created from nothing.

Buddhist Cosmology

• Universe exists in dependence on karma of its inhabitants.

• If beings cease, the world ceases.

• No absolute beginning or end; infinite cycles of arising and passing.

• Countless universes pass through the same rhythms.

Islamic Cosmology (briefly referenced)

• God (Allah) creates the universe, Earth’s physical environment, and humanity.

Hindu Cosmology

• Cosmos viewed as symbolic text for meditation.

• Creation is timeless and cyclic.

• Multiple parallel universes, each undergoing creation and dissolution.

• Major cycle: $1000$ Maha Yuga per creation–dissolution round.

The Turn Toward Scientific Cosmology

• Development of tools + scientific method began challenging purely religious explanations.

• 1915: Einstein’s General Theory of Relativity.

• 1920s: Edwin Hubble discovers external galaxies + cosmic expansion ➔ prompts origin models.

Major Scientific Theories of Cosmic Origin

Steady State Theory (Fred Hoyle, Thomas Gold, 1948)

• “Continuous Creation” / “Infinite Universe.”

• Universe uniform in space and unchanging in time.

• Constant density maintained by continual matter creation.

• Embodies Perfect Cosmological Principle (same everywhere & everywhen).

• Critiques & Demise:

  • Predicts equal average stellar ages everywhere (observationally false).

  • Discovery of Cosmic Microwave Background Radiation (CMBR) contradicted steady state, supporting Big Bang.

  • Now considered obsolete, yet historically pushed cosmology forward.

Big Bang Theory (Georges Lemaître, 1927)

• Universe began as an infinitely small, dense singularity $\text{(t = 0)}$.

• Rapid expansion ~$13.8$ Ga (billion years) ago, flinging space, time, matter, and energy outward.

• Rooted in General Relativity; supported by three key evidences:

  1. Galactic Redshift – Hubble observed galaxies receding; farther = faster.

  2. CMBR – Afterglow of early universe (~380 kyr after Big Bang); microwave due to red-shifting.

  3. Primordial Abundances – Proportions of light elements (H, He, Li, Be) match Big Bang Nucleosynthesis predictions.

Four Fundamental Forces (emerged via Spontaneous Symmetry Breaking)

1. Strong Nuclear – short-range, binds nuclei.

2. Electromagnetic – long-range, attractive/repulsive, binds atoms.

3. Weak Nuclear – short-range, drives radioactive decay.

4. Gravitational – weakest, long-range, binds large-scale structures.

Common Misconceptions

• Not an explosion; it is space itself expanding (balloon analogy).

• Singularity did not appear in pre-existing space; space-time originated with it.

• Prior to $t=0$: no space, no time, no matter, no energy.

Unresolved Problems

1. Flatness Problem – Why is observed curvature $\approx 0$?

2. Monopole Problem – Predicted magnetic monopoles never observed.

3. Horizon Problem – Distant CMBR regions share equal temperatures despite never being in causal contact per simple expansion models.

Inflation Theory (Alan Guth, Andrei Linde, Paul Steinhardt, Andy Albrecht, 1980)

String Theory (multiple contributors)

• Replaces point particles with one-dimensional “strings” (length $\approx 10^{-35}\ \text{m}$).

• Strings vibrate; each vibrational mode corresponds to a particle (electron, quark, graviton…).

• Offers path to unify all four forces in a single quantum framework: potential Theory of Everything (TOE).

• Challenges: exceedingly mathematical, little/no experimental evidence yet.

M-Theory (extension of string approach)

• Introduces higher-dimensional objects called branes (2-D, 5-D, etc.) to which strings attach.

• Postulates 11 space-time dimensions (4 large + 7 compact).

• Cosmic origin scenario: Collision of huge branes triggers a new universe (Hawking & Mlodinow).

• Allows infinite parallel universes that may intermittently interact.

• Limitations: Highly theoretical, no direct empirical tests to date.

• Kalam Cosmological Argument – Everything that begins to exist has a cause; universe began to exist; therefore the universe has a cause.

• Contingency Argument – Universe is contingent; requires an external necessary being/cause.

• Presented as metaphysical complements to scientific models.