Universe Age
The Universe Age is the time elapsed since the big-bang, currently estimated at approximately 13.8 billion years. This metric serves as the fundamental temporal coordinate for cosmological models and the history of structure formation.
Key Milestones
- Planck Era & Inflation: Occurred within seconds to fractions of a second after the Big Bang, establishing initial conditions.
- Recombination & CMB: At ~380,000 years, electrons bound to nuclei, allowing photons to travel freely, creating the cosmic-microwave-background.
- Cosmic Dawn: The first stars and galaxies began forming between 100 million and 500 million years after the Big Bang.
Star Formation History
The rate of star formation across cosmic history is visualized via the madau-plot, which tracks the Stellar Mass Density over redshift.
- Peak Formation: Star formation rates peaked at “Cosmic Noon” (roughly 2–3 billion years after the Big Bang).
- Decline: Rates have significantly declined in the recent cosmic epoch due to gas depletion and feedback mechanisms.
- See detailed analysis: The Universe’s Star Formation History: The Madau Plot and Cosmic Noon
References
The Universe’s Star Formation History: The Madau Plot and Cosmic Noon by Dr. Becky