Chapter 1 · the first 380,000 years

Particle Age

From a singular instant of impossible heat, through unification and inflation and the first quarks freezing into protons, to the fog lifting and light streaming free for the very first time. The universe rewrites itself fifteen times before it is one second old.

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the first second

Fifteen rewrites before t = 1 second

Most of what makes the universe interesting happens before the universe is a single second old. In that first second, gravity separates from the other three forces. Space exponentially inflates. Strong and electroweak forces split. Quarks freeze into protons and neutrons. By the time a human heartbeat could have completed, the cosmos has gone through more phase transitions than the rest of its history combined.

The Particle Age — Chapter 1 of Our Cosmic History — is about that astonishing first stretch, from t = 0 at the Big Bang singularity all the way to 380,000 years later, when the cosmos finally cooled enough for light to stream free. Everything we are made of, every force we feel, every ingredient of every star — all of it is set during this window.

figure 1.0.1 · The First 380,000 Years
interactive
10^-40 s10^-30 s10^-20 s10^-10 s10^0 s10^10 sPlanck / GravityInflationEW SplitQuarks Confineν DecoupleNucleosynthesisRecombination
t = 10^-35 s
Exponential Growth
T ≈ 1.0e+28 K
Inflation · Strong Separates
Strong nuclear force splits off. The release of energy drives a sudden exponential expansion — space itself grows by ≥10²⁶ in a fraction of a second.
-12.0 → 0.0 ns
Planck1 second380,000 yr
Fig. 1.0.1/The Particle Age is a fifteen-orders-of-magnitude story compressed into 380,000 years. Click any event to read what's happening; or drag the scrubber to feel the universe cool.
four lessons

Zoom into each act

The tour above is the whole picture. The four lessons below each spend more time inside a single phase — the forces, the particles, the nuclei, and the light.

  1. 1.0 overview here
    Particle Age

    The whole 380,000-year story — a tour of the first instants, the four forces emerging, and the moment light streamed free.

  2. 1.1 forces
    The Four Fundamental Forces

    Gravity, electromagnetism, strong, weak — how one Superforce became four through cosmic phase transitions.

  3. 1.2 matter
    Formation of Elementary Particles

    The Standard Model — bricks (fermions), mortar (bosons), and the Higgs that gives them mass.

  4. 1.3 synthesis
    Synthesis of Elements

    Cosmic alchemy: in the first 15 minutes, the universe locked in the 75/25 hydrogen-helium ratio forever.

  5. 1.4 cmb
    Cosmic Microwave Background

    Recombination, the fog lifts, photons stretched by a factor of 1100 — the oldest light we will ever see.

The Particle Age is over before our species can begin to imagine its own beginning. Everything that came after — every star, every world, every reader of every word — is downstream of these 380,000 years.