Reionization: When the Universe Lit Up
How the first light sources transformed a dark, neutral universe into the ionized cosmic web we observe today
Baryon Acoustic Oscillations: Sound Waves from the Early Universe
Acoustic oscillations frozen at recombination provide cosmology with a standard ruler to measure cosmic expansion across billions of years.
Gravitational Lensing: Using Mass as a Telescope
How the curvature of spacetime transforms the cosmos into a lens for mapping the invisible universe
The Cosmological Constant Problem: Physics' Worst Prediction
Why quantum theory predicts a vacuum energy 10^120 times larger than observed—the worst discrepancy in physics
Baryogenesis: The Universe's Unexplained Matter Surplus
One part per billion—the tiny cosmic imbalance that made your existence possible.
Inflation's Smoking Gun: The Search for Primordial Gravitational Waves
Quantum ripples from the universe's first instant may still be detectable in the cosmic microwave background's polarization
Cosmic Inflation: The Theory That Made Predictions
How a theory from the 1980s made precise numerical predictions about the universe's first moments—and subsequent observations proved it right.
Dark Matter Candidates: A Particle Physics Bestiary
From weakly interacting particles to primordial black holes, the theoretical hunt for dark matter spans ninety orders of magnitude in mass—and counting.
The Flatness Problem: Why Space Doesn't Curve
Why the universe's perfect Euclidean geometry demands explanation—and how inflation transforms sixty decimal places of fine-tuning into inevitable physics.
The Hubble Tension: When Measurements Disagree
A five-sigma discrepancy between cosmic expansion measurements may herald new physics beyond the standard cosmological model.
The Multiverse Question: Science or Speculation
Where theoretical physics meets the boundaries of testability, eternal inflation and string theory force us to reconsider what scientific evidence truly means.
The Horizon Problem: Why the Universe Looks Too Uniform
Discovering why regions that never communicated share identical temperatures—and how this paradox revolutionized our understanding of the universe's first moments.
Why the Universe Has a Temperature: The Cosmic Microwave Background Explained
The 2.7 Kelvin whisper from creation's first visible moment that encoded everything cosmology now knows about the universe's age, geometry, and composition.
Dark Energy's Fingerprint: How Supernovae Revealed Cosmic Acceleration
How exploding white dwarfs revealed that cosmic expansion is accelerating, transforming our understanding of the universe's past and future.