Present Day

13.797 billion years · Present

Temperature (K): 2.72548
When: 13.797 billion years
Redshift: z = 0
Era: Present
Seconds After Big Bang: 435390963210000000

What Happened

68% dark energy, 27% dark matter, 5% ordinary matter — and of that 5%, only a fraction has ever been seen. The two ways of measuring the expansion rate disagree by 5σ and nobody knows which one is wrong.

Researchers

Fritz Zwicky Vera Rubin Georges Lemaître Edwin Hubble Adam Riess

Equations

Hubble's Law First Friedmann Equation Critical Density FLRW Metric

Theories

Dark Energy Dark Matter Big Bang Cosmology

Referenced by

equation

Critical Density FLRW Metric First Friedmann Equation Hubble's Law

researcher

Adam Riess Edwin Hubble Fritz Zwicky Georges Lemaître Vera Rubin

theory

Big Bang Cosmology Dark Energy Dark Matter

Open on the Timeline of the Universe shelf — the interactive card, the filters, and everything alongside it.

From the Cosmic Timeline database in Notion, last edited 2026-08-16. This page is the row, rendered by the build; nothing on it is written by hand.