Evidence That Convinced Everyone

The Big Bang isn't just a theory — it rests on three pillars of evidence so strong that virtually no cosmologist disputes it.

• Cosmic Microwave Background: detected by accident in 1965, this faint radiation matches Big Bang predictions precisely
• Hubble's Law: every galaxy is racing away from every other, and the farther one sits, the faster it recedes — space is expanding
• Elemental abundances: the theory predicts about 75% hydrogen and 25% helium by mass, and that is exactly what we see

The microwave background and the helium abundance were both predicted before they were ever measured.