George Smoot obituary: Charismatic cosmologist who revealed ripples in the Big Bang’s afterglow
Summary
George Smoot, a Nobel laureate cosmologist, has died aged 80. He led the detector team on NASA’s Cosmic Background Explorer (COBE) satellite and in 1992 reported the first clear detection of temperature variations — the so‑called “ripples” — in the cosmic microwave background (CMB). That discovery provided direct evidence of the early density fluctuations that grew into today’s galaxies and supported models invoking dark matter.
Smoot trained at MIT and built his career at UC Berkeley and Lawrence Berkeley National Laboratory. Early work with high‑altitude balloons and differential microwave radiometers paved the way to COBE. His 1992 result (G. F. Smoot et al., Astrophys. J. 396, L1–L5) reshaped observational cosmology and spawned many follow‑on experiments that refined our picture of the Universe.
Article Date: 17 November 2025 • Authors: Douglas Scott, Joseph Silk & Tom Broadhurst
Key Points
- Smoot led the COBE detector team; their 1992 measurements revealed temperature anisotropies in the cosmic microwave background.
- The COBE results supported the idea that early density fluctuations seeded the formation of galaxies and matched expectations involving dark matter.
- Smoot shared the 2006 Nobel Prize in Physics for this work, which catalysed a generation of increasingly precise CMB experiments.
- His background included physics and mathematics degrees from MIT and a research career at UC Berkeley and the Lawrence Berkeley National Laboratory.
- Early experimental efforts (including balloon‑borne instruments) and theoretical prompts helped move the field from speculation to precision measurement.
Why should I read this?
Because this is the short, human story behind one of the great leaps in cosmology. Smoot didn’t just measure numbers — he changed how we see the Universe’s beginnings. If you care even a little about where galaxies come from or how big questions in physics get answered, this obituary gives you the key moments without the waffle. We’ve saved you the digging; read this for the highlights and the context.