Guides

Evergreen guides for reading scientific results more carefully: what each tool measures, what the numbers mean, and what they don't prove.

Guide

Last reviewed · 13 July 2026

What Lyman-alpha tells astronomers

Hydrogen writes one far-ultraviolet line — 1216 ångström — into the sky two ways: as emission that lights up distant galaxies, and as the absorption 'forest' a quasar's light gathers on its way to us. Here is what each one tells astronomers.

Guide

Last reviewed · 13 July 2026

How JWST works

The James Webb Space Telescope is not a bigger Hubble. It is a cold infrared observatory that gathers very faint light and turns it into spectra — reading planets, galaxies and atmospheres from the fingerprints in that light. Here is how.

Guide

Last reviewed · 13 July 2026

How DESI works

DESI does not photograph dark energy. It measures the three-dimensional positions of millions of galaxies and reads the universe's expansion history out of the pattern they make. Here is how.

Guide

Last reviewed · 6 July 2026

What statistical significance means

Sigma levels and confidence intervals can look like verdicts. They are not. They measure how strongly data support a statistical claim — and why that is only the first question.

Guide

Last reviewed · 4 July 2026

How to read a clinical result

A line like “aOR 0.77, 95% CI 0.55–1.08, P = 0.13” looks like a wall. It isn’t. Here is how to take one apart, number by number — and, just as important, how to put it back together.