How black holes form, and how we finally photographed one
Nothing can escape a black hole, not even light. In 2019, a network of telescopes the size of Earth produced the first image of one.
Articles by Tomás Ferreira
How vaccines train your immune system
A vaccine gives your body a safe preview of a germ, so it can respond faster if the real thing arrives. Different vaccines deliver that preview in different ways.
Why the sky is blue, and sunsets are red
Sunlight contains every colour. Air scatters the blue part far more than the red, and that one fact explains both the daytime sky and the evening glow.
What really causes the seasons (it is not distance from the Sun)
Earth is actually closest to the Sun in early January. The seasons come from the tilt of Earth’s axis.
Inside the James Webb Space Telescope
A gold-coated mirror, a sunshield the size of a tennis court and an orbit 1.5 million kilometres away: how Webb sees the early universe.