What Is a Virus? (The Biology)
A virus is a tiny package of genetic material that can only reproduce by hijacking living cells. This guide explains what viruses are made…
Dr. Nadia Okoro
342 reading now
Science
Research, discovery and the natural world — from the cosmos to the cell.
184 stories
What Causes the Seasons?
The seasons are caused by the tilt of Earth's axis, not its distance from the Sun. This guide explains why the tilt matters, why the…
Dr. Nadia Okoro
431 reading now
How Do Rainbows Form?
A rainbow forms when sunlight is bent, split and reflected inside raindrops, spreading white light into a band of colours. This guide…
Dr. Nadia Okoro
336 reading now
What Is a Galaxy?
A galaxy is an enormous, gravity-bound system of stars, gas, dust and dark matter. This guide explains what galaxies are made of, the main…
Dr. Nadia Okoro
450 reading now
How Does the Human Eye Work?
The eye works like a living camera, bending light onto a light-sensitive screen at the back and sending signals to the brain. This guide…
Dr. Nadia Okoro
354 reading now
How Do Solar Eclipses Happen?
A solar eclipse happens when the Moon passes directly between the Earth and the Sun, casting its shadow on our planet. Here is the geometry…
Dr. Nadia Okoro
343 reading now
What Are Tectonic Plates?
Tectonic plates are the giant slabs of rock that make up the Earth's outer shell, drifting slowly over the hot interior. Here is how they…
Dr. Nadia Okoro
391 reading now
What Is the Ozone Layer?
The ozone layer is a band of gas high in the atmosphere that absorbs most of the Sun's harmful ultraviolet radiation. Here is what it is…
Dr. Nadia Okoro
454 reading now
How Does GPS Work?
GPS pinpoints your location by timing radio signals from a fleet of satellites orbiting thousands of miles overhead. Here is the science of…
Dr. Nadia Okoro
469 reading now