Start here · Essential guide
Making Sense of the Universe: A Guide
A plain-language tour of the universe's scale and structure, from planets and stars to galaxies and the observable universe, and what we still do not know.
Explained
Understand how the world really works.
Plain-language explainers on space, physics, the human body and mind, the environment, history, scientists and technology.
154 in-depth guides
20 topics
Nov 2026 latest guide
Featured guides
Guides to start with
Each one links on to more specific articles in its topic.
Key Concepts in Modern Physics
A plain-language tour of relativity, quantum theory and particle physics: the main ideas that reshaped physics after 1900 and the questions that remain open.
A Guide to Understanding the Water Cycle
Follow water step by step through evaporation, condensation, precipitation and runoff, and see how the same water keeps moving between sea, air and land.
Human Evolution: A Story of Adaptation
A plain-language overview of how the human lineage evolved over millions of years, from early upright walkers to Homo sapiens, and what is still debated.
Discovering the Wonders of the Human Body
A plain-language tour of the main organ systems of the human body, from bones and muscles to the brain and immune defenses, and how they cooperate.
Browse
Explore by topic
Universe and Matter
Space, physics and the building blocks of nature.
Our Universe Space, the solar system and how we picture the cosmos. 7 guides Physics and Matter Modern physics, light, the elements and everyday math. 6 guides Stars and Galaxies How stars live and die and how galaxies and the early universe are understood. 10 guides Planets and Space Exploration Missions, the Moon, eclipses and the search for life beyond Earth. 10 guides Forces, Energy and Motion Classical physics that explains everyday motion, heat, sound and electricity. 10 guides Chemistry and Materials Reactions, everyday substances and how common materials are made. 10 guides
Earth and Life
The planet, its climate and the history of living things.
Earth and Environment Water, climate and the living reef. 5 guides Life and Evolution How life changed over time and what fossils tell us. 5 guides Weather and Geology Atmosphere, storms, rocks and the moving crust of the Earth. 10 guides Ecosystems and Wildlife How living things depend on each other and on their environment. 9 guides
Body and Mind
How the human body, brain and medicine work.
Body and Medicine How the body works and how medicine has advanced. 7 guides Mind and Brain The brain, psychology and mental wellbeing. 6 guides Senses, Genes and Immunity How we sense the world, inherit traits and defend against disease. 10 guides Emotions and Behavior Feelings, memory, habits and how psychologists study them. 10 guides
People, History and Technology
Scientists, the past, inventions and learning.
Scientists and Careers Famous scientists and the work they do. 5 guides History and Culture Revolutions, ancient worlds and old stories. 6 guides Technology and Computing Inventions, the internet and artificial intelligence. 5 guides Learning and Education Languages, schooling and their wider effects. 3 guides Exploration, Empires and Ideas Turning points in world history from ancient cities to the Scientific Revolution. 10 guides Energy and Everyday Technology Power sources and the technology behind phones, navigation and the web. 10 guides