The FREE online science and technology book
Want to know why giant ships can float, how your earbuds make music, what graphene is, or how windows can clean themselves? You've come to the right place! Here you'll find simple explanations you can really understand—hurrah!
Hard stuff... made simple!
Explain that Stuff is an online book written by science writer Chris Woodford (author of many popular science books for adults and children, including Atoms Under the Floorboards: The Surprising Science Hidden in Your Home). It includes over 400 easy-to-understand articles, richly illustrated with clear artworks and animations, covering how things work, cutting-edge science, cool gadgets, and computers. We take the "pain" from explain and the "tough" out of stuff! There's more information on this website than in your average expensive science book, it's continually updated, and it's completely free to use! Explain that Stuff also helps to support curriculum learning (conventional STEM education and home-schooling).
What's hot in January 2021?
In the news now...
Narinder Kapany, the Indian-born pioneer of fiber optics, has just died at the age of 94. We learn in school that light travels in straight lines, but Kapany's genius insight was to realize there are ways of making it "bend" down cables.
China's Chang'e 5 probe has brought back the first new samples from the Moon for decades. But how exactly do you put a rocket into space?
A landmark inquiry in the UK has made history by ruling that air pollution killed a young girl living near a busy road. Why, indoors and out, does dirty air end an estimated 7–10 million lives a year?
NASA is considering using nuclear fission (splitting atoms) to power future space rockets to Mars. Why do you get so much energy when you split an atom?
Plans to launch the world's first "exascale" supercomputer in the USA in 2021 have suffered a major setback. Meanwhile, Fugaku, at RIKEN Center for Computational Science (R-CCS) in Japan remains the fastest machine on Earth.
These are some more of our classic, ever-popular articles:
- Water pollution: Rivers and seas take a long time to recover from the effects of careless human treatment. What causes pollution and what can we do to stop it?
- Electricity: The most versatile and useful form of energy in our world, electricity is going to become a whole lot more important in future.
- Nanotechnology: Can we build a brave new world just by shuffling atoms and molecules under a microscope?
- Magnetism: One of the first bits of science people studied, magnetism is still just as relevant today in everything from electric cars to body scans at the hospital.
- Gears: Wheels with teeth carved around them can make you go faster or bump up your power—and here's how.
- Batteries: We all need electricity, wherever we happen to be, so thank goodness for batteries—miniature power plants you can carry in your pocket.
- Electric motors: These amazing machines turn electricity and magnetism into movement, powering everything from handheld toothbrushes to bikes, cars, and trains.
- Cloud computing: Why buy yourself an expensive computer or programs to go with it when you can get access to something just as good over the Internet?
- Global warming: Is the planet really heating up? What can we do about it?
What else is on our site?
The articles on our site are divided up into broad topical areas, listed below. We've also given you a rough idea of the kind of questions you're going to find answers to in each section:
- Communications: Why do we bounce telephone calls off satellites? How do cellphones work? What's the difference between digital radio and ordinary radio?
- Computers: How can you make a computer think like a human brain or cause climate change inside your PC? Who invented the computer—and why on Earth did it take them so long?
- Electricity and electronics: How can you make coffee with a stream of electrons? How can magnets detect burglars in your home?
- Energy: How does wind energy come from the Sun? Is nuclear power safe or not?
- Engineering: What stops a bridge falling over? How come a person can lift more stuff with a crane than with their bare hands?
- Environment: Can we still stop dangerous climate change? What causes air and water pollution and how can the world clean up its act?
- Gadgets: How does a flash memory card store your holiday snaps? Why can a synthesizer mimic any musical instrument that's ever been invented (and even ones that haven't been)?
- Home life: How can you make windows turn dark at the flick of a switch? How does an artificial leg work? If an energy-saving lamp saves energy, how come it still makes exactly the same amount of light?
- Materials: If you had a piece of platinum as big as a man, how much would it be worth? Why doesn't a dry-stone wall fall over? Is it true that glass is a kind of liquid?
- Science: Which part of a candle flame is the hottest? Why does chocolate actually taste good? Where's the best place to sit on a rollercoaster if you want to scare yourself to death?
- Tools, instruments, and measurement: How does an iris scanner recognize your eyes? Why don't fireproof clothes catch fire? Can a robot really learn to play drums?
- Transportation: If a man can't fly, how can a plane fly if it weighs as much as 5000 men? How come we say a wheel reduces friction if it's got a tire that grips the road?