Earth & nature
Planetary motion, oceans, weather, light and the systems beneath everyday experience.
Explore the library →Science · Space · How the world works
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Featured explainerSpace & TimeA Day on Venus Outlasts Its YearWatch and read →
Gravity ✦ Light ✦ Oceans ✦ Relativity ✦ Technology ✦ Time ✦ Perception ✦ Climate
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All existing Claude explainers have been preserved, restructured, and presented with a true 4:5 cover, portrait summary, full article, caveats, FAQs, and sources.
014:5How Things Work · Full explainer
How Do Airplanes Fly?
Airplanes fly because their wings push air downward and the air pushes back up. Lift balances weight and engine thrust overcomes drag. The full explanation, minus the myths.
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024:5How Things Work · Full explainer
How Do Batteries Work?
A battery stores energy as chemistry, not electricity. A reaction between two materials pushes electrons through your device, turning stored chemical energy into power.
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034:5How Things Work · Full explainer
How Do Noise-Cancelling Headphones Work?
Noise-cancelling headphones use tiny microphones to listen to surrounding noise, then play an opposite sound wave that collides with it and cancels it out.
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044:5How Things Work · Full explainer
How Do Rainbows Form?
Rainbows form when sunlight enters raindrops, bends, reflects off the back and bends again, splitting white light into colours that reach your eye at a fixed angle.
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054:5How Things Work · Full explainer
How Does a Microwave Oven Heat Food?
A microwave oven heats food by broadcasting radio waves that make water molecules jiggle billions of times a second, and that molecular motion is heat.
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064:5How Things Work · Full explainer
How Does a Refrigerator Keep Things Cold?
A refrigerator doesn't create cold; it pumps heat out of the food and dumps it into the room, using a refrigerant that cycles between evaporating and condensing.
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074:5Science explained · Full explainer
How Does Bluetooth Work?
Bluetooth is short-range 2.4 GHz radio. Learn how pairing, frequency hopping and low-power design let your devices talk wirelessly without tangling.
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084:5Science explained · Full explainer
How Does GPS Know Where You Are?
GPS finds you by timing signals from four or more atomic-clock satellites and turning the delays into distances, all at the speed of light.
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094:5Science explained · Full explainer
How Does Sunscreen Work?
Sunscreen works mainly by absorbing UV light and releasing it as heat, with some scattering. Learn what SPF means and how to use sunscreen correctly.
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104:5How Things Work · Full explainer
How Does Wi-Fi Work?
Wi-Fi works by encoding your data onto invisible radio waves that a router and your devices broadcast back and forth, turning bits into signals and back again.
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114:5Science explained · Full explainer
What Would Happen If the Sun Suddenly Disappeared?
A physics thought experiment: if the Sun vanished, Earth would keep light and gravity for ~8 min 20 sec, then fly off in a straight line and slowly freeze.
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124:5Science explained · Full explainer
What Would Happen If the Earth Stopped Spinning?
If Earth stopped spinning suddenly, everything would keep moving at up to 1,600 km/h. Even a gradual stop would bring six-month days and a reshaped world.
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134:5Science explained · Full explainer
Why Do Onions Make You Cry?
Onions make you cry because cutting them releases enzymes that build a volatile tear-inducing gas. Learn the chemistry — and how to stop the tears.
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144:5Science explained · Full explainer
Why Do We Have Seasons?
Seasons come from Earth’s ~23.4-degree axial tilt changing the angle of sunlight and length of day, not from the planet’s distance to the Sun.
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154:5How Things Work · Full explainer
Why Does the Earth Spin?
Earth spins because it inherited angular momentum from the spinning cloud it formed in 4.5 billion years ago. With almost nothing to slow it, it just keeps turning.
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164:5How Things Work · Full explainer
Why Does the Moon Cause Tides?
The Moon's gravity stretches Earth's oceans into two bulges, and as the planet spins beneath them we get two high and two low tides a day. The Sun helps too.
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174:5Science explained · Full explainer
Why Is the Ocean Salty?
The ocean is salty because acidic rain dissolves minerals from rock and rivers carry them to sea, where salt builds up to about 3.5% and stays steady.
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184:5How Things Work · Full explainer
Why Is the Sky Blue?
The sky is blue because tiny air molecules scatter the short blue wavelengths of sunlight far more than the longer red ones, spreading blue light across the whole sky.
Watch and read →194:5Space & Time · Full explainer
A Day on Venus Outlasts Its Year
Venus takes about 243 Earth days to rotate but only 225 days to orbit the Sun. The headline is true—depending on what ‘day’ means.
Watch and read →What we explain
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Space & time
Worlds, orbits and the physics that challenges common sense.
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Explore the library →Everyday science
Clear mechanisms behind food, color, sound and the human body.
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Responsible thought experiments that reveal how nature is connected.
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