Technology
Discover facts about technology. Small discoveries that change the way you see familiar things.
Technology
Telescopes rely on curved mirrors to avoid color distortion
Mirrors reflect rather than refract light, avoiding the color-splitting halos that can blur images from large lenses.
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Weather radar detects rain by bouncing microwaves off water
Radar sends out microwave pulses, and some energy scatters back when it hits falling precipitation. The returning signal helps meteorologists detect rain and…
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Why cement is responsible for so many emissions
Making cement releases carbon dioxide when limestone is heated in kilns: the heat drives a chemical reaction that sends the gas into the air.
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How factories turn liquid steel into a continuous ribbon
Liquid steel flows into a water-cooled copper sleeve, where its outer shell solidifies. Rollers pull the metal downward as it hardens into a continuous slab.
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China’s Three Gorges Dam can lengthen Earth’s day
By holding so much water in one place, the dam slightly shifts Earth's mass and increases its moment of inertia, making each day a tiny fraction of a second…
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A waterjet cuts titanium by throwing tiny abrasive grains at it
High-pressure water accelerates garnet particles into the metal, removing material along a narrow cut. Unlike a torch, the process does not rely on melting…
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Why barometers once used poisonous mercury
Mercury is dense enough for atmospheric pressure to move it in a short glass tube; water would require a tube about 20 feet tall. Its toxicity made it…
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Forging aligns internal metallic grains to boost strength
Forging deforms hot metal so its grain flow follows the shape of the part, which can improve strength and durability compared with casting.
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Vertical farming exploits specific red and blue wavelengths
Chlorophyll absorbs red and blue light for photosynthesis, so indoor farms often use purple grow lights that combine those wavelengths.
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QR codes can scan with 30% covered or damaged
QR codes use Reed–Solomon error correction, which can let a scanner read a code even when up to 30% is covered or damaged.
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Glass that could preserve data for a million years
Specialized lasers etch microscopic 3D data pits inside fused silica glass. Because the glass resists heat, water, and scratches, researchers project the data…
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Early computers stored bits as sound traveling through mercury
Electrical pulses were converted into sound waves that traveled through a tube of mercury. A receiver converted the arriving pulses back into electricity and…
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Why Unplugging an Inductor Can Create a Huge Voltage Spike
An inductor resists sudden changes in current; when disconnected, its magnetic field collapses and can generate a dangerously high voltage spike.
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How tin can grow tiny metallic whiskers
Pure-tin finishes on electronic components can spontaneously grow microscopic conductive filaments called tin whiskers. If one bridges circuit points, it can…
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Printed circuit boards bake copper into rigid plastic
Manufacturers bond copper foil to fiberglass sheets, etch away unwanted copper, then press multiple layers together with heat and pressure. The result is a…
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Tantalum capacitors hold massive charge in tiny spaces
Porous tantalum lets capacitors pack high capacitance into a tiny space, but too much voltage can make them fail dramatically, sometimes catching fire.
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The tiny battery that keeps your computer's clock alive
A small coin-cell battery on the motherboard keeps the computer’s clock running when it’s unplugged. When the battery dies, the clock can reset.
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Your hard drive's head flies above the platter
The spinning platter creates a microscopic cushion of air beneath the read/write head; the gap is so tiny that even a particle of cigarette smoke can threaten…
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An insulator stops electricity—until the electric field wins
Rubber, glass, and air resist current, but none is an unlimited barrier. A strong enough electric field tears electrons loose and creates a conducting path, a…
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The tiny gold wires inside your microchip
Ultrasonic welding bonds microscopic gold or aluminum wires—far thinner than a human hair—from silicon-chip pads to the package’s metal pins, creating the…
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Computer chips are patterned with light-sensitive chemistry
A wafer is coated with photoresist, then carefully exposed to a pattern of light. The exposure changes which regions dissolve during development, leaving a…
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A single carbon nanotube can conduct heat remarkably well
Simulations of isolated nanotubes found thermal conductivity comparable to exceptional conductors such as diamond. Heat travels along their orderly atomic…
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The Enigma machine had over 100 trillion settings
Despite more than 100 trillion possible settings, operators often ended messages with predictable sign-offs, making the machine less secure than its…
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Your processor slows down to keep from overheating
When a processor gets too hot, it lowers its clock speed to produce less heat, sacrificing performance to protect itself.
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