A-Z index
Last updated: January 7, 2022.
How does it work? What makes it go? What's the science behind it? If those are the kinds of questions you like to ask, you've come to the right place! Explore our site and you'll find around 400 free, easy-to-understand articles (including around 2000 photos and 800 full-color, how-it-works illustrations), covering science, technology, gadgets, inventions, and how things work.
Topics
Our articles are arranged into these 12 broad topic areas:
- Communications
- Computers
- Electricity and electronics
- Energy
- Engineering
- Environment
- Gadgets
- Home life
- Materials
- Science
- Tools, instruments, and measurement
- Transportation
A-Z list of articles
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
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A
- Accelerometers
- Acidity (pH) meters
- AC induction motors
- Adhesives (glues)
- Aerials (antennas and transmitters)
- Aerodynamics
- Aerosol cans
- Airbags
- Air conditioners
- Airplanes
- Airplane history
- Airplane jet engines
- Air pollution
- Air purifiers, photocatalytic
- Alarms:
- Alloys
- Alloys, shape-memory
- Altimeters
- Aluminum
- Ammeters
- Amplifiers
- Analog versus digital technology
- Analog radio
- Anemometers (wind-speed meters)
- Antennas and transmitters
- Anti-reflective coatings (thin-film interference)
- Anti-static coatings
- Anti-theft security ink
- Arc lamps (includes xenon lamps)
- Artificial intelligence
- Artworks, how to draw scientific art
- Atoms:
- Augmented reality
- Autoclaves
- Automobiles, history of
- Axles and wheels
- Aztec codes (2D barcodes, data-matrix codes)
B
- Baby-monitors (intercoms)
- Balances and weights
- Balloons, hot-air
- Barcodes and barcode scanners
- Barcodes, 2D (data-matrix codes)
- Barometers (pressure measuring instruments)
- Batteries:
- Beepers (radio pagers)
- Bicycles:
- Bicycles (general introduction)
- Bicycle helmets
- Electric bicycles
- Binoculars and field glasses
- Biofuels
- Biomass boilers
- Bioplastics and biodegradable plastics
- BitTorrent
- Bluetooth
- Blu-ray discs
- Boats and ships
- Boilers, biomass
- Boilers, gas central heating
- Books, electronic
- Brain and Internet
- Brakes:
- Breadmaking machines
- Bricks
- Bridges
- Broadband Internet:
- Buildings
- Bulletproof glass
- Bullets
- Buoyancy and floatation (ships and boats)
- Burglar alarms
- Burners, CD and DVD
C
- Calculators
- Cameras:
- Cams, web
- Cams and cranks
- Candles
- Capacitors
- Capacitors (supercapacitors)
- Carbon allotropes (graphene)
- Carbon capture and storage (CCS)
- Carbon monoxide detectors
- Carbon offsets
- Carburetors
- Cars:
- Catalysts, zeolite
- Catalytic converters
- CCD (charge-coupled device) and CMOS image sensors
- CDs (compact discs) and DVDs (including CD-R, CD-RW, and Blu-ray)
- Cellphones (Mobile phones)
- Cellphone broadband (how HSDPA works)
- Center of gravity
- Central heating and gas boilers
- Centrifuges
- Ceramics
- Cermets
- Chainsaws
- Charge-coupled devices (CCDs) and CMOS image sensors
- Chargers, induction
- Chocolate science
- CHP cogeneration
- Chromatography
- Chromic (color-changing) materials:
- Circuit breakers, RCD
- Circuits, integrated
- Clean coal and CCS
- Cleaning cloths, microfiber
- Climate change and global warming
- Clocks:
- Clothes:
- Cloud computing
- Coffee (pod) makers
- Cogeneration
- Color-changing (thermochromic) materials
- Combine harvesters
- Combined heat and power (CHP)
- Communication, history of
- Compasses
- Composites (composite materials) and laminates
- Composting toilets
- Compressors and pumps
- Computers:
- Introduction
- Artificial intelligence
- Buyer's guide
- Cloud computing
- Computer-aided design (CAD)
- Computer graphics
- History of computers
- Keyboards
- Laptop repairs
- Memory (general, RAM, ROM, etc)
- Memory (flash memory)
- Mice
- Networks
- Printers
- Quantum computing
- Computer screens, touch-sensitive
- Software
- Speech synthesis
- Supercomputers
- Webcams
- Concrete, reinforced
- Conservation of energy, law of
- Contact details for this website
- Converters, catalytic
- Cookers:
- Copiers (photocopiers)
- Copper
- Cranes
- Cranks and cams
- Criminal investigation
- Cryptography (encryption)
- Cycles (bicycles)
- Cycle helmets
D
- d3o and energy-absorbing plastics
- Data-matrix codes
- Decibel sound level meters
- Dehumidifiers
- Design, computer-aided (CAD)
- Detectors, smoke
- Detective work and criminal investigation
- Detergents and soaps
- Dictation (speech recognition) software
- Diesel engines
- Digital cameras
- Digital pens
- Digital radio
- Digital technology (general introduction)
- Diodes and light-emitting diodes (LEDs)
- Diodes, laser
- Directional loudspeakers
- Dishwashers
- Displays:
- DLP® television projectors
- Doorbells, electric
- Dots, quantum
- Drawing scientific artworks
- Drilling
- Dryers, clothes (tumble dryers)
- Dry-stone walls
- DVDs and CDs
- Dynamometers
E
- Earbud headphones
- Earthquakes
- E-books (electronic books)
- Eco-labelling
- e-commerce
- Eddy-current brakes
- Electricity:
- Introduction
- Electrical energy monitors
- Electric cars
- Electric bikes
- Electric doorbells
- Electric guitars
- Electricity generators
- History of electricity
- Electric motors:
- Electric kettles
- Electric showers
- Electric toasters
- Electric toothbrushes
- Electricity transformers
- Electric surge protectors
- Fuses
- Piezoelectricity
- Static electricity
- Triboelectricity
- Voltage optimisation
- Electrochromic smart windows
- Electrolysis
- Electrolyzers
- Electromagnetic brakes (eddy-current brakes)
- Electromagnetic spectrum
- Electronic books (E-books)
- Electronics:
- Electron microscopes
- Electroplating
- Electrostatic smoke precipitators
- Elevators (lifts)
- Encryption and steganography
- Energy:
- Energy-absorbing plastics
- Engines:
- Environment:
- Ethernet (computer networks)
- Exams, how to pass
- Experiments:
- External combustion steam engines
- External combustion Stirling engines
- Eyeglasses, photochromic
F
- Fair trade
- Fax machines
- Fiber optics
- Field glasses and binoculars
- Filament (incandescent) lamps
- Film cameras and basic photography
- Filters, HEPA
- Fingerprint scanners
- Fire:
- Fireworks
- Fission, nuclear
- Flames, candles
- Flares
- Flash memory
- Flatscreen television
- Flight (airplanes)
- Flight (history)
- Fluid dynamics (aerodynamics)
- Fluorescence:
- Compact fluorescent lamps (CFLs)
- Luminescence (general introduction)
- VFDs( Vacuum fluorescent displays)
- Flush toilets
- Flywheels
- Flywheels (regenerative brakes)
- Foam mattresses
- Forces and motion
- Forensic science
- Fountain pens
- Fracking
- Fresnel lenses
- Fridges (refrigerators)
- Fuel cells
- Fuels, biofuels
- Fuses and surge protectors
- Fusion, nuclear
G
- Galvanometers
- Gas central heating boilers
- Gases, liquids, and solids
- Gas, liquified petroleum (LPG)
- Gasoline engines
- Gas plasma waste treatment
- Gas springs
- Gauges, strain
- Gears
- Geiger counters
- Generators, electricity
- Geoengineering
- Glass:
- Global warming and climate change:
- Glues (adhesives)
- Goggles, night vision
- GORE-TEX® waterproof clothing
- GPS satellite navigation
- Gramophone
- Graphene
- Graphics, computer
- Gravity (introduction)
- Gravity, center of
- Greywater
- Green energy (renewable energy)
- Guitars, electric
H
- Hall-effect sensors
- Halogen cooking hobs
- Handwriting recognition (OCR)
- Happiness, science of
- Hard drives
- Harvesters, combine
- HDTV (high-definition television)
- Headphones:
- Heat:
- Helicopters
- Helmets, bicycle
- HEPA filters
- History of science and technology:
- Home automation and smart homes
- Home insulation
- Holograms
- Hot-air balloons
- Hot-water systems, solar
- Hovercraft
- HSDPA and mobile (cellphone) broadband Internet
- Hub motors
- Humidity meters (hygrometers)
- HVAC air conditioners
- Hybrid and electric cars
- Hybrid solar lighting (HSL)
- Hydrants, fire
- Hydraulics
- Hydraulic fracturing (fracking)
- Hydrogen electrolyzers
- Hydrogen fuel cells
- Hydroponics
- Hygrometers
I
- Image sensors (CCD and CMOS)
- Incandescent (filament) lamps
- Induction chargers
- Induction motors (AC)
- Induction motors, linear
- Induction cooktops
- Infrared remote control
- Injection lasers (semiconductor laser diodes)
- Ink, electronic
- Ink, invisible
- Inkjet printers
- Insulation, heat
- Integrated circuits
- Intelligence, artificial
- Intercoms
- Interference, thin-film
- Interferometers
- Internet:
- Intruder alarms
- Inventors and inventions
- Inverters
- Invisible ink
- Ionization smoke detectors
- IPTV (Internet Protocol Television)
- Iris scanners
- Iron and steel
J
K
L
- Labels, eco
- Laminates and composites
- Lamps:
- Lamson (pneumatic transport) tubes
- Land pollution
- Laptop repairs
- Lasers:
- Laws of motion
- LCD (liquid-crystal display) screens
- LEDs:
- Lenses:
- Lenticular printing
- LEPs (light-emitting polymers)
- Leucodyes (thermochromic materials)
- LIDAR
- Lifts
- Light
- Light detection and ranging (LIDAR)
- Light-emitting diodes (LEDs)
- Lights:
- Linear motors (induction motors)
- Linux (computer operating system)
- Liquids, solids, and gases
- Liquid-crystal displays (LCD televisions)
- Liquid crystals, thermochromic uses
- Lithium-ion batteries
- Locks
- Locomotives, steam
- Logic gates
- Loudspeakers
- Loudspeakers, directional/parametric
- Low-e, heat-reflecting windows
- LP record players
- LPG (liquified petroleum gas)
- Lubricants
- Luminescence
M
- Machines, simple
- Magnetic compasses
- Magnetism
- Magnetrons
- Mass spectrometers
- Materials science
- Matter, states of
- Mattresses, visco-elastic (memory-foam)
- Media players (streaming media)
- Memory, computer
- Memory flash
- Memory-foam mattresses
- Metals:
- Metal detectors
- Meters, moving-coil
- Microfiber cleaning cloths
- Microphones
- Microscopes, optical
- Microscopes, electron
- Microwave ovens
- Micro-wind turbines
- Milk pasteurization
- Mirrors
- Misters and aerosol cans
- Mobile broadband
- Mobile phones
- Modems
- Molecular beam epitaxy
- Molecular manufacturing (nanotechnology)
- Motion
- Motors:
- Mouse, computer
- Moving-coil meters
- MP3 players
- Multi-factor authentication (security tokens)
- Musical instruments:
N
- Nanotechnology
- Navigation:
- Neon lamps
- Neoprene wetsuits
- Networks, computer
- Neural networks
- Newton's laws of motion
- Night vision goggles
- Nixie tubes
- Noise-cancelling headphones
- Noise-reduction (soundproofing)
- Nomex®
- Nonnewtonian materials (energy-absorbing plastics)
- Nonstick cooking pans (Teflon® and PTFE)
- Nuclear power:
- How nuclear power plants work (nuclear fission)
- Nuclear fusion
- Nylon
O
- OCR (optical character recognition)
- Ocean energy (OTEC)
- Ohmmeters
- Office photocopiers
- One-time passwords (security tokens)
- Optical character recognition (OCR)
- Optical fibers
- Optical smoke detectors
- Optics, thin-film
- Organic food and farming
- Organic LEDs and LEPs (light-emitting polymers)
- Oscilloscopes
- OTEC (ocean thermal energy conversion)
- Outboard motors
P
- Padlocks
- Paint
- Pagers
- Paper and papermaking
- Paper, electronic
- Parachutes
- Parametric loudspeakers
- Passive-solar energy
- Passwords, one-time
- Pasteurization
- Pedometers
- Pendulum clocks
- Pens, digital
- Pens, fountain
- Personal Water Craft (PWC)—JetSki® and Sea-Doo®
- pH meters
- Phones (Cellphones/cellular phones/mobile phones)
- Phones (landlines)
- Phonograph
- Phosphorescence
- Photocatalytic air purifiers
- Photocatalytic self-cleaning windows
- Photochromic lenses
- Photocopiers
- Photoelectric cells
- Photography:
- Photovoltaic (PV) cells
- Physics experiments, examples of great
- Pianos
- Piezoelectricity
- Planes (how they fly)
- Planes (history of flight)
- Plasma arc recycling
- Plasma flatscreen televisions
- Plastics:
- Platinum
- Pneumatics:
- Pocket calculators
- Pod coffee makers
- Point-of-sale scanners, barcode
- Pollution:
- Power plants (power stations):
- Power, solar electric
- Power, solar thermal
- Pressure cookers
- Pressure washers
- Printers and printing:
- Privacy & cookies
- Probes, Hall-effect
- Projection television
- Propellers
- Protective materials (Kevlar)
- Pulleys
- Pumps and compressors
- Pyranometers
- Pyrometers
- Psychology:
Q
R
- Radar
- Radiation detectors (Geiger counters)
- Radiation, electromagnetic (electromagnetic spectrum)
- Radio:
- RCD circuit breakers
- Reality, augmented
- Reality, virtual
- Rechargeable batteries
- Record players
- Recycling
- Recycling, plasma arc
- Reed switches
- Refrigerators
- Regenerative brakes
- Relays
- Remote control
- Renewable energy
- Repairing a laptop computer
- Residual-current device (RCD) circuit breakers
- Resistors
- RFID tags
- Rivers
- Robots:
- Rockets (space)
- Rollercoasters
- Roomba robot vacuum cleaners
- Rubber
S
- Sampling (Analog and digital technology)
- Satellite navigation, GPS
- Satellites
- Scanners:
- Science—what is it and why does it matter?
- Science of buildings
- Science of chocolate
- Science of happiness
- Scientific artworks (how to draw)
- Sea-Doo® and Jet Ski®
- Seas, extracting thermal energy from (OTEC)
- Security tokens
- Seismometers and seismographs (covered under Earthquakes)
- Self-cleaning windows
- Self-healing materials
- Semiconductors (integrated circuits)
- Semiconductor laser diodes
- Sensors, Hall-effect
- Sewing machines
- Shape-memory alloys
- Shear-thickening, energy-absorbing plastics
- Ships and boats
- Showers, electric
- Simple machines
- Silicon-controlled rectifiers (thyristors)
- Smart homes
- Smoke detectors
- Smoke scrubbers, electrostatic
- Snowmobiles (includes snowmachines and Ski-Doos)
- Soaps and detergents
- Software
- Soil erosion and land pollution
- Solar energy:
- Soldering and welding
- Solids, liquids, and gases
- Sound:
- Space rockets
- Space telescopes
- Spectrometers, mass
- Speech recognition software
- Speech synthesis
- Speedometers
- Split-testing websites
- Sport, science of
- Spread-spectrum frequency hopping (Bluetooth)
- Springs
- Springs, gas
- States of matter
- Static electricity
- Static, anti-static-electricity coatings
- Steam engines
- Steam turbines
- Steel and concrete (reinforced concrete)
- Steel and iron
- Steganography and encryption
- Step counters (pedometers)
- Stepper (stepping) motors
- Sterilizing with autoclaves
- Stirling engines
- Stone (dry-stone) walls
- Strain gauges
- Streaming media
- Strobe lights
- Submarines
- Sunglasses, photochromic
- Supercapacitors
- Supercomputers
- Superconductors
- Surfing
- Surge protectors
- Swimming, science of
- Switches, reed
- Synthesizers, music
- Synthesizers, speech
T
- Talking computers (speech synthesizers)
- Teaching guide: Ideas for using this website for curriculum-based science teaching
- Teflon® and PTFE nonstick cooking pans
- Telephones
- Telescopes in space
- Television:
- Television (general principles and cathode-ray tube TVs)
- Television (3D)
- DLP® television projectors
- Internet Protocol Television (IPTV)
- LCD televisions
- HDTV (high-definition television)
- Plasma televisions
- Projection televisions
- Text to speech (speech synthesis)
- Thermal insulation
- Thermochromic materials
- Thermocouples
- Thermometers
- Thermometers, infrared (pyrometers)
- Thermostats
- Thermos® flasks
- Thin-film deposition, molecular beam epitaxy
- Thin-film interference
- Three-dimensional (3D) printers
- Three-dimensional (3D) television
- Thyristors
- Tin
- Titanium
- Toasters
- Toilets (flush and composting)
- Tokens, security
- Tools and machines
- Toothbrushes, electric
- Touchscreens
- Tower cranes
- Tractors
- Transformers (electricity)
- Transistors
- Transmitters and antennas
- Trash recycling
- Triboelectric effect (static electricity)
- TTS (Text to speech/speech synthesis)
- Tumble dryers (clothes dryers)
- Turbines
- Turbochargers
- TV remote control
- Typewriters
U
- Ultrasound
- Universal motors
- USB (Computers)
V
- Vacuum cleaners
- Vacuum cleaners, Roomba robot
- Vacuum flasks
- Vacuum fluorescent displays (VFDs)
- Valves
- Vehicles, electric
- Virtual reality
- Visco-elastic, memory-foam mattresses
- Vision, night
- Voice Over Internet protocol (VOIP)
- Voice recognition software
- VOIP
- Voltage optimisation
- Voltmeters
- Vertical/Short Takeoff and Landing (VSTOL) aircraft
W
- Walkie-talkies
- Walls:
- Washing machines:
- Waste recycling
- Waste treatment, gas plasma
- Watches and clocks (quartz)
- Watches and clocks, radio-controlled
- Water
- Waterproof GORE-TEX® clothing
- Water pollution
- Water filters
- Webcams
- Websites:
- Weights and balances
- Welding and soldering
- Wetsuits
- Wind-speed meters (anemometers)
- Wheels and axles
- Wheels, energy-storing (flywheels)
- Wind tunnels
- Wind turbines
- Windows:
- Windup (clockwork) mechanisms
- Wireless Internet
- Wireless remote control
- Wood
- World Wide Web (WWW)