ONE WEEK ONLY ~~~ 5 FOR 3 BOOKS ~~~ 19–25 JULY
February 14, 2015
With curious little minds always starting a sentence with ‘How does…?’ or ‘Did you know…?’, you’re probably thinking there’s not much you haven’t been asked – but we’ve put together a list of 10 things you didn’t know about how things work including the everyday objects and gadgets in our lives. Keep them up your sleeve, and bring them to the table when you want to outsmart the kids! 1. How do computer keyboards work?Under each key are two pieces of metal conductor separated by a small gap. Pressing the key pushes them together so electricity flows. Each key has its own code of electrical pulses.
2. How does a camera lens work?As light rays pass from air to glass, they bend or refract. A convex lens (bulging in the middle) makes them refract inwards, or converge, to a focal point where they can form a clear image, as in a camera.
3. How does a hard drive work?A hard drive is one or a stack of spinning discs, each coated with a magnetic substance. Read-write heads swivel over the disc surface, hardly touching. They write information in specific places by creating patterns of magnetic spots, or read information by detecting these spots.
4. How do plasma screens work?A plasma screen has millions of tiny compartments or cells, and two sets or grids of wire-like electrodes at right angles to each other. Each cell can be ‘addressed’ by sending electric pulses along two particular electrodes that cross at the cell. The electric pulse heats the cell’s gas into a form called plasma, and this makes an area of coloured substance, the phosphor, glow for a split second. Millions of pulses every second at different ‘addresses’ all over the screen build up the overall picture.
5. How does GPS work?At any place on Earth’s surface, a GPS receiver can ‘see’ in a clear line three or more of the system’s satellites, and so receive signals from them. Radio waves go fast, but there is a slight difference between them reaching the receiver. The receiver works out the delay in time from each satellite and compares them, to know its distance from them and so work out its own position.
6. How does camera zoom work?The zoom system uses a moveable concave lens (one that is thinner in the centre than around the edges, to spread out or diverge the light rays. Some zooms are worked by an electric motor, others are twisted or pulled by hand.
7. How do CDs and DVDs work?Each disc has a spiral track of tiny hollows or pits with flat areas, called lands, between. These contain the digitally coded information. As the disc spins, a laser beam reflects off the pits but not the lands. The flashes of reflection are picked up by a detector.
8. How do printers work?The print head whizzes across the paper, squirting out lots of tiny ink drops as it goes. To produce each drop, a tiny heating wire makes the ink expand into a bubble, forcing a small amount through the narrow nozzle at the tip.
9. How do motion sensors work? Some handheld gaming controllers are able to sense movements and send information to the console about the player’s actioms. One version has a tiny gyroscope inside, which is a spinning weight that resists being tilted or moved. Others have flexible strips or weights on springs that lag behind when the controller is moved about.
10. How do mobile phones work?Each area or cell has a radio transmitter-receiver mast that regularly sends out its identification code. A mobile phone detects the strongest code. The mast links by radio, microwaves or wires to a main hub, which communicates with the whole telecom network. The network finds the receiver mobile phone and sends the message to the nearest mast.
If you've enjoyed this blog, you'll love our How Things work book.
If you know something we don’t, please share your technology facts for kids about how things work in the comment section below or on Facebook or Twitter!
January 08, 2021
January 27, 2020
January 17, 2020