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Everyday Tech: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
GPS
GPS works out where you are by timing signals from several satellites. With at least four in view, your phone can pin down its position.
Key fact
GPS satellites carry atomic clocks, accurate to billionths of a second.
Touchscreens
Most phone screens sense touch through tiny electrical changes: your finger conducts electricity. That’s why ordinary gloves often don’t work.
Key fact
Special gloves have conductive fingertips.
Microwave Ovens
Microwaves make the water molecules in food jiggle, and that motion becomes heat. The oven was invented after a chocolate bar melted in a lab in 1945.
Key fact
Microwaves heat from the outside in, not from the inside out.
QR Codes
QR codes were invented in 1994 in Japan to track car parts. They still work even when part of the code is damaged.
Key fact
QR stands for Quick Response.
Lithium-ion Batteries
Phones and laptops use lithium-ion batteries, which store a lot of energy for their weight. Their inventors won the 2019 Nobel Prize in Chemistry.
Key fact
Batteries slowly lose capacity with each charge cycle.
Wireless Charging
Wireless chargers use magnetism: a coil in the pad makes a changing magnetic field, which drives a current in a coil inside your phone.
Key fact
Electric toothbrush chargers work the same way.
Voice Assistants
Voice assistants listen for a wake word, then send your request to computers that turn speech into text, work out what you meant, and reply.
Key fact
Speech recognition got much better in the 2010s, thanks to machine learning.
Fun facts
GPS is American, but Europe, Russia and China each run their own satellite systems too, and phones often use several at once.
A sausage can work a touchscreen, and in South Korea sausage snacks once sold well for exactly that in winter.
The first microwave oven, from 1947, was almost 1.8 m tall and weighed about 340 kg.
The QR code’s inventor was inspired by the black and white stones of the board game Go.
Much of the world’s lithium comes from salt flats in the “lithium triangle” of Argentina, Bolivia and Chile.
Wireless charging is convenient, but it wastes more energy as heat than plugging in a cable.
In 1952, Bell Labs’ “Audrey” could recognise only spoken digits.
Story: Listening to Sputnik
Listening to Sputnik
October 1957. Two young physicists in Maryland, William Guier and George Weiffenbach, tune in to the beeps of Sputnik, the first satellite.
The pitch rises as it approaches and drops as it passes. From that shift alone, they work out Sputnik’s whole orbit.
Their boss asked: turn it around. If you know where the satellite is, can you find where you are? That idea led to satellite navigation, and GPS.
True or false?
Tap your answer to see if you got it, and why.
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Question 1 of 10
A GPS receiver uses timing signals from several satellites.
Show the answer
True. Comparing when each signal arrives.
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Question 2 of 10
Phone touchscreens sense the electricity in your finger.
Show the answer
True. Your finger changes the screen’s electric field.
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Question 3 of 10
Microwaves heat food by making water molecules move.
Show the answer
True. The jiggling turns into heat.
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Question 4 of 10
QR codes were first made to track car parts.
Show the answer
True. By Denso Wave, part of the Toyota group.
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Question 5 of 10
Phone batteries slowly lose capacity as they’re used.
Show the answer
True. A little with each charge cycle.
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Question 6 of 10
Wireless charging needs a coil in both the pad and the phone.
Show the answer
True. A changing magnetic field links them.
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Question 7 of 10
Voice assistants listen for a wake word.
Show the answer
True. Like “Hey Siri” or “Alexa”.
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Question 8 of 10
GPS satellites keep time with ordinary quartz watches.
Show the answer
False. They carry atomic clocks, accurate to billionths of a second.
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Question 9 of 10
Phone touchscreens work only by sensing pressure.
Show the answer
False. Most sense electrical changes, not pressure.
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Question 10 of 10
Microwave ovens cook food from the inside out.
Show the answer
False. They heat the outer few centimetres; heat spreads inwards.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. Everyday Tech has 6 more ideas at the Advanced and Expert levels.
Sources
- GPS.gov — How GPS works
- Nobel Prize — Chemistry 2019, lithium-ion batteries
- Denso Wave — History of QR Code
- Smithsonian Magazine — The invention of the microwave oven
- Encyclopaedia Britannica — touchscreen, inductive charging
- The Nobel Prize — Physics 2009 (CCD sensor) and 2014 (blue LEDs)
- Bluetooth SIG — Origin of the Bluetooth name
