Best Ever Q&A Space Our World Nature History Science & Technology Human Body Senses & Organs Science of Life Chemicals & Matter Atoms & Molecules Materials Forces & Energy Sound Electricity & Magnetism Heat & Light Everyday Science Industry Transportation Computers Machines Ships Undersea Exploration Land Travel Cars Flight Structures Buildings Farming	Everyday Science How do thermometers work? What is inside a video camera? Why do bicycles have gears? How does a vacuum bottle keep liquids hot? How do hair dryers blow out hot air? How does a digital watch work? How does a camera work?   Previous: Back to Everyday Science Book: Best Ever Q&A Section: Science & Technology Chapter: Everyday Science