You Asked: Reading lots about cell phone technology but the unanswered question that keeps popping up to me is how do they vibrate? — Alan, Winnipeg, Canada Marshall Answered: Cell phones vibrate in the same way that a “Tickle Me Elmo” doll vibrates. In the case of a cell phone there is a tiny electric [...]

You Asked: Why do iPod Touchs’ only recognize fingers, not pens or other objects? — Drew, Knoxville, Tennessee Marshall Answered: An iPod’s touch screen is capacitive, in the same way that a touch sensitive lamp is capacitive. Your body is a large, wet object that can hold (relatively speaking) a lot of electrical charge. When [...]

You Asked: How does a touch screen work? — Xavier, Chennai, India Marshall Answered: There are a couple of different ways, but the simplest to understand involves a grid of transparent wires etched onto the screen’s glass, along with a piece of plastic with another set of transparent wires resting above the glass. When a [...]

You Asked: How do radio antennas work? — Sathya, Bellary, India Marshall Answered: The basic idea behind a radio antenna is to capture electromagnetic radio waves as they pass by. The electromagnetic waves create a very small electric current in the antenna. Antennas have different sizes (and shapes) depending on the length of the radio [...]

You Asked: How does a radio receiver work? — Daniel, Suhum, Ghana Marshall Answered: A radio receiver for something like an AM radio station can be very simple. You need an antenna (picks up the radio waves), a tuner (picks one radio frequency out of the millions being broadcast), a demodulator (pulls the intended information [...]

You Asked: How does my TV remote work? — Julie, Hesperia California Marshall Answered: Almost all TV remotes in use today use infrared light to send signals to the TV. So, when you push a button on the remote, a small computer inside the remote sends signals to an infrared LED. The LED turns on [...]