In this weeks episode of Massiomo Banzi’s official Arduino tutorials he shows us how to build a magic crystal ball by using his recently released Arduino Educational Starter Kit (The Arduino Starter Kit). Banzi’s electronic version of a Magic 8 Ball is built by using an LCD screen and a tilt sensor. Everytime the user is shaking the tilt sensor, the Magic 8 Ball will return a randomly generated answer.
In his new video tutorial Bill the Engineer Guy explain the anatomy of a basic microwave oven, then come through with a great, memorable visualization that intuitively links the wave’s oscillating electric and magnetic fields to the rotational vibrations of water molecules, in the food, that actually heat it up. Other highlights include mapping the standing wave in the cooking cavity by heating a platter of grated cheese, and a cross-section of a real magnetron with overlays and a handy analogy explaining how it works.
Within this video, the Engineering Guy Bill Hammack, explains how signals are sent over fiber optical cables. Bill uses a bucket of propylene glycol to show how a fiber optic cable works and to show how engineers used them to send signals across oceans. Again a nice tutorial which explains how most of the signals, and therefore most of the internet traffic travels across the ocean.
The essence of how they send information through a fiber optical cable is very simple. I could have a pre-arranged code with someone at the end – perhaps we’ll use Morse code – and I just block the laser so that the person at that end sees flashes that communicate a message. To transmit an analog signal like voice from a phone call along the cable engineers use pulse code modulation.
We take an analog signal and cut it up into sections and then approximate the wave’s loudness or amplitude as best we can. We want to make this a digital signal, which means discrete values of loudness and not just any value. [Bill Hammack]
Did you ever wondered how to explain your grandmother how the internet works? Well if you have no idea how to do that, that’s why Greg Boustead and the nice folks at the World Science Festival put together this short video, explaining the basics of the Internet, with a special issue of packet switching. Especially the thing with packet switching, never mind if your grandmother would care about packetswitching, but the video should help the average person understand the Internet just a little better and it has been run by several experts for accuracy, Boustead says.