A selection of the physics goodies we handed out at this year's Comic-Con International.
Image Credit: Dave Ellis
As we've done for the past few years, the Physics Central team brought the world of physics to the over 130,000 attendees of Comic-Con International 2013. We handed out our comic books along with fliers for our free spectroscope app, SpectraSnapp, and LED "throwies."
Light emitting diodes (LEDs) allow current to run only in one direction. Consequently, you have to attach the leads (the metal ends of the diodes) correctly to a battery before light will emit. To keep the leads attached — and the current flowing — we use a magnet on one side of the battery and a sticker on the other side.
We handed out hundreds of these LEDs this year, and they'll stay lit for days due to the diodes' efficiency. With a magnet attached, you can also throw (hence the name) them onto many metal surfaces.