Harvard-MIT Center for Ultra-Cold Atoms Kids Day 2012, 3/3:
Using very cold liquids is not the only way to cool things down. Single atoms or ions (charged atoms that lack an electron) can actually be cooled down to temperatures close to absolute zero (-459.67 Fahrenheit) using lasers. In order to do this, we isolate the particle from the environment by trapping it. We demonstrate the use of a trap, which is very similar to real ion traps used in the laboratories. Ion traps consist of electrodes kept at different voltages, so that the charges on the electrodes keep the particles floating in space. The particles we use in this demonstration are spores of the lycopodium plant, which are extremely small, around the thickness of a human hair (about 30 micrometers).
Music: "Pinball Spring" by Kevin MacLeod (incompetech.com)