This exhibit shows visitors the electrical signals that correspond to their heartbeat. The signals are picked up by electrical sensors in contact with their hands. The output takes the form of an oscilloscope-like pattern drawn onto a constantly rotating drum coated with orange luminescent paint. The paint is dull orange when at rest, but when excited with a bright light with a short wavelength (such as the blue LEDs), it lights up brightly and glows for 20 seconds or so. The drum rotates slowly and by the time it has completed a revolution, the portion of the drum that was excited by the LED has become dim again.