Mediums used to go into spirit cabinets to channel fields, in order to contact spirits who would often make musical sounds ...

Although the mediums were more often than not unscrupulous con-artists preying on innocent victims, we realized that we could (almost) literally make a spirit cabinet by detecting a low-frequency electric field that we could radiate from the "medium's" body. This interest grew out of our work on developing the instrumentation and algorithms to detect the interaction between people and such fields and then invert the signals to determine the mass distribution in the field.

One of the most famous mediums, Marjorie, lived in Boston. At the request of Scientific American, Houdini investigated her, and not surprisingly he exposed her as a fraud. Inspired by this, we worked with the magicians Penn & Teller to create a "Spirit Chair" for them to contact Houdini and discuss the incident. Joe Paradiso built the Spirit Chair (the hardware is described in this paper , and Tod Machover composed a mini-opera for it.


Download an MPEG movie of Penn playing the Spirit Chair (16.8MB)