I'd like to add a belated echo to Helen Glazer's objection to motion
detectors turning off lights in museums. I mentioned this to a safety
specialist, who thought it was a terrible (and possibly illegal)
idea--as I suspected. It's more than just a question of "disconcerting"
a museum visitor "deep in contemplation"--having lights turn off
unexpectedly could represent a safety hazard to both visitors and
employees. You can't trade human safety for the preservation of museum
artifacts. --David Haberstich