The cathedral has a heliometer (solar "observatory") of 1690, one of a number built in Italy in the 17th and 18th centuries. The device itself is quite simple: a tiny hole in one of the minor domes acts as pinhole camera, projecting an image of the sun onto the floor at solar noon (12:00 in winter, 13:00 in summer). There is a bronze line, la Meridiana on the floor, running precisely N/S. The ends of the line mark the positions as at the summer and winter solstices; signs of the zodiac show the various other dates throughout the year.
The cathedral has a heliometer ( solar " observatory " ) of 1690 , one of a number built in Italy in the 17th and 18th centuries . The device itself is quite simple : a tiny hole in one of the minor domes acts as pinhole camera , projecting an image of the sun onto the floor at solar noon ( 12:00 in winter , 13:00 in summer ) . There is a bronze line , la Meridiana on the floor , running precisely N / S. The ends of the line mark the positions as at the summer and winter solstices ; signs of the zodiac show the various other dates throughout the year .
What image is projected on the floor of the heliometer?
What image is projected on the floor of the heliometer ?
the sun
the sun