Is the Pantheon a gigantic sundial?

29. January 2009 17:27


The Pantheon in Rome

The Pantheon in Rome is one of the most stunning and well-preserved buildings that survives from antiquity. But could it have been more than just a temple? In today's issue of New Scientist I've written a news story about the idea that this domed building was actually a colossal sundial. An opening in the roof of the dome lets through a dramatic shaft of sunlight. During the six months of summer the noon sun falls on the walls and floor of the temple, and in winter (when the sun is lower in the sky) it falls onto the inside of the roof itself. But at the exact moment of the two equinoxes, in March and September, the sun falls at the junction between the roof and the walls, directly above the northern doorway, and shines through a grill there onto the porch floor beyond. The idea that the building was purposely designed to mark the equinoxes was suggested in the 1970s, but no one really picked up on it. Now an expert in timekeeping called Robert Hannah, who's based at the University of Otago in New Zealand, has discussed the idea in detail in his latest book, Time in Antiquity. Equinoxes occur when the Sun is on the celestial equator, and Hannah reckons that the Romans may have seen the equinox as a sacred time, when the Emperor could be raised up to dwell there with the gods.

Hannah now plans to look for other buildings and landscapes from the ancient Greek and Roman worlds that could have similar celestial significance. For example, he points out that if you stand at the Pnyx, which was the ancient political assembly area of Athens, to the west of the Acropolis, the midsummer sunrise appears directly behind the peak of Mount Lykabettos, a prominent hill to the northeast. The summer solstice was the point in time from which the Athenians measured the start of their calendar year. Hannah argues that ancient civilisations were much more aware then we are of how natural events signalled the passing of time, and he thinks they could well have used the sunrise behind Mount Lykabettos to mark the arrival of the new year.

I've written a short review of Time in Antiquity in the same issue of New Scientist. It's a lovely book about how the ancient Greeks and Romans marked the passing of the seasons and told the time. Among other things, Hannah gives a detailed analysis of the various calendars used on the Antikythera mechanism. But what makes it for me are the anecdotes from plays and poems, which give you a vivid taste of daily life in these societies. One play has a character who is a prostitute, nicknamed Clepsydra, which was the name for a type of water clock, because she used one to time her sessions with clients. Another features a guest invited to dinner when his shadow measures twenty feet long, but he's so eager for food that he measures it at dawn instead of dusk, and arrives hours early. But my favourite is probably a poem written by a Roman disgruntled that he can no longer eat when he wants because meal times are being set by new-fangled sundials. I used it in Decoding the Heavens too, here's that version:

The gods confound the man who first found out

How to distinguish hours! Confound them too,

Who in this place set up a sundial,

To cut and hack my days so wretchedly

Into small portions! 


Comments (5) -

5/16/2009 12:58:05 PM #

I have been to the Pantheon 2 times it is one of the most stunning places on earth, not sure if it is a gigantic sundial or not.

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9/2/2009 4:32:00 PM #

I think the Greeks has multiple purposes for everything. They were very into design and architecture, and I think the Pantheon could have been a gigantic sundial, marking the equinoxes and all that. In my opinion, everytime the Greeks put up a new building it had multiple meanings, secret purposes, signs and symbolism, and in each instance we are amazed that they accomplished what they did. The ancient Greeks were really amazing.

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9/2/2009 4:36:00 PM #

The Egyptians were also marvelous architects. Each of their various pyramids and Sphinx and all those things, were designed for multiple purposes. Many had booby traps, secret passageways, and numerous additional functions. Each of their architectural accomplishments always had something to do with the sun or the stars. Ancient civilizations were amazing. What happened to them between their times of success and the birth of Jesus?

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9/2/2009 4:43:00 PM #

The Greeks and Egyptians were two very advanced civilizations, but there were also many more located throughout the world. What about the Aztecs and Incas? All of these peoples built many significant structures, many of which had to do with the sun and stars, like the previous poster mentions. I agree that the ancient civilizations were really advanced at these strategies.

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9/2/2009 5:18:00 PM #

You guys are all crazy. These structures do not have secondary purposes. The Pantheon is not a sundial. These ideas are all conspiracy theory and wishful thinking.

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