Human Journey

Revealing the Secrets of Brunelleschi’s Dome

The dome of the Cathedral of Santa Maria del Fiore, designed by innovative Renaissance architect Filippo Brunelleschi and built in the 1420s-30s, has been a Florentine landmark and mystery for centuries.

The big unknown is exactly how Brunelleschi managed to construct a dome so enormous with an open center and without the use of a wooden support frame. Theories abound but have been difficult to confirm or refute because of the inability to examine the interior structure without destroying the priceless Renaissance paintings on its interior.

But now, after nearly 40 years of research into the nature and structure of the dome, including the recent use of a high-tech optical probe, professor Massimo Ricci is going to present his final conclusions to the public at a live-streaming conference taking part in the city of Florence, this week.

Send in your questions and watch the conference live Wednesday, November 9, 2011 at 3pm ET (8pm UT).


More Florentine Images and Inspiration

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Andrew Howley is a longtime contributor to the National Geographic blog, with a particular focus on archaeology and paleoanthropology generally, and ancient rock art in particular. In 2018 he became Communications Director at Adventure Scientists, founded by Nat Geo Explorer Gregg Treinish. Over 11 years at the National Geographic Society, Andrew worked in various ways to share the stories of NG explorers and grantees online. He also produced the Home Page of for several years, and helped manage the Society's Facebook page during its breakout year of 2010. He studied Anthropology with a focus on Archaeology from the College of William & Mary in Virginia. He has covered expeditions with NG Explorers-in-Residence Mike Fay, Enric Sala, and Lee Berger. His personal interests include painting, running, and reading about history. You can follow him on Twitter @anderhowl and on Instagram @andrewjhowley.
  • C. Blainey

    I plan to make every effort to watch this presentation, but if viewers are unable to observe the live portion of the presentation, will there be any scheduled replays?
    Thank you

  • Robert Bixby

    I think they constructed a model and used a modification of the lost wax forging technique. The interior might have been formed around a pile of something–clay, ice, sand, or horse manure–which was then washed away when the dome was finished and the dome was lifted by cranes to the top of the building. An alternative means would be to construct roughly circular beams to form the circumference of the dome. Initially, they would have grown in size and then they would have been reduced in size as they reached the peak of the dome. By soaking wood in water or steaming it, the builder could have created flexible vertical members that would bind to two non-consecutive circles with the intervening circle fitted to the center of the vertical member. By staggering these, the vertical strength of the dome would be as great as if the dome had interior vertical beams. Because the vertical members link three levels together and the levels are each of different sizes, it would be nearly as strong as a geodesic dome as the arrangement of the vertical members would be sections of a triangle. .

  • David AlluĂ© Ainsa

    Hi, Anyone know where I can watch the conference delayed?

    thank you

  • Andrew Howley

    Thanks for all your interest. For anyone unable to access the live stream, we are hoping to have an archived video soon.

  • Francisco Silva

    I found a page where they say it will be possible to view a replay soon, in Italian.
    Here is the address:
    I will be visiting that page because I only knew about the conference today on the newspaper.

  • ruth miriam carmeli

    Dear, here you can find the video of the conferenze about the Secret of 9/11/11

    See you 🙂

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