The Pantheon Dome and its Amazing Structure! With Linda Seymour PhD

[@nexpro6985]

I have visited the Pantheon several times over the years. It is truly astonishing.

[@distant._.]

I love domes. I don’t have the Pantheon, but was able to build a wooden 3’ diameter rhombic triacontahedron to use as a “chandelier” in a modern built barn/shed. Awesome content thank you for all of your efforts!

[@PaulKassabian]

You're welcome!

[@harveysmith100]

Can I make a small point to clear up any confusion. It was indicated when describing the concrete that cement was used to bind the materials together. In Roman concrete, lime was used, not cement.

[@treecrusher]

Would love a longer video on this!

[@hariharansankaran9012]

Thank you.

[@PaulKassabian]

You're welcome!

[@thalesbastos400]

Thank you for the info and dedication!

[@JasonGerroll]

Linda, Paul - great video. Thank you for putting together.

[@PaulKassabian]

Thanks Jason!!! Good to hear from you

[@StereoSpace]

They made the walls thick. Exactly how thick they would have to work out. That's what fascinates me here. Did they build scale models, larger and larger, to see if the structural mechanics scaled up? I'm curious how they worked out what is sufficient to carry the loads. They built domed baths too, so I wonder if they developed a formula that gave them a ratio of dome size to wall thickness, something practical/empirical like that.

[@Jabmateh8]

Thanks Paul! Great video!

[@PaulKassabian]

Glad you liked it!

[@deborahlee8312]

Thank you Mr. Kassabian and Dr. Seymour for this great video! I just used it in my middle school engineering tech class connecting our lessons on materials, shapes, and forces. It was a perfect segway into their iconic structure research project.

[@PaulKassabian]

That’s great! Also sounds like you’re teaching an amazing course!

[@schoolofducttape]

Loved the form on this one! Breaking down one structure at a time is golden to me! I link to you whenever I make something structural, love the content! What are some abnormal building materials you find interesting?

[@PaulKassabian]

Thanks and I’m lucky to have designed, and designing, with lots of materials…bamboo, mass timber, 3d printed glass/steel/concrete, the new carbon/glass frp pavilion at MIT, and recently structural stone…I love working to bring more variety of materials to our built environment…

[@schoolofducttape]

@@PaulKassabian bamboo is super cool! Too bad it's expensive in the USA

[@olgajoachimosmundsen4647]

Why does the hoop-forces transition from compression into tension? As a person with almost zero knowledge, but great interest in engineering I've watched most of your videos but struggle to really get the lesson home.

[@PaulKassabian]

Good question because it's much easier to picture/see the bottom of a dome wanting to spread outwards as it flattens...what happens at the top is less intuitive but is fully real...one way to picture it is that, as a dome flattens (and really picture it flattening out), the bottom has space to spread out but the top is trying to all move towards the center where there is no space, hence compression. The common physical experiment is to take half an orange and scoop out the fruit so you have a dome then shove down on it...have fun!

[@MikeAG333]

Imagine what they might have achieved if they had thought to rivet iron together to form a band all around the base of a dome.

[@scottcallow4593]

hi Paul, random question but one I can't seem to get an answer for. Theoretically what's the lowest vertical radius you can have with a dome using stone or concrete whilst it still is self-supporting and without framing? For a workable scenario, say a dome with a base equator diameter of 40m? thanks!!! obviously I'm not an engineer, just curious :)

[@tururu6370]

I still don't get why is better to have the circle at the top for the structure😢

[@carlomariamosco]

If for circle you mean the hole, it is not better, it's possible

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