How does the earth support heavy buildings?
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Moment of Um comes to you from APM Studios. I'm Anna Weigel, and it's my first time in New York City. Just look at it. New York City. People from all walks of life. The bright lights of Broadway. The food. The subway. The buildings. Dare I say those skyscrapers sure look like they're actually scraping the sky.

I've been keeping my eye out for one building. That one! The Empire State Building. 102 stories of pure magnificence. It's beautiful inside and out. A true architectural marvel. And it's the mama of all buildings, weighing 365,000 tons. That's more than 54,000 elephants!

And there are lots of really heavy buildings out there. So how is the Earth able to support them all? Jasper had this question too. Hi, my name is Jasper Cavanaugh. I am nine years old and from Chapel Hill. My question is, how does the Earth support really heavy buildings like the Empire State Building? The crust of the Earth is actually very thick. It's about 20 miles thick.

My name is Rona Cox and I'm a professor of geosciences at Williams College. If you imagine that the earth is like an orange, so you know when you hold an orange it's got all the little lumpy bits on the skin? The mountain ranges on the surface of the earth would be smaller

than the lumps on the skin of the orange. So the Empire State Building looks really big to us and it looks really heavy, but compared to how big the Earth is and compared to how thick the crust of the Earth is, it's really not very big at all. And so the Earth doesn't even notice that it's there.

But of course, if you go to a place where you're not actually building on the bedrock of the Earth's crust, but you are putting your building up on soft sediments like dirt, mud, sand, then your building could sink into it.

But it wouldn't be sinking into the crust. It would be sinking into the soft goo. It would be like instead of making a Lego castle on a table, if you went and tried to build a Lego castle on a soupy, gooey, swampy tub of mud, and the Lego castle would sink into that. And that's why the Leaning Tower of Pisa is leaning because it's not on solid rock and the ground that it was built on is settling underneath it.

Um... Since I've been spending so much time on my vacation walking around New York City, I thought I would look up what the smallest skyscraper in the world is. It's the Newby McMahon Building, commonly referred to as the world's littlest skyscraper, and it's found in downtown Wichita Falls, Texas. It's only 40 feet tall, and it's 18 feet deep and 10 feet wide. So cute and tiny. ♪

If you like this episode, take a second to subscribe wherever you listen to podcasts. And if you want to learn more about tall things, check out the Smash Boom Best podcast, where we have a whole episode that pits the redwood tree and the prickly pear cactus against each other. If you have a moment of um question, we'd love to help you answer it. Drop us a line by going to brainson.org slash contact. See you next time and the next day and every weekday. Until then, um. Um.

New York City.