Majestic Catenary Arch

[@smadaf]

The Gateway Arch, in St. Louis, Missouri, is as tall as its base is wide (630 feet, or 192 meters); but most published photos of it, in my experience, are taken diagonally, so that it looks tall and skinny. The arch gets its name from the idea that the city of St. Louis is the gateway to the West. Building of the arch started in 1963. On the day on which the keystone piece (not made of stone) was lowered into place, in 1965, firetrucks had to be brought in to spray water on the two sides of the arch: they had been built up from the ground in segments; on the final day, in the heat of the sun, they expanded so much that the gap between them was too small for the keystone; the water from the firetrucks cooled them enough for it to fit.

[@jeremiahbullfrog9288]

Neat! Thanks for the info

[@camelopardalis84]

That was fantastically low-level magic of television that took place at 00.52.

[@CuriosityShow]

Thanks for noticing our sophisticated technology . . . we simply turned the television camera upside down! Deane.

[@stanlee2200]

@@CuriosityShow did we know you just flipped the TV upside-down?? Im glad you asked bc in fact NO no we didnt ..love the show..its my newest viewing pleasure.

[@bland9876]

@@CuriosityShow you recorded it with an upside camera instead of flipping the footage in post? Very interesting.

[@pepe6666]

i was reading about parabolas and different kinds of curves for totally unrelated reasons, and learned about catenary curves yesterday. then by the magic of the internet i discover this and learn its about arch ways and stuff. you guys were so ahead of your time.

[@stevethecatcouch6532]

3:21 It even holds up under earthquake conditions? Cynical me wanted to see the next few seconds of that scene.

[@CuriosityShow]

It's still standing !! Try it with your friends. You'll be amazed. Deane.

[@timharig]

Not likely as shown. An arch is extremely strong in compressive force and a catenary cable is extremely strong in tensile force (materials depending of course). But both are useless against their opposite force. A 2d arch is also strong for a force directly down or along its axis. But a force that comes at any other angle would induce tension on one side of wall or the other and topple the wall sideways quite easily. An arched dome alleviates the side force issue (a little) but side forces still induce tension. Heavy rocks are great for keeping the compression outweighing the tension under normal circumstances, but in and earthquake the rocks themselves can bounce up eliminating the compression and letting the tension get the upper hand. The solution to this is to back the arch with an upside down catenary cable tightened down so that its tension provides compression to the arch. Think about a rubberband tightened down over the top of the blocks shown. Now, even if the blocks are bounced, the rubber band will keep them compressed together through its own tension.

[@sarahdaviscc]

Gosh I loved this show as a kid. Still do.

[@Maninawig]

I still have my cateneries and parabolas mixed up at times but I find not only how simple it is to explain, but how organic the examples are... And nowing how old this discovery is makes it even more fascinating

[@CuriosityShow]

Thanks for your interest. There are many more science stories and activities to come on the Curiosity Show KZbin channel. Keep watching! Deane.

[@Maninawig]

@@CuriosityShow can't wait!

[@dartanion0075]

Dummy's.haaaa

[@williamfoy599]

A catenary is a hyperbolic cosine curve and a parabola is a (second order) polynomial curve. Speaking mathematically, the parabola is considerably more simple than the catenary.

[@FreakinFred08]

@@williamfoy599 Do you mind dumbing that down further? I still don’t understand why they are distinguishable from one another.

[@rahmspinat]

The font used in the captions is Albertus MT. I'll always recognise Albertus MT.

[@rockbellstormcloud7365]

i love that outro song, super groovy^^

[@musikSkool]

I don't remember when I first ran across this physics concept, but it is amazing how even modern science can't really do better for designing bridges than someone a thousand years ago hanging a rope and marking the shape. Isn't this awesome!?

[@justin9744]

Dean is so calming to listen to.

[@garyv2196]

OHDEAN.

[@gorillaau]

Looks like a great rainy day activity for kids. Well done!

[@alderusdmc]

I'm FROM St. Louis!

[@CuriosityShow]

St Louis is a beautiful city. The Gateway Arch sparked my interest in architectural tricks and secrets. In Barcelona, Spain, you can find many spectacular examples of catenary arches in the buildings of Antoni Gaudi. Deane.

[@Keithykins007]

Deane’s actions at 1:30 was a staple dance move for every man in nightclubs during the 80’s. No female could resist! Guaranteed results 💋

[@TheKnobCalledTone.]

I'd love to know how many takes it took to build that arch at the end. 😁

[@PatClevenger0709]

As a transmission line engineer, we use catenary curves for conductor sagging.

[@MN-sc9qs]

This is great for families to do at home!

[@sreenathc]

Fascinating !….Subscribed….wonder why this channel was not recommended by YT earlier

[@percivalhowell7516]

Lots of cool info in 3 minutes 😎

[@richkretzschmar7170]

I can't stress how important this concept is. Caternary has even found her way into the realm of language design. For example the mouth piece of the Tamil letter "O" speaks of the architects Arch. And let's not forget that nation of atomic particles Cate. Humm let's check in with Iran and see what exposition is being cooked up in the font donuts.

[@RameshKumar-hw1ve]

Hi Rich.. cud u pls give a little more on this?? "mouth piece of the Tamil letter "O" speaks of the architects Arch"

[@beegee22]

Do the ends of a hanging catenary exert inward force or is it strictly vertical? Conversely for the arch, is an outward force exerted that needs to be buttressed?

[@KodakYarr]

It will depend on how tall or wide the catenary curve is. The taller it is the less sideways force, the wider it is the more sideways force will be exerted.

[@xCorvus7x]

The Catenary Arc is a hyperbolic cosine curve, right?

[@timharig]

Yes, but it is often easier to use the exponential form for calculations.

[@xCorvus7x]

@@timharig What other form would there be?

[@timharig]

@@xCorvus7x There are several equivalent forms. The one I'm talking about is the one that you get when you actually solve the balanced forces for each point in a line hanging from two supported ends. Since this is the solution top an ODE, the solution is naturally the sum of exponential powers. Here is the image from wikipedia since youtube has no good way to typeset equations: wikimedia.org/api/rest_v1/media/math/render/svg/1e2d387d79e500a90035448068febb17e69d8e5c . There are other equivalent forms depending what you actually want it expressed in terms of. For instance, the form of the curve expressing the curve radius in terms of the arc length of catenary is quite eloquent. wikimedia.org/api/rest_v1/media/math/render/svg/a3a424672ce2053ded644050377808daf97b8f18 . This should look very familiar if you work with Laplace transforms much.

[@gorillaau]

Oh I was thinking the other night, isn't this curve a parabola? Short answer: No, but the difference is complicated. Deane, Rob And the team was right to leave that bit out.

[@superkgy]

I learned something.

[@89horizon]

I'm from Pennsylvania... AKA The Keystone State! :D

[@augustburnsorange1748]

The catenary is a hyperbolic cosine

[@BuildingCenter]

This + the clothespin crossbow = raucous afternoon. kzbin.info/www/bejne/qXe1modphLiFmKM

[@CuriosityShow]

Please subscribe to kzbin.info . . . . we have many more science activities waiting for you and your friends. Deane.

[@TheLuismaBeaTle]

So you’re telling me this isn’t a real old kids science show? Duuude

[@TheLuismaBeaTle]

Oh now I saw the channel intro

[@CuriosityShow]

Thanks. Curiosity Show was a national science program for children featuring Dr Rob Morrison and Dr Deane Hutton. It was made in Adelaide, South Australia and screened nationally in Australia as well as in Europe, Asia and Australasia (14 countries and dubbed in German for Europe) from 1972-1990. Deane and Rob intentionally used everyday items around the house (like old rusty cans) so that children could repeat the demonstrations with materials they had to hand. In 1984 Curiosity Show won the Prix Jeunesse International, the world's top award for children's TV programs. Rob and Deane are steadily uploading segments at kzbin.info Why not subscribe?

[@TheLuismaBeaTle]

CuriosityShow I subscribed after this video ✌🏻

[@lexluthor3890]

First?

[@A3Kr0n]

D'Oh! First...

[@lxnavarro6579]

!!!!!