Defeating earthquakes, and more free videos from the American Geophysical Union

Remember when you had to build a bridge out of popsicle sticks in high school science class? The goal was to construct the miniature bridge that could withstand the most physical stress. Your materials were just sticks and glue. So the real challenge was to find strong shapes.

On the day of testing, we all learned very quickly what those shapes were. Bridges built out of lots of squares collapsed almost instantly. Bridges built out of triangles made the finals.

This is a pretty basic lesson, but it's not one that the global construction industry has learned yet, says the US Geological Survey's Ross Stein. Last week at the meeting of the American Geophysical Union, he began a talk on "Defeating Earthquakes" by demonstrating the difference between the cube-centric structures we build all over the world and how much stronger those structures can be if you just add triangles in the corners. It's a powerful demonstration of how simply having the technology to solve a problem isn't enough. You have to get people to use it.

This whole video is worth watching and easy for laypeople to follow. And it's just one of a huge collection of lecture videos from AGU 2012 that are now available online. They cover everything from the chemistry of lighting to the geology of volcanoes to the effects of space storms and solar flares. Very cool stuff!


  1. Haven’t watched the whole thing yet, but at least one of his points could sort of be paraphrased: if we had never developed an architecture more complex than timber framing (where knee braces are standard), we’d be better off.

  2. Oh this brings back memories of a middle school project at a summer program…

    My team (totally made up of the outcasts) built a bridge with interlocking triangles with wood and glue that wasn’t as pretty as some of the others. We were certain we would lose as each new brick was piled on, but they eventually ran out of bricks. Our bridge stood strongest of all, but we were disqualified because of that. I remember thinking that was messed up, but oh well. Popularity contests and all.
    I should’ve kept it!

  3. I thought the lesson we’ve learned is that we _don’t_ want rigid structures. You want it all to flex and bend, not stand straight. The building I’m working in is fairly recent, and it stands on stilts in the basement, buffered by giant springs and meter-high rubber cushions. The whole thing is designed to sway like a ship on rough seas if a large earthquake hits.

    1. The rubber cushions and springs don’t make the building flexible, they isolate it from the ground, so the quake has no effect on the building. That is verry expensive to set up. If you don’t have dampening, then having a strong building is the next best thing.

  4. I’ve never used Popsicle sticks to make bridges. At our school we bought regulation bridge-building kits for a dollar or two, made from around 12 ounces of various sized lengths of balsa wood. We had a specific kind of glue as well, and the construction could only use those materials. And we had to span something like 28 inches, with a height of no more than 14 inches, and have two stress points about 12 inches apart at the top of the span. Otherwise, anything was allowed in the design. I remember building a span that withstood over 300 pounds before it failed.

    Looks like this kind of contest is still going strong in Canada and elsewhere: — and some of the rules are changed (no gusset plates? what?) so I guess I was building bridges old school.

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