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We all know that failure is bad... but is it? Actually, engineers need things to fail so they can understand how to make things better. In this episode of Crash Course Kids, Sabrina chats to us about failure points and how they can help us find better solutions to problems.

///Standards Used in This Video///
3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

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Producer & Editor: Nicholas Jenkins
Cinematographer & Director: Michael Aranda
Host: Sabrina Cruz
Script Supervisor: Mickie Halpern
Writer: Jen Szymanski
Executive Producers: John & Hank Green
Consultant: Shelby Alinsky
Script Editor: Blake de Pastino

Thought Cafe Team:
Stephanie Bailis
Cody Brown
Suzanna Brusikiewicz
Jonathan Corbiere
Nick Counter
Kelsey Heinrichs
Jack Kenedy
Corey MacDonald
Tyler Sammy
Nikkie Stinchcombe
James Tuer
Adam Winnik


(0:10) Have you ever heard of the expression: 'if at first you don't succeed, try, try again'? Well, now you have. And if you think about it, you can't try again without failing first. 

Engineers fail all the time when they're trying to find the best solution to a problem. In fact, failing is really important because it helps you figure out how to make a solution that does work, and to do that, engineers need to find their failed solution's failure point.

 Big Question

So, what is a failure point? 

(0:39) To answer that question, let's revisit some of the steps we've been using to design and test the possible solutions to a certain problem. We started by picking out a single variable: the angle of the ball ramp. Then we did several trials where we changed the angle of the ramp each time, and we had a few failures along the way.

In our first trail, we knocked only some of the pins down, and in the second trial, we got no pins down at all, but on our third trial, we got the outcome that we wanted. Strike! And we decided that our solution was a success.

Now because we took the time to pick out one variable, we could be pretty sure that it had to do with why our first two trails failed. We figured out that when the angle of the ramp wasn't right, it sent the ball rolling right into the gutter.

(1:20) Now, in the bowling alley, our solution pretty much either worked, or it didn't, but sometimes solutions to a problem work for a while and then don't anymore, and this point- the point where a solution doesn't work anymore- is called a solution's failure point.

To explore this idea, let's look at some different examples.
Say you're out in the woods, and you need to cross a stream. Fortunately, there's a solution handy: a small wooden bridge. You can take the bridge safely across the stream, right? Oh, but did I forget to mention that you're also driving a bulldozer? Now that bridge might not work. At some point, too much weight will make the bridge collapse, and that specific amount of weight would be the bridge's failure point. It's the point where the solution wouldn't work anymore. It's a place where an engineer can say, "Here's why the bridge failed."


(2:04) Let's look into a pretty famous failure point, involving another bridge. The Tacoma Narrows Bridge crosses a body of water called the Puget Sound in Tacoma, Washington. As you can see, the current bridge has two decks, one that goes in each direction. But that's not the original bridge.

The original Tacoma Narrows Bridge opened in July of 1940 and it looks pretty good, right? It was a solution to the problem of getting people across Puget Sounds. That is until November of 1940.

By then the bridge had earned itself a nickname: Galloping Gertie, and it's easy to see why. Woah! It turned out that the failing point of the original Tacoma Narrows Bridge was wind hitting it at a certain speed and angle. At this angle and speed the bridge would twist back and forth. Eventually, it collapsed, though no one was hurt.

Once engineers figured out that failure point, they designed and built a new bridge, one that could withstand winds like the one that made old Gertie gallop, and that bridge is still standing. Thanks to what engineers learned from the failure point of Galloping Gertie, suspension bridges are stronger and safer than ever. It's a success story that started out as a failure.


(3:16) So, sometimes solutions have a point where they don't work anymore. Engineers call these 'failure points', and engineers try to find them as they develop solutions for a problem. Really, they want to identify these points before the final solution is put in place. That saves lots of time and money, and sometimes lives.
And sometimes failure points are pretty easy to find, and sometimes, they're harder to figure out, but when engineers do find them, they learn from them to find even better solutions to a problem.

You wonder how they do that exactly? That's another story for another time. Don't fail to meet me back here soon.