Right now, somewhere out there, an educator is delivering a mind-altering lesson to their class. I want to engage your brains in this. Chris Anderson: I tried to get my head around how vast our Earth is. Logan Smalley: The lesson only reaches the students in that room. What would happen if we captured it? It's a toothed wheel. LS: What if pro animators and visualization artists could bring that lesson to life? CA: It's a common object that literally fits one million Earths. It's got a bunch of notches and a bunch of teeth. Fizeau's solution... LS: When that lesson lands, curiosity is ignited. CA: It seems impossibly big. AS: Something interesting happens. CA: In the great scheme of things, it's a pinprick. AS: A door closes on the light beam that's coming back to his eye. LS: Then that group of students is one thought closer to being what every teacher hopes their students will become: a lifelong learner. AS: Based on the distance between the two stations... CA: The quest for knowledge and understanding never gets dull. AS: He calculates the speed of light to within two percent of its actual value. CA: The more you know, the more amazing the world seems. That's the central mission of TED-Ed: to capture and to amplify the voice of the world's greatest teachers. He does this in 1849. CA: It's the crazy possibilities, the unanswered questions, that pull us forward. So stay curious. [TED-Ed: Lessons Worth Sharing]