Abstract :
One billionth of a meter is small. Conveying how small 1 nm is to students can be challenging. In class when this topic comes up for the first time, I always rely on the marble and Earth example. I ask my students that, if the Earth (with a diameter of approximately 12,756 km) was scaled to 1 m, then what normal-sized object on Earth would be representative of 1 nm? The responses vary from a 747 passenger plane to a small car. Rarely is suggested an object smaller than a soccer ball. The students are then told the answer, “It´s a marble!,” which usually triggers a reaction in which many students´ jaws drop wide open. This response is short lived, however, because the next question the students ask is, “How do controls fit in with nano?” This column describes an approach used to introduce undergraduate students to control at the nanoscale.
