Students in Nasif Iskander\u2019s astronomy class at San Francisco University High School (UHS) retrace humanity's relationship with the cosmos from stone-age astronomers to the latest discoveries of extrasolar planets. With UHS in the third year of a 1:1 iPad program, Iskander redesigned his course to make extensive use of the iPad as an access point for information, an astronomical laboratory, and a production and communication tool. Here is a glimpse into how Iskander uses iPads to transform learning in the science classroom.\nCrunching stargazing into one period\n\tIn the past, astronomy students would spend night after night observing and tracking patterns in the sky. For Iskander's students, the Redshift - Astronomy app allows them to observe the position of the sun, planets, and stars throughout the seasons within a single class period. The app accelerates understanding and allows them to experiment with observation by varying the observer's position on earth, time of day, and season. This kind of observation would be impossible in any other way. Students also use Redshift as a laboratory to replicate the various astronomical techniques they're studying.\nSeeing 3D relationship among sun, moon, and earth \n\tDuring a unit on moon phases, students develop a model for why we see the phases as we do. To understand the orientation of the sun, moon, and earth during that 29-day cycle, students use two apps, Redshift and Solar Walk -- 3D Solar System Model. Students first watch the moon using the Redshift until it's in a particular phase that they're interested in. Then, they go to that phase in Solar Walk -- a simulated model of our solar system -- to see how the sun, moon, and earth are arranged. Using Redshift and Solar Walk in tandem quickly gives students the tools to generate a 3D simulation of how the moon undergoes its various phases.\n\nDrawing on data to enhance the sundial\n\tUHS has a traditional equatorial sundial. The rate at which the sun moves across the sky is sometimes ahead, sometimes behind the clock by as many as 15 minutes. The "equation of time" tracks these variations as the earth moves around its orbit of the sun. Every year, Iskander challenges his classes to figure out how the sundial works, how to properly align it, and to come up with ways to enhance the sundial to provide a correction for the equation of time. In previous years this project was attempted, but there was never enough time to complete it.\nWith the iPads, students tracked the movement of the sun across in the sky in a simulated environment while looking at the actual sun. They figured out how to make sure the gnomon (part of the sundial that casts the shadow) was pointing parallel to the earth\u2019s axis by aligning it to the star Polaris. Then, they used the Analemma app to see a graphic description of the equation of time. (Analemma is somewhat limited and text heavy by itself, but was really helpful in Iskander's hands.) The analemma graphs the position of the sun in the sky at a certain time of day and at a specific location. Students then decided to enhance the sundial to account for variation of time throughout the year by making a model of an analemma as part of the gnomon to provide corrections for everyday of the year. The sundial is now accurate within a minute or two.\nFor Iskander's students, the iPad\u2019s intuitive interface, portability, and suite of content and production apps have enhanced the ability to collaborate, create connections, and demonstrate knowledge in novel and profound ways. Learning has accelerated. And perhaps most importantly, students are empowered to think like astronomers.\nSundial Photo Credit: Marc Roberts. Photo of students and Nasif Iskander, courtesy of San Francisco University High School.