How do you measure the distance to something you cannot reach? Parallax — the shift in where an object appears when you view it from two different spots — is one answer astronomers use to measure distances to stars. In this experiment, you set up six candles on stools and a distant reference light in a dark room. Sitting in one chair, you hold graph paper at arm's length and record the spacing between each candle and the reference light. When you move to a different chair and repeat, each candle's position shifts against that reference. From those two sets of measurements, you calculate how far away each candle is — the same method astronomers use to determine stellar distances.