Look at the location dot on a phone map. It can appear to show exactly where you are, even though your phone cannot see you from above. How does a small device turn invisible signals into a place on a screen?

In this lesson, you will follow that mystery from satellites in space to the location shown on a map. You will meet the ideas of timing, distance and clocks, and discover why Einstein’s work matters to a technology used for travel, games and everyday life.