Guest from the past

Hertz: Imagine throwing a pebble into a pond. Ripples spread outward across the water.

Electromagnetic waves are similar, except they travel through space. Sunlight, television signals, Wi-Fi, and mobile phone signals are all electromagnetic waves. They travel through the air, bringing us light, warmth, and even the messages on our phones.

They’re invisible, and they help almost everything in this town work—but it looks like something has gone wrong, and things are starting to fail.

Hertz: You managed to fix the rides, but it’s still quiet here because the electromagnetic waves also disrupted the music playing over the radio. We can’t let the amusement park visitors miss out on the fun—we need some live music instead! I spotted an old piano nearby, but it’s badly out of tune. Help me fix it!