Air Waves

Air waves are a form of very low-frequency light. Since the mid-1400s Vol, they have been used as a method of communication across the Cluster Islands. They are not blocked by large buildings or land formations, making them invaluable for sending messages to and from cities and mountainous regions.
A subset of air waves, called night waves, paradoxically travel better at night than during the day. Their range is long enough to reach deep into the great ocean Gaps, which has made the recent resurgence in ocean exploration possible.

Manifestation

When there is a storm nearby, natural lightning air waves can be heard as a burst of crackling noise in the background of some artificial air-wave transmissions.

Localization

In nature, air waves are associated with lightning. When they were first investigated, they were thought to be a kind of thunder too low in frequency to be heard and far faster than sound. At that time light was thought to be a substance that could propagate waves only while the sun was above the horizon. Since air waves were first noticed at night, they were taken to be a property of the atmosphere. We now understand better the broader range of light, but have kept using the incorrect name out of habit.

Type

Natural