Blackout

The term blackout refers to a cessation of electromagnetic activity through electric power transmission systems.

In general during peacetime, a blackout is an unintentional total electrical power outage. It is sometimes contrasted with the term brownout which is a reduction in power, and selected power outages, when demand exceeds supply.

However a blackout can be intentional, for instance collectively minimizing external light (during war), especially upwards directed (or reflected) light, to "hide" from enemy aircraft (in the case of an occupied country: the enemy of the occupying force).

See also

• 2003 US-Canada Blackout
• communications blackout
• List of power outages

Alternate meanings

• Alternatively, blackout can mean a short dysfunctioning of the brain (loss of consciousness or not being able to think well).