"Alpha waves" are a type of brainwave activity, not a specific event. They are present in the brain when a person is relaxed but awake.

If you're asking about a specific event related to Alpha waves, please provide more context. For example, are you asking about:

* A scientific discovery about Alpha waves?

* A specific time period when Alpha waves were studied intensively?

* A specific event that triggered the production of Alpha waves in a person?

Please provide more information so I can help you find the answer you're looking for.