A black and white photo of Frank Drake. He has short hair and glasses, and is wearing a dark suit with a dark, striped tie. Drake is seated, with his left elbow resting on his thigh. He is visible from roughly the waist up. Drake is smiling and looking just to the left of the photographer.

Notices where this attachment appears

1. Robert McNees (mcnees@mastodon.social)'s status on Tuesday, 28-May-2024 14:29:51 UTC Robert McNees

   Astronomer Frank Drake was born #OTD in 1930.

   Can we productively talk about how many alien civilizations throughout the Milky Way might be actively broadcasting or receiving messages? How would we estimate that?

   N ≈ R×fp×ne×fl×fi×fc×L

   R = ⭐️ formation rate
   fp = fraction of ⭐️ with 🌎
   ne = 🌎 per ⭐️ on avg that could support life
   fl = fraction with life
   fi = fraction of life becoming intelligent
   fc = fraction that 📡 into 🌌
   L = how long they broadcast