Douglas Adams understood the difference in time scales: A line in Hitchhiker's Guide to the Galaxy, talking about how the Earth has to be destroyed to make room for a new freeway (well, actually a hyperspatial express route): "There's no point in acting surprised about it. The plans and demolition orders [for the Earth] have been on display at your local planning department in Alpha Centauri for *fifty* Earth years. If you can't be bothered to take an interest in *local* affairs, that's your own lookout." --- Perhaps some aliens have been trying to communicate with use via ice ages -- e.g., 20,000 years per symbol -- or via sunspot cycles, and we just haven't been paying attention? At 04:18 PM 11/22/2018, Tom Knight wrote:
I've always wondered why we think messages have to happen at time scales similar to ours.
Why couldn't a perfectly plausible alien civilization send messages at the rate of a bit per year, or a bit per century?
We have a very narrow view of what "short" or "long" time periods are.