Cities are building out, Farmland is only produce a tiny narrow frequency. Un- humanised areas, including ocean surface, are relatively the same. Temperature dependent, of course.

A time mapping of the globe's reflective frequency spectrum would be interesting data set.

Also shows a data set that extraterrestrials would partially get and analyze.
-- wjt, Jan 09 2022

bright lights, big ET Bright_20Lights_2c_20Big_20ET
[theircompetitor, Jan 09 2022]

A mathematical landscape of all frequencies and energies, well i my mind would make an interesting view. The spray of hard particle deflections could count also.
-- wjt, Jan 19 2022



random, halfbakery