[quote="Chris Peterson" post_id=300172 time=1583509368 user_id=117706]
[quote=heehaw post_id=300171 time=1583509263]
[quote=BDanielMayfield post_id=300160 time=1583504102 user_id=139536]
As a test for astronauts hoping to go to Mars they should make them live for a while in rooms with nothing but red...
[/quote]
...and where the sun is dim. And where there is no water....
[/quote]
The Sun is not dim at Mars. You'd have to be a skilled observer indeed to notice a difference from what you experience on Earth.
[/quote][quote=https://www.etymonline.com/search?q=dim]
dim (adj.) Old English dimm "dark, gloomy, obscure; not clearly seen, indistinct," from Proto-Germanic *dimbaz (source also of Old Norse dimmr, Old Frisian dim, Old High German timber "dark, black, somber"). Of eyes, "not seeing clearly," early 13c. Of sound from early 14c.; of light, "not bright, faintly luminous," from early 14c.[/quote][quote=https://www.firsttheseedfoundation.org/resource/tomatosphere/background/sunlight-mars-enough-light-mars-grow-tomatoes/]
<<Above the Earth’s atmosphere the solar irradiance is slightly more than 1300 W/m[sup]2[/sup] (1300 watts per square metre). The Earth’s atmosphere is not perfectly transparent to sunlight and about one quarter of the Sun’s light is absorbed or scattered before it reaches the surface.
At the Earth’s surface, with the Sun directly overhead at local noon (clear dry atmosphere), the solar irradiance is reduced to about [b][u][color=#0000FF]1000 watts per square metre[/color][/u][/b]. This value is highly variable depending upon such things as the amount of dust and water vapor in the atmosphere.
At local noon on Mars, with Sun directly overhead, the solar irradiance is [b][u][color=#FF0000]590 watts per square metre[/color][/u][/b].
All the above measurements are taken with the incident light perpendicular to the absorbing surface. If the sunlight falls on the surface at an angle, less energy will be incident (per square metre) on the surface.>>[/quote]