Citat:
Ursprungligen postat av
gason
En liten kontrollfråga bara, vad bestämmer avståndet till horisonten där allt befinner sig i ögonhöjd?
Vilka variabler finns det och hur ser formeln ut?
Detta va de jag hittade när jag kolla upp de lite snabbt
How far can the human eye see on perfectly flat land?
It depends on atmospheric conditions, since air itself and things in the air block and scatter some of the light passing through. If you look horizontally you can't see as far as if you look vertically because there is more atmosphere in the horizontal direction. In very clean air, horizontal visibility is about 50 miles. More typical visibility levels are 2 to 20 miles. In a strong rain storm or snow storm, visibility can go down to a few feet.
Visibility is one of the items reported in a standard weather report. For instance, wunderground.com tells me that the visibility right now in Lowell, MA is 10.0 miles, meaning that if I look out over the trees, I could see a mountain 10 miles away but not 11 miles away.
If you look vertically on a clear day, a human has effectively infinite visibility, assuming the distant object is big enough or bright enough to send enough light your way.