2006-08-27 07:23:59 · 19 answers · asked by mr_flea103 1 in Science & Mathematics ➔ Geography
The distance to the horizon can be calculated, in metric units, using the formula d = sqrt(h(2r+h)), where sqrt is the square root, h is the height of the observer (or rather his eyes) above sea level and r is the radius of the planet. All units are in meters. The distance (d) you get out of this formula is the distance in direct line from the observer's eyes to the horizon. It is not the distance along the curvature of the planet. The difference between these two figures is, however, very small for moderate values of h (i.e., values below 100 kilometers). If you really, absolutely, positively must know the distance along the curvature of the planet, the formula to use is d = r * arccos(r/(r+h)) where arccos is the inverse cosine, the slash (/) is division, the star (*) is multiplication and the other symbols are as above.
2006-08-27 07:28:25 · answer #1 · answered by Barkley Hound 7 · 2⤊ 0⤋
Boy, so many people just guess. Why do they bother?
Anyway, the quickest formula is:
3.57 x sq root of height.
That works for metres, giving the answer in kilometres.
So, if you are viewing from a 100 metre cliff:
horizon - 3.57 x sq rt 100 = 3.57 x 10 = 35.7 kilometres away.
2006-08-27 11:42:04 · answer #2 · answered by nick s 6 · 0⤊ 0⤋
about 7 miles
2006-08-27 07:27:46 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The horizon doesn't really exist I think
2006-08-27 07:37:54 · answer #4 · answered by Rosco C 2 · 1⤊ 0⤋
approximately 20 miles, assuming you are not standing on top of a cliff, but are standing on the beach at the shoreline.
2006-08-27 09:07:30 · answer #5 · answered by idiot detector 6 · 0⤊ 0⤋
you are looking on a level plane, the curvature of the earth is what causes a ship to slip out of sight... depends on too many variables for a simple answer...
2006-08-27 07:29:18 · answer #6 · answered by mobileminiatures 5 · 0⤊ 0⤋
from what vantantage point? If you are at sea level it depends how tall you are (or hight of your vision).
Go to boatsafe.com for a calculater
2006-08-27 07:30:10 · answer #7 · answered by Hathor 4 · 0⤊ 0⤋
approximately 20 miles.
2006-08-27 07:26:24 · answer #8 · answered by Anonymous · 0⤊ 0⤋
12 miles give or take a couple of feet
2006-08-27 07:38:37 · answer #9 · answered by memories 1 · 0⤊ 0⤋
The second star to the right and straight on 'til morning.
2006-08-27 07:27:00 · answer #10 · answered by Anonymous · 1⤊ 0⤋