Distance To The Horizon
Ignoring the effect of atmospheric refraction, distance to the horizon from an observer close to the Earth's surface is about
where d is in kilometres and h is height above ground level in metres.
Examples:
- For an observer standing on the ground with h = 1.70 metres (5 ft 7 in) (average eye-level height), the horizon is at a distance of 4.7 kilometres (2.9 mi).
- For an observer standing on the ground with h = 2 metres (6 ft 7 in), the horizon is at a distance of 5 kilometres (3.1 mi).
- For an observer standing on a hill or tower of 100 metres (330 ft) in height, the horizon is at a distance of 39 kilometres (24 mi).
- For an observer standing at the top of the Burj Khalifa (828 metres (2,717 ft) in height), the horizon is at a distance of 111 kilometres (69 mi).
With d in miles and h in feet,
Examples, assuming no refraction:
- For an observer on the ground with eye level at h = 5 ft 7 in (5.583 ft), the horizon is at a distance of 2.9 miles (4.7 km).
- For an observer standing on a hill or tower 100 feet (30 m) in height, the horizon is at a distance of 12.2 miles (19.6 km).
- For an observer on the summit of Aconcagua (22,841 feet (6,962 m) in height), the sea-level horizon to the west is at a distance of 184 miles (296 km).
Read more about this topic: Horizon
Famous quotes containing the words distance and/or horizon:
“Like a man traveling in foggy weather, those at some distance before him on the road he sees wrapped up in the fog, as well as those behind him, and also the people in the fields on each side, but near him all appears clear, though in truth he is as much in the fog as any of them.”
—Benjamin Franklin (1706–1790)
““Dark times” is what they call it in Norway when the sun remains below the horizon all day long: the temperature falls slowly but surely at such times.—A nice metaphor for all those thinkers for whom the sun of mankind’s future has temporarily disappeared.”
—Friedrich Nietzsche (1844–1900)