SUP for Clean Cookstove Education: The View for the Journey

Friday, July 11, 2014

A little science lesson (in metric and imperial) for anyone that is interested :)

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;

d \approx 3.57\sqrt{h} \,,

where d is in kilometres and h is height above ground level in metres, or

d \approx 1.22\sqrt{h} \,.

where d in miles and h is height above ground level in feet,

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 36 kilometres (22 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 103 kilometres (64 mi).
For an observer atop Mount Everest (8,848 metres (29,029 ft) altitude), the horizon is at a distance of 336 kilometres (209 mi).