Earth Curvature
Earth curvature eyesight is the ability of a person to see objects over long distances and how the curvature of the Earth affects visibility. Since the Earth is an oblate spheroid (meaning it flattens at the poles and widens at the equater), its curvature limits how far a person can see before objects dip below the horizon.
Key Points about Earth Curvature
Earth’s Curvature - Due to the curvature of the Earth, objects eventually disappear from sight as they go further away. The Earth curves away from you at approximately 8 inches per mile squared. This means that as you move further away from an object, the bottom part of the object will disappear first, and eventually, the entire object will be out of view.
Horizon Distance - For an average person standing at 5 to 6 feet in height, the horizon is about 3 miles away. This means that if you're looking at something at your eye level, it will disappear below the horizon if it’s beyond that distance.
Tall Objects and Height - Higher objects (like mountains, tall buildings, or towers) remain visible from greater distances before the Earth's curvature hides them. Also, if you're observing from a higher elevation, the horizon distance increases, allowing you to see farther.
Earth Curvature Formula |
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\( d_h \;=\; \sqrt{ ( r + h )^2 - r^2 } \) |
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Symbol | English | Metric |
\( d_h \) = Distance to the Horizon | \(mi\) | \(km\) |
\( h \) = Eyesight Level above Mean Sea Level | \(ft\) | \(m\) |
\( r \) = Earth's Radius (3959 miles) (6371 km) | \(ft\) | \(m\) |
Tags: Communication System