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##### Asked by: Heraclia Urwin

science space and astronomy# How much does the earth curve over 100 miles?

**average curvature**of 7.98 inches per mile or approximately8inches per mile (squared).

Hereof, how much does the earth curve in 6 miles?

However, it turns out that while the **earthdoescurve** 8 inches in one **mile**, it **does** not take9**miles** to **curve** 72 inches. To show this, let usreturnto the Pythagorean Theorem method used by Harley, butusing**6** feet for the **curvature**.

**eight inches per mile**squared”isa rule of thumb to determine the

**drop**height due tothecurvature of the

**Earth**. It

**does**not account fortheobserver's height and atmospheric refraction. The“

**8inches**” rule is also an approximation. Itremains usableuntil up to about 100

**miles**.

Similarly, how far can you see with the curve of the earth?

The old saying turns out to be just about true. Forasix-foot tall person, the horizon is a little more than 3 miles(5km) away. Geometry tells us that the **distance** of thehorizon– i.e. the farthest point the eye **can see**before**Earth** curves out beneath our view – dependssimply onthe height of the observer.

Most sources consider 8 **inches per mile** asthemost accurate estimate. It means that for every **mile** ofthedistance between you and **a** second object,the**curvature** will obstruct 8 **inches** ofitsheight.