Science · 6 pages · 12 min

How an orbit is a fall that misses the ground

An orbit is a fall that moves sideways fast enough for the ground to curve away.

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From the opening

An orbit is a continuous fall in which the falling body moves forward fast enough that the curved Earth, or whichever body it circles, drops away beneath it. The path is a miss that keeps missing, not a cancellation of gravity. The opening covers newton's cannon on a mountain, why a circle is a special ellipse, and why thin air ends a low orbit.

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Inside

Newton's cannon on a mountain
Why a circle is a special ellipse
Why thin air ends a low orbit
How a thrown ball is related
Where the idea stops applying
A distinction worth keeping

Sources

Newton's orbital cannon thought experiment
Closed elliptical orbits under inverse-square gravity

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How an orbit is a fall that misses the ground

From the opening

Inside

Sources

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