How much does the horizon drop per mile on earth?

Answer 1

An object will fall 4.9 meters in the first second [d=0.5*g*t^2]. Orbital velocity is 7,700 m/s (both at sea level) [V=(g*m/R)^0.5]. By definition, at orbital velocity the earth falls away at the same rate as you travel. So, 7.7 kilometers from where you are standing the earth has 'dropped away' 4.9 meters. Re-calculating for 1 kilometer: d=0.5*9.8*(1/7.7)^2 = 0.08 meters.

Answer 2

The horizon drops approximately 0.2 degrees per mile on Earth due to the curvature of the planet. This means that for every mile you travel, the horizon will appear to drop by that angle.