Find the distance above the ground that should not be visible due to curvature from 60 miles away- What is the angle in radians and degrees made by this 60 mile arc (Earth radius ~ 4000 miles)? Perhaps using sin, cos, or tan, or maybe using the Pythagorean Theorem, find the hypotenuse of a triangle whose longer short side is 4000 miles, and has this angle between those sides. The length of the hypotenuse is the closest to the center of the Earth that one could see over Chicago, viewing along a tangent line to the arc of the Earth where they are standing. Put more simply, the hypotenuse length minus 4000 mi is the height that buildings must have for the top of them to be seen. Are buildings taller than this? If not, is it actually possible for light to curve (check back next semester, but think about inverted mirage mirror images on hot highways)? Discover this photo: https://www.freep.com/storyews/local/michigan/2015/05/06/weather-mirage-chicago-skyline-lake-michigan/70902190/

arc of Earth= 60 miles Line of sight short side of triange = ~60 miles Earth radius = 4000 miles hypotenuse: radius of Earth PLUS height buildings must be to be seen (you expect to get a number just slightly over 4000 for this)