If you draw an angle of 30 degrees on a piece of paper, it looks moderately large, but small compared to a complete circle. However, this is a very large distance on the surface of the earth. As viewed from the center of the earth, angles between points fairly far apart on the surface of the earth are small.

The following table gives the distances from Monterey, CA to a few places in the United States. The angle as viewed from the center of the earth is included as well as the travel time walking and driving.
 

From San Francisco To:	Distance in Miles	Distance in Km	Angle at Earth Center (Degrees)	Walking Time (Days at 10 hr/day)	Driving Time (Days at 10 hr/day)
Monterey	90	145	1.3	2.5	0.15
Salt Lake City	605	975	8.8	16	0.9
Denver	1055	1695	15.2	28	1.7
Chicago	1865	3000	27.0	50	3.0
New York	2475	3985	35.8	66	4.0

 

 Another consequence of the size of the earth is the distance to the horizon.  Looking out over a flat area, or the sea, the horizon is about 20 km or 12 miles away.   This is as seen from a height of 10 m ( 30 ft ) above the sea.  It takes about 3 hours to walk that 20 km. Of course when you got there, the horizon will still be 20 km away.
 
 

 

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