Later, as the months wear on, a series of additional messages arrive from Gerry -- always delivered in the most remarkable and surprising of ways. With each new message comes a new adventure, and each letter signs off in the same familiar way: P.S. I love you..
For a person standing at sea level, however, the horizon is only about 3 miles away. Lets do the calculations. The figure below shows an observer whose eyes are a distance E above sea level. A straight line drawn from the observers eyes tangent to the seas surface touches it at the distance d1, which is the distance to the horizon. If R is the radius of the earth, then, to first order in E/R, it is easy to show that.
Look for the faint brownish lines (contour lines) when fully zoomed in, that are marked with numbers (e.g. 5, 10, 15 etc). If your house is for example, between a 10 line and a 15 line then your house is 10-15 metres above sea level. If you're on very flat land it may be hard to find contour lines nearby though.A more accurate way would be to download Google Earth (http://earth.google.com/download-earth.html).f your house is for example, between a 10 line and a 15 line then your house is 10-15 metres above sea level. If you're on very flat land it may be hard to find contour lines nearby though.