I have researched the topic of lines of sight extenstively, see [1]. The view from Lookout Mountain (near to Rock City) is here.
Take the claim about Virginia. The distance to the nearest point in Virginia is 150 miles (240 km) and rises to about 800 metres. The height of Rock City is about 700 meters; the height of the relevant intervening terrain is about 200 meters. To get the horizon distance (in km), multiply the square root of the height difference in metres by 3.85.
For Rock City in the direction of Virginia, that's sqr(700-200)*3.85 = 86 km. For Virginia in the direction of Rock City, that's sqr(800-200)*3.85 = 94 km.
Total 180km. Line of sight to Virginia? No way. Even North Carolina is marginal. The fact that they want us to believe that seven states are visible does not alter the terrestrial facts. Viewfinder 03:08, 25 April 2007 (UTC)[reply]
I believe the argument is that, from the lookout, you can see mountains that are in the particular states. This may be possible by use of a telescope or similar device.--Bedford 03:30, 25 April 2007 (UTC)[reply]
Telescopes make no difference. It is the curvature of the earth that is the issue. You cannot see below the horizon even with a telescope. There are higher mountains in Virginia than the one I mentioned but they are also further away. Apparent height loss due to curvature varies with the square of distance. The article [2] admits that the distance claims made at the site of the telescopes are way out. Viewfinder 03:57, 25 April 2007 (UTC)[reply]
In fact, closer examination of my SRTM and USGS relief models shows that the relevant intervening terrain contains several intervening ridges rising to 350m which would obstruct the line of sight. But the amusement park has been selling the "seven states" theme for decades. If there were a line of sight it would have been found and illustrated, but the professor cited in the article specifically denies any knowledge that this has been done. Viewfinder 05:01, 25 April 2007 (UTC)[reply]
