Signpost

Revision as of 02:15, 19 May 2008

We have all seen those signposts - the ones stuck in the middle of nowhere with a multitude of signs pointing to famous places (London, New York, Yoko, Rowville, etc).

• http://images.google.com/images?q=signpost

They all point across the surface of the earth - presumably to follow a great circle to the desired locale.

I want one which points in a true straight line. As the laser shoots. THROUGH THE EARTH!

Especially from Australia, this would be pretty neat I think, with North America and Europe being the most 'down' you can get from an australian perspective. More interesting stuff would be in the directions of africa, Asia, south america, antarctica, NZ...

For bonus points, instead of a signpost, make it out of actual lasers! (and sealed in a cage with appropriate gas so the line of the laser is visible. Say, ALL lasers always visible in red, then you select a city and it goes GREEN!).

Another method for a permenant exhibit might be to start with a point central to the room, (normal signpost), but then ALSO place markers on the walls and floor of the room to indicate the marker - so as to make clearer the path and descent taken.

Using this site: http://www.marinewaypoints.com/learn/greatcircle.shtml, I calculate the "raw data". That is, the distance on the great circle, and the degrees - ie, the direction I travel in. The final data converts the great circle distance into both a straight line (distance, and angle down (0 being tangent to here, 90degrees being straight down)

The raw data from Canberra is:

Brisbane

940km, 24 degrees

Sao Paulo, Brazil

13269km, 196 degrees

Las Palmas, Canary Islands

18353, 245 degrees

Perth

3088km, 267 degrees.

Cairo

14266km, 282 degrees

New York City

16224km, 292 degrees

Los Angeles

12313km, 297 degrees

Honolulu

8410km, 309 degrees

London

16985km, 316 degrees

Tokyo

7949km, 351 degrees

• I'm not trusting the degrees from this site though. Canberra to Honolulu at 309 degrees??