Hello. I hope I can explain what I am looking for in the right way in English. I’m involved in the first attempt of an global art project. A part of this project is the (virtual) visualization of a circle around the earth. This circle had to touch as much solid ground as possible. It is preferable, not necessary, that this circle is a great circle, like the equator is. Which way this (great) circle is going does not matter.

Is there somebody around here maybe that can easily calculate how this circle should go? You could help me a lot!

Thank you in advance

Can you clarify the requirements? Does the circle have to represent the circumference of Earth, or can it be shorter, as in the example of using one of lines of latitude? By "touch as much solid ground as possible" do you mean raw numbers alone, or do you mean "has the highest percentage of the total measurement of the circle" touching land?

Today I used a globe and a string to find out some lines that are possible. Maybe if you see my options you can imagine the kind of line I am looking for. A circle around the world that touches as much solid ground as possible, preferably a great line, so you can dig a hole trough the earth from any place on the line to get to the opposite part of the line. this last criterium is not as important as the solid-ground thing.

I've tried to estimate for how many kilometers (or miles) these circles touched solid ground.

The measurements arn't too accurate because I've used quite a small globe (scale 1cm:510km) and I rounded off at half centimeters. But anyway, it gives quite a good idea of the possible routes

1. Bering Strait – Russia – Finland – Sweden – Norway – Greenland – Canada – Alaska (17340 Km or 10.774,58 mi)
2. South Africa – Red Sea (okay, this is not land, I know) - Saudi Arabia – Russia – Alaska (16830 Km or 10.457,68 mi)
3. Southern East Australia – Indonesia – Thailand – Vietnam – Birma – Himalaya – Russia – Europe – Brazil – Argentina – Antartica (27030 Km or 16.795,66 mi)
4. Chili – Bolivia – Argentina – Brazil – Venezuela – Cuba – United States – Canada – North pole – Russia – Mongolia – Philippines – a part of Australia (24990 Km or 15.528,07 mi)
5. Mexico – United States – Canada – Artic Ocean (okay, again no land here..) – India (16830 Km or 10.457,68 mi)
6. Macdonald Island or Kerguelen Island (somewhere in the pacific ocean) – India – Russia – North pole – Canada – California (20400 Km or 12.675,97 mi) (this is a great circle – Macdonalds island is on the exact other and of the world as California is. It would be a nice to end at a McDonnalds building – just for fun :P )
7. The Equator (only 8670 Km or 5.387,29 mi)
8. South Africa – Zaïre – Sudan – Saudi Arabia – Irak – Iran – Russia – Hawaii (20910 Km or 12.992,87 mi) (another great circle, starting on Hawaii, going somewhere to a place in south Africa)

Please give some comments about these options, or maybe some advice or other possible lines? Two interesting points right at the other end of the world are interesting to hear too - like the Macdonalds islands and a Macdonalds establishment somewhere in california

Some (at least) of your examples do not describe Great Circles. Take a look at the definition, here. It also shows an interesting great circle. There is an infinite number of great circles. Trying to find circles having longest lengths over land would need some hefty computing power I guess. IMHO, it would be more interesting to start at a given point and see what other places of interest also lay on a great circle passing through your chosen start.

yes, I came to the conclusion also that there is only 1 great circle; the equator, because the earth is more like an elepsoid. anyway, I still think it is interesting to find a circle around the earth that touches as much continental land masses above sea level as possible, and crosses the centre of the earth. that way, when you go trough the earth at one spot, you find another spot on the line.

An interesting way to find the opposite place on the earth from a given point I just found on the net. It's a tool you can use to make the world a sandwich.

Screen Cap

with this tool you can find the two coördinations on the planet that are the exact opposite

Also we've found a program that can draw great circles on a map by filling in the right coördinates. Too bad it isn't working on this computer, but someone I know did use it and it works. You can find the program at: http://hem.passagen.se/sm3gsj/gcm/download.htm. The highest download is the program. maybe, if it doesn't work you need to download "VBRUN300.exe" also.

The problem with this last program is that you can draw a line on a card, but you can not do anything with the data behind it. I want to know how long this line is and which is the longest line touching continental land masses above sea level.

does anyone know if there is a program like that?
Edited to remove overlarge image.

This message has been edited. Last edited by: DorianGreyed,