Comment by snowwolf
7 years ago
For the water challenge couldn't you just sail the 60th parallel south forever? https://en.wikipedia.org/wiki/60th_parallel_south
Also could we challenge flat earthers to the same challenge and see who travels the furthest?
Straight line here is taken to mean geodesic, the shortest possible path on the surface between two points. Parallels on the sphere are not geodesics!
If we're going to split hairs, an actual straight line would be tangent to Earth at the point of the boat, and you could sail forever, so long as you do it at the speed of light and don't hit the land masses on some other celestial body.
There is some definition of "straight line" that includes a course of a constant bearing, or a rhumb line. It's straight when plotted on a Mercator projection.
By that definition, keeping to a true east or true west bearing would be a straight line.
Meh, this is the worst kind of pedantry imo. Like, first of all, doesn't matter. But if you must, you're going to have to go with 'as would be defined by mathematicians' - because they spend a lot of time thinking about these things, and thus are by far the most qualified to have an opinion....
And the mathematicians have thought long and hard about how the Euclidean concept of a straight line generalizes to other geometries... and came up with geodesics... aka great circles...
4 replies →
You’d have to constantly turn your boat to the right to stay on course.
That's not a straight line (it only looks like that on this map).
There are no actual straight lines.
And we'd need a frame of reference in any case.
The problem seems ill-defined.
I think the problem is fairly well defined, the headline just doesn’t define it fully (with good reason).