This already seems suspect, given that the earth's surface is curved. A true straight line from the starting point would take us off into space.
So this feels like it's all just quibbling about different curved lines and which is closest to some definition of straight.
> To be pedantic, by ‘straight line’ here I really mean ‘geodesic’ — the
> generalisation of ‘straight line’ for curved surfaces and space as well
> as ‘flat’, Euclidian spaces.
> A geodesic is just the shortest path between two points in a surface. If
> you’re placed on a surface and continually walk “forward”, by definition
> you will trace out a geodesic.
> Some people replying to my original tweet pointed out that a straight
> line from the original point and direction would take you into space."To your point, this a straight line relative to the traveller while staying on the surface of the globe (which is the premise).
How do you know? "Straight" relative to what? The expanding universe? Would continuous adjustments need to be made to account for the displacement due to that expansion? Does this then assume some 'outer' universe / reference container?
At least if we ignore the first 10km or so of your journey. A true straight line (geodesic) from the starting point would take us straight into a tree, hill or building. At that point the journey would end since humans can't phase through solid objects. You never reach another country.
As has already been said as soon as you “go”, if you aren’t turning some infinitesimal amount you aren’t going east. It’s only a surprising result when misleading people by arguing that east is a particular heading.
It gets tricky if you suggest that you can only travel along a great circle in the direction of the rotation along that axis. Since the axis is actually tilted, this is the result you get from traveling along that great circle.
It's like handing someone a compass pointing East, then saying "walk in a straight line", and expecting them to slowly travel in a wandering arc. It's insane.
Also, the GGGGP that I replied to started by trying to walking a tangential line to a sphere resulting in a space walk. That's like THC induced levels of strained thinking of the subject.
Then the first line of the puzzle should be "completely ignore the title of this puzzle because it's somehow not part of the puzzle. It's unrelated. It will completely mislead you"...