You must log in or # to comment.
in case there are others like me who have to see what it looks like on a Mercator projection map:
Can we have a map projection/grid system where this uh, great circle, is the prime meridian, defines the new ‘poles’ via another 90 degree orthogonal great circle that touches both actual poles?
Wow. I can’t believe my perspective of the world is that distorted. It makes me want to only look at it in 3D. If we’ve all mainly looked at Mercator projections our whole lives our sense of where everything is relative to everything else and what direction is completely off.
People complain about the proportional sizing of Mercator but the sense of direction it gives us is completely broken. I think the average person knows it’s off and people think there is an error factor to consider that a really straight like might be a little squiggly. But nope. This made me realize the Mercator gives pretty much zero accurate sense of direction if real distance is involved.
People complain about the proportional sizing of Mercator but the sense of direction it gives us is completely broken.
With respect, this is silly. People complain about the proportional sizing of the Mercator projection because disproportionate sizing is literally the only problem with the Mercator projection.
The sense of direction being off has got literally nothing to do with Mercator. That’s an inherent drawback of trying to project a three dimensional globe onto a 2D image. Literally every single projection has this exact problem, in one form or another. It is considered ot be an acceptable trade-off for not having to work with globes all the time.
Stop looking for yet more baseless reasons to bash the Mercator projection, which is a perfectly reasonable and acceptable projection to use within its intended usecase (which this specific example literally is).
Short distances are fine, and obviously directly east/west are fine. Directly north/south is also pretty alright, but, as you move further from the equator, any east or west movement is covering less distance, and vice versa.
Right. That is the size issue. I’m saying there is a substantial direction issue as well.
So would there be turning involved still orrrrr?
You’re constantly, gradually turning downward, technically.
Actually not turning would be falling. You are constantly being turned upward.
what
no, that’s a straight line
No. Similarly, if you look at how planes fly, they fly in what looks like arcs, going north and then back south. On a mercator projection in looks longer, but it is the shortest straight (ignoring the curve of the earth) line.
The word “can” Is doing some heavy lifting here. I mean, there is a difference between theoretically possible and actually being done.
[PROCEEDS INTO HURRICANE]
Dexter?
Anf also probably a bit of the antarctic ice sheet
Yeah, it’s going through the most dangerous water passage in the world IIRC, between South America and Antarctica. We do go through it fairly regularly at this point, but it’s still not “safe.”
Don’t the circumpolar winds essentially prevent this, or at least make it really impractical?
Sorry, can’t hear you down here in my submarine
DON’T THE CURCUMPOLAR WINDS ESSENTIALLY PREVENT THIS, OR AT LEAST MAKE IT REALLY IMPRACTICAL?
Ping.
Sailing near the south pole is not advisable, you might die. But thats also true for many other things, so whatever.
No diesel sub is going to have the range to make that trip. And NZ doesn’t allow nuclear subs in its waters.
nuclear subs are all over the place and could even be in their waters with out them realising
It’s true I’ve got all the locations of the nuclear subs right here and this conjecture is totally correct.
Lmao I do love abit of sarcasm
Yeah, sure you do.
What about Stirling engine like on a Gotland class?
Oh that’s fascinating! I had no idea those existed!
As for answering the question. I searched to see if I could find the range of the Gotland class, but the best I got was this:
Submarines don’t sail, they steam.
The only place you can’t sail is directly into the wind. You can go all the other places eventually but it’s a lot of back and forth.
Tacking back and forth is kinda the opposite of a straight line though, isn’t it?
If you zoom out far enough, the zig zags look like a straight line. Something like a fractal or how they measure coastlines.
All your tacks are straight, they just turn every so often. Over time that adds up to Velocity Made Good.
“sail”
If it makes you feel better, the line is actually curved along the surface of the earth, you know, if you believe in a spherical earth.
Nah. I’ve come to believe it’s shaped like Dick Cheney’s black, twisted heart.
The earth is obviously a sac of 1 dimensional space.
That southern ocean is brutal tho
Especially going the wrong direction!
It’d be less bad on the return trip, but then you’re fighting the trade winds and the Canary current instead.
Just rename it as Pacific Ocean and voila, no storm hence the name!
Even better, imho, you can sail in a direct line from OG Zeeland (Netherlands) to New Zealand.
Can you, though? You’d have to squeeze through the narrow English Channel first, and that would probably require some turns.
Never mind the English Channel, Drake Passage will probably kill you.
How bad can it be, really. I’ve got a boat. I can swim. We’re good.
“This, then, was the Drake Passage, the most dreaded bit of ocean on the globe—and rightly so. Here nature has been given a proving ground on which to demonstrate what she can do if left alone.” -Lansing
Below 40 degrees south there is no law; below 50 degrees south there is no God -sailing proverb
Yes
You can go north across the arctic ocean (not sure if it gets ice free enough) and through the bering strait, but you end up around 500 kilometres away from new zealand.
You can plot a course in a straight line. Unfortunately, weather.
You can also build a nearly straight railway going from California through Canada and Alaska all the way to China.
That’d be awesome. That probably wouldn’t work because it would take 100 years for California to build their first high speed rail
The USA-Russia border crossing might prove troublesome. Also, keeping railways running through the middle of Siberia in an operational state all year round would be challenging.
Also, keeping railways running through the middle of Siberia in an operational state all year round would be challenging.
Definitely don’t let Deutsche Bahn handle that part
Die Verbindung fällt heute aus. Grund dafür ist 1mm Schneefall auf den Gleisen.
Ahh, die vier Feinde der Deutschen Bahn. Frühling, Sommer, Herbst und Winter.
I believe Vivaldi composed this one.
Now all we need is some insane person with a kayak.
I volunteer— not like you go through most dangerous sea passage in the world or anything…
This kind of kayak. No exceptions, I don’t make the rules.
You could probably convince him if you just pretend you’re not impressed.
I got this far on the Wikipedia and gave up:
On a curved surface, the concept of straight lines is replaced by a more general concept of geodesics, curves which are locally straight with respect to the surface. Geodesics on the sphere are great circles, circles whose center coincides with the center of the sphere.
I went down a rabbit hole about globes and maps recently
Basically, to find the shortest distant between two places on a globe (a ‘straight’ line), imagine a hoop or circle round the earth that cuts it exactly in half, and rotate it until it passes through both places (still cutting it exactly in half)
That’s a great circle.
There are 2d map projections that are built around this, but they only work when one of the locations is at the center of the map. So it could show the shortest distance from, say, London to anywhere with a straight line, but it wouldn’t work for a route not including London
In case anyone else finds visual guides to be helpful for this sort of thing, I made a graphic to accompany your words:
Another way to think about it is with elastic bands.
Imagine getting a globe and putting a pin in each place. One pin in the UK, and one in New Zealand. Now put an elastic band between those two pins so that it’s tight. The elastic will be as short as possible, which is as straight a line as possible. But, since the globe is curved the elastic has to curve with it. So, that’s your straight line on a curved surface.
If you wrap the elastic around the other side of the globe (you might need a bigger elastic), you can find the other half of the circle. It’s the place where the elastic is at its tightest, but also where its evenly balanced between slipping to either side. For example, say you have a pin in California and another one in Japan. Both Japan and California are at about 30-40degrees north latitude. But, if you put an elastic starting in Japan and then going around the earth at 30 degrees north through China, Turkey, Spain, etc. when you let go the elastic will slip to the north until there’s no tension anymore. To keep it from slipping you have to balance the tension so it doesn’t slip to the north and doesn’t slip to the south, so it’s going flat around the whole globe. That makes the long half of the great circle.
Ah, okay that makes more sense! Thanks!
Another way to say it, if you cut a sphere in half and both sides are equal, its a great circle. All lines of longitude and the equator are great circles.
All that and not even one rabbit.
“Locally straight” is just a mathsy way of saying “it’s straight if you zoom in a bunch”.
There is also a route that can be drawn from Halifax, Nova Scotia on the Canadian east coast on the Atlantic … head a bit south east and without touching land and only going over the ocean, you can end up on the west coast of British Columbia, in Canada on the Pacific coast.
I used to reference a website that showed that … but now I can’t seem to find it. :(
Another fun one is to ask someone if they were to take off in an airplane from Miami and fly due south, which South American countries would they fly over?
The answer is none of them. You end up missing the entire continent because you are too far west.
You hit Panama first, but small portions of Ecuador and Peru are west of Miami (80.2 degrees west). The broader point that South America is much farther east than many Americans think is definitely true, though.
Does work for Tampa though
To expand on this idea: the most eastern part of the South American continent (Brazil) and the most western part of Iceland are only about 10° longitude apart. Meanwhile, Iceland shares lines of longitude with a number of countries in western Africa.
??? … da fuck??? … I was going to correct you when you said “too far west”
Now my brain is broken :(
I looked at that on Google Earth, now I’m uncomfortable in two directions…
I tried replicating this with Google Earth, but once you get past the halfway mark it tries to flip around and draw a line in the other direction. Guestimating it by drawing two lines seems to work ok, but I can’t find a way to avoid Australia, while shifting the start and end points between northern and southern NS and BC, and keeping the midpoint either just missing Africa or just missing Antarctica.
There used to be a website or post where I originally saw this … I can’t find it any more. And there are no more easily accessible websites that can diagram maps with ‘great circles’ on a globe. This was ten years ago and it used to be easy to find this stuff … interesting to see that most of those sites are either now gone or don’t work any more.
But from what I remember, the line between Halifax and the west of Canada skirted the edge of Africa and the edge of Australia to make it across the globe without touching any land mass or island.
Hopefully someone shares this with Geowizard, ultimate straight line challenge.
Only with an icebreaker
I’m no sailing historian, but that’s probably how they actually discovered New Zealand.
“Heya mates, how’bout we be goin’ straight ahead 'til back’ome we arrrggggh!!”
The Polynesians took the long route.
The European explorers actually took a very similar route, so this seems to be an obvious option for sailors doing island hops in that area.
One of the few world maps with New Zealand on it.
