Stingo
Well-known member
Apparently, it is possible to do this in a straight line!
Sailing from India to the West Coast of the USA
- Thread starter Stingo
- Start date
reallycoliholic
Well-known member
Surely you'd go the other way? West to east?
AntarcticPilot
Well-known member
The great circle route (the straightest route) doesn't work that way. Actually I'm not sure the route above works; I think the South Shetland Islands get in the way. Admittedly, any deviation imposed by them would be small.
coopec
N/A
While ocean currents and Antarctic ice sheets might make this route practically impossible, many commenters on the post shared on X (formerly Twitter) user Epic Maps were amazed by this discovery.
Even Elon Musk, CEO of X was impressed, simply saying: 'Woah'.
Social media users have been trying to wrap their heads around this map which shows it's possible to sail directly from India to the USA in a completely straight line
Map shows how you can sail from India to the USA in a straight line
Neeves
Well-known member
Personally I don't mind the odd corner or two - it would be very monotonous if you did not need to tackWhile ocean currents and Antarctic ice sheets might make this route practically impossible, many commenters on the post shared on X (formerly Twitter) user Epic Maps were amazed by this discovery.
Even Elon Musk, CEO of X was impressed, simply saying: 'Woah'.
Social media users have been trying to wrap their heads around this map which shows it's possible to sail directly from India to the USA in a completely straight line
Map shows how you can sail from India to the USA in a straight line
Jonathan
coopec
N/A
I'd enjoy it until I got to Cape Horn
cape
cape
AntarcticPilot
Well-known member
And Cape Horn is nowhere near Antarctica, being positively balmy by comparison! Cape Horn is at 56 degrees S - large parts of the UK are nearer the Pole than that; Edinburgh is at about the same latitude north! Antarctica (by international treaty) is the lands and ice shelves south of 60 degrees S, and the Antarctic Circle is at 66.5 degrees S. I do get a bit cross when people advertise cruises to South Georgia as "Antarctic" - it's at about the same latitude S as Manchester is N.
As I noted above, I think you'd get into trouble with the South Shetland Islands - from the look of the track, it comes awfully close to some of them, and definitely crosses the line of the islands. Maps on a scale to show the great circle from India to Alaska tend not to have enough detail of smallish islands like the South Shetlands - but they form an almost continuous line that is right across the track shown. I THINK that you'd hit Clarence or Elephant Island.
Mister E
Well-known member
Am I being thick but the line is not straight.
AntarcticPilot
Well-known member
It's a great circle, which is the shortest route between two points on a sphere - i.e. the straightest line between the points. The map is a 2D representation of a 3D surface, so it distorts shapes.
ean_p
Well-known member
the short answer is yes .......
cpedw
Well-known member
Just checking and ignoring all practical problems - a great circle route would need lots of course changes wouldn't it?
Bilgediver
Well-known member
Not many commercial grain ships seem to be sailing this shortest route ???
AntarcticPilot
Well-known member
No more than any other. Of course, to follow a great circle you do change course - but once a day at sailing boat speeds would be ample, and for large portions of the route shown (the equatorial bits), even less frequently would not give rise to big deviation from the accurate great circle. However, no sailing boat follows a great circle - it's often the least efficient route once you take into account prevailing winds and ocean currents. The one shown here would have you facing a headwind for a lot of the time!
Laser310
Well-known member
since when is a great circle a straight line?
dunedin
Well-known member
You can’t do a straight line anywhere on a globe, as would rise off the surface
Laser310
Well-known member
exactly - any line on the surface of a sphere is not straight
AntarcticPilot
Well-known member
If you want to think of it this way it may help.
A straight line is the shortest distance between two points.
On the surface of a sphere, the shortest distance between two points is the intersection with the surface of the earth of a plane passing through both points and the centre of the earth. That is known as a Great Circle.
You can verify this on a globe by stretching a string between two points.
Maps represent the surface of the spherical earth on a plane sheet of paper. It is impossible to do this without introducing distortions and discontinuities (try peeling an orange without breaking the skin!) Therefore the Great Circle is a curve on most maps. The only exception is a map on the Gnomonic Projection, where Great Circles are straight lines - but which are awful in many other respects.
sarabande
Well-known member
This is the book that explains very nearly everything about map projections thoughout man's written history, and how we humble sailors made it possible to launch satellites and , less favourably, ICBMs
Amazon.co.uk
I learned in the International Geophysical Year way back in 1957, that the variations on height and depth on the earth's surface are very very close in scale to the roughness of the shell of a hen's egg.
Amazon.co.uk
I learned in the International Geophysical Year way back in 1957, that the variations on height and depth on the earth's surface are very very close in scale to the roughness of the shell of a hen's egg.
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Laser310
Well-known member
so what?
it is still not a straight line:
"A straight line is an endless one-dimensional figure that has no width. It is a combination of endless points joined on both sides of a point. A straight line does not have any curve in it...."
Note: one-dimensional.., no curves...
A line contained within the surface of a sphere is not one-dimensional.., and it definitely has a curve..
Such a line is not straight.
ean_p
Well-known member
Oh dear..........
