# What do they mean "a straight line" in this image?

Asked by flo (6792 ) August 20th, 2013

This
“38. The Longest Straight Line You Can Sail on Earth
(Pakistan to Kamchatka Peninsula, Russia – 20000 miles)”
That doesn’t look like a striaght line does it?

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I don’t really know. I thought maybe it meant without having to make landfall but a quick look at Google Earth proved that theory wrong.

flip86 (3775 )

Thanks I thought I was missing something.

flo (6792 )

I figured it out. It is what it means. This video will help you understand.

flip86 (3775 )

If you want to go westward, I don’t see Africa in the video, they moved it up and sideways.

flo (6792 )

It seems really weird at first, but it actually is a straight line.

flip86 (3775 )

I disagree @flip86

flo (6792 )

You go between Africa and Madagascar, continue on to go between Antarctica and South America and from there it’s open ocean to Russia.

flip86 (3775 )

It’s a straight line on a globe, but on a flattened map, it doesn’t look that way.

amujinx (4826 )

http://en.wikipedia.org/wiki/Map_projection

What you see on a normal map isn’t a accurate projection.

johnpowell (5391 )

@flip86 has the correct answer. It’s not “a straight line of longitude” or “a straight line of latitude”, but it is a more or less straight line superimposed on the globe.

Of course, it’s not at all “straight”, since it’s superimposed on the surface of an oblate spheroid, but let’s not quibble about that.

CWOTUS (18670 )

So why not make maps that reflect the way things are? I’m just not getting this. Thanks everyone for the answers.

flo (6792 )

There is no way to flatten a sphere out into a two dimensional rectangle without distortion. Like the others said, that’s a “straight” line around a globe but doesn’t look that way on a map.

Mariah (18214 )

Actually, the video shows the best representation of “the way things are”, but you chose not to like that because it’s not a flat map, which, distorted as it is, is the way you normally view the world. I thought that video was amazing, and highly informative. (That whole website is amazing in its way, because it lets / forces you to see things from different perspectives. I once worked with an Argentinian gentleman who had an “upside-down” world map and globe in his office. That was a pretty interesting first exposure to “the world seen differently”. North is not necessarily “up”; it’s just a choice that the first – northern – map-makers chose for their own convenience.)

CWOTUS (18670 )

@flo In real life, Greenland isn’t the size of South America. On a flat map, it looks that way.

Seek_Kolinahr (28248 )

So you go south till antarctica and then turn right till Russia? Once you make a turn it is no longer one straght line.
As to the rest of it, I’ll have to give up on it.

flo (6792 )

^They’re not making a turn! Look at flip’s video or look at a globe. Then look at this wiki article on map projection. If it looks like too much, scroll down to the part with the various full-color maps of the world.

Flo, think of it as a hula hoop wrapped around a ball.

Seek_Kolinahr (28248 )

Let’s just forget it folks. This is not that crucial to me, good thing too.

flo (6792 )

This really is something everyone should understand before they finish high school, like knowing the three branches of government or knowing what the liver does. Just look at a globe and it will start to make sense.

Now excuse me while I look up “liver” on Wikipedia.

@CugelTheClueless “This really is something everyone should understand before they finish high school, ...” that is really transparent.

flo (6792 )

How come Africa is in a lying position and South America’s position hasn’t changed, as in it is in a standing position?

flo (6792 )

That doesn’t even make sense.

Look, this is as simple as I can make it:

When you peel n orange, the peel doesn’t become a flat sheet. If you try to lay it out that way, there would be holes.

To get a flat looking sheet to depict a round object, you have to stretch what is there to fill in the holes.

There are other forms of maps that show less distortion by leaving the holes in instead of stretching. But it would be even harder to understand in this context.

Until computer monitors are replaced with hologram projectors, you’re going to have to get used to the idea of a distorted flat map.

Seek_Kolinahr (28248 )

That doesn’t address the question. Africa, and South America.

flo (6792 )

None of the positions of the continents have changed in that video. You’re just looking at an ordinary globe from a different angle. See where Antarctica is? What happens to Africa and South America if you turn a globe so that Antarctica is in that position?

Just go to a library, office supply store, or toy store, pick up a globe in your own two hands, and see for yourself. We’re not messing with you.

If Africa appears horizontal why doesn’t S. America appear horizontal?

flo (6792 )

Look at where the tip of S. America is pointing. It does change as the globe turns.

Look at the map of the UN. It’s centered over the north pole. How would it look if it were centered over Paris? Over Sydney, Australia?

This really would make more sense if you played with an actual globe for 5 minutes.

[Edit: I meant the map on the flag of the UN.]

I went to 4 places for a globe.
-they have it only online.
-they don’t have it.
-they don’t have it.
-it costs an obscene amount (three digit figure)
Going to the library tomorrow.

flo (6792 )

A straight line southward between Madagascar and Africa from Pakistan, I hit Vinson Massif (or close to it) in Antarctica.

flo (6792 )

…on the globe by the way.

flo (6792 )

You can more or less draw the line yourself on Google Earth.

2. Pick a point on the Kamchatka Peninsula (south of the end of the Aleutian Islands archipelago) in Eastern Russia and use Google Earth’s “ruler” tool that will allow you to calculate “straight line” distances over the globe.

3. From that point on the Kamchatka Peninsula (I just guessed at a point close to where the linked map and video showed; I didn’t attempt to get it perfect.

4. “Draw the line” with the ruler tool by heading generally southeast from the Kamchatka Peninsula and take it to the point of land at Graham’s Land (the long finger-like peninsula on Antarctica that generally points toward the Falkland Islands.

5. You’ll have to stop the first line at that point to set it as a waypoint (using this tool in Google Earth), because as you attempt to pass it in one go (on this application), the line will snap back toward Kamchatka (which makes sense, as you’re attempting to draw a line between points on a globe, after all, and the application (programmers) would not expect you to be taking the long way around the globe between those points.

6. From this new waypoint, continue on a course that will take you between Madagascar and the African continent, ending in Pakistan, as shown on the video and map that you continue to question. It really does seem to work.

CWOTUS (18670 )

And why would I need to do aaaaalllll that, when I’ve just found out (with just a globe and a string), that this is supposed to be one big practical joke, hmm?

If someone asks you to find out the distance from your sofa to the bookshelf what are you going to download? Are you going to answer: “Sorry, I can’t do it without a computer”?

flo (6792 )

Google Earth…....that will allow you to calculate “straight line” distances over the globe.
Okay, it helps me to know the distance, but does it say anything about being able to sail though without hitting land? My guess is no.

Added: By the way in my analogy above there is supposed to be a coffe table between the sofa and the bookshelf.

flo (6792 )
Response moderated (Spam)

Crazy busy this week. I finally stopped by the library to look at a globe myself. It looks to me like you can do it. My string wasn’t long enough to go all the way, but it looks to me like you can get from Pakistan through the straits between Antarctica and S. America. I’m not sure why you landed on Vinson Massif.

I suspect the problem may be that it is a straight line but does not lie on a “great circle”, i.e., a path that traces the full circumference of the sphere. Think of latitude lines: they are all “straight lines” (as that term applies to this discussion), but except for the equator they do not trace the full circumference of the earth. Now think of trying to draw a perfect circle on the globe that is not a great circle and does not run perfectly east-west or north-south. Someone watching you might not think you were drawing a “straight line”. Same thing with using string. If you saw me running the string from Pakistan past Madagascar and Cape Horn, you might think I was cheating by allowing the path to curve when in fact it was straight.

But I could show that I was making a straight line by taking a loop of string that was the right size and laying it on the globe in such a way that it made a circle, not an ellipse, and holding the globe in such a way that the circle was parallel to the floor, so that you could look down on it from above and see that it was in fact a circle.

Now, if we can do that in a way that puts Pakistan and Kamchatka on the circle without touching any other land in between them (along the arc that connects them through the southern hemisphere, of course), then that will show that there is in fact a straight-line water route that connects them.

You can also get your mind around it by imagining a flat plane intersecting the Earth in such a way that makes such a circle.

(If you tried to sail it you’d probably be sunk by drifting icebergs, but that’s beside the point.)

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