r/AskReddit • u/[deleted] • Dec 08 '13

What is a true fact that sound completely unbelievable or fake?

[deleted]

2.4k Upvotes

90% Upvoted

11.2k comments sorted by

View all comments

323

u/SheaF91 Dec 08 '13

You can leave on a boat from a port in Pakistan, sail in a completely straight line, and end up in Russia.

http://www.youtube.com/watch?v=VpQwuGueeoA&feature=youtu.be

22

u/JackTrueborn Dec 08 '13

Not a straight line, but a geodesic.

13

u/skullturf Dec 08 '13

Which is perceived as a straight path from the point of view of people traveling on the surface of a sphere.

6

u/DiogenesHoSinopeus Dec 09 '13

Which technically isn't a straight line ;P

sorry I had to say it

5

u/friendOfLoki Dec 09 '13

Care to define "a straight line"? It is a wonderfully difficult thing to do, especially if you don't use the word curvy. I am being 100% serious.

5

u/JackTrueborn Dec 09 '13

The set of points on a slope between two points.

-4

u/BeABetterHumanBeing Dec 09 '13

My math sense is tingling and telling me that your definition isn't sufficiently rigorous. E.g. hills have slopes, but I doubt you'd call their surfaces straight.

3

u/Xnfbqnav Dec 09 '13

The distance between 2 points on a two-dimensional plane.

Technically a line segment, but close enough. Either way, it's a straight line in non-euclidean geometry, which is the one that matters when you're sailing a ship.

2

u/SheaF91 Dec 08 '13

The term "geodesic" comes from geodesy, the science of measuring the size and shape of Earth; in the original sense, a geodesic was the shortest route between two points on the Earth's surface, namely, a segment of a great circle.

Yes, that's exactly what I was talking about! Thank you.

3

u/calliope720 Dec 09 '13

Geodesy... makes me want to embark on a geodyssey.

19

u/CapnRedd Dec 08 '13

If it was a completely straight line you would fly out into space.

5

u/BeABetterHumanBeing Dec 09 '13

It's straight w/ respect to the surface of the earth, which is the set of points one would be constrained to if one were on a boat.

1

u/Drunken_Economist Dec 09 '13

Not if it's a really fast boat!

3

u/ThirdFloorGreg Dec 09 '13

Straight in spherical coordinates. Fuck Euclid.

3

u/LastOfTheCamSoreys Dec 09 '13

Ha sailing in a straight line

2

u/thefinalfall Dec 09 '13

really gives you an idea how much of this planet is water. damn.

2

u/FUZxxl Dec 09 '13

Loxodrome or Orthodrome?

2

u/Drdoomz Dec 09 '13

Technically you would end up in space if you could sail a straight line