brain teaser quiz

masraum · 10-12-2006, 01:00 PM

You travel in a straight line for a given distance A, make a 90* turn to the left, travel in a straight line of length A, make a second 90* turn to the left, and then after travelling in a straight line of length A you find that you've arrived back at your starting point and arrived at a point 90* off from the direction you initially left. So you travelled 3 straight lines that made 90* angles to the each other. That means that you travelled in a triangle, except that the sum of the three angles is 270*.

What's the deal?

Not terribly difficult but still interesting to think about. Anyone got another??

Jim Richards · 10-12-2006, 01:04 PM

Starting at one of the Earth's poles, you're traveling on the surface of the earth along a meridan, then turn at the equator, then travel along another meridan, 90 degrees from the first. The length A is 1/4th the circumference of the earth at the equator, though this assumes the earth is really a perfect sphere. Do I win a cookie?

stevepaa · 10-12-2006, 01:08 PM

Got me, I don't think it is possible in Euclidean space.

A straight line in Euclidean space is planar.

masraum · 10-12-2006, 01:08 PM

Quote:

Originally posted by Jim Richards
Starting at one of the Earth's poles, you're traveling on the surface of the earth along a meridan, then turn at the equator, then travel along another meridan, 90 degrees from the first. The length A is 1/4th the circumference of the earth at the equator, though this assumes the earth is really a perfect sphere. Do I win a cookie?

Now what do you do about the fact that a triangle is a shape that has 3 angles that collectively should add up to 180*, but yours just added up to 270*?

Jim Richards · 10-12-2006, 01:13 PM

Just intersect my "path traveled" on the 3-d sphere with a 2-d plane and you'll end up with an equilateral triangle with all angles 60 degrees. Do I get two cookies?

Jim Richards · 10-12-2006, 01:23 PM

I want my cookies!

masraum · 10-12-2006, 01:24 PM

no cookies, now you have to give us another...

svandamme · svandamme's Garage

Quote:

Originally posted by Jim Richards
Starting at one of the Earth's poles, you're traveling on the surface of the earth along a meridan, then turn at the equator, then travel along another meridan, 90 degrees from the first. The length A is 1/4th the circumference of the earth at the equator, though this assumes the earth is really a perfect sphere. Do I win a cookie?

if you do this on the earths surface , then perfect 90 degree turns would not end up where you started , not even if it were a perfect sphere...

EDIT , crap , the equator... got it now... duh on my behalf

Jim Richards · 10-12-2006, 01:26 PM

WTF, after all that thinking, no cookies?

Jim Richards · 01:32 PM

Quote:

Originally posted by svandamme
if you do this on the earths surface , then perfect 90 degree turns would not end up where you started , not even if it were a perfect sphere...

Huh? Pole to equator, turn left, go 1/4th the way around, turn left again, back to pole and when you get there, you're facing 90 degrees from your initial course. Pole to equator is 1/4th the circumference, too. Right?

Saw your edit...nevermind.

Jim Richards · 10-12-2006, 01:33 PM

Cookies!!! Must have cookies!!!

masraum · 10-12-2006, 01:51 PM

No cookie for you!

motion · 10-12-2006, 01:53 PM

Which is further west? Reno, NV or Los Angeles, CA.

Jim Richards · 10-12-2006, 02:03 PM

Quote:

Originally posted by masraum
No cookie for you!

Grrrrr!

BRPORSCHE · 10-12-2006, 02:38 PM

Name the Northern most, Southern most, Eastern most, and Western Most points of the U.S

Jim Richards · 10-12-2006, 02:41 PM

How much wood could a woodchuck chuck?

teenerted1 · 10-12-2006, 02:54 PM

Quote:

Originally posted by BRPORSCHE
Name the Northern most, Southern most, Eastern most, and Western Most points of the U.S

48 or 50 states?

sammyg2 · 10-12-2006, 02:54 PM

Travelling in an arc that follows the surface of the earth is not the same as travelling in a straight line.

The correct answer is, it can't be done unless we can further our understanding of warping time and/or space.
The cookies don't exist in our universe either.

teenerted1 · 10-12-2006, 02:57 PM

Quote:

Originally posted by masraum
That means that you travelled in a triangle, except that the sum of the three angles is 270*.

wtf?

i traveled 3 sides of a square. and i am no where near my starting point. 90* is a right angle in my book

BRPORSCHE · 10-12-2006, 03:30 PM

tenner it is all 50 states.