Do parallel lines REALLY meet in space or is that a lie?
342727
No, parallel lines never meet
582411
2 paralel lines that are not perpendicular to the object they measure
143927
the second proposition is a formulation of Euclid's postulate of the paralleles.\nIt's precisely a postulate, as the same Euclid posed it; rinascimental mathematicians tried to prove it as a theorem, but they failed: in fact Euclid knew well what he was doing.\nThe postulate of the paralleles defines the Euclidean geometry, which is "platonic": it needs abstraction, because you can't apply it on the spherical surface of the Earth.\n\nSo the answer to your first question is no: if you assume spherical geometry, and thus parallels as maximum circles on the sphere, the angles postulate doesn't work anymore.\n\n(Notice that ancient Greeks were able to measure the Earth's radius by astronomycal calculations: so they knew very well how the Earth was not planar ... )
216225
Einstein's theories (never mind that they have checked out in reality) are incredible: space is curved; the shortest distance between two points is not a straight line; the universe is finite but unbounded; \n\nparallel lines eventually meet;
951551
A line that runs parallel to the Y axis.
666924
Same plane and not parallel as other answers have said, but the reference to moving balls complicates things. The balls are not guaranteed to meet, and since they are in unidirectional motion, their paths will not cross if they diverge initially. Such paths are not extended in both directions as the definition of a line requires.
160807
Yes they are there.  Apparently when the membrane like structure of different universes collide, they create new universes.  Look up string theory.
271997
It's amazing isn't it?! It's so beyond our technology to fully test the theory though. I do however believe in parallel universes because math proves that you can have more dimensions beyond what we possess. Have to be able to open your mind to understand, ya know?
780820
NO it is NOT true\nThis is a very common misconception and urban legend.\nsee:\n\nhttp://pomonahistorical.org/12times.htm\n\nhttp://mathworld.wolfram.com/Folding.html
402813
No, I think it'll take too long for them to join together.  They're generally so far apart that the gravitational pull on each other is very very small.  Besides, the universe is constantly expanding, so instead we'll end up in a position where everything is just cold and the density of matter is very small.  That's just one theory, though.
1060257
Lines that do not intersect are parallel or skew; lines that intersect are perpindicular or non-perpindicular.
1026839
In geometry, two lines are said to be skew lines if they do not intersect but are not parallel.\n\nSkew lines only exist in three or more dimensions; any two distinct lines in the plane which are not parallel must intersect at some point. In fact, two lines are skew lines if and only if they do not lie in a single plane together. This means that if each line is defined by two points, these four points must not be coplanar; put another way, they must be vertices of a tetrahedron of nonzero volume. Any three of them will still be coplanar, since three points define a plane, but no three points will be collinear, since this would make all four points coplanar.
535406
Latitude lines are placed so that they are parallel to each other- they form parallel circles around the earth.  Longitude lines, on the other hand, are not parallel- they intersect at the north and south poles.  Because they intersect at the north and south, the closer you get to the either of the poles, the shorter the distance from east to west between lines of longitude. Because latitude lines never intersect each other, the distance between them remains the same from north to south, across the globe.
175717
I've heard of this parallel universe theory..well, it's not a theory really it would be like a conclusion if string theory is someday proved ; there may be infinite universes each with a different law of physics and ours will be just one of many others .\nsounds weird huh? that there are hidden worlds beyond ours, well, that's because there are particles like e- that can stay in more than one place at a time ..so one explanation could be that this particles don't exist just in our universe but in an infinite number of them ( parallel universes)..reality is even more amazing than fiction sometimes :P
540627
Not an uncommon thing to see. The "sky" is laid out in compass points and most commercial air craft are assigned flight paths that are like "high ways" in the sky. Generally you will find those "trails" are on true points, 00%,45%,90% etc. The reason for the near perfect "X" is due to the vectors the two were heading on.
377295
If it has no solutions, then the two lines are parallel but different.  If it has infinitely many solutions, the two lines are actually the same line (think of them as one right on top of another).\n\nWhen you try to solve them algebraically, in both cases the x and y (or whatever two variables are used ) will both cancel out.  If there is no solution, you will end up with two unequal numbers, such as 0 = 3.  If there are infinitely many, you will end up with two equal numbers, such as 6 = 6.
1092455
Yes.  Infinity goes in both directions.  Space is space, large or small.  IMHO  ;-)