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survivorboi
Apr 4, 2009, 10:46 AM
OKay, consider this:

If 2 parallel lines fall into a black hole, will the meet (or intersect)? Since black hole squeeze space and time together, I think that the parallel line will eventually meet.

Capuchin
Apr 4, 2009, 11:14 AM
You don't need something as exotic as black holes - 2 parallel lines on the equator of the earth will meet at the poles. It's a result of the earth's positively curved geometry.

survivorboi
Apr 4, 2009, 11:22 AM
Wow! Thanks

Perito
Apr 4, 2009, 02:15 PM
If 2 parallel lines fall into a black hole, will the meet (or intersect)? Since black hole squeeze space and time together, I think that the parallel line will eventually meet.

Parallel lines only exist in Euclidean space. There is no concept of black holes in Euclidean space. The squeezing of space and time has not been defined in that space.

By definition, parallel lines never meet. Your hypothetical question is not possible to answer.

ngasnier
Apr 6, 2009, 12:13 PM
You don't need something as exotic as black holes - 2 parallel lines on the equator of the earth will meet at the poles. It's a result of the earth's positively curved geometry.

In the case of lines intesecting at the poles, then they wernt really parallel in the first place.

The very definition of "parallel" means that they don't intersect

Capuchin
Apr 6, 2009, 01:01 PM
In the case of lines intesecting at the poles, then they wernt really parallel in the first place.

The very definition of "parallel" means that they dont intersect

You're right, but I was trying to explain it simply and perhaps muddled my terms - I meant 2 lines on the equator that initially appeared to be parallel - i.e. 2 lines at right angles to the equator.

Capuchin
Jun 2, 2009, 11:45 AM
A car driving around the equator leaves 2 parallel lines and DON'T meet at the poles. Balancer

And? The lines have to be parallel at the equator, but neither of the lines touch the equator. This is not the case I specified..

DrJ
Jun 2, 2009, 11:57 AM
If two lines are TRULY parallel, they will never meet or intersect each other... however, they may loop back around to meet themselves

galactus
Jun 2, 2009, 01:52 PM
As we know, parallel lines do not intersect in Euclidean space. But, in positively curved

Spacetime, they do. In negatively curved spacetime, they get farther apart.

ZoeMarie
Jun 2, 2009, 01:57 PM
Parallel lines must be located in the same plane. The earth is round...

Capuchin
Jun 2, 2009, 03:53 PM
parallel lines must be located in the same plane. the earth is round...

Thanks for the correction, you're correct, parallel lines don't exist on a spherical surface, by definition.

galactus
Jun 2, 2009, 04:13 PM
But the original query was about black holes, not the Earth. A whole nuther matter.

Capuchin
Jun 3, 2009, 03:08 AM
I think the best answer is "Parallel lines don't exist because space-time is not Euclidean" :p

jurei
Feb 7, 2012, 02:24 PM
They will meet they will always meet

jurei
Feb 7, 2012, 02:26 PM
I'm in school they teach us this I now