OT - Is the universe finite in size?

[Kamog]

There has been news lately saying that the universe may not be infinite in size, but could be only about 70 billion light years across. Space wraps around so that light from a galaxy would eventually come back to where it started. Somehow they figured this out by observing the background microwave radiation of space, but I don't understand exactly what their reasoning is.

Anyway, it's very interesting that we may soon know whether the universe is finite or infinite in size. Here is an article about this:
http://www.newscientist.com/news/news.jsp?id=ns99994250

[narf poit chez BOOM]

so, if space wraps a millionth of a degree right, you simply keep turning a millionth of a degree left.

so it is infinite, wether it curves or not.

[parabolize]

Originally posted by narf poit chez BOOM:
so, if space wraps a millionth of a degree right, you simply keep turning a millionth of a degree left.

so it is infinite, wether it curves or not.

no
stuff going into a black hole is falling because space/time is folding (its called gravity).

[narf poit chez BOOM]

it's not folding. if it where folding, gravity would be 'random'. it's either stretched or squished, i'm not sure which. that is, if gravity is a function of space-time.

so, what specifically do you mean by curved? if you traverse an expanding series of circles in a straight line, to someone who's vision is defined by the circles, you curve. that's my point.

[dogscoff]

Boy, we're really, getting the easy questions this week: What's the meaning of life? Is space truly infinite? Just how bad was "Contact"?

only about 70 billion light years across

only 70 billion light years? Is that all?

I have to say I'm not surprised- after all, if you believe in the big bang then a finite universe is kind of inevitable. I like the idea of it wrapping back round on itself, too. The way the combat area should in se4...

[Suicide Junkie]

Take things to 2-D for a moment, and consider a Flat universe (or planet)
goes straight along, and if there's no discontinuity, then its infinite in size.

Now have it curved around into a sphere.
Its finite in size, and if you're persistent enough to travel in a straight line you'll go all the way around and end up where you started.

You'll also notice that for large triangles, the angles DON'T add up to 180 degrees. Depending on the radius of the sphere and the size of the triangle, it will be somewhat greater than that.
(Take three points "almost" along the equator of your sphere - Three points form a triangle, but the internal angles are all "almost" 180 degrees!)
One point at the pole, and two others on the equator "east" and "west" will make 90+90+180 = 360 (!)

In practical situations of course, you only have a small triangle compared to the radius of the sphere, so you don't notice it very easily.