Posted: Thu Jul 10, 2008 4:37 pm Post subject: can someone explain eternity/infinfity to me?
I cannot grasp it. Has there always been matter? I cannot understand that here is no beggining. I can almost understand no end but no beggining?
Does space really go on forever? I guess it must because it can't just stop somewhere. Did you ever think that if space is infinite that even light waves will never reach the end of it. So even a beam of light travelling FOREVER will not get to the end of space??? So there is an infinite amount of space that will never see light....
The idea isn't that the universe is infinite, it's that it's expanding infinitely. This is a topic I'm relatively new to as well so I can't really provide any links. Hopefully someone else knows a basic resource about it that they could link us to.
Posted: Fri Jul 18, 2008 1:15 am Post subject: Re: can someone explain eternity/infinfity to me?
I cannot grasp it. Has there always been matter?
No one knows. The best answer at the moment is "probably not".
I cannot understand that here is no beggining. I can almost understand no end but no beggining?
The simplest answer is, there was probably a begining to space and time. But no one really knows.
The tricky thing is when people start talking about this in the context of causality; that is, "well, the universe has a begining, so obviously someone caused it!"
It's not really that simple when you're talking about space and time themselves; that sort of thinking only works when you already have space and time to work with.
Does space really go on forever? I guess it must because it can't just stop somewhere.
Maybe. No one really knows.
From the looks of things, it just goes on forever.
But it may also be the case that there's a finite amount of space and that you can keep going without ever hitting an edge; perhaps space wraps around on itself.
Think of it like the surface of the earth; you can walk or swim in any direction, for as long as you want, and you'll never hit an edge, a begining, or an end to the earth's surface. And yet, the earth's surface area is finite in size.
Did you ever think that if space is infinite that even light waves will never reach the end of it. So even a beam of light travelling FOREVER will not get to the end of space??? So there is an infinite amount of space that will never see light....
And if that's the case, things may be quite bleak for the universe as time goes on. Light and energy and matter continue to spread out forever, and the result is that, at some point indefinitely far into the future, the universe ends up cold, dark, and dead.
I do not profess any expertise or even significant experience on the subject, but if any find it useful, a helpful analogy for understanding the observed expansion of the universe may be the following: (I apologize if I am incorrect, and I welcome corrections)
Space does not expand from its periphery outwards. If we think of our 3-dimensional space as being the 2-dimensional surface of a balloon, then the expansion of our space is analogous to if one inflates the balloon. Any two points on the balloon surface, no matter how close together or far apart, will be separated by an increasing distance (and I believe the current consensus is the rate of this increase is accelerating). Thus, the expansion takes place at all points in space.