Introduction

jerschgen · June 5, 2009

I'm new to this site and would like to share a little about my unremarkable self. I'm retired and I have just have an increasing interest in astronomy. My only formal background was a five hour introductory course to astronomy at the Univiersity of Missouri-Columbia many years ago. I wasn't even able to use the telescope. It was all theory, math, chemistry and physics and I was quite overwhelmed. But, it was inspiring to know what I didn't know and didn't comprehend.

I love to watch programs and read articles on astromony. I'm totally astounded by how math, chemistry and physicsact in concert. And the many philosophical questions that it raises are also infinite. I'm sorry that my knowledge and understanding is so finite due to my lack of education and comprehension. But, the more I learn the more enthused I am. I wish I had the means and time to learn more. Astronomy is a liesurely past-time for me.

I do have two questions. If the known universe is expanding, what are the properties of the medium in which it is expanding? Is it infinite? And if the premise of the big-bang is acurate, will the process repeat itself indefinitely and if so, is it possible that eventually there could be an eventual exact duplicate repitition resulting in a duplicate (or even many duplicates) of the universe as we experience it now?

Thank you for permitting me to introduce myself.

freeztar · June 6, 2009

Welcome to Hypography! :hihi:

I do have two questions. If the known universe is expanding, what are the properties of the medium in which it is expanding? Is it infinite?

It's not useful to think of what the universe is expanding into. The Universe, by definition, encapsulates *everything*, all mediums. I know it's counter intuitive to not imagine space expanding into something, much like the skin of a balloon expands into the surrounding air as it is inflated, yet, if there is no space ("outside" the universe) then there is nothing to expand into.

Of course, we can never know for sure because light (which is the transmitter of information) is inaccessible at such distances. Also, some theories claim that space is bent into itself, like a closed loop. Other theories speculate that our universe is an expanding bubble in a sea of other universes.

No theory is any better than any other simply because there is (currently at least, and most assuredly forever) no way to know for sure. Ahh, life's mysteries. :)

And if the premise of the big-bang is acurate, will the process repeat itself indefinitely and if so, is it possible that eventually there could be an eventual exact duplicate repitition resulting in a duplicate (or even many duplicates) of the universe as we experience it now?

Current cosmology believes that the universe does not have enough mass to overcome critical density and the universe will continue to expand and cool, eventually ceasing to have any matter at all. It's quite dystopian, but it looks to be that way with the current data we have. Thus, the idea of a cyclic universe has gone by the wayside in mainstream science.

If you'd like to discuss these subjects more, please find a relevant thread or create a new one. I'm sure many of us would love to discuss such things with you.

Here's a couple to get you started:

http://hypography.com/forums/astronomy-and-cosmology/16032-what-lies-outside-the-universe-vacuum.html#post236622

http://hypography.com/forums/astronomy-and-cosmology/18977-whole-mess-will-start-over-again.html#post259563