Where's the Nearest Edge of the Universe?

So, after definitively answering in a previous blog about the center of the Universe, I was then asked by my brother where the nearest edge of the Universe might be located. (He enjoys taking long road trips.)

Is there an edge or boundary of the Universe?  Unfortunately, we are limited in how far out into space we can see.  There is probably more beyond that distance…but that light hasn’t had enough time to travel the distance to earth just yet.

Since we don't know for sure whether or not the universe has a boundary, scientists have a few theories:  

a)  The universe is a closed universe, curving around on itself.  Hence, no boundary.

b)  It is infinite in size…hence no boundary.

c)  There is “dark flow” on the outside of the observable universe which generates massive gravitational forces, causing our rapid expansion.

d)  String Theory calls for multiple universes, each it’s own space-time bubble.  The interaction of these “bubbles” causes disturbances in the force, such as Big Bangs. 

The universe that we can observe (by using the Hubble ultra deep field detector) is around 90 billion light years wide.

If you want to travel to the observable edge, the best I can offer is:  turn left at Pluto….and take an extra sandwich, it make take a while to get there.

Some references and further reading:

http://www.fromquarkstoquasars.com/what-lies-beyond-the-edge-of-the-observable-universe/

http://www.cfa.harvard.edu/seuforum/faq.htm#s1

Major Earth-Shattering Events - Which Will Come First?

All of the following major, earth-shattering events will eventually occur   But, can you guess which one will come first?

a)  The Sun will grow so large, and generate so much heat that life will cease on Earth.

b)  The Milky Way and the Andromeda galaxies will collide and merge, creating one combined galaxy.

c)  North and South America continents will collide with the African continent; the Atlantic ocean will no longer exist.

The answer is:  c).  The merging of Earth's continents will occur in about 250 million years from now - one earthquake at a time.  

The next major event will be in 1.1 billion years from now when the sun, in it's gradual demise, will start to grow larger and generate so much additional heat that it will not be possible for life on Earth to sustain itself (I guess by then my portable greenhouse will no longer be needed). There are some theories that earth's orbit may adjust itself and survive a growing sun...at least for a while longer.

The Andromeda galaxy is currently hurdling on a collision course with our own Milky Way. The two galaxies will "collide" around 3.8 billion years from now.  Since distances between stars is so great, scientists do not believe that any true collisions will occur.  But the light show will be amazing.  

Here is a great animation of that potential collision:

http://hubblesite.org/newscenter/archive/releases/2012/20/video/a/

So...hold on to your hat...it's going to be an amazing ride!  

Other References:

http://math.ucr.edu/home/baez/timeline.html#future