a) The the mikly way is estimated to be 100,000 light-years in diameter, and up to 5,000 light-years thick. And in this galaxy, our Solar System is located about 26,000 light-years away from the very center. The Solar System isn't at the middle of the galaxy, but it's not at the edge. Astronomers now know that the center of the milky way contains a super massive black hole, containing millions of times the mass of the sun. Fortunately, we're very far away from this center, where stars are clustered much more closely together.
http://www.universetoday.com/guide-to-space/the-solar-system/solar-system-galaxy-universe/
Universe today - Page updated: July 30, 2008
b) The big bang theory states that at some time in the distant past there was nothing. A process known as vacuum fluctuation created what astrophysicists call a singularity. From that singularity, which was about the size of a dime, our Universe was born.
http://cosmology.berkeley.edu/Education/IUP/Big_Bang_Primer.html
Last Modified: 1/27/98 cfpaedu@physics.berkeley.edu
http://www.universetoday.com/guide-to-space/the-solar-system/solar-system-galaxy-universe/
Universe today - Page updated: July 30, 2008
b) The big bang theory states that at some time in the distant past there was nothing. A process known as vacuum fluctuation created what astrophysicists call a singularity. From that singularity, which was about the size of a dime, our Universe was born.
http://cosmology.berkeley.edu/Education/IUP/Big_Bang_Primer.html
Last Modified: 1/27/98 cfpaedu@physics.berkeley.edu