Astronomy or cosmology give us answers to our fundamental questions. The following article gives an excellent summary of the present status of the scientific knowledge on the formation of our universe: Scientific American: Four Keys to Cosmology [ SPECIAL REPORT ]. From this article I would like to select the following 7 points as a logical extension of my Friday Dec 19th post: "Humans or the earthly bacteria":
1. "The big bang is best thought of not as a singular event but as an ongoing process, a gradual molding of order out of chaos."
2. "From the perspective of life on Earth, cosmic history started with inflation--a celestial reboot that wiped out whatever came before and left the cosmos a featureless place. The universe was without form, and void. Inflation then filled it with an almost completely uniform brew of radiation. The radiation varied from place to place in an utterly random way; mathematically, it was as random as random could be."
3. "Gradually the universe imposed order on itself. The familiar particles of matter, such as electrons and protons, condensed out of the radiation like water droplets in a cloud of steam. Sound waves coursed through the amorphous mix, giving it shape."
4. "Matter steadily wrested control of the cosmos away from radiation. Several hundred thousand years after inflation, matter declared final victory and cut itself loose from radiation. This era and its dramatic coda have now been probed by high-precision observations of the fossil radiation."
5. "Over the ensuing eons, matter organized itself into bodies of increasingly large size: subgalactic scraps, majestic galaxies, galactic clusters, great walls of galaxies. "
6. "The universe we know--a set of distinct bodies separated by vast expanses of essentially empty space--is a fairly recent development, cosmologically speaking. This arrangement has now been systematically mapped."
7. "Starting several billion years ago, matter has been losing control to cosmic acceleration. Evidently the big bang has gotten a second wind, which is good for it but will be bad for us. The ever faster expansion has already arrested the formation of large structures and, if it continues, could rip apart galaxies and even our planet."