An arbitrary homework assignment for a class that really does exist is asking for the arguments for and against the big bang theory and my Google button is broken.

Question

underhill · Answer

Hop on over to the Cosmology section of the Physics Forums: http://www.physicsforums.com/forumdisplay.php?f=69 It's an interesting topic. Notice it hasn't been added to the "Do Not Discuss" list!

anonymous · Answer

Haha I'm not looking for a resource, trust me, I've read my physics.  I'm looking for a discussion, I want to know what *you* think.

anonymous · Answer

i think if big bang was there there will be big crunch too,

which means time will run backwards,

which doesnt seem right at all

anonymous · Answer

What about the big bang would imply a big crunch?  And what about a big crunch would imply time running backward?

turingtest · Answer

I'm sure everyone here knows this, but the most immediate and pointed argument in favor of the big bang is the fact that the universe is expanding. Therefor if we run the clock backwards we fins that the universe must have come from some kind of singularity. Einstein's attempts at formulating the cosmological constant as way to show that the universe is stable are a notorious failure, though more recent studies on dark energy have given it new life to some extent, though I am not very well-versed in the details on that.

anonymous · Answer

I have an alternative argument.  The universe was either created at a point in time or the universe is eternal and therefore steady-state.  Intelligent life can exist (see man).  If intelligent life exists and the universe is eternal, intelligent life always existed and came into existence many times and we would have been overrun with billion-year-old ET tourists willing to travel millions of light years in search of fun and adventure.  We are currently alone.  Therefore, the universe is not eternal.

If the universe came into existence, either it was created in a state of expansion (see Creationism) or it evolved from a different state.  There is no other state that would evolve into an expanding universe except a big bang.