one alternative view that i have not heard else where (alternative to the big crunch or the fizzle-out) is that our universe could impact another parrellel universe in the 11th dimension....this could cause another big bang...destroying our universe and the one it collided into....but creating another one in the process

one of the wonderful aspects of m thoery is that given enough energy, say the energy of two colliding universes, a string can infalte to become a universe sustaining membrane

the smallest thing in nature becoming the biggest thing in nature.....

in destruction there is creation
when a star goes supernova it spreads new elements into the heavens, which form other stars, planets, nebulee, etc

the cycle of nature

how do you think the universe will end?