While Joss Whedon is busy adapting "The Avengers"
into a highly anticipated blockbuster, another one of his stories has come back from the undead, not unlike one of Buffy's titular baddies. To the delight of nerds everywhere, "Firefly" will be back on cable
after being acquired by the Science Channel. Hooray! And after every episode, Dr. Michio Kaku -- a physicist who is clearly gunning for Carl Sagan's old job -- will discuss the ...