Growing up most had one of two educational paths to follow - humanities or sciences. Without question most writers did not pursue sciences beyond what they remember from grade/middle school. I've seen lots (most, actually) bad science in film & print, but this one's near the top for this year's Ig Nobel Award for Stupid Science. No, the Sun's fusion doesn't abruptly stop (the consequences are far more severe than this film's no light plot), and more so to abruptly start again - Gawd!! Usual storyline of people fighting (in this case mostly arguing) over food, shelter, etc. as resources become scarce. But, there is light (metaphor for door to Heaven, or ...) at the end of the ...