Immortality

Consider they finally invented a drug to stop the aging, what the heck will we do with all the people?

In the long run, immortal humanity would either have to revert to natural, or social Darwinism. And I don't know which of the two prospects is scarier. The first would be easier on the ethics, but the second let's you hold on to a bit of culture, preserving a veneer of a civilization. I think I'd eventually agree to the soylent green approach. Although, going the primitive route would eventually destroy the knowledge needed to stop aging, allowing the civilizing processes to start anew (once the population reduces in size, unaided by modern convention)

Alchemy

Alchemy..a marriage of philosophy and art in a crucible of unfermented science. Ethics, magic, medicine, astrology, law, poetry, heresy combined in equal parts, permeated, filtered, diffused and diluted into a dancing water of life.

As above, so below, a most elated game of clouded minds. At once wicked and virtuous, ingenious and foolish, a poisonous panacea. But are these faulty premises of any use?

Without them, you are a lonely slab of man-shaped meat, dangling on sticks, with them, you are a being of a higher order, god's vassal on earth, passing through the world of shadows, finding your golden path. Every action, event or instance - becomes a strand in a magical pattern of infinite complexity.