SL2 tech: major genetic engineering, medical immortality, interstellar travel, and new “alien” cultures SL3 tech: Immortality, nanotechnology, human-equivalent

SL2 tech: major genetic engineering, medical immortality, interstellar travel, and new “alien” cultures SL3 tech: Immortality, nanotechnology, human-equivalent AI, intelligence increase, uploading, total body revision, intergalactic exploration, megascale engineering I think we're making progress toward SL3 tech as well as SL2 tech. Things like interstellar travel and "alien" cultures seem off (unless you could today's culture "alien" to the past). However with recent work in nanotechnology and AI (even megascale engineering), we can already see ourselves working on SL3 tech today.