Nuclear weapons is a maybe somewhat controversial choice as a "greatest invention".While I do see maybe some benefits to there existence,like they might actually have prevented major wars as that would mean a nuclear holocaust and most people (maybe all) being ******,so due to that everyone has restrained themselves but only barely at times.They also mean mankind has the power to destroy itself and we all know from history that such power almost will ineviatably be used at some point as long as they exist.
And I have to say that while technology and invention has vastly improved our lives it all has a down side in the way we have managed it.Technology and invention have allowed us to grow the population immensly while increasing the impact humans have on the planet.Technology is great except if it ends up ******* most of us and threating our existence on the planet.Maybe we are too smart for our own good sometimes or in aother words not advanced enough to have such technologies without the wisdom to manage them.