Medicine & Treatments
Vaccines
A medical intervention effective enough to have completely eliminated one deadly disease from the entire planet — smallpox hasn't caused a single natural case since the late 1970s.
Antibiotics
A single accidental discovery in a London laboratory in 1928 turned once-routinely-fatal bacterial infections into something treatable in days.
Modern Surgery
Before three specific breakthroughs, surgery meant being fully conscious, at serious risk of deadly infection, and hoping you didn't bleed out on the table.