Isaac Newton published his magnus opus — Principia Mathematica when he was in his mid 40’s.
Many of Bach’s greatest musical works were composed in his 40’s and 50’s. Bach assembled his last large work, the Mass in B minor, near the end of his life, when he was in his 60’s.
William Harvey published his famous work done a decade prior” “On the Motion of the Heart and Blood” at nearly age 50.
“Isaac Newton published his magnus opus — Principia Mathematica when he was in his mid 40’s.”
There are always outliers. And, I have read that he had WRITTEN it considerably earlier. There was generally a lot of time between writing something and having it widely distributed then, as I recall :).
However, many contemporaries were on his trail (Liebnitz, for example). IMO, “Opticks” took even more imagination and is _still_ the bedrock template for scientific discovery. What he did, and documented, was incredible leap of process and knowledge.