Why is it that all scientific discoveries were made by European men after 1400 AD?

Most discoveries after 1400 AD were well recorded, but before that there were many inventions (including automated weapons) whose information was lost. Most records of such ancient things were in libraries like those in Alexandria. Alexandria, as I recall was revanged with a fire some time ago that destroyed many of their records. Other ancient societies have similar problems with their histories.

Archimedes predated 1400. Pythagoras and Euclid made significant discoveries which are still useful after dozens of centuries.

A few things happened in Europe. The first was the Gutenberg printing process which greatly expanded literacy.

The next was the inventions of microscope and telescopes.

Thirdly, Isaac Newton demonstrated the connection between mathematics and physical observations.

Not true.

Important scientific discoveries occurred throughout history, all over the world: Metallurgy, medicine, mathematics, agricultural and geographic sciences were developed thousands of years ago by Asian, Arab, and African peoples. This is how humanity emerged from the stone age, developed stable sources of food, extended human life, migrated across the globe, and built cities.

Women have contributed too, in recent years. Consider Marie Curie's work in nuclear physics or Grace Hopper's computer work.

Not true. The most recent theory of everything was made by a California surfer dude with a Ph.D in physics. It's called the "Extraordinarily Simple Theory of Everything" and it uses the E8 geometrical model. Look it up.