Riemann – Cantor's Archive
Series
The Mind-Boggling Properties of the Alternating Harmonic Series
Riemann’s simple algorithm to approximate computationally any real number
Philosophy
The Demons of the Mathematicians
There is a rich history of mathematicians, philosophers, and other thinkers invoking demons (real or imaginary) in their reasonings. The tradition goes back at least to the iconic ancient Greek philosopher Socrates.
Topology
The Hardest Math Problems
Six Difficult Ways of Becoming a Millionaire
Complex Analysis
A Gentle Introduction to Analytic Continuation
How to Extend the Domain of Analytic Functions

History
The Mathematical Center of the Universe
The inception of quantum mechanics can essentially be traced back to a single “Golden Age” in the mid-1920s at one university: the Georg-August University of Göttingen, in the city of Göttingen in Germany.
Physics
Extending Einstein’s Field Equations
Wave Properties of Matter in Gravitational Fields