In the medieval feudal system, the nobility were generally those who held a fief, often land or office under vassalage in exchange for military allegiance to their sovereign. Living alongside serfs, ...

The Middle Ages were a dark period in history. This period was not just about dragons, righteous knights, and princesses. From 500 CE to 1500 CE, Europe was dominated by the Catholic Church, feudalism ...

The Dark Forest theory is one proposed solution to the famed Fermi Paradox, which has bewitched astronomers for more than half a century. To put it concisely, the paradox asks if the cosmos is nearly ...