These set of rings/disks that are formed in the exhaust plume are known as Shock Diamonds or Mach discs (and by many more names).
How to build Beijng’s Forbidden City with 100-tonne stone blocks tens of miles away
This “How to” may not be that relevant in modern times, but in the XIV and XV century, I could think of a few civilizations that would have loved to learn how Chinese engineers moved huge volumes of rock from quarries tens of miles away. Such blocks of stone, weighing at least 100 tonnes, were used to build the splendid
Fluid dynamics shapes beautiful hexagon honeycombs, not the bees themselves
Honeybees are exquisite and majestic beings, which have always caught the imagination of people. Bees are typically associated with feminine energy, because they are ruled by queens, particularly with the roman goddess Venus. In some cultures, bees also represent wisdom. From a biological point of view however, bees could be definitely associated with motherhood. Without bees, a myriad of plants would