Li Tian is credited with the invention of firecrackers. Li Tian lived near the city of Liu Yang in the Hunan Province. During the Song Dynasty, the local people built a temple to worship Li Tian for his invention. To this day, China celebrates the invention of the firecracker every April 18^th. Almost every important event or festival is celebrated with fireworks. Reaction stoichiometry is critical for understanding the relationships between reactants and products. It can be used to calculate the quantity of how much product is produced as well as how much reactant was used to create the products. As mentioned in the lesson, “proportions matter,” during reactions. Stoichiometry plays a role in understanding what are the best proportions of reactants in order to create the most products.William of Rubruck was a Flemish Franciscan missionary and explorer. His account is one of the masterpieces of medieval geographical literature comparable to that of Marco Polo.The most impressive fireworks shows (from 2011): "Fourth of July Fireworks should be larger than life. As Independence Day rounds the corner for the 235th time, we decided to take a look at the biggest pyrotechnic celebrations across the U.S." Also, here's the fireworks show over Cinderella's castle in the Magic Kingdom in Walt Disney World.The history of the cannon spans several hundred years. First used in China, they were among the earliest forms of gunpowder artillery, and over time replaced siege engines—among other forms of aging weaponry—on the battlefield. The first cannon in Europe were probably used in Iberia, during the Islamic wars against Spain, in the 13th century; their use was also first documented in the Middle East around this time. English cannon were first used during the Hundred Years' War, at the Battle of Crécy, in 1346. It was during this period, the Middle Ages, that cannon became standardized, and more effective in both the anti-infantry and siege roles. After the Middle Ages, most large cannon were abandoned, in favor of greater numbers of lighter, more maneuverable pieces. In addition, new technologies and tactics were developed, making most defenses obsolete; this led to the construction of star forts, specifically designed to withstand bombardment from artillery.