These are known as shock diamonds. They are caused by the interaction of a fluid's velocity and pressure. When a fluid moves quickly, its pressure decreases. You can conceive of it as the molecules moving so quickly that they don't have time to stop and push forth. You'll need to learn about the Navier-Stokes equations, which explain fluid dynamics, if you truly want to dive into it. Photo by Niklas Jonasson on Unsplash The crucial thing to understand about shock diamonds is that hot exhaust is the fluid (not liquid; all liquids are fluids, but gases are also fluids), and it's moving at a high speed. You want the exhaust to be rapid because equal-and-opposite-reaction means the engine will be moved very quickly in the opposite direction. That means the exhaust has low pressure, and when it expands out into the air, the ambient air pressure rises. The air pressure forces the exhaust to collapse inward until it becomes too compressed and the air pressure is no longer stro

In Mandarin Chinese, the word "Tai Chi" is pronounced more closely to "Taiji." If you want to pronounce Taijiquan, say it like this: Tie-Jee-Tchwanne. "Tai Chi" is essentially a Westernized pronunciation of the word "Taiji." Similarly, in Mandarin Chinese, Kung Fu is more appropriately pronounced as "Gong Fu" (spoken almost like 'Goon-Fu'). In summary, if you're a Chinese speaker, you wouldn't say "Tai Chi" or "Kung Fu." The terms "Taiji" and "Gongfu" are more accurate. Photo by Uriel Soberanes on Unsplash The Yin-Yang cycle, or the interaction between complementary imbalances, is referred to as "Tai Chi" or "Taiji." "Chuan" or "Quan" means "Fist," and it refers to a martial arts system (not literally just the fists). As a result, Taijiquan or Tai Chi Chuan is a martial art system based on the interaction of Yin (Negative) and Yang

A combination of discipline and bravery. You're correct that everyone with enough upper body power can wield a pike and stab-stab, but not everyone can maintain that pike held. Before bullets, warfare was about instilling dread in the ranks of the adversary. Because guys in formation were difficult to kill from the front, you had to kill them while their backs were turned. Photo by Jonathan Kemper on Unsplash The psychological dread that the cavalry charge produced - every fiber in your body wanted to run from this stampede of gigantic monsters - was what made it effective. If the pikemen stayed strong, "fear bent backwards" and the riders broke off their charge without ever striking the enemy. This gave the pikemen confidence to repel the enemy horse's second, third, and fourth passes if they came. But first, they had to overcome the first obstacle. Disciplined pikemen were valued because they had expertise fighting charges, which levies with long sharp sticks did n

Due to the 20-year rule, we cannot go all the way "up to now," although there have been significant fluctuations in popular opinion and some viewpoints, however the basics have not changed since 2002. This is a HUGE issue with many details I'd like to go into, so I'll try to offer a summary at the conclusion, followed by a more extensive history. We'll begin by going back a few hundred years for context. Taiwan has been a part of what is now known as China proper since the Qing Dynasty. In 1661, a Ming loyalist named Zheng Chenggong (, also known as Koxinga) invaded the island with an army of nearly 25,000 troops from the Chinese mainland. The Zheng family ruled the island until 1683, when admiral Shi Lang () seized it on behalf of the Kangxi Emperor. Taiwan remained under Qing Dynasty control until it was surrendered to Japan in the Treaty of Shimonoseki following the first Sino-Japanese War in 1895 (along with the Liaodong peninsula and the Penghu islands; the S

Even at the first hurdle, this type of theory fails. As you point out, the "Viking Age" begins with an attack on England and continues with large-scale attacks, largely on England, who clearly did not fight the Saxons. The replies were also not timely; the invasion on Lindisfarne in 792 occurred about a decade after the Franks' conquest of Saxony under Charlemagne. Photo by hao qin on Unsplash While the Saxon Wars lasted several decades, it would be a risky strategy for Norse polities to aid the Saxons in their fight against the Frankish army by assaulting English monks in Northumbria. Small and infrequent attacks on isolated and weakly defended areas of wealth (both treasure and slaves) in the British Isles and around the Baltic lasted for most of the 8th and early 9th centuries. Viking attacks on the Franks, who were clearly attacking the Saxons rather than the English, Irish, Picts, or any other group of people, only increased after the reigns of Charlemagne and his s

If you believe the Queen is an exception to the rule that royals are worthless leeches because "she appeared like a kind old lady," please continue reading. Sources: Further reading Online Article: https://www.heraldscotland.com/news/19620904.queen-privately-spending-millions-prince-andrews-virginia-giuffre-sexual-assault-lawsuit-defence/ https://archive.ph/YEl61 https://archive.ph/fYMO4 https://www.theguardian.com/news/2017/nov/05/revealed-queen-private-estate-invested-offshore-paradise-papers https://archive.ph/82hnt https://archive.ph/OODJg https://archive.ph/Tu2Er https://archive.ph/zCEgn https://lejournaldelafrique.com/elisabeth-ii-une-reine-inoxydable-et-un-empire-qui-refuse-de-mourir/ https://twitter.com/spiritoflenin/status/1567977152515039232?s=21&t=d_hh3Tv5rx9nsHDIbVq8Fg Let's go over everything, from personal to political. For starters, she made numerous decisions concerning the royal family's and its support staff's activities. Photo by Mathew Brow