Around 2400 BC, the ancient Sumarians, who used six as their mathematical base, divided a circle into 360 degrees, with each degree subdivided into another 60 parts, and so on. The Romans called these units minute prima, or first small part, and secunda minuta, or second small part. This system was perfect for round clock faces, and that’s why we use minutes and seconds as divisions of time.
The expression dates back to the English Crown’s first efforts to control the Irish by outlawing their language and customs. But the unruly Irish were just that, and by the fifteenth century the English still controlled only a small area around Dublin, protected by a fortification called “The Pale,” meaning sharp sticks (i.e., impaled). To the British, to go “beyond The Pale” meant that you were entering the uncivilized realm of the wild Irish.
Early in human history, people used anything that they could find to keep their teeth clean. Usually a thin, sharp object, like a stick, was used to pick out food left between teeth. Chewing on the end of certain sticks would fray the wood, making a kind of brush, which could then be rubbed across the teeth. (Even today, members of primitive tribes chew sticks to keep their teeth clean. The constant chewing produces more saliva than usual, which helps wash food away.) Later, people found that if they rubbed abrasive elements, like salt or chalk, across their teeth, they could get rid of grime. They also used water and pieces of rough cloth to clean their teeth. Toothpicks made of all kinds of materials also became popular. Rich people had jeweled toothpicks made of gold and silver. Toothbrushes for the wealthy, with fancy handles and hog bristles, came into use in the eighteenth century.
Only much later, when cheaper, woodenhandled toothbrushes were made, and the importance of good dental hygiene became known, did most people start to regularly use them.
Because one meaning of the word “bald” that is not commonly used anymore refers to white markings. “Bald” used to refer to people with white hair. Due to excessive hunting, environmental pollution, and loss of habitat, the bald eagle population became dangerously low at one point, prompting the U.S. Congress to pass a law protecting it. Bald eagles were once listed by the U.S. Fish and Wildlife Service as an endangered species, meaning they were close to being extinct. Thanks to the laws protecting it, these birds have rebounded a bit. They are now listed as threatened, which means they are not as close to being extinct as they once were, but their numbers are still few (only about 50,000 in the United States), and it is illegal to hunt them.
Although D-Day has become synonymous with the Allied landing on June 6, 1944, in Normandy, it was used many times before and since. The D in D-Day simply stands for “day,” just as the H in H-Hour stands for “hour.” Both are commonly used codes for the fixed time when a military operation is scheduled to begin. “D minus thirty” means thirty days before a target date while “D plus fifteen” means fifteen days after.
The practice of using laurels to symbolize victory came from the ancient Greeks. After winning on the battlefield, great warriors were crowned with a wreath of laurels, or bay leaves, to signify their supreme status during a victory parade.
Because the first Olympics consisted largely of war games, the champions were honoured in the same manner: with a laurel, a crown of leaves. To “rest on your laurels” means to quit while you’re ahead.
Every country has a national flag, including the United States. Flags date back to around 1000 B.C.E., when the Egyptians used primitive versions of flags—some were even made out of wood or metal—to identify themselves and to signal to others. Ships started using flags at sea to signal to each other and to harbors, often to let them know they had a diseased crew aboard. Flags are still used today to let sailors know what weather conditions await at sea. The military also made use of flags to rally its troops. During the ancient wars, capturing an enemy’s flag was considered an honorable seizure.
Today, the most popular use of flags is to identify and symbolize the world’s countries, which became commonplace in the 1700s. When new lands are discovered—and, for example when Mount Everest and the Moon were conquered—explorers raise their country’s flag as a sign of their being the first to set foot on these unchartered lands.
Dogs bark to communicate with other dogs and with humans. Dogs are descendants of wolves, which are social animals that live in packs, and they share many of the behaviors that define the complex relationships that exist within such animal groups. Few domestic dogs live together in packs (though they often consider their human family their group), but they still use complicated behaviors that involve smell, sight, and hearing to communicate. A dog has many scent-producing glands that it uses to communicate. The scent that a dog leaves behind (in its urine, feces, and paw prints) can reveal its sex, age, and even its mood to other dogs that come sniffing by.
A dog uses its posture, facial expression, and ear and tail position to communicate with other dogs, too. And it uses its voice to communicate by whining, growling, howling, or barking. A dog usually whines or whimpers when it is in distress: when it is hungry, cold, or in pain. Growls indicate that a dog is angry and ready to fight. Barks usually show excitement.
Babies are born with about 300 to 350 bones, but many of these fuse together between birth and maturity to produce an average adult total of 206. Bone counts vary according to the method used to count them, because a structure may be treated as either multiple bones or as a single bone with multiple parts. There are four major types of bones: long bones, short bones, flat bones, and irregular bones. The name of each type of bone reflects the shape of the bone. The shape of the bone also tells about its mechanical function. Bones that do not fall into any of these categories are sesamoid bones and accessory bones.
In the days of feudalism, when noblemen gathered for a meal in the castle, those of higher rank sat at the head of a T-shaped table, and the rest sat in order of diminishing importance away from them.
For such occasions a yard-long loaf of bread was baked, and the honour of making the first cut belonged to the highest-ranking person at the head table, who would then pass the bread down in order of rank, but always keeping for himself the “upper crust.”