Why do we say that someone looking for trouble has a “chip on his shoulder”?

In early England, one man would challenge another to a duel by slapping his face with a glove. The challenge was a serious matter of honour, and if the slapped man did not accept it, he would be branded a coward. Having a chip on your shoulder was kind of an early Wild West equivalent of the glove slap, though generally less mortal in nature.

Boys and men would place a woodchip on their shoulder, challenging anyone who dared knock it off to a fistfight. So, if a man had a “chip on his shoulder,” he was clearly in an aggressive mood and spoiling for a fight.

Where do babies come from?

Babies grow in their mother’s uterus, a special organ that houses the baby until it is born. At the start of pregnancy, a mother’s egg is fertilized, which makes a new cell. The cell divides quickly into many more cells. At about one week, this tiny mass, called an embryo, sticks to the wall of the uterus, and begins to grow. From the moment of conception, 46 chromosomes and tens of thousands of genes combine to determine a baby’s physical characteristics—the sex, facial features, body type, and color of hair, eyes, and skin. At the eighth week, the embryo is called a fetus.

By the end of the twelfth week, the fetus is completely formed and is able to make a fist, can turn his or her head, and can squint and frown. Until the baby is ready to come out, it grows inside its mother’s uterus. When the baby is ready to be born, at about 40 weeks, the mother starts to feel labor contractions. The uterus squeezes and pushes the baby out of the uterus and into the world.

What does it mean to “rest on your laurels”?

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.

Why do the British drive on the left side of the road while Americans use the right?

The British custom of driving on the left was passed down from the Romans. The chariot driver stayed to the left in order to meet an approaching enemy with his right sword hand. Americans switched to driving on the right because on covered wagons, the brakes were built on the left, forcing the driver to sit on that same side and, consequently, to drive on the right so they could have a clear view of the road.

How does a vacuum cleaner pick up dirt?

James Spangler, a janitor at an Ohio department store who suffered from asthma, invented his “electric suction-sweeper,” in 1907 as way of picking up the dust and debris that triggered his health condition. His invention was the first practical domestic vacuum cleaner. It used an electric fan to generate suction, rotating brushes to loosen dirt, a pillowcase for a filter, and a broomstick for a handle.

Because it was heavy and hard to handle, Spangler sold the rights of his invention to his relative, William Hoover, whose redesign of the appliance coincided with the development of the small, high-speed universal motor, in which the same current (either AC or DC) passes through the appliance’s rotor and stator. This gave the vacuum cleaner more horsepower, higher airflow and suction, better engine cooling, and more portability than was possible with the larger, heavier induction motor. Hoover’s model has since been refined, but the mechanics of his vacuum cleaner are still used in vacuum cleaners today.

Is there such a thing as a funny bone?

The funny bone exists in your body, but it’s not a bone at all! The funny bone is a part of the ulnar nerve located at the back of the elbow. If you accidentally bump this area it can cause a tingling sensation toward the front of your forearm.

This tingling or dull pain is caused by the ulnar nerve bumping up against the humerus, the long bone that starts at your elbow and goes up to your shoulder. Although it might feel weird, tapping your funny bone doesn’t do any damage to your elbow, arm, or ulnar nerve.

How do birds replace their feathers?

Birds replace their feathers by molting, the periodic shedding of old feathers and the growing of new ones. They do this one to three times each year, although different birds molt at different times of the year. Male goldfinches, for example, molt from a dull greenish yellow to bright yellow during spring. The periodic shedding of feathers and their replacement with new ones makes perfect sense in the animal kingdom.

Feathers are incapable of further growth, and may get worn down, broken, and faded over the year from normal wear-and-tear. Molting replaces these damaged feathers and helps the males look attractive to females, which is why many molts take place during the mating season.

Why does the letter K signify a strikeout on a baseball scoresheet?

Early in baseball history, a man named Henry Chadwick designed the system we still use for keeping score. Because his system already had an overabundance of Ss scattered throughout his scoresheet — safe, slide, shortstop, sacrifice, second base, etc. — he decided to use the last letter of struck, as in, “he struck out,” rather than the first. And that’s why K signifies a strikeout in baseball.

Why do we say a person isn’t “up to scratch”?

During the early days of bare-knuckle boxing, a line was scratched across the centre of the ring, dividing it into two halves. This is where the fighters met to start the contest, or where they “toed the line” to begin each round. If, as the fight progressed, one of the boxers was unable to toe the line without help from his seconds, it was said he had failed to come “up to scratch.”