How are a water lily’s leaves different?

A water lily is a floating aquatic plant with large, fragrant, white or pink flowers and flat, round, floating leaves. The leaves have long stems and are bright green above and reddish or purplish underneath. The underside of the leaf contains air spaces; the air that traps beneath the leaf makes it float on water. The leaves’ strong stems help them grow and stay upright in the water—which allows the leaves to absorb sunlight and stay alive.

Does it hurt to die?

Nobody who has died has been able to come back to tell us about it, so it is impossible to know whether dying hurts. But people who have had “near-death” experiences— those whose hearts have stopped, for instance, but were later restarted— have only good things to report. Most tell of a peaceful sensation of floating above their bodies. A number also describe traveling through a tunnel toward a beautiful light or having loving meetings with friends and relatives who have died before them.

Scientists know that when a person is in a state of very low oxygen—often a condition that precedes death—he or she experiences feelings of euphoria, or great happiness. So as far as we know, the act of dying is not painful at all. Many sick people welcome death. The same wonders of medicine that have allowed people to reach old age have also enabled them to live through long, and sometimes painful, illnesses. Often, death is seen as a welcome end to pain, both for the ill person and for the family and friends who have watched their loved one suffer. People with strong religious faith, too, may fear death less because they believe they will journey to a better place.

If “possession is nine-tenths of the law,” what are the points it outweighs?

The expression “possession is nine-tenths of the law” is from the eighteenth century and means that in the pursuit of justice possession in a dispute over property outweighs these nine other essential elements of a good court case: a lot of money, a lot of patience, a good cause, a good lawyer, good counsel, good witnesses, a good jury, a good judge, and good luck.

What did people use before toothbrushes were invented?

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.

What makes a plant bloom at the right time of year?

All flowering plants have a mechanism to make sure that their blooms develop at just the right time of year, whether in the springtime or autumn. Most respond to the amount of sunlight, and can distinguish between 16 hours of light and 8 hours of light. Some flower only when days are long and nights are short, such as radishes, asters, petunias, and beets. Others, such as chrysanthemums, goldenrods, and poinsettias, flower only when nights are long and days are short.

What’s a charley horse?

A charley horse a muscle cramp, or sudden, uncontrolled contraction of a muscle. This type of pain is generally felt in the legs, sometimes after heavy exercise, and usually lasts just a few minutes.

The expression probably came from the word “charley,” which is used to describe a horse that is lame.

How does a coffeemaker cook up the morning’s brew?

With the most common coffeemaker, the drip coffee machine, hot water drips down freely onto ground coffee beans to make coffee. The water inside the machine’s water bucket is heated as it passes along a heat-resistant tube. The tube goes into the drip area and releases heated water, just below boiling temperature (212 degrees Fahrenheit [100 degrees Celsius]). The water is heated by a heating element (a resistive heating coil that gives out heat when electricity is passed through it). The heating element has direct contact with the water inside the water bucket, and also heats the heating pad on which the glass coffee container is rested. Today, most models of coffee machines are either semi-automatic or automatic. Buttons and switches have replaced the manual coffee straining and lever-pushing of espresso machines. And some machines now have special features, such as built-in coffee bean grinders and froth makers.

Why is the Grand Canyon unique?

Located in Arizona and stretching to Colorado, the Grand Canyon is 18 miles (29 kilometers) wide, 227 miles (365 kilometers) long, and 6,000 feet (1,828 meters) deep in its deepest section. It takes about two days by foot or mule to travel from the top to the bottom.

Although it is not the biggest canyon in the world—Barranca de Cabre in northern Mexico and Hell’s Canyon in Idaho are deeper—it is known for its amazing landscape. The canyon’s walls are made up of rocks, cliffs, hills, and valleys formed millions of years ago, and it is home to hundreds of species of mammals, reptiles, and birds. Although people lived in the canyon some 4,000 years ago, today it is a national park and national landmark.

What was a “computer” before the electronic age?

The word computer first appeared in the seventeenth century as the job title of a person who did calculations as an occupation.

Although slide rules were sometimes called computers, it wasn’t until the 1940s, with the development of massive electronic data machines, that the human occupation of computing became obsolete. These mechanical devices became known as computers.