Most people have a specific position they prefer to sleep in. For some of us, this position is lying on our stomachs. However, sleep experts disagree about whether or not this position is good. Although some promote it as an easy way to reduce snoring, the majority agree that it is more harmful than you think. One of the most serious negative effects is that it changes the position of your spine. This can eventually lead to painful neck problems.

Although a baby's teeth start growing before the baby is born, they don't appear until the baby is about six months old. When a child turns five or six, these teeth start falling out. They fall out because adult teeth grow in their place and push them out. When the child reaches 12 or 13 years of age, they will have lost all their baby teeth and grown a full set of adult teeth.

If you can't hear well in a noisy situation, use your right ear. Each brain hemisphere has certain functions and is more closely connected to the opposite side of the body. The left hemisphere, which handles spoken language, is more closely connected to the right ear. Therefore, understanding words through the right ear is easier than understanding words through the left. So the next time you can't hear, put your right ear forward. The closer your right ear is to a speaker, the better you will be able to hear.

Although a polar bear's skin is black and individual hairs are hollow and clear, polar bears do not appear black. This is due to luminescence, which allows sunlight to get to the skin but causes the fur to look white. The process starts when sunlight hits the fur. Some of the light energy travels into the hair, and it gets trapped there. The energy bounces around inside the hollow part of the hair and divides into more beams that travel in different directions. Every time a beam of light touches a hair, the light is caught and reflected towards other hairs. The process continues until the energy escapes the fur, emitting a whitish light, which makes the polar bear appear white.

A sociologist categorized play into four types. The first type, Agon, focuses on competition and includes games such as soccer and chess. The next is named Alea. This type of play, which includes card games and the lottery, depends on randomness to decide a winner. The third type, Mimicry, covers play that involves pretending, such as dressing up for Halloween. The last type is named Ilinx. This is play that uses rapid movement to create a pleasurable state of disorder. Examples include riding a roller coaster or simply spinning in circles. The sociologist pointed out, however, that a single type of play could be placed in different types by different people. With baseball, for example, one person might play it for the competition, while another might enjoy betting on the outcome.

The water that is embedded in our food and manufactured products is called "virtual water. "For example, about 265 gallons of water is needed to produce two pounds of wheat. So, the virtual water of these two pounds of wheat is 265 gallons. Virtual water is also present in dairy products, soups, beverages, and liquid medicines. Every day, humans consume lots of virtual water and the content of virtual water varies according to products. For instance, to produce two pounds of meat requires about 5 to 10 times as much water as to produce two pounds of vegetables.

A zebra's stripes are used as camouflage to help it avoid predators. The wavy lines of these stripes blend in with those of the tall grass that grows in the areas where the zebra lives. Although its stripes are black and white and the grass is yellow and green, the zebra can hide effectively. Because lions, which are the zebra's primary predator, are colorblind, they are unable to detect a zebra standing still in a patch of tall grass. Zebra stripes are even more effective if zebras are gathered together in a herd. When individuals stand near one another, the patterns of their stripes blend together. This confuses lions, which see one large object instead of a group of individual animals. This makes it harder for them to catch their prey.

Dogs have lived with humans for a long time, and it is interesting to see how their roles have evolved. Once used as guards, they later became companions. These days they are serving even more valuable roles. Some dogs, for example, are trained to sense when people with epilepsy are going to have a seizure. When people are alerted to this, they can get help or go to the hospital. It is not fully understood how dogs sense this, but they may be able to smell changes in the chemical levels of the person's breath. Other dogs, known as diabetic alert dogs, are trained to detect dangerously high or low blood sugar levels.

Acoustic concerns in school libraries are much more important and complex today than they were in the past. Years ago, before electronic resources were such a vital part of the library environment, we had only to deal with noise produced by people. Today, the widespread use of computers, printers, and other equipment has added machine noise. People noise has also increased, because group work and instruction are essential parts of the learning process. So, the modern school library is no longer the quiet zone it once was. Yet libraries must still provide quietness for study and reading, because many of our students want a quiet study environment. Considering this need for library surroundings, it is important to design spaces where unwanted noise can be eliminated or at least kept to a minimum.

Although we are all aware of the damaging effects of climate change on the environment, new research shows that our personal health may also be at risk. According to a study, a type of bacterium called Vibrio is rapidly increasing in numbers because it prefers warm water. Vibrio is usually found in salty water near the coast. It infects people who eat raw seafood or swim with open cuts on their skin. Approximately 80,000 people in the U.S. get sick from Vibrio each year. This results in about 100 deaths annually. The number of people suffering from a Vibrio-related illness has been higher in recent years in both the U.S. and northern Europe. It is believed that rising temperatures in the Atlantic Ocean, which are caused by climate change, are to blame.

As restaurants are proud of the Michelin stars that they've received, you might think that the Michelins themselves were food critics. In fact, brothers Andre and Edouard Michelin, the men who created the Michelin Guide, owned a company that made tires. The original Michelin Guide promoted restaurants in the hope that it would encourage people to buy cars, and therefore tires, in order to visit them. It was given away for free and also included lists of mechanics and gas stations. As the guide's popularity grew, the brothers hired a team to anonymously visit restaurants as inspectors. Today, a three-star Michelin review remains one of the highest honors a restaurant can receive.