People are not only left and right-handed. They're also either left or right-nostriled. The dominant nostril has greater airflow through it than the non-dominant one. Researchers confirmed the existence of nostril dominance by measuring airflow through the nostrils of test subjects. If you're left-handed, you're probably also left-nostriled, and if you're right-handed, you're probably right-nostriled.

The Smithsonian Institution contains in its archives an oyster that grew on a set of false teeth. The toothy oyster was found in the Chesapeake Bay in 1898 and soon after was sent to the Smithsonian. When put on display, it became a popular attraction. Three people who had lost false teeth while sailing in the Chesapeake came forward to claim ownership of the oyster-teeth. However, the Smithsonian officials refused to arbitrate the paternity of the teeth and kept them in the museum. Fifty years later, yet another man claimed the teeth were his, but this time officials easily dismissed the claim, noting that the man hadn't even been born when the teeth were found.

People who are freezing to death will often remove all their clothes, as if they were burning up. This strange behavior (referred to as "paradoxical undressing") is caused by a cold-induced paralysis of nerves, which creates a sensation of extreme warmth. This leads people to try to cool down by undressing, even though they're freezing. Because of this, people who have frozen to death are often found naked and are misidentified as victims of violent crime.

British troops that invaded Sudan in 1884 wrote the cryptic phrase "Pears Soap Is The Best" on a rock in the desert, to mark the furthest point of their advance toward the town of Berber. The phrase referred to a brand of soap that was thought to be quintessentially British. Three years later Pears Soap ran a newspaper ad that featured an illustration imagining how Sudanese fighters might have reacted when coming upon this advertising slogan in the desert. The illustration was titled, "The Formula of British Conquest."

While traveling through Europe as a tourist during the mid-1960s, the sociologist Norbert Elias conducted an informal experiment to find out how people in different countries would react if he walked around in public with his shoelaces untied. The results: in Spain some people noticed, but no one said anything to him; in England a number of elderly gentlemen warned him about the danger of stumbling and falling; in France two people sitting in cafes pointed out his shoe-lace problem and a young man shouted "prenez garde" ("take care") into his ear, much to the amusement of the young man's companions; and in Germany Elias noticed a number of older men looking at him contemptuously, but it was women who reacted directly and tried to "clean up" the shoe-lace disorder by giving him a short warning about what might happen if he didn't take care of the problem.

In the 1950s, the curators of the Northampton Museum shoe collection began to receive reports of shoes (some of them very old) that had been found hidden in buildings. The shoes, usually discovered by people doing repairs, were concealed under floors, inside walls, in chimneys, or above ceilings. As more of these shoe finds were reported, the curators eventually concluded that the shoes hadn't been hidden accidentally. Instead, hiding shoes inside a building was evidently an ancient, deliberate practice. The Museum began keeping a record of these shoe finds, and now has over 1900 reported cases. It's not entirely clear why people hide shoes inside buildings, but the leading theory is that it's a form of protection superstition, done to ward off forms of evil such as witches, bad luck, or the plague.

Modern, four-wheeled shopping carts were invented in 1937 by Sylvan Goldman, owner of the Humpty Dumpty grocery store chain in Oklahoma. Before then, shoppers had either used hand baskets or two-wheeled carts. The four-wheeled carts paved the way for the rise of massive supermarkets and big-box stores, by allowing shoppers to accumulate more stuff before heading to the checkout. However, shoppers were initially reluctant to use the carts. They reminded women of pushing a baby carriage, and men thought they were unmanly. So Goldman hired attractive models to push the carts around his stores. When customers saw other people using the carts, they quickly accepted them.

The "surprise question" is a technique used by doctors to predict which patients have a high risk for early mortality and should, therefore, receive priority care. The doctor simply asks him or herself, "Would I be surprised if this patient died in the next year?" If the answer is, "No, I wouldn't be surprised," then this indicates that the patient is at high risk. A study published in the Clinical Journal of the American Society of Nephrology found that the surprise question does have high predictive value. Doctors classified 147 dialysis patients into "yes" and "no" groups on the basis of the surprise question. (i.e. No, I wouldn't be surprised if they died.) Sure enough, the No group died within the next year at a rate 3.5 times higher than the Yes group.

During the Second World War, prisoners held by the Japanese in an internment camp in Dutch Indonesia subsisted primarily on dry bread they made themselves in a camp bakery. But when their captors stopped supplying them with yeast, it became impossible to keep making the bread — until some of the inmates who were trained chemists figured out it was possible to use urine as a yeast substitute. Everyone's urine was collected daily in large drums, then distilled to form ammonium carbonate. Added to flour, this further decomposed into ammonia and bubbles of carbon dioxide, which allowed the dough to rise. The inmates lived on this urine bread for two years. Reportedly, it tasted "OK."

Yellowstone National Park contains a 50-square mile "zone of death" where, legal scholars suggest, a person could commit murder without fear of prosecution. This zone is the part of the park that extends into Idaho. The reason for this free-pass-for-murder lies with the Sixth Amendment which guarantees a defendant the right to a trial by a jury "of the state and district wherein the crime shall have been committed." The zone is in the State of Idaho, but because of the unique legal status of Yellowstone, it's in the judicial District of Wyoming. Therefore, to prosecute anyone a court would need to form a jury of people who live simultaneously in the State of Idaho and the District of Wyoming. No one fits that bill because no one lives in the Idaho part of Yellowstone. Without being able to create a jury, a trial couldn't proceed.