The idea of using human urine for washing clothes is widely known. But few people know that urine was also used by ancient Romans for health purposes — as a toothpaste in particular. It was believed that urine made teeth white, smooth, and shiny; and also removed plaque perfectly.

This fact suggests that the vast majority of banknotes in USA circulation passed through the hands of drug dealers or cocaine users. Scientists believe that most often cocaine gets on money because of the use of bills acting as a “tube” for breathing in a drug, as well as from recounting money in transactions for the purchase of cocaine. Such studies were conducted with different banknotes, and the highest percentage of residue found was in the USA and Canada, and the lowest in China and Japan (12-20%).

Turns out there is no need to rush to the bathroom after a meal in order to clean your teeth. That’s because our saliva itself contains special enzymes that help to break down food leftovers and wash them out of the mouth. Moreover, the acidic environment of our mouths softens the enamel for some time to make it easier for the saliva to get rid of food leftovers. That’s why brushing teeth right after a meal can damage the softened enamel — it’s recommended to wait for at least 30 minutes before doing so. Instead, there is a way to help your mouth produce more saliva: chew some gum for 20 minutes or eat some candy such as a Tic Tac. It will help to get rid of unwanted food residue and keep your enamel strong.

The peculiar marks that appear on the human body after a lightning strike are known as Lichtenberg figures. These are traces of burns that fade more and more with age but do not completely disappear. They are the result of the expansion of the capillaries located in the zone of contact of the lightning with the body.

Bulls do not distinguish the color red from other colors since they see the whole world in black and white. The bull reacts not to the color but to the movement of the fabric. Busters of this myth conducted an experiment: they installed 3 scarecrows with rags of different colors, and the bull rushed to the moving rag, regardless of its color.

The natural duration of sleep in a person is individual and depends on factors such as genetics, age, health status, and external circumstances. In addition, recent studies have shown that life expectancy, levels of happiness and productivity are higher in people who sleep from 6.5 to 7.5 hours per day.

The number of nerve endings in the female breast is invariable and does not depend on its size. However, a smaller breast may be more sensitive, and the breast of a larger size is less because it has a thicker, subcutaneous fat layer.

Marsupial mice reach puberty at the age of 11 months, after which they begin to intensively mate from 12 to 14 hours in a row. This is due to the fact that males have to be competitive in order to transfer their genes. That’s the reason why most of them don’t live to see the birth of their offspring.

There are tons of gold lying at the bottom of the ocean. It got there thanks to ships that sometimes carried jewelry between countries and continents along with many passengers carrying gold jewelry. And quite often, such ships sank taking with them innumerable treasures.

In the 16th century, European doctors recommended smoking in order to get rid of bad breath. In addition, the tobacco was attributed to many healing properties. For example, it was used as medicine for migraines, toothaches, colic, joint pain and other disorders of the body. Of course, later these “magic” properties of tobacco were refuted. Studies show a direct link between smoking and high mortality. So don’t forget that smoking tobacco has a very negative impact on health, leads to a variety of diseases and early death.

The flounder gene was introduced into genetically modified tomatoes in order to make them beautiful, round and shiny.

Forests are considered to be the “lungs” of the planet, but in fact, most of the world’s oxygen is produced by the phytoplankton of the ocean. Most of the oxygen produced by forests is used for the processes of decay and decomposition.

During sleep at the space station, astronauts need additional air blasting. Without the added oxygen, they can wake up from oxygen deprivation in a cloud of carbon dioxide that they’ve been inhaling.

Scientists derived a formula by which they could calculate the cost of celestial bodies. This special equation includes information about the date of discovery, mass, age, and temperature of a planet, as well as the brightness and location of the rotating star around it. According to calculations, the cost of planet Earth is $5 quadrillion, while the cost of Mars is $14,000 due to the fact that its climate is less comfortable.

Some researchers connect the length of the fingers with the testosterone level in the blood of a man. But the effect of this hormone is more likely to affect the amount of hair on his body and overall physical development than on the level of his sex drive.