Big Think

Is it true that newborns have no moles? In most cases, yes. Moles in newborns are rare, and the ones that are present are generally small. The fact is that a mole is a cluster of melanocytes, that is, cells that produce the pigment melanin. Melanin synthesis and formation of melanocytes is stimulated by the melanotropic hormone. The release of this signaling substance is highly dependent on the amount of light hitting the retina. And before a baby is born, of course, light cannot reach the retina.

Why is warm air rising above cold? For it expands. In still air, the pressure at a constant height is the same at all points. If air is heated at a certain spot, its pressure increases, and it expands until the pressure equalizes due to a decrease in density. But then it turns out that the weight of the air column in the place of heating is less than in the neighboring place. The heavy cold air begins to flow under the heated air, pushing it upwards. In fact, this effect is a manifestation of the same Buoyant Force that makes a tree float in water. If the air continues to heat, for example from the hot surface of the earth, a steady upward flow will occur.

Why are Marie Curie's coffin and tombstone made of lead? The name of the Polish-French scientist, Nobel Prize winner in Physics (1903) and Chemistry (1911) Marie Skłodowska Curie. is inextricably linked to the discovery of radioactivity. Along with her husband, later also a Nobel laureate, Pierre Curie, back in the 1890s, Marie discovered chemical elements such as polonium and radium in the course of experiments, and also introduced the terms "radioactivity" and "radioactive element". Later, the Curies' discoveries formed the basis of research into methods to fight cancer. After their deaths, their remains were moved to the Pantheon in Paris. That's when it was found out that they were still "radiactive" and would be dangerous for hundreds of years for the employees of the tomb and the tourists. Then lead coffins and tombstones were created for Pierre and Marie Curie: they protect visitors of the Pantheon from radiation.

Why is there no cure for color blindness? Unfortunately, no cure for color blindness exists. There are special glasses and corrective lenses on the market that, according to advertisements, help with color recognition, but they come with undesirable side effects. Lenses improve color recognition in one part of the spectrum, but in the other part, they worsen it. Many patients also experience unnaturally bright colors during the day and can barely distinguish their surroundings at night. In addition, lenses can ruin depth perception. For this reason, most people with color blindness learn to adjust. They have no problem with everyday activities. Many companies these days also consider the needs of people with color blindness: video games and apps often have special modes of operation for colorblind people.

Why doesn't it tickle when you tickle yourself? The brain decreases the sensitivity of the skin. Tickling is caused by irritation of the tactile receptors on the skin. Their sensitivity is controlled by the spinal cord and brain. If the irritation is caused by touching another part of your own body (which the receptors of the touched part tell the brain), the brain dulls the sensitivity of the receptors, preventing the tickle from occurring. Apparently, this mechanism serves to avoid "false alarms" in performing the main function of tickling — alerting us to the presence of foreign creatures on the skin, which may turn out to be parasites.

Why do the names of some currencies derive from measures of weight? The designations of many currencies are closely related to various measures of weight. A typical example is the British pound sterling: sterling was the name given to silver coins, and 240 such coins weighed one pound. Similar is the origin of the foreign currency in several countries called the lira, which is the Italian equivalent of the weight unit pound. In medieval Western Europe, a mark was used to measure the weight of silver, which was slightly lighter than the pound — from it came the Deutschmark.

Why does one's nose turn red and fingers bluish when cold? Vessels in our fingers narrow whereas those in our nose dilate In the cold, the lumen of the blood vessels in the fingers narrows, so the surface tissues turn pale to translucent, and blood stagnates in the deeper layers. By losing oxygen, the blood darkens and, shining through the skin, gives the fingers a bluish tint. The vessels of the nostril walls, on the contrary, expand in the cold: the upper airways, including the nasal cavity, warm the air supplied to the lungs. The colder it is outside, the stronger the heating must be. The increased blood supply to these tissues of the nose leads to its redness.

Why is Facebook designed in blue? In the mid-twenties, Facebook founder Mark Zuckerberg took a color-blindness test and realized that he was color blind. He had trouble distinguishing between shades of red and green. This is one of the reasons why Facebook, and now Meta, are designed in blue – all variations of blue are available to Zuckerberg. In this way, one man's peculiarity influenced the color scheme of the world's most visited site, and may have set a whole trend in social media design. Later VKontakte, Twitter, LinkedIn and Telegram used shades of blue and navy blue in their design.

Why doesn't the bottom button of a jacket get buttoned? This etiquette has been observed since the beginning of the XX century. Historians assume that the rule of wearing a jacket appeared thanks to the English King Edward VII (1841-1910), who was obese. He used to leave the bottom button undone so that a tight vest would fit better. As a sign of respect for his king, the British court, and after him all the inhabitants of England and the British colonies, no longer buttoned the bottom vest. This theory is not taken seriously by everyone, and some trendsetters have challenged it with other versions. Fashion designer Hardy Amies explained the single-breasted suit was first introduced in 1906 and was later called the "leisure suit". It became a casual garment, had a wide cut, and the three buttons gave the suit a proper fit. Over time, the jacket replaced traditional riding coats. And as the third button was below the waist, it was unbuttoned while sitting on a horse for comfort.

Why do you laugh when nothing funny happens? Actually, humor is not the main reason we laugh. Laughter is a social emotion that brings us together and helps us bond, whether we are actually laughing or not. So people of different cultures don't get each other's intonations well, but they can unmistakably guess laughter. Laughter is a clear sign of an intimate or peaceful relationship.