Why?

WHY is space debris dangerous? Debris does not pose a danger to those on the surface of the Earth. After all, the probability of debris falling is 1:3200. However, it can put the space industry at risk of destruction. The January 28, 2013 disaster with the Russian 7.5-kilogram scientific satellite BLITS demonstrates this. After working in orbit for four years, it collided with a fragment weighing only 0.017-0.019 g, which was moving at 8 km/h. And it fell apart. So about 3-4 satellites per year are killed in this way, which is not a very big number at the moment. But the theory is that the fragments of one debris-cracked satellite will at some point shatter another satellite. That, in turn, will shatter a third, and so on. And one day a piece of debris could also hit human-piloted ships. As an example, in May 2016, a piece of metal a thousandth of a millimeter in size crashed into an ISS porthole, leaving a 7-millimeter-diameter dent.

WHY is Lake Natron phenomenal? A lake covered with a crust of salt can change color throughout the year. Thanks to the halophilic cyanobacteria microorganisms that live in Natron, the water takes on juicy reddish and pinkish hues several times a year. When the temperature rises, the bacteria release a pigment red, staining the lake. The concentrations of salt and alkali in Lake Natron are so strong that animals and birds that accidentally enter the water are killed and mummified. The exception is the lesser flamingos: these birds have ideal breeding conditions here. High water temperature, reaching 50°C in the wetlands, allows flamingos to incubate their eggs at any time of the year.

WHY can hot milk be whipped into a foam? ⠀ The proteins have curdled in it. ⠀ The albumin and globulin proteins in milk coagulate at 60 °C and their molecules stick together. If you saturate hot milk with air bubbles, films of coagulated protein form around these bubbles. That’s is the milk foam. ⠀ Still commonly cold milk is also poured into the cappuccinator so that the device can control the heating process.

WHY does meat have to "rest" after cooking? ⠀ All meat should "rest" after cooking: at least 10 minutes for small pieces and 15-20 minutes for large pieces, such as chicken baked whole. Why is this so important? ⠀ As the juice of just cooked meat is too liquid. If you cut the meat, it will leak out, leaving the piece too dry. The "resting" time allows the juice to spread evenly over the meat fibers and thicken, making the meat tender, juicy and flavorful.

WHY do dogs stick their heads out the car window when driving? The Internet is full of funny pictures of dogs sticking their heads out of car windows while driving: the wind blows their fur and their muzzles are full of bliss. Dogs clearly love doing this, but for what reason? It's all about smells. Dogs rely on their noses for everything, since their eyesight is not so good, but their sense of smell is amazing. Human olfactory membranes have 5 million receptors, or "smell cells," but dogs have more than 225 million. When air moves over the olfactory membrane, odor molecules are deposited on the receptors and odor recognition occurs. The wind blowing in its muzzle during fast movement carries a great deal of information to the canine brain, which is why the dog sticks its nose out of the window: to better imagine the world around it and to gain new impressions at the same time.

WHY does a human only breathe through one nostril? Roughly every 4 hours, there is a change in the "lead" nostril. This phenomenon has a name: the nasal cycle. Namely, the two parts of the nose are able to change the resistance of the mucosa in response to the air flow passing through them. That's possible due to the special structure of the blood vessels in the nose. The cavernous body swells, blocking the passage of air, or, conversely, shrinks in size.

WHY and how did Theodore Roosevelt address the voters for an hour and a half with a bullet in his chest? When Theodore Roosevelt was running for president in 1912, he was shot during one of his meetings with voters. The bullet hit him in the chest, penetrating his eyeglass case and the thick 50-page manuscript of the speech he wanted to give. But Roosevelt stayed in place - he drew the audience's attention to the fact that he had just been shot and then spoke for an hour and a half. His hunting experience helped him to realize that the wound was not life-threatening - since he wasn't coughing up blood, the bullet hadn't pierced a lung. It was later confirmed that the bullet had entered his chest at 76 mm, but it was even riskier to remove it than to leave it as it was, and Roosevelt wore it all his life.

WHY do multifruit trees exist? All the ingredients for fruit salad on one tree! These artificially bred trees are capable of "producing" up to 8 different types of fruit simultaneously. Multifruit trees are created using "grafting," a sexless breeding technique in which tissues from one plant are inserted into another so that they can mate. There are four kinds of "fruit trees." - Peach, plum, nectarine, apricot, and peach-apricot trees; - Citrus trees - oranges, mandarins, lemons, limes, grapefruit, pomelo and tangelo; - Multi-apples - different varieties of apples; - Multi-pears - various types of pears.

WHY do scientists hang cameras on animals? BBC cameramen equipped the animals with miniature video cameras, allowing them to learn their secrets. The crew leader separately noted that their experiment gave them the opportunity to see the baby meerkats that had just been born. Even scientists, who study these animals, had never seen this in the wild. Another interesting discovery was the penguins' behavior: they swam indifferently past fish, shrimp and other food objects. Perhaps, in addition to availability, the birds are guided by some other criteria.

WHY working more than 8 hours is harmful? It was found out that over-working is bad for your health. It is even more harmful than alcohol and nicotine. Calculations have shown that a person, who works 11 hours a day, has up to a 70 percent higher chance of getting a heart attack. Apart from heart disease, about 60 percent of those, who work overtime, are more likely to fall ill with acute respiratory infections and suffer various injuries. And the illnesses have nothing to do with the nature of the work at all. ⠀ Scientists from the University of Otago in New Zealand discovered another plague. They found that even a 10-hour working day can provoke a tendency to alcoholism. After all, the more a person works, the stronger the desire to relax. And the easiest way to do this is with alcohol.