SCIENCE APPEARED FOR THE NECESSITY TO ANSWER PEOPLE'S QUESTIONS. And it seems that most of the complex phenomena have been studied along and across, but only "very little" remains - to comprehend the nature of dark matter, to deal with the problem of quantum gravity, to solve the problem of space / time dimensions, to understand what dark energy is (and a few hundred more similar questions). However, there are still seemingly simpler phenomena that scientists are unable to fully explain.
What is glass?
Nobel laureate Warren Anderson once said: "The deepest and most interesting of the unsolved problems in solid state theory lies in the nature of glass." And although glass has been known to mankind for more than a millennium, what is the reason for its unique mechanical properties, scientists still do not understand. From school lessons, we remember that glass is a liquid, but is it? Scientists do not know exactly what is the nature of the transition between liquid or solid and glassy phases and what physical processes lead to the main properties of glass.
The glass formation process cannot be explained with any of the current instruments of solid state physics, many-particle theory, or the theory of liquids. In a nutshell, liquid molten glass gradually becomes more and more viscous when cooled, until it becomes hard. While in the formation of crystalline solids, such as graphite, atoms at one moment form the usual periodic structures.
Glass behaves in such a way that it cannot yet be described by equilibrium statistical mechanics
Tarun Chitra, a molecular dynamics researcher, explains the organization of molecules in different substances through dance. A perfect solid body is like a slow dance, when two partners, along with other couples, move around their starting position on the dance floor. The ideal fluid is like a dating party, when everyone tries to dance with everyone in the room (this property is called ergodicity), while the average pace with which everyone is dancing is about the same. By this analogy, glass is like a dance, when a group of people is divided into smaller subgroups, and each one spins in its own round dance. You can change partners from your circle, and this dance happens forever.
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Glass behaves in such a way that it cannot yet be described by equilibrium statistical mechanics. In particular, subexponential autocorrelation and glass cross-correlation function can be obtained by an infinite number of random processes. Up to a certain point, the system works more or less clearly and predictably, but if you watch it long enough, you begin to see how some features are better described by the theory of probability and random processes.
How does a placebo work?
Placebos, or substances that have no obvious healing properties, but have a positive effect on the body, have been known for a long time. The placebo effect is based on psycho-emotional impact. But researchers have proven more than once that a placebo that does not have active substances can stimulate real physiological responses, including changes in heart rate and blood pressure, as well as chemical activity in the brain. The placebo also helps relieve pain, depression, anxiety, fatigue, and even some of the symptoms of Parkinson's disease.
How our psyche can affect health is still not fully understood, and scientists cannot uncover the mechanisms underlying physiological responses to placebo. Obviously, many different aspects are intertwined in the effect, and the pacifiers do not affect the source or cause of the disease. It has been experimentally established that the body's response differs depending on the method of delivery of the placebo (when taking pills or injections). Also, placebos give only the expected, that is, known in advance, therapeutic effect. And the higher the expectations, the stronger the placebo effect. In addition, it is known that it can be enhanced by active verbal exposure to the patient. Not everyone is affected by a placebo. More often, placebo acts on extroverts, people with increased levels of anxiety, suspiciousness, and self-doubt.
In October 2013, a study was published demonstrating that the placebo effect is associated with increased alpha activity in the brain. Alpha waves arise in a relaxed state, which is similar to a light trance or meditation - that is, in the most suggestible state. The placebo effect has a significant effect on the human nervous system in the area of the spinal cord. But so far no one has been able to describe in detail the mechanism of its effect.
What did the wow signal from deep space mean?
On August 15, 1977, one of the most mysterious events in the history of space exploration took place. Dr. Jerry Eiman, while working on the Big Ear radio telescope as part of the SETI project, recorded a strong narrow-band space radio signal. Its characteristics (transmission bandwidth, signal-to-noise ratio) were in line with those expected from an extraterrestrial signal. Struck by this, Eiman circled the corresponding characters on the printout and signed “Wow!” In the margin. This signature gave the name to the signal.
The signal came from a region of the sky in the constellation Sagittarius, about 2.5 degrees south of the star group Chi. However, after years of waiting for something like this to happen again, nothing happened.
Scientists claim that if the signal was of extraterrestrial origin, then the beings who sent him must belong to a very, very advanced civilization. To send such a powerful signal, you need at least a 2.2 gigawatt transmitter, which is much more powerful than any of the earth's. For example, the HAARP system in Alaska, one of the most powerful in the world, is supposedly capable of transmitting a signal of up to 3,600 kW.
One hypothesis for signal strength is that the initially weak signal was significantly enhanced by the action of the gravitational lens; however, this still does not exclude the possibility of its artificial origin. Other researchers suggest the possibility of rotation of the radiation source like a beacon, periodic change in the frequency of the signal, or a single signal. There is also a version that the signal was sent from a moving alien spacecraft.
In 2012, for the 35th anniversary of the signal, the Arecibo Observatory sent a response of 10,000 encoded tweets in the direction of the alleged source. However, it is not known whether anyone received them. Until now, the wow signal remains one of the main mysteries for astrophysicists.
Why are people divided into left-handers and right-handers?
Over the past 100 years, scientists have studied quite well the problem of why people predominantly use one hand and why more often it is the right hand. However, there is no standard empirical testing for right-handers or left-handers, as scientists cannot fully understand what mechanisms are involved in this process.
Scientists disagree on what percentage of humanity is right-handed and what percentage is left-handed. In general, it is believed that the majority (70% to 95%) are right-handed, the minority (5% to 30%) are left-handed, and there are also an indefinite number of people with complete symmetry. Genes have been shown to influence left-handedness and right-handedness, but the exact "left-handed gene" has not yet been identified. There is evidence that social and cultural mechanisms can influence propensity to use the right or left hand. The most typical example of this is how teachers reeducated children, forcing them to switch from left to right hand when writing. At the same time, at the moment, more totalitarian societies have fewer left-handed people than more liberal societies.
We only have a general idea of the causes of right-handedness, and researchers still have to figure it out in detail.
Some researchers talk about "pathological" left-handedness associated with brain injury during childbirth. In the 1860s, French surgeon Paul Broca noted the relationship between hand activity and the hemispheres of the brain. According to his theory, the halves of the brain are connected to the halves of the body in a criss-cross pattern. But at the moment it is known that these connections are not as simple as Broca described them. Research in the 1970s showed that most left-handers have the same left-brain activity, which is typical of all people. However, only a part of left-handers have various deviations from the norm.
Studying the problems of left-handedness and right-handedness in primates, scientists have established that most animals in a particular population are either left-handed or right-handed. In doing so, individual monkeys often develop their individual preferences. As a result, we still have only a general idea of the causes of right-handedness, and researchers only have to understand in detail all the mechanisms of their formation.
How does inanimate matter become living?
In the scientific world today, the concept of biological evolution prevails, according to which the first life arose by itself from inorganic components as a result of physical and chemical processes. The theory of abiogenesis describes how living matter comes from inanimate matter. However, there are many problems in it.
It is known that the main components of living matter are amino acids. But the probability that a certain amino acid-nucleotide sequence will accidentally occur corresponds to the probability that several thousand letters from the typesetting type will be thrown from the roof of a skyscraper and folded into a certain page of Dostoevsky's novel. Abiogenesis in its classical form assumes that such a "font dropping" happened thousands of times - that is, as many times as it took until it formed into the required sequence. However, according to modern estimates, this would take much longer than the entire universe exists.
At the same time, scientists continue to try to create an artificial living cell under laboratory conditions. A complete set of amino acids and nucleotides and the simplest bacterial cell still divide the chasm. Perhaps the first living cells were very different from those that we can observe now. Also, a large number of scientists support the hypothesis that the first living cells could enter our planet thanks to meteorites, comets and other extraterrestrial objects.
Why are we sleeping?
We sleep 36% of our lives, but scientists cannot fully explain the nature of sleep. Sleep is inherent in humans, since it is in our genes, but why this state appeared in the process of evolution and what are the benefits of sleep is a mystery.
Scientists have already found that muscles grow faster during sleep, wounds heal better, and protein synthesis is accelerated. In other words, sleep helps the body replenish what it has lost while awake. Recent studies have shown that during sleep, our brain is cleared of toxins, and if a person interferes with this process (in other words, does not sleep), he increases the risk of neurological disorders. In addition, during rest in the brain, connections between cells are weakened or disconnected - thus, we free up space for the receipt of new information. New synapses are generated in the brain, so lack of sleep threatens to reduce the ability to acquire, process and remember information.
During sleep, the brain often replays some of the episodes that happened to us during the day, and, according to researchers, this process helps to strengthen our memory. Although the content of dreams is determined by real impressions, our consciousness in a dream is different from our consciousness during waking. In a dream, our perception of the world turns out to be much more imaginative and emotional. We see various pictures, we worry about them, but we cannot properly comprehend. Scientists believe that the synchronizing mechanisms that dominate the carotid brain are more associated with the first signaling system and the emotional sphere. But what are dreams, it is still impossible to answer unequivocally.
Why do cats purr?
No one knows for sure why cats purr. Purring differs from many other animal sounds in that vocalization occurs throughout the entire respiratory cycle (both on inhalation and exhalation). It was once thought that sound was produced by the flow of blood through the inferior vena cava, but now most scientists agree that the larynx, laryngeal muscles and a neural oscillator are involved in the process of sound production.
Kittens learn to purr as soon as they are a couple of days old. Veterinarians assume that their purr means something like the human words "mom," "I'm fine," or "I'm here." These sounds help to strengthen the bond between the kitten and its mother.
But when the kitten grows up, it also continues to purr, and many researchers are convinced that in adulthood, this sound is associated with pleasure and joy. Sometimes cats purr when injured or sick. Dr. Elisabeth von Muggenthaler suggests that the purr and the low-frequency vibrations it produces are a "natural self-healing mechanism" that strengthens, heals wounds and relieves pain.
The vocal trait of domestic cats is not unique. Other felines, such as lynxes, cheetahs, and cougars, purr as well. Although some big cats (lions, leopards, jaguars, tigers, snow leopards, and clouded leopards) cannot do this.