What is the glass, why not bike falls on its side, and eschёNauka appeared for the need to respond to people's questions. And like most of the complex phenomena studied the length and breadth, but remained "very little" - to understand the nature of dark matter, to deal with the problem of quantum gravity, solve the problem of space-time dimension, to understand what the dark energy (and a few hundreds of similar questions ). However, are still more simple, seemingly phenomenon, but scientists are unable to explain to the end.
What is glass?
Nobel laureate Warren Anderson once said, "The deepest and interesting of the unresolved problems in the theory of the solid state is in the nature of glass." Although glass known to mankind is not the first millennium, the reason for its unique mechanical properties, scientists still do not understand. Out of school lessons, we remember that the glass - it is a liquid, but is it? Scientists do not know exactly what the nature of the transition between the liquid and solid phases and glassy, and what physical processes lead to the basic properties of the glass.
The process of forming the glass fails to be explained by any of the existing instruments of solid state physics, many-body theory, or the theory of liquids. If you describe briefly, liquid molten glass when cooled gradually becomes more and more viscous until it obtains rigidity. While the formation of crystalline solids, such as graphite, the atoms at one point to form the usual periodic structure. Tarun Chitra, a researcher of molecular dynamics, explains the organization of molecules in different materials on the example of dance:
Ideal rigid body - it's like a slow dance when the two partners, together with other couples moving around its starting position on the dance floor.
Ideal fluid - it's like dating a party when everyone is trying to dance with everyone in the room (this property is called ergodicity), while the average rate at which all dance, about the same.
Glass is on this analogy, like a dance, where a group of people divided into smaller sub-groups and each spinning in his dance. You can change partners from the circle, and this dance takes forever.
Glass behaves in such a way that it is impossible to describe the equilibrium statistical mechanics. In particular, subexponential autocorrelation and cross-correlation function of glass can be produced by an infinite number of random processes. Up to a certain point, the system "works" more or less clear and predictable, but if you watch it long enough, you begin to see how some of the features are better described by the theory of probability and stochastic processes.
Why the bicycle falls over on his side?
The design of the bike is quite simple, and it seems that has long understood how and why the two-wheeled vehicle maintains excellent stability. It was always considered that maintaining the balance of the bike crucial role played by two mechanisms. The first - an automatic steer, or the effect of castor: if the bike leans into some side front wheel itself turns there, and then centrifugal force returns to the initial position of the wheel. The second mechanism is associated with the gyroscopic moment of the rotating wheels.
American engineer Andy Ruina and colleagues undertook to refute both of these allegations. They constructed a bicycle, scooter-like, whose front wheel bearings concerns ahead of the point of intersection with the axis of the front fork her that "cancels" the action of Kastoria. Besides, the front and rear wheels are connected to the other two, rotating in the opposite direction, and thus zeroed gyroscopic effect.
Nevertheless, this bike is not so quickly falls to the side. In fact, he holds the balance no worse than a conventional bicycle, and even shows the same auto-steer. The experiment results the authors concluded that both effects - and Castor and gyro - play an important role in maintaining the balance of riding a bike, but both are not critical for him.
Why not bike falls, until the end and it is not known. According to the latest assumptions engineers, a key role in this is a special distribution of load.
How does a placebo?
On placebo, or compounds which have no clear therapeutic properties, but a positive effect on the body, it has long been known. The placebo effect is based on the psycho-emotional impact. But researchers have repeatedly argued that the placebo has no active substances can stimulate the real physiological reactions, including changes in heart rate and blood pressure, and chemical activity in the brain. Placebo also helps to get rid of pain, depression, anxiety, fatigue, and even some of the symptoms of Parkinson's disease.
The way our mind can affect health, are still not fully clear, and scientists can not reveal the mechanisms underlying the physiological reactions on placebo. Obviously, in effect it is woven many different aspects, and the dummy medicine do not affect the source or cause of the disease. Empirically it determined that the response of the body varies depending on the method of delivery of a placebo (when taking tablets or injections). It is also expected to provide only a placebo, that is known in advance, the therapeutic effect. And the higher the expectations - the stronger the placebo effect. Furthermore, it is known that it is possible to strengthen the active verbal effects on the patient. Susceptible to placebo effects, not all. Most placebo effect on extroverts, people with high levels of anxiety, suspiciousness, insecurity.
In October 2013 a study was published showing that the placebo effect is associated with an increase in alpha brain activity. Alpha waves occur in 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 spinal cord. But as long to describe in detail the mechanism of its action so no one could.
What do you mean wow-signal from the distant cosmos?
August 5, 1977 was one of the most mysterious events in the history of space exploration. Dr. Jerry Ayman while working on radio "Big Ear" in the SETI project gave a strong narrowband radio signal space. Its characteristics (transmission band, the ratio of signal and noise), comply with the expected signal of extraterrestrial origin. Struck by this, Ayman swept related characters on the printed and signed in the fields of «Wow!». This signature and gave the name of the signal.
The signal came from the region of the sky in the constellation Sagittarius, about 2.5 degrees south of the stellar group Hee. However, after years of waiting repetition of something like nothing happened.
The very sound of wow-signal
Scientists say that if the signal and had an extraterrestrial origin, the creatures that sent him, must belong to the very, very advanced civilization. To send a powerful signal that requires a minimum of 2, 2-gigawatt transmitter, which is much more powerful than any of the Earth (for example, the HAARP system in Alaska, one of the most powerful in the world, supposedly able to transmit a signal up to 3,600 kW).
As one of the hypotheses to explain the power of the signal, it is assumed that initially weak signal was significantly enhanced by the action of a gravitational lens; however, this still does not exclude its synthetic origin. Other researchers suggest the possibility of rotation of the radiation source, like a lighthouse, a periodic change in the signal frequency or once. There is also a version that the signal was sent from the moving alien spaceship.
In 2012, the 35th anniversary of the Arecibo Observatory signal to transmit a response of 10,000 tweets encoded in the direction of the alleged source. However, if they got someone unknown. Until now, wow-signal remains one of the major puzzles of astrophysics.
Like inanimate matter becomes a living?
In the scientific world today is dominated by the concept of biological evolution, according to which the first life emerged by itself from inorganic components as a result of physical and chemical processes. The way out of inanimate matter comes alive, describes the theory of abiogenesis. However, it contains a lot of problems.
It is known that the main components of living matter are amino acids. But the likelihood of accidental certain amino acid-nucleotide sequence corresponds to the likelihood that thousands of letters from typesetting typographic font will be dropped from the roof of a skyscraper, and will develop in a certain page of Dostoevsky's novel. Abiogenesis in its classical form suggests that this "dumping the font" occurred thousands of times-that is, as long as it took until he emerged in the required sequence. However, according to modern calculations, it would take much more time than there is a whole universe.
In the laboratory, all attempts to create an artificial living cells never come to fruition. The complete set of amino acids and nucleotides, and the simplest bacterial cell still divides the gulf. Perhaps the first living cells are very different from what we can observe today. Also, a large number of scientists support the hypothesis that the first living cells could get to our planet because of meteorites, comets, and other extraterrestrial objects.
Why do people fall into lefties and righties?
Over the past 100 years, scientists have studied the issue quite well why people are advantageously used with one hand, and why this is often the right hand. However, the standard empirical testing of right-handers or left-handers not, as scientists can not fully understand what mechanisms are involved in this process.
Scientists disagree, what percentage of humanity is right-handed and left-handed some. It is generally believed that the majority (70% to 95%) - right-handed, a minority (5% to 30%) - left-handed, there is also an indefinite number of people, there is complete symmetry. It is proved that left-handedness and right-handedness affect genes, but the exact "gene lefties" have not yet identified. There is evidence that the tendency to use the right or left hand can be affected by social and cultural mechanisms. The most characteristic example of this, retrained as a teacher of children, making the switch when writing with the left hand on the right. This is currently a totalitarian society have fewer left-handers than the more liberal societies.
Some researchers talk about "pathological" left-handedness associated with brain injury during childbirth. In the 1860s, a French surgeon Paul Broca noted the relationship between the activity of the hands and the brain hemispheres. According to his theory, the halves of the brain are connected to the body halves crosswise. But at the moment it is known that these relationships are not as simple as they described Brock. Studies conducted in the 1970s showed that the majority of left-handers have the same left-hemisphere activity, typical for all people. However, only part of the left-handers have different deviations from the norm.
By studying the problem of left-handedness and right-handedness of primates, the researchers found that most of the animals in a separate population is either left-handed or right-handed. The individual monkeys often develop their own individual preferences.
As a result, we still have only a general idea about the causes of right-handedness, and researchers now only have to thoroughly understand all the mechanisms of their formation.
Why do we sleep?
We sleep 36% of its life, but scientists can not fully explain the phenomenon. People tend to sleep, because it is in our genes, but why such a state emerged in the course of evolution - a mystery. In addition to warm-blooded animals (mammals and birds), none of these forms of living beings sleep there, and what are the benefits of sleep - is still unclear.
Scientists have found that during sleep the muscles grow faster, better wound healing and accelerates the synthesis of proteins. In other words, sleep helps the body make up for what he lost during wakefulness. Recent studies have shown that during sleep our brain is cleansed of toxins, and if a person hinders this process (in other words - not sleeping), he may begin mental disorders. In addition, during the rest of the brain are weakened or disconnected communication between cells, so we "freed space" for new information. The brain generates new synapses, so lack of sleep threatens to decrease the ability to acquire, process and recall information.
During sleep, the brain often "lose" some episodes that happened to us during the day, and, according to the researchers, this process helps to strengthen our memory. Although the content of dreams is determined by the actual experiences, our consciousness during sleep is different from our consciousness during wakefulness. In the dream, our attitude is much more imaginative and emotional. We see a different picture, worry about them, and to understand properly can not. Scientists believe that the timing mechanisms that dominate the sleepy brain is increasingly associated with the first signaling system and the emotional sphere. But what is a dream, can not yet be answered unequivocally.
Why do cats purr?
Nobody knows for sure why cats purr. Purring is different from many other sounds made by animals that vocalization occurs throughout the respiratory cycle (and inspiratory and expiratory). It was once thought that the sound was produced thanks to the flow of blood passing through the inferior vena cava, but now the majority of scientists agree that the process of extracting sound involved larynx, throat muscles and neural oscillator.
Kittens learn to purr as soon as they turn a couple of days. Veterinarians suggest that they purr means something like human words "mother", "I'm OK" or "I'm here." These sounds help to strengthen ties between the kitten and his mother.
But when the kitten grows up, he also continued to purr, and many researchers believe that in adulthood this sound is associated with pleasure and joy. Sometimes cats purr when injury or disease. Dr. Elisabeth von Muggenthaler suggests that the purr and low-frequency vibrations that it produces are "natural mechanism of self" and strengthen, heal wounds and relieve pain.
Voice feature of domestic cats is not unique. Other species of the cat family such as the lynx, cheetahs and pumas also purr. Although some big cats (lions, leopards, jaguars, tigers, snow leopards and clouded leopard) are not able to do that.
Author: Artem Lucko em>
Source: Look at me em>
blockquote> via factroom.ru