As a rule, few students like school science about the properties and structure of matter. And in fact - a tedious solution to problems, complex formulas, incomprehensible combinations of special characters, etc. In general, sheer gloom and melancholy. If you think so, then this material- definitely for you.
In this article we will tell you the most interesting facts about physics, which will make even an indifferent person look at natural science differently. Without a doubt, physics is a very useful and interesting science, and there are a lot of interesting facts about the Universe related to it.
1. Why is the sun red in the morning and evening? A wonderful example of a fact from physical phenomena in nature. Actually, the light is incandescent celestial body- white. White glow, with its spectral change, tends to acquire all the colors of the rainbow.
In the mornings and evenings, the sun's rays pass through numerous layers of the atmosphere. Air molecules and tiny dry dust particles can block the passage of sunlight, best allowing only red rays to pass through.
2. Why does time tend to stop at the speed of light? If you believe general theory relativity proposed, the absolute value of the speed of propagation of electromagnetic waves in a vacuum medium is constant and equal to three hundred million meters per second. This is actually a unique phenomenon, given that nothing in our universe can exceed the speed of light, but this is still a theoretical opinion.
In one of the theories, authored by Einstein, there is an interesting section that says that the higher your speed, the slower time begins to move in comparison with surrounding objects. For example, if you drive a car for an hour, you will age a little less than if you were just lying on your bed at home, watching television programs. Nanoseconds are unlikely to have a noticeable impact on your life, but the proven fact remains a fact.
3. Why doesn’t a bird sitting on an electric wire die from electric shock? A bird sitting on a power line is not shocked because its body is not conductive enough. In places where the bird comes into contact with the wire, a so-called parallel connection is created, and since high-voltage wire is the best conductor of current; only a minimum current flows through the body of the bird itself, which is not able to cause significant harm to the health of the bird.
But as soon as a feathered and downy vertebrate animal standing on a wire comes into contact with a grounded object, for example, a metal part of a high-voltage power line, it instantly burns out, because the resistance in this case becomes too great, and the entire electric current pierces the body of the unfortunate bird.
4. How much dark matter is there in the Universe? We live in a material world, and all we can see around us is matter. We have the opportunity to touch it, sell it, buy it, we can dispose of the material at our discretion. However, in the Universe there is not only objective reality in the form of matter, but also dark matter (physicists often talk about it “ dark horse") is a type of matter that does not tend to emit electromagnetic waves and interact with them.
For obvious reasons, no one has been able to see or touch dark matter. Scientists have come to the conclusion that it is present in the Universe, having repeatedly observed indirect evidence of its existence. It is generally accepted that its share in the composition of the Universe occupies 22%, while matter familiar to us occupies only 5%.
5. Are there Earth-like planets in the Universe? Undoubtedly they exist! Taking into account the scale of the Universe, the probability of this is estimated by scientists to be quite high.
However, only recently scientists from NASA began to actively discover such planets located no further than 50 light years from the Sun, called exoplanets. Exoplanets are Earth-like planets that orbit the axis of other stars. To date, more than 3,500 Earth-like planets have been found, and scientists are increasingly discovering alternative places for people to live.
6. All objects fall at the same speed. It may seem to some that heavy objects fall down much faster than light objects - this is a completely logical assumption. Surely a hockey puck falls at a much higher speed than a bird feather. In fact, this is so, but not due to the fault of universal gravity - the main reason why we can observe this is that the gas shell surrounding the planet provides powerful resistance.
400 years have passed since I first realized that universal gravity applies to all objects equally, regardless of their gravity. If you could repeat the experiment with a hockey puck and a bird feather in space (where there is no atmospheric pressure), they would fall down at the same speed.
7. How do the northern lights appear on Earth? Throughout their existence, people have observed one of the natural wonders of our planet - the northern lights, but at the same time they could not understand what it is and where it comes from. Ancient people, for example, had their own idea: a group of indigenous Eskimo peoples believed that this was a sacred light that was emitted by the souls of deceased people, and in the ancients European countries They assumed that these were military operations that the defenders of their state who died in wars were forever doomed to wage.
The first scientists came to the solution mysterious phenomenon a little closer - they put forward for worldwide discussion the theory that the glow arises as a result of the reflection of light rays from ice blocks. Modern researchers believe that the multi-colored light is caused by the collision of millions of atoms and dust particles from our atmospheric shell. The fact that the phenomenon is widespread mainly at the poles is explained by the fact that in these areas the power of the Earth's magnetic field is especially strong.
8. Quicksand sucking deep. The force of pulling a stuck foot out of the sand, supersaturated with air and moisture from rising sources, at a speed of 0.1 m/s is equal to the force of lifting an average passenger car. A remarkable fact: quicksand is a non-Newtonian fluid that is not able to completely absorb the human body.
Therefore, people mired in quicksand die from exhaustion or dehydration, excessive ultraviolet radiation or other reasons. God forbid, you find yourself in such a situation; it is worth remembering that it is strictly forbidden to make sudden movements. Try to tilt your body back as high as possible, spread your arms wide and wait for the rescue team to help.
9. Why is the unit of measurement for the strength of alcoholic drinks and temperature called the same - degree? In the 17th-18th centuries, the generally accepted scientific principle of caloric was in effect - the so-called weightless matter, which was located in physical bodies and was the cause of thermal phenomena.
According to this principle, more heated physical bodies contain many times more concentrated caloric than less heated ones, therefore the strength of alcoholic beverages was determined as the temperature of the mixture of substance and caloric.
10. Why doesn't a drop of rain kill a mosquito? Physicists have managed to figure out how mosquitoes manage to fly in rainy weather and why raindrops do not kill bloodsuckers. The size of insects is the same as the size of a raindrop, but one droplet weighs 50 times more mosquito. The impact of a drop can be compared to a car or even a bus crashing into a person’s body.
Despite this, the rain does not disturb the insects. The question arises - why? The flight speed of a raindrop is about 9 meters per second. When an insect gets inside the shell of a drop, enormous pressure is applied to it. For example, if a person were subjected to such pressure, his body would not be able to withstand it, but a mosquito is able to safely withstand such stress due to the specific structure of the skeleton. And in order to continue flying in a given direction, the mosquito simply needs to shake off its hairs from a drop of rain.
Scientists say that the volume of the drop is quite enough to kill a mosquito if it is on the ground. And the absence of consequences after a drop of rain hits a mosquito is attributed to the fact that the movement associated with the drop allows one to minimize the transfer of energy to the insect.
There is still an unlimited number of facts in this science. And if today’s famous scientists were not interested in physics, we would not know all the interesting things that are happening around us. The achievements of famous physicists allowed us to understand the importance of substantiating laws-prohibitions, laws-statements and absolute laws for the life of mankind.
Interesting facts about physics, a natural school science, will allow you to learn the most ordinary, at first glance, processes from an unusual side.
A drop of rain weighs more than a mosquito. But the hairs, which are located on the surface of the insect’s body, practically do not transmit impulse from the drop to the mosquito. Therefore, the insect survives even in heavy rain. Another factor contributes to this. The collision of water with a mosquito occurs on a loose surface. Therefore, if the blow falls on the center of the insect, it falls with a drop for some time, and then quickly frees itself. If the rain falls off-center, the mosquito's trajectory deviates slightly.
Interesting facts about the atom
Splitting atoms is not only a chemical process, in some cases it can be a human hobby. And there is an example from Sweden - a man (apparently having nothing to do) set up a mini-laboratory in his small kitchen in the form of a “nuclear reactor” and there, in fact, he carried out such simple experiments, investing only less than $1000 in this fascinating expedition .
Interesting factors about temperature.
Did you know that man was able to create an incredibly high temperature of -4 billion degrees Celsius for a living organism? And this, so that you can navigate, is 250 times more than the temperature of the solar core!
Interesting facts about light.
Light has zero mass but has enormous kinetic energy, exerting pressure on any object it illuminates. This amazing ability Designers are trying to use light to move satellites in space.
Interesting fact about thunderstorms .
Not everyone knows why you can’t swim during a thunderstorm.Since water is an excellent conductor of electricity, thanks to various mineral salts dissolved in it, the likelihood of being struck by lightning is quite high. If water is distilled, then, on the contrary, it will turn into a dielectric.
An interesting fact about the operation of the elevator.
Anyone has ridden in an elevator at least once in their life. And many people thought about what to do if he started falling from a height. Most would conclude that there was no chance of survival under such circumstances. Or that at the moment of impact you need to jump. In fact, it is impossible to calculate this time. But if you make sure that the impact force falls on as large a surface area of the body as possible, perhaps everything will work out. That is, you simply need to lie down on the floor. As you can see, interesting facts about physics can save lives.
Why doesn't a bird sitting on a wire die from electric shock?
A bird sitting on a high-voltage power line does not suffer from current, because its body is a poor conductor of current. Where the bird's paws touch the wire, a parallel connection is created, and since the wire conducts electricity much better, a very small current flows through the bird itself, which cannot cause harm. However, as soon as the bird on the wire touches another grounded object, for example, a metal part of a support, it immediately dies, because then the air resistance is too great compared to the resistance of the body, and all the current flows through the bird.
Which elementary particles are named after the sounds of ducks?
Murray Gell-Mann, who hypothesized that hadrons were made of even smaller particles, decided to call these particles the sound that ducks make. James Joyce’s novel “Finnegans Wake” helped him formulate this sound into a suitable word, namely the line: “ThreequarksforMusterMark! Hence the particles received the name quarks, although it is not at all clear what meaning this previously non-existent word had for Joyce.
Interesting fact about infrasound.
It is known that infrasound is sound with vibrations less than 16 hertz. So, once, for a play about the Middle Ages, a pipe almost 40 meters long was brought to the theater where the action was supposed to take place. Since it is known that the longer the pipe, the lower the sound it produces. It was calculated that the frequency of the sound of the new pipe should be 8Hz, and in theory, a person should not hear it, but it was a full house. When the trumpet was played, the sound came out at a frequency of 5 Hz, which corresponds to the alpha rhythm human brain. There was panic in the hall as this sound caused fear in everyone present.As a result, the public someone ran away.
A little more physics.
1) Nothing can burn again if it has already burned.
2) The bubble is round, since the air inside it presses equally on all its parts, the surface of the bubble is equidistant from its center.
3) Black attracts heat, white reflects it.
4) The whip makes a clicking sound because its tip is moving faster than the speed of sound.
5) Gasoline does not have a specific freezing point - it can freeze at any temperature from -118 C to -151 C. When gasoline freezes, it does not become completely solid, but rather resembles rubber or wax.
6) The egg will float in water to which sugar has been added.
7) Dirty snow melts faster than clean snow.
8) Granite conducts sound ten times faster than air.
9) Water in liquid form has a higher molecular density than in solid form. That's why ice floats.
10) If a glass of water is enlarged to the size of the Earth, then the molecules that make it up will be the size of a large orange.
11) If you remove the free space in atoms and leave only the elementary particles that make them up, then a teaspoon of such a “substance” will weigh 5,000,000,000,000 kilograms. So-called neutron stars are made of it.
12) The speed of light depends on the material in which it propagates. Scientists have managed to slow down photons to 17 meters per second by passing them through a rubidium ingot cooled to a temperature very close to absolute zero (-273 Celsius)
Interesting facts about physics, a natural school science, will allow you to learn the most ordinary, at first glance, processes from an unusual side.
- 1. The temperature of lightning is five times higher than the temperature on the surface of the Sun and is 30,000K.
- 2. A drop of rain weighs more than a mosquito. But the hairs, which are located on the surface of the insect’s body, practically do not transmit impulse from the drop to the mosquito. Therefore, the insect survives even in heavy rain. Another factor contributes to this. The collision of water with a mosquito occurs on a loose surface. Therefore, if the blow hits the center of the insect, it falls with a drop for some time, and then quickly frees itself. If the rain falls off-center, the mosquito's trajectory deviates slightly.
- 3. The force of pulling a leg out of quicksand at a speed of 0.1 m/s is equal to the force of lifting a car. Interesting fact: quicksand is a Newtonian fluid that cannot completely absorb a person. Therefore, people stuck in the sand die from dehydration, sun exposure or other reasons. If you find yourself in such a situation, it is better not to make sudden movements. Try to roll over onto your back, spread your arms wide and wait for help.
- 4. Did you hear a click after a sharp swing of the whip? This is due to the fact that its tip moves at supersonic speed. By the way, the whip is the first invention that broke the supersonic barrier. And the same thing happens with an airplane that flies at a speed greater than sound. The explosion-like click is due to the shock wave created by the aircraft.
- 5. Interesting facts about physics also apply to living beings. For example, during flight, all insects are guided by the light of the Sun or Moon. They maintain an angle where the lighting is always on one side. If an insect flies into the light of a lamp, it moves in a spiral, since its rays diverge not parallel, but radially.
- 6. The rays of the Sun that pass through droplets in the air form a spectrum. And its different shades are refracted at different angles. As a result of this phenomenon, a rainbow is formed - a circle, part of which people see from the ground. The center of the rainbow is always on a straight line drawn from the observer's eye to the Sun. A secondary rainbow can be seen when the light in a droplet is reflected exactly twice.
- 7. The ice of large glaciers is characterized by deformation, that is, fluidity due to stress. For this reason, the Himalayan glaciers are moving at a speed of two to three meters per day.
- 8. Do you know what the Mpemba effect is? This phenomenon was discovered in 1963 by a Tanzanian schoolboy named Erasto Mpemba. The boy noticed that hot water was prone to freezing in the freezer faster than cold water. To this day, scientists cannot give an unambiguous explanation for this phenomenon.
- 9. In a transparent medium, light travels slower than in a vacuum.
- 10. Scientists believe that no two snowflakes have the same pattern. There are even more design options for them than there are atoms in the Universe.
1. How did life begin?
The appearance of the first living creature from inorganic material about 4 billion years ago is still shrouded in mystery. How did relatively simple molecules contained in the primordial ocean form increasingly complex substances? Why did some of them acquire the ability to absorb and transform energy, as well as self-reproduction (the latter two properties are the distinctive features of living things)? At the molecular level, all these events undoubtedly represent chemical reactions, and therefore the question of the origin of life should be considered within the framework of chemistry.
Chemists are not tasked with understanding the myriad scenarios of how things might have played out billions of years ago. Whether or not inorganic catalysts, such as lumps of clay, participated in the creation of self-replicating polymers (like DNA or protein molecules); or whether in the distant past there was an “RNA world” in which “ cousin» DNA (RNA molecule) catalyzed the formation of proteins and appeared earlier than other biopolymers.
It is necessary to test the validity of these hypotheses by conducting chemical reactions in a test tube. It has already been shown that some relatively simple chemical substances can interact with each other to form the “building blocks” of biopolymers such as proteins and nucleic acids, i.e. amino acids and nucleotides, respectively. In 2009, a team of molecular biologists led by John Sutherland from the Laboratory of Molecular Biology in Cambridge demonstrated the possibility of obtaining nucleotides from molecules believed to be present in the primordial ocean. Another group of researchers was interested in the ability of some RNAs to act as catalysts, indicating the possible existence of an RNA world. In this way, step by step, we can build a bridge from inanimate matter to self-reproducing living systems.
Now that we have learned a lot about our neighbors in the solar system - about the presence of water on Mars, about hydrocarbon lakes on Titan, a moon of Saturn, about the cold salty oceans apparently hidden under an icy crust on Europa and Ganymede, moons of Jupiter, and about many other things - the question of the origin of terrestrial life forms has become part of a global problem: what conditions are necessary for the origin of life and within what limits can its chemical bases vary? The range of questions has expanded further over the past 15 years, during which more than 500 planets orbiting other stars have been discovered outside the solar system. These worlds, of extraordinary diversity, remain to be explored.
Such discoveries forced chemists to change their ideas about the chemical basis of life. Thus, for a long time it was believed that an absolutely necessary prerequisite for its origin is the presence of water. Today scientists are not sure about this. Maybe instead of water, liquid ammonia, formamide, liquid methane or hydrogen would be suitable under ultra-high pressure conditions in the upper layers of Jupiter? And why should the appearance of DNA, RNA and proteins be a necessary prerequisite for the formation of living systems? Artificial chemical structures have been created that are capable of self-reproduction without any nucleic acids. Perhaps it is enough just to have a certain molecular system that can serve as a matrix for copying itself?
“Analysis of modern life forms on Earth,” says Steven Benner of the Foundation for Applied Molecular Evolution in Gainesville, Florida, “does not answer the question of whether their fundamental similarities (the use of DNA and proteins) are due to the presence of common ancestor or testifies to the universality of life.” However, if we persist in the fact that we must remain within the framework of known facts, then we won't get anywhere.
2 How are molecules formed?
The structure of molecules is the main subject studied by students of chemical specialties, while the graphical representation of molecules in the form of a set of circles and lines between them, corresponding to atoms and chemical bonds, is a pure convention, which is resorted to for convenience. There is still no agreement among scientists about which image of molecules is closest to reality.
In the 1920s German theoretical physicists Walter Heitler and Fritz London showed that chemical bonds can be represented using the equations of the newly emerging quantum physics, and the great American chemist Linus Poling hypothesized that bonds form when overlap in space of electron clouds of different atoms. An alternative theory by Robert Milliken and Friedrich Hund proposed that chemical bonds (except ionic ones) are the result of the overlapping atomic orbitals of the outer electrons of interacting atoms and the appearance of a molecular orbital enclosing these atoms. Here we fall into the sphere of competence of theoretical chemistry, which is essentially one of the areas of physics.
The concept of forming chemical bonds by overlapping atomic orbitals has become widespread, but not everyone believes that it is universal. The fact is that the model structures of molecules constructed on its basis are based on a number of simplifying assumptions and, thus, represent only an approximation. In reality, any molecule is a certain group of atomic nuclei immersed in an electron cloud, and the nuclei, figuratively speaking, compete with each other in “pulling it towards themselves,” so that the entire structure “breathes” and changes. In the current models, molecules are static formations, built taking into account only some of the important properties.
Within the framework of quantum theory it is impossible to give general definition chemical bond, which would correspond to the ideas about it of chemists, whose work ultimately comes down to the destruction of some chemical bonds and the formation of others. Currently, there are many ways to represent molecules as atoms bonded to each other. According to quantum chemist Dominic Marx of the University of Bochum in Germany, almost all of them are “good in some cases and completely unsuitable in others.”
Using computer modeling, today it is possible to predict with high accuracy the structure and properties of molecules based on the principles of quantum mechanics - but only as long as the number of electrons involved in the formation of chemical bonds is relatively small. “Computational chemistry allows you to get the most realistic picture of what is happening,” says Marks. Computer modeling can be considered as a virtual experiment that reproduces the course of a chemical reaction. But as soon as the number of electrons approaches several dozen, numerical methods become powerless even with the most powerful computers. In this regard, the question arises: how, for example, can we model complex biochemical processes occurring in a cell, or the behavior of multicomponent systems?
3. How do external factors influence our genes?
For a long time, the prevailing idea in the biological community was that the individuality of each of us is determined by what genes we possess. However, what is equally important is which ones we use. As elsewhere in biology, the latter is inextricably linked with the same chemistry.
The cells of the embryo at the earliest stages give rise to tissues of all possible types. As it develops, the so-called pluripotent stem cells differentiate and turn into specialized ones (blood cells, muscle cells, nerve cells etc.). The latter retain their individual properties throughout the life of the organism. The formation of the human body is essentially a chemical transformation of the chromosomes of stem cells, as a result of which the set of functioning and silent genes changes.
One of the revolutionary discoveries in the field of cloning and studying stem cells is that these transformations are reversible. During the process of differentiation, cells do not inactivate some genes, maintaining in working order only those that are needed now. They turn them off and keep them in a state of combat readiness. These genes can be activated, for example, under the influence of certain chemicals external environment.
Particularly interesting and mysterious from the point of view of chemistry is the fact that the regulation of gene activity is carried out at the supraatomic and supramolecular levels, with the participation of entire groups of molecules interacting with each other. Chromatin, the complex between DNA and proteins that forms chromosomes, has a hierarchical structure. First, a double-stranded DNA molecule wraps around cylindrical particles consisting of special proteins - histones. Then the resulting “string of beads” is arranged in space into structures of a higher order. The cell strictly controls the folding process - its activity depends on where in the chromatin a given gene ends up.
Restructuring of chromatin structure occurs with the participation of special enzymes that play a key role in cell differentiation. In embryonic stem cells, chromatin has a loose, disordered structure, which becomes denser as genes are turned off during differentiation.
Chromatin structuring is accompanied by chemical transformations of both DNA and histones. Small molecules are attached to them - markers that indicate to the cell which genes to turn off and which, on the contrary, to turn on. Such marks are called epigenetic factors because they do not affect the information contained in genes.
To what extent can mature cells be returned to a state of pluripotency? Will they have the stem cell properties necessary for use in the regeneration of various tissues? The answer depends on the extent to which epigenetic marking can be reversed.
It is clear that in addition to the genetic language in which many key instructions are written, cells use a completely different language from a chemical point of view - epigenetic. "A person may have a genetic predisposition to a disease, such as cancer, but whether it occurs or not depends on environmental factors acting through the epigenetic channel," says Bryan Turner of the University of Birmingham in England.
4. How does the brain form memory?
The brain can be likened to a chemical computer. Communication between the neurons that make up its “electrical circuits” is carried out using special molecules - neurotransmitters. They are released by one neuron, cross the synaptic cleft, bind to the receptors of another neuron, activate it, which activates a third, etc. As a result, the nerve impulse spreads along the chain of neurons. Chemical nature mental activity It manifests itself during memorization, when some information - a telephone number or some event - is “imprinted” using chemical signals in the form of various states of the nervous network. How based chemical processes is a memory formed that is both persistent and dynamic? What does it mean to remember, rethink, forget?
We only have answers to some questions. We know, for example, that an unconditioned reflex occurs in response to a certain cascade of biochemical processes leading to a change in the amount of neurotransmitters in the synapse. But even such a simple process has short-term and long-term components. A more complex phenomenon - the so-called declarative memory (for faces, for places, etc.) - has a different mechanism and a different localization in the brain. The main player here is the receptor for the neurotransmitter dopamine, which is present in some neurons. Blocking it interferes with the retention of declarative memory.
The formation of everyday declarative memory is often mediated by so-called long-term potentiation, which involves dopamine receptors and is accompanied by expansion of the region of the neuron that forms the synapse. With the expansion of this area, the connection between the neuron and its partners is strengthened, manifested through an increase in the potential difference in the synaptic cleft under the influence of a nerve impulse. The biochemistry of the process has become more or less clear in the last few years. It was discovered that actin filaments are formed inside the neuron, a protein that forms the internal framework of the cell, which determines its size and shape. The process can be interrupted if the newly emerged filaments are prevented from stabilizing.
Long-term memory, once formed, is preserved due to the inclusion of genes encoding special proteins. There is reason to believe that these include prions. The latter can be in one of two alternative conformations. In the first case, prions are easily soluble, in the second they are insoluble and transfer all protein molecules to this state. of this type with whom they happened to come into contact. As a result, large prion aggregates are formed, which are implicated in the development of various neurodegenerative disorders. It was precisely this negative property of prions that became the impetus for their identification and study. It was discovered that the aggregates also perform useful functions in the body - they are involved in preserving memory.
There are still many blank spots in the story of how memory works, which biochemists will have to fill in. How to interpret, for example, the concept of “remembering something” if this “something” is stored in our memory? “This problem, which we are just beginning to solve, is very difficult to understand,” says Nobel Prize-winning neuroscientist Eric Kandel of Columbia University.
Speaking about the chemical nature of the phenomenon of memory, one cannot help but touch upon such an issue as the impact of pharmaceuticals on it. Some memory-enhancing substances are already known. Among them are sex hormones and synthetic compounds that act on receptors for nicotine, glutamate, serotine and other neurotransmitters. As neuroscientist Gary Lynch of the University of California notes, the fact that a long chain of events leads to the formation of long-term memory indicates that there are many targets in the body that memory drugs could target.
5. Is there a limit to the replenishment of the periodic table of elements?
periodic table chemical elements, which hangs in a prominent place in every chemistry classroom, is constantly replenished. With the help of accelerators, nuclear physicists obtain new, superheavy elements with a large number protons and neurons in the nucleus than those 92 that exist in nature. They are not very stable, some disintegrate within a fraction of a second after birth. But while such elements exist, their status is no different from the others: they have an atomic number and mass number, and have certain chemical properties. In the course of ingenious experiments, some properties of the atoms of seaborgium and hassium were studied.
One of the goals of such studies is to find out whether there is a limit to the expansion of the periodic table, in other words, whether superheavy elements exhibit the periodicity in their behavior that determines their location in the table. We can already say that some meet these requirements, others do not. In particular, their massive nuclei attract electrons with such force that they begin to move at speeds approaching the speed of light. As a consequence, the mass of electrons increases dramatically, which can lead to disorganization energy levels, on which the chemical properties of elements depend, and therefore their position in the periodic table.
There is hope that nuclear physicists will be able to find an island of stability - a certain area, slightly beyond the current capabilities of obtaining synthetic elements, in which superheavy elements will live longer. However, a fundamental question remains about their maximum sizes. As fairly simple quantum mechanical calculations show, electrons can be held by a nucleus in which the number of protons does not exceed 137. More complex calculations reject this limitation. “The periodic table does not end with number 137; in fact, it is unlimited,” says nuclear physicist Walter Greiner of Goethe University in Frankfurt am Main, Germany. Experimental verification of this statement is still very far away.
6. Is it possible to create a computer based on carbon atoms?
Computer chips based on graphene - networks of carbon atoms - are potentially faster and more powerful than silicon. The production of graphene brought its creators Nobel Prize in physics for 2010, but the practical application of such “carbon” nanotechnology ultimately depends on whether chemists will be able to create structures with atomic precision. In 1985, fullerenes, hollow closed network structures consisting entirely of carbon atoms, were synthesized, and six years later, carbon nanotubes with network walls. It was expected that extremely strong electrically conductive structures would find a wide range of applications - from the production of ultra-strong composite materials based on them to the production of tiny conductors and electronic devices, miniature molecular capsules and membranes for water purification. However, the full potential has not yet been realized. Thus, it is not possible to integrate nanotubes into complex electronic circuits. Recently, graphite has become the focus of nanotechnologists' attention.
It was possible to divide it into ultra-thin layers (this is graphene), from which subminiature, cheap and durable electronic circuits can be made. Computer developers using narrow, tiny strips of graphene will be able to make chips that are more advanced than silicon. “Graphene can be used to create structures that can be easily interconnected and integrated into electronic circuits,” says Walt de Heer of the Georgia Institute of Technology. However, the etching method used in microelectronics is not suitable for creating graphene electronic circuits - it is too crude, so today graphene technology is a matter of speculation, not real action. Perhaps the key to solving the problem of design at the atomic level will be the use of organic chemistry methods - connecting polyaromatic molecules from several hexagonal carbon rings, analogues of small fragments of a graphene network, to each other.
7. Is it possible to capture more solar energy?
Each sunrise reminds us that man uses only a small fraction of the energy that our luminary provides. The main obstacle to its widespread use is the high cost of silicon solar cells. But life itself on our planet, which is ultimately supported by photosynthesis, which is carried out by green plants when they absorb solar energy, indicates that solar cells do not have to be highly efficient, it is enough to have a lot of them (like leaves on trees) and they would be cheap.
“One of the most promising areas for developing ways to harness solar energy is in fuel production,” says Devens Gust of Arizona State University. The easiest way to do this is by splitting water molecules using sunlight to form hydrogen and oxygen gas. Nathan S. Lewis and his collaborators at the California Institute of Technology are working to create an artificial sheet of silicon nanowires that would carry out such cleavage.
Recently, Daniel Nocera from the Massachusetts Institute of Technology reported the creation of a silicon membrane in which, with the participation of a cobalt-based photocatalyst, the splitting of water molecules actually occurs. Nocera estimates that one gallon (~3.8 L) of water can produce enough fuel to power a small home for 24 hours.
The development of such technology is hampered by the lack of suitable catalysts. “A cobalt catalyst like the one Nocera used and new catalysts based on other metals are in principle what is needed, but they are too expensive,” says Gast. “Unfortunately, we do not know how the natural manganese-based photosynthetic catalyst works.”
Gast and his colleagues intend to create molecular assemblies for artificial photosynthesis that mimic natural ones. They have already managed to synthesize a number of substances that will be included in one of these ensembles. But serious obstacles are foreseen on this path. Organic molecules, like those used by nature, are unstable. Plants immediately replace them with new ones, but artificial leaves are not yet capable of this: they, unlike living systems, do not have biosynthetic mechanisms.
8. What is the best way to obtain biofuel?
Instead of developing technology to produce fuel using solar energy, is it better to use the ability of green plants to store energy and convert biomass into fuel? Biofuels such as ethanol come from corn and biodiesel from seeds, and these products already have a place in the market. But there is a danger that grain, which forms the basis of the human diet, will be used. This is especially undesirable for developing countries - exporting biofuels can be very profitable and leave the local population without food. In addition, in order to meet current fuel needs, vast areas currently occupied by forests will have to be plowed.
Thus, converting grain into fuel does not seem to be the best solution. One solution could be to use other, less valuable types of biomass. In the United States, enough waste from agriculture and the wood processing industry is generated to satisfy one third of the transportation needs for gasoline and diesel fuel.
Processing such low-grade biomass requires breaking down durable molecules such as lignin and cellulose. Chemists already know how to do this, but existing methods are too expensive, energy-intensive and unsuitable for producing large quantities of fuel.
John Hartwig and Alexey Sergeev of the University of Illinois recently succeeded in overcoming one of the most serious difficulties in lignin breakdown - breaking the bonds between the carbon and oxygen atoms that connect the benzene rings to each other. They used a nickel-based catalyst.
Producing fuel from biomass on an industrial scale involves processing biosolid material on site in order to transport the resulting liquid through pipes. One serious problem arises here - the raw materials are heavily contaminated with various foreign impurities, and classical catalytic chemistry deals only with pure substances. “It is not yet clear how the situation will ultimately be resolved,” says Hartwig. One thing is clear: the problem largely relates to the field of chemistry, and its solution comes down to finding a suitable catalyst. “Almost all industrial processes involve the use of appropriate catalysts,” Hartwig emphasizes once again.
9. Is it possible to develop new ways to obtain medicinal substances?
Chemistry at its core is a creative and at the same time practical science. It produces molecules that can then be used to create a variety of products - from materials with new properties to antibiotics that can destroy pathogenic microorganisms that are resistant to other drugs.
In the 1990s. At the peak of its popularity was combinatorial chemistry, when thousands of new molecules were obtained by randomly combining “building blocks” and selecting products with the desired properties. This direction, initially proclaimed as the future of medicinal chemistry, soon lost its relevance, since the result turned out to be close to zero.
But perhaps combinatorial chemistry is in for a rebirth. It will take place provided that a sufficiently wide set of molecules of a certain type is obtained and a method is found for isolating microscopic quantities of the necessary substances from this mixture. Biotechnology is ready to help. For example, each molecule can be equipped with a DNA-based barcode, making it easier to identify and isolate. An alternative approach would be to cull unsuitable candidates sequentially—a kind of Darwinian selection in vitro. To do this, you can represent the amino acid sequence of a protein - a candidate for the role of a drug - in the form of a nucleotide sequence of a DNA segment and then, using the replication mechanism with its inherent propensity for errors, obtain more and more new variants that approach the ideal with each round of replication and selection .
Other new methods rely on the intrinsic ability of certain molecular fragments to join together in a given sequence. Thus, the amino acid sequence of proteins is determined by the corresponding genes. Using this principle, chemists could in the future program molecules with the inherent ability to self-assemble. This approach has the advantage that it minimizes the amount of by-products, and this in turn reduces the energy intensity of the processes and the consumption of materials.
Currently, David Liu and his colleagues at Harvard University are trying to implement this idea. They attached to each building block of future molecules a short segment of DNA encoding a linker, and in addition synthesized a certain molecule that moves along the DNA and sequentially attaches monomer units to the building block, guided by the instructions encoded in the DNA segment - a process similar to the synthesis of proteins in living cell. Liu's method may be useful for creating targeted drugs. “Many molecular biologists involved in pharmacology believe that macromolecules will play an increasingly important role, and then main role in therapy,” says Liu.
10. Is chemical monitoring of our body possible?
Recently, in chemistry there has been an increasingly clear tendency towards convergence with information technology, in particular to the use of chemical products for communication with living cells. The idea itself is not new: biosensors with leaks in them chemical reactions They began to be used to determine blood glucose concentrations in the 1960s, although they have only recently become widespread in diabetes monitoring with the advent of inexpensive portable devices. The scope of application of chemical sensors is wide: it detects various harmful substances in food products and water at very low concentrations, determining the level of air pollution and much more.
But there is another area - biomedicine - where the potential of chemical sensors can be fully realized and bring invaluable benefits. For example, some gene products associated with a particular cancer begin to circulate in the bloodstream long before visible symptoms of the pathology appear, when conventional testing methods do not detect anything. Early identification of such chemical precursors of cancer will make it possible to make a more accurate diagnosis, and most importantly, to make it in a timely manner. Rapid construction of a genomic profile will make it possible to select an individual treatment regimen and reduce the likelihood of side effects.
Some chemists envision an era of continuous, patient-friendly monitoring of a wide variety of biochemical markers of the body's condition. Such information can be useful to the surgeon directly during the operation; it can be transmitted automated system administration of medications, etc. The implementation of these ideas depends on whether chemical methods can be developed to selectively identify markers, even when they are present in trace amounts in the body.
Molecular physics is often associated with a boring and difficult topic. But often we don't even realize how many physical phenomena we see and use in our daily lives.
Physics can be quite interesting. Instead of talking about complex equations we will tell you about funny, interesting and useful facts from physics.
PHYSICISTS HAVE MANAGED TO COOL MOLECULES TO ALMOST ABSOLUTE ZERO
Scientists were able to cool strontium monofluoride molecules to almost absolute zero “in one fell swoop.” Physicists described the technology they used in an article in the journal Nature. Unlike molecules and atoms at room temperature, matter cooled to temperatures close to absolute zero (minus 273.15 degrees Celsius, or 0 degrees Kelvin) begins to demonstrate quantum properties (in heated matter they are “clogged” by thermal effects ).
Physicists often cool atoms using a laser - the atoms absorb photons and then emit them. When this process is repeated many times, the atoms gradually lose their kinetic energy, that is, they cool down. This method has not yet been used for molecules - they are heavier and lose energy worse. In addition, in molecules, “extra” energy is stored in the bonds between atoms, as well as in the rotational movements of the entire molecule.
In most cases more early works the atoms were cooled, and then molecules were “assembled” from them. The authors of the new study decided to cool the molecules directly. Scientists experimented with strontium monofluoride, which has less vibrational energy than many other molecules. In addition, physicists selected the color of the laser so that its impact did not cause the molecules to rotate. Finally, the researchers pre-cooled strontium monofluoride in a special way.
As a result, the authors managed to cool the molecules to 300 microkelvins (a microkelvin is one millionth of a kelvin). Calculations show that the technology used by scientists allows them to lower their temperature to even lower values.
In early 2010, another team of researchers, working with potassium and rubidium molecules cooled to ultra-low temperatures, was able to directly observe quantum mechanical effects.
A few more facts...
- Average Human I’m used to thinking that any liquid essentially does not have its own form, however, this is a misconception. It is noteworthy that even the school curriculum talks about this. But the natural shape of any liquid is spherical. The only reason she is not in this form is the force of gravity.
- Speed The movement of molecules in water can reach 650 meters per second. Of course, when it comes to a boil.
- Did you know that a plane that takes off from Moscow to Vladivostok can arrive at the same time as time departure? The fact is that the difference in the clock poles is 9 hours . That is , if the plane can travel the route in three hours, then you will arrive at the same time time , to which they departed.
- It is worth noting that physics has many inaccuracies and shortcomings, but today it is the only science that can explain what is happening from the point of view of a general approach. Most of what is presented in this article is school curriculum modern Western schoolchildren, so learn more and learn to think to keep up with them.
All objects around us are made of atoms. Atoms are so small that in the time it takes us to complete this sentence, 100,00 atoms could be formed.
In fact, the Greeks were the first to talk about the existence of atoms 2400 years ago. But the idea of atoms came and went and was not returned to until 1808, when John Dalton experimentally demonstrated that atoms do exist.
Atoms are part of the molecules of objects that we use every day, that we touch and see. There are so many atoms in one grain of sand that their number can be compared to the number of grains of sand themselves on the beach.
Solids and liquids
In a liquid, on the other hand, the molecules also stick together tightly, but not as tightly as in solids, so they can move around and change shape. However, liquid cannot be compressed.
Gas molecules are loosely bound to each other, so they can spread out and fill space. In addition, gas molecules can be compressed to smaller sizes.
Curiously, glass is not solid body. In reality, glass is a liquid, but it is so viscous that we cannot notice how it flows.
- The largest reserves of water in the Solar System are, strange as it may seem at first glance, in the Sun. Water molecules in the formThe pair are concentrated in sunspots, the temperature of which is one and a half thousand degrees lower than in the surrounding areas, as well as in the region of temperature minimum - a narrow layer under the surface of the star.
- There is a special state of matter called “disordered superhomogeneity,” in which the substance has the properties of a crystal and a liquid at the same time. It was first discovered by physicists in liquid helium and simple plasmas, but recently biologists also encountered it while studying chickens another eye. How and others have daytimex birds, chickens have five types of photoreceptors: red, blue, green, violet and responsible for the perception of light. All of them are located on the retina in one layer, at first glance, randomly, but upon detailed study of the patterns, it turned out that around each cone there is a so-called forbidden zone, in which the appearance of other cones of the same type is excluded. As a result, the system cannot take on a single ordered form, but strives to be as homogeneous as possible.
- Sometimes under the thickness sea ice Large icicles similar to stalactites may appear. When ice forms, there is no salt left in its crystal lattice, and at some points, downdrafts of very cold and very salty water form. Under certain conditions, a layer of ice begins to grow downward around such a flow. If the sea is shallow in a given place, the icicle reaches the bottom and continues to grow in some horizontal direction.