The most important scientific discoveries

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The 20th century can be considered the century of revolutions. And not only political, but also scientific. Many believed that scientists were of no use at all. They sit, they say, in their offices and laboratories for years and all to no avail. What's the point of spending money on research? But scientists, through a series of significant discoveries, have convinced the whole world that this is not so. At the same time, in the XX century, significant discoveries were made extremely often, radically changing our life. We will tell below about the ten most significant scientific discoveries of the last century, just a decade for each.

1) Max Planck arranged the first revolution at the beginning of the century. At the end of the 19th century, he was invited to the post of professor at the University of Berlin. Planck was so devoted to science that in his free time from lectures and work he continued to deal with the distribution of energy in the spectrum of a black body. As a result, the stubborn scientist in 1900 derived a formula that very accurately described the behavior of energy in this case. This had absolutely fantastic consequences. It turned out that energy is not emitted uniformly, as previously thought, but in portions - quanta. These conclusions at first confused Planck himself, but he nevertheless reported on the strange results on December 14, 1900 to the German Physical Society. Not surprisingly, the scientist was simply not believed. However, on the basis of his conclusions, already in 1905, Einstein created the quantum theory of the photoelectric effect. After that, Niels Bohr also built the first model of the atom, according to which electrons revolve around the nucleus in certain orbits. The consequences of Planck's discovery for humanity are so great that it can be considered incredible, brilliant! So, thanks to the scientist, atomic energy, electronics, genetic engineering subsequently developed. Astronomy, physics and chemistry received a powerful impetus. This happened due to the fact that it was Planck who clearly marked the border where the Newtonian macrocosm ends with the measurement of matter in kilograms, and the microcosm begins, in which it is necessary to take into account the influence of individual atoms on each other. Thanks to the scientist, it became known at what energy levels electrons live, and how they behave there.

2) The second decade brought a discovery that also turned the minds of all scientists. In 1916, Albert Einstein's work on general relativity was completed. It also received another name - the theory of gravity. According to the discovery, gravity is not a consequence of the interaction of fields and bodies in space, but a consequence of the curvature of the four-dimensional space-time. The discovery immediately explained the essence of many hitherto incomprehensible things. So, most of the paradoxical effects that occur at near-light speeds simply contradicted common sense. However, it was the theory of relativity that predicted their appearance and explained the essence. The most famous of them is the effect of time dilation, in which the observer's clock runs slower than those moving relative to him. It also became known that the length of a moving object along the axis of motion is compressed. Today the theory of relativity is applied not only to objects moving at a constant speed relative to each other, but also to all reference frames in general. The calculations were so complex that the work took 11 years. The first confirmation of the theory was the description of the curve of the orbit of Mercury, produced with its help. The discovery explained the bending of rays from stars as they pass next to other stars, the redshift of galaxies and stars observed through telescopes. Black holes have become a very important confirmation of the theory. Indeed, according to calculations, when a star shrinks like the Sun up to 3 meters in diameter, light simply cannot leave its limits - this will be the force of attraction. Recently, scientists have found many such stars.

3) After the discovery, made in 1911 by Rutherford and Bohr, about the structure of the atom by analogy with the solar system, physicists around the world were delighted. Soon, on the basis of this model, using the calculations of Planck and Einstein about the nature of light, it was possible to calculate the spectrum of the hydrogen atom. But when calculating the next element, helium, difficulties arose - the calculations showed completely different results from the experiments. As a result, by the 1920s, Bohr's theory faded and began to be questioned. However, a solution was found - the young German physicist Heisenberg was able to remove some assumptions from Bohr's theory, leaving only the most necessary. He established that one cannot simultaneously measure the location of electrons and their speed. This principle was called "Heisenberg uncertainty", while electrons appeared to be unstable particles. But even here the oddities with elementary particles did not end there. By that time, physicists had already become accustomed to the idea that light can manifest the properties of both a particle and a wave. The duality seemed paradoxical. But in 1923 the Frenchman de Broglie suggested that ordinary particles can also have wave properties, demonstrating the wave properties of the electron. De Broglie's experiments were confirmed in several countries at once. In 1926, Schrödinger described de Broglie's material waves, and the Englishman Chirac created a general theory, the assumptions of Heisenberg and Schrödinger entered it as special cases. In those years, scientists did not even suspect about elementary particles, but that theory of quantum mechanics perfectly described their movement in the microcosm. Over the next years, the basis of the theory has not undergone any obvious changes. Today, quantum mechanics is used in any natural sciences reaching the atomic level. These are engineering sciences, medicine, biology, mineralogy and chemistry. The theory made it possible to calculate molecular orbitals, which in turn allowed the emergence of transistors, lasers, and superconductivity. It is quantum mechanics that we owe the appearance of computers. Also on the basis of it, solid state physics was developed. That is why new materials appear every year, and scientists have learned to clearly see the structure of matter.

4) The decade of the thirties can be called radioactive without error. Although back in 1920, Rutherford expressed a hypothesis, strange at that time. He tried to explain why positively charged protons do not repel. The scientist suggested that in addition to them in the nucleus there are also some neutral particles, equal in mass to protons. By analogy with the already known electrons and protons, Rutherford proposed to call them neutrons. However, the scientific world did not take the physicist's ideas seriously at that time. Only 10 years later, the Germans Becker and Bothe discovered unusual radiation when boron or beryllium was irradiated with alpha particles. In contrast to the latter, the unknown particles emitted from the reactor had a much higher penetrating power. And their parameters were different. Two years later, in 1932, the Curies decided to direct this radiation to heavier atoms. It turned out that under the influence of these unknown rays, they become radioactive. This effect is called artificial radioactivity. In the same year, James Chadwick was able to confirm these results, and also to find out that nuclei from atoms are knocked out by new uncharged particles with a mass slightly larger than that of a proton. It was the neutrality of such particles that allowed them to penetrate into the nucleus, destabilizing it. So Chadwick discovered the neutron, confirming Rutherford's thoughts. This discovery has brought not only benefits to humanity, but also harm. By the end of the decade, physicists were able to prove that nuclei can fission under the influence of neutrons and that even more neutral particles are released. On the one hand, such use of such an effect led to the tragedy of Hiroshima and Nagasaki, decades of the Cold War with nuclear weapons. On the other hand, the emergence of atomic energy and the use of radioisotopes in various scientific fields for wide application.

5) With the development of quantum theories, scientists could not only understand what was happening inside the substance, but also try to influence these processes. The neutron case is mentioned above, but in 1947, employees of the American company At @ T Bardeen, Brattain and Shockley were able to learn how to control large currents flowing through semiconductors using small currents. For this they will subsequently receive the Nobel Prize. So a transistor was born, in it two p-n junctions are directed towards each other. Through the transition, the current can go only in one direction; when the polarity changes at the transition, the current stops flowing. In the case of two transitions directed towards each other, there are unique possibilities for working with electricity. The transistor gave a huge impetus to the development of all science. Lamps were gone from electronics, which dramatically reduced the weight and volume of the equipment used. Logic microcircuits appeared, which gave us a microprocessor in 1971, and later a modern computer. As a result, today there is not a single device, car or even home in the world that does not use a transistor.

6) German chemist Ziegler studied the Grenyard reaction, which helped to greatly simplify the synthesis of organic substances. The scientist wondered - is it possible to do the same with other metals? His interest had a practical side, because he worked at the Kaiser Institute for the Study of Coal. The by-product of the coal industry was ethylene, which needed to be disposed of somehow. In 1952, Ziegler studied the decomposition of one of the reagents, as a result, low-pressure polyethylene, HDPE, was obtained. However, it has not yet been possible to completely polymerize ethylene. However, unexpectedly, a case helped - after the end of the reaction, not a polymer unexpectedly dropped out of the flask, but a dimer (a compound of two ethylene molecules) - alpha-butene. The reason for this was the fact that the reactor was poorly cleaned of nickel salts. This ruined the main reaction, but analysis of the resulting mixture showed that the salts themselves did not change, they only acted as a catalyst for dimerization. This conclusion promised huge profits - previously, to obtain polyethylene, it was necessary to use a lot of organoaluminiums, apply high pressure and temperature. Now Ziegler began to look for the most suitable catalyst, looking for transition metals. In 1953, several of them were found at once. The most powerful of them turned out to be based on titanium chlorides. Ziegler told about his discovery to the Italian company Montecatini, where his catalysts were tested on propylene. After all, that, being a by-product of oil refining, costs ten times cheaper than ethylene, which also gives an opportunity to experiment with the structure of the polymer. As a result, the catalyst was slightly modernized, resulting in stereoregular polypropylene, in which all propylene molecules were located in the same way. This gave the chemist a great deal of control over polymerization. Artificial rubber was soon created. Today, organometallic catalysts have made it possible to carry out most syntheses cheaper and easier; they are used in almost all chemical plants in the world. However, the most important remains the polymerization of ethylene and propylene. Ziegler himself, despite the enormous industrial application of his work, always considered himself a theoretical scientist. The student who poorly washed the reactor did not become famous either.

7) April 12, 1961 became a significant milestone in the history of mankind - its first representative visited space. This was not the first rocket to fly around the earth. Back in 1957, the first artificial satellite was launched. But it was Yuri Gagarin who showed that dreams of stars can someday become reality. It turned out that not only bacteria, plants and small animals, but also humans can live in zero gravity. We realized that the space between the planets is surmountable. The man visited the moon, an expedition to Mars is being prepared. The solar system is full of space agency vehicles. Close-up man studies Saturn and Jupiter, Mars and the Kuiper belt. Several thousand satellites are already rotating around our planet. These include meteorological and scientific instruments (including powerful orbiting telescopes) and commercial communication satellites. This allows us to call anywhere in the world today. Distances between cities seem to have decreased, thousands of television channels have become available.

8) The birth of the girl Louise to the Brown family on July 26, 1978 was a scientific sensation. Gynecologist Patrick Staptoe and embryologist Bob Edwards, who participated in the birth, were extremely proud. The fact is that the girl's mother, Leslie, suffered from obstruction of the fallopian tubes. She, like millions of other women, could not conceive a child on her own. The attempts lasted 9 long years. Steptoe and Edwards undertook to solve the problem, who made several scientific discoveries for the sake of this. They developed a method of extracting an egg from a woman, without damaging it, creating conditions for its existence in a test tube, then artificially fertilizing and returning it back. The experiment was crowned with success - experts and parents were convinced that Louise is an absolutely normal child. In the same way, her parents helped to give birth to her sister. As a result, by 2007, more than two million people were born using the method of in vitro fertilization (IVF). If not for the experiments of Steptoe and Edwards, this would be simply impossible. Today, medicine has gone even further - adult women give birth to their own granddaughters, if their children are unable to do this themselves, women are fertilized with the sperm of already dead men ... The IVF technique is gaining more and more popularity - after all, multiple experiments have confirmed that test-tube babies are no different from those who are naturally conceived.

9) In 1985, scientists Robert Curl, Harold Kroto, Richard Smalley and Heath O'Brien studied the spectra of graphite vapors generated by a laser on a solid sample. Unexpectedly, strange peaks appeared for them, which corresponded to atomic masses of 720 and 840 units. Scientists soon came to the conclusion that a new type of carbon, fullerene, had been found. The name of the find came from Buckminster Fuller's designs, which were very similar to the new molecules. Soon, the carbon varieties of football and rugby appeared. Their names are associated with sports, as the structure of the molecules was similar to the corresponding balls. Fullerenes with unique physical properties are now used in many different devices. But most importantly, these techniques allowed scientists to create carbon nanotubes, which are twisted and cross-linked layers of graphite. Today science has been able to create tubes 5-6 nanometers in diameter and up to 1 centimeter long. The fact that they are made of carbon allows them to exhibit a variety of physical properties - from semiconductor to metallic. New materials for fiber optic lines, displays and LEDs are being developed on the basis of nanotubes. With the help of the invention, it became possible to deliver biologically active substances to the right place in the body, to create so-called nanopipettes. Supersensitive chemical sensors have been developed and are now being used in environmental monitoring, medical, biotechnology and military applications. Nanotubes help create transistors, fuel cells, and nanowires are made of them. The latest development in this area is artificial muscle.In 2007, studies were published showing that a bundle of nanotubes can behave similarly to muscle tissue. Although the conduction of electric current in artificial formation is similar to natural muscles, over time, nanomuscles do not wear out. Such a muscle withstood half a million compressions at 15% of its original state, the shape, mechanical and conductive properties did not change as a result. What does it do? It is possible that someday disabled people will receive new arms, legs and organs, which can be controlled only by the power of thought. After all, thought for muscles is like an electrical signal to activate it.

10) The 90s became the era of biotechnology. The first worthy representative of the work of scientists in this direction was an ordinary sheep. Usually she was only outwardly. For the sake of her appearance, the employees of the Roslin Institute, which in England worked hard for several years. The egg cell, from which the famous Dolly was later born, was completely gutted, then the cell nucleus of an adult sheep was placed in it. The developed embryo was put back into the uterus and began to expect the result. Dolly in the rank of candidates for the title of the first clone of a large living creature bypassed almost 300 candidates - all of them died at different stages of the experiment. Although the legendary sheep survived, its fate was unenviable. After all, the ends of DNA, telomeres, which serve as the biological clock of the body, have already counted 6 years in Dolly's mother's body. After another 6 years of life of the clone itself, in February 2003, the animal died from old age diseases that had fallen on it - arthritis, specific pneumonia and other ailments. But Dolly's appearance on the cover of Nature magazine in 1997 made a splash - it became a symbol of the superiority of man and science over nature itself. The next years after Dolly's cloning, the appearance of copies of a wide variety of animals - dogs, pigs, gobies, was noted. We even managed to get clones of the second generation - clones from clones. So far, however, the problem with telomeres remains unresolved, and human cloning around the world remains prohibited. But this area of ​​science remains very interesting and promising.

Watch the video: Everything and Nothing: What is Nothing? Jim Al-Khalili. Science Documentary. Science

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