Scientific picture of the world

The scientific picture of the world is one of the fundamental concepts in the philosophy of science - a special form of systematization of knowledge, a qualitative generalization and worldview synthesis of various scientific theories . Being an integral system of ideas about the general properties and laws of the world, the scientific picture of the world exists as a complex structure, which includes, as components, a general scientific picture of the world and a picture of the world of individual sciences. The pictures of the world of individual sciences, in turn, include the corresponding numerous concepts - certain ways of understanding and interpreting any objects, phenomena and processes of the objective world that exist in each individual science ^[2] .

The belief system that affirms the fundamental role of science as a source of knowledge and judgment about the world is called scientism .

In the process of cognition of the world in the human mind , knowledge , skills, types of behavior and communication are reflected and fixed. The totality of the results of human cognitive activity forms a certain model ( picture of the world ). In the history of mankind , a rather large number of the most diverse pictures of the world were created and existed, each of which differed in its vision of the world and its specific explanation. However, the progress of ideas about the world is achieved mainly through scientific research ^[3] . The scientific picture of the world does not include private knowledge about the various properties of specific phenomena, about the details of the cognitive process itself . The scientific picture of the world is not the aggregate of all human knowledge about the objective world, it represents an integral system of ideas about the general properties, spheres, levels and patterns of reality ^[2] .

The picture of the world is a systemic formation, therefore its change cannot be reduced to any single (albeit the largest and most radical) discovery. This usually refers to a series of interconnected discoveries (in the main fundamental sciences), which are almost always accompanied by a radical restructuring of the research method, as well as significant changes in the norms and ideals of science themselves ^[1] .

The scientific picture of the world is a special form of theoretical knowledge that represents the subject of research of science according to a certain stage of its historical development, through which specific knowledge obtained in various fields of scientific research is integrated and systematized ^[4] .

For Western philosophy in the mid-90s of the 20th century, attempts were made to introduce new categorical means into the arsenal of methodological analysis, but at the same time, a clear distinction was made between the concepts “world picture” and “scientific picture of the world”. In our domestic philosophical and methodological literature, the term “picture of the world” is used not only to designate a worldview, but also in a narrower sense - when it comes to scientific ontologies, that is, those ideas about the world that are a special type of scientific theoretical knowledge. In this sense, the scientific picture of the world acts as a specific form of systematization of scientific knowledge, which sets the vision of the objective world of science in accordance with a certain stage of its functioning and development ^[5] .

The phrase natural science picture of the world can also be used ^[6] .

In the process of development of science there is a constant update of knowledge , ideas and concepts , earlier representations become special cases of new theories . The scientific picture of the world is not dogma or absolute truth . Scientific ideas about the world around us are based on the totality of proven facts and established causal relationships, which allows us to draw conclusions and predictions about the properties of our world that contribute to the development of human civilization with a certain degree of confidence. Inconsistency between the results of testing the theory, hypothesis, concept, revealing new facts - all this forces us to reconsider existing ideas and create new, more relevant realities. In such a development is the essence of the scientific method .

The picture of the world is a term used in various senses to mean ^[4] :

• worldview structures that lay in the foundation of the culture of a certain historical era. The terms world image, world model, world vision , which characterize the integrity of the worldview, are used in the same meaning.
• scientific ontologies, that is, those ideas about the world that are a special type of scientific theoretical knowledge. In this sense, the concept of a scientific picture of the world is used to mean:
  • horizon systematization of knowledge gained in various scientific disciplines. The scientific picture of the world at the same time acts as a holistic image of the world, including ideas about nature and society
  • a system of ideas about nature arising as a result of the synthesis of natural science knowledge (in the same way, this concept denotes the totality of knowledge obtained in the humanities and social sciences)
  • through this concept, a vision of the subject of a particular science is formed, which develops at the corresponding stage of its history and changes during the transition from one stage to another.

According to these values, the concept of a scientific picture of the world is split into a number of interconnected concepts, each of which designates a special type of scientific picture of the world as a special level of systematization of scientific knowledge ^{[4] [7]} :

• general scientific picture of the world (systematic knowledge obtained in various fields)
• natural science picture of the world and socially (publicly) scientific picture of the world
• concrete scientific picture of the world ( physical picture of the world , picture of the investigated reality)
• special (private, local) scientific picture of the world of individual branches of science.

Also distinguish the "naive" picture of the world ^[8]

The scientific picture of the world is neither philosophy nor science; the scientific picture of the world differs from scientific theory in the philosophical transformation of the categories of science into fundamental concepts and in the absence of the process of obtaining and reasoning knowledge; Moreover, the scientific picture of the world is not reduced to philosophical principles, since it is a consequence of the development of scientific knowledge. ^[7]

Clearly and unambiguously fixed radical changes in the scientific picture of the world, scientific revolutions in the history of the development of science, three can be distinguished, which are usually customary to personify by the names of three scientists who played the largest role in the changes ^[1] .

Aristotelian

Period: VI — IV centuries BC

Conditionality:

Reflection in the works:

• The most complete is Aristotle: the creation of formal logic (the doctrine of proof, the main tool for deriving and systematizing knowledge, developed a categorical-conceptual apparatus), the assertion of a peculiar canon of organization of scientific research (history of the problem, statement of the problem, arguments for and against, substantiation of the solution), differentiation knowledge itself (separation of nature science from mathematics and metaphysics)

Result:

• the emergence of science itself
• separation of science from other forms of cognition and world exploration
• the creation of certain norms and models of scientific knowledge.

Newtonian Scientific Revolution

Classical science

Period: XVI — XVIII centuries

Starting point: the transition from the geocentric model of the world to the heliocentric.

Conditionality:

Reflection in the works:

• Discoveries: N. Copernicus, G. Galileo, I. Kepler, R. Descartes. I. Newton summarized their research, formulated the basic principles of a new scientific picture of the world in general.

Major changes:

• The language of mathematics, the allocation of strictly objective quantitative characteristics of terrestrial bodies (form magnitude, mass, motion), their expression in strict mathematical laws
• Methods of experimental research. The studied phenomena are under strictly controlled conditions.
• Rejection of the concept of a harmonious, complete, purposefully organized space.
• Views: the universe is infinite and united only by the action of identical laws
• Dominant: mechanics, all considerations based on the concepts of value, perfection, goal setting, were excluded from the scope of scientific research.
• Cognitive activity: a clear opposition of the subject and the object of study.

Bottom line: the emergence of a mechanistic scientific picture of the world on the basis of experimental mathematical science.

Einstein Revolution

Period: the turn of the XIX — XX centuries.

Conditionality:

• Discoveries:
  • complex atom structure
  • radioactivity
  • discreteness of the nature of electromagnetic radiation
• and etc.

Bottom line: the most important premise of the mechanistic picture of the world was undermined - the belief that with the help of simple forces acting between immutable objects, all natural phenomena can be explained.

The very concept of "picture of the world" is not self-evident. Martin Heidegger points out that such a term is characteristic only of the new European culture; neither antiquity nor the Middle Ages knew it. The world, understood as a picture, is possible only when a person becomes “the first and exclusive subject”, makes himself a reference point for existing as such. ^{[9] The} scientific picture of the world is one of the possible pictures of the world, therefore it is inherent in something in common with all other pictures of the world - mythological, religious, philosophical - and something special that distinguishes the scientific picture of the world from the diversity of all the others images of the world ^[10] Doctor of Philosophy Pavel Chelyshev believes that the scientific picture of the world is incomplete and not final, science gives only “facts” that can be used to find explanations from different worldviews. To search for ideological foundations, one must turn to philosophy, religion, art, and ordinary consciousness ^[11] .

With Religious

The scientific picture of the world may differ from religious ideas about the world, based on the authority of the prophets , religious traditions, sacred texts, etc. Therefore, religious ideas are more conservative in contrast to scientific ones, changing as a result of the discovery of new facts . In turn, the religious concepts of the universe can change to get closer to the scientific views of their time. The basis of obtaining a scientific picture of the world is an experiment that allows us to confirm the validity of certain judgments. The basis of the religious picture of the world is a belief in the truth of certain judgments belonging to any authority. Nevertheless, due to the experience of all kinds of “ esoteric ” states (not only of religious or occult origin), a person can get personal experience confirming a certain picture of the world, but in most cases, attempts to build a scientific picture of the world on this belong to pseudoscience .

With art and household

The scientific picture of the world also differs from the worldview characteristic of everyday or artistic perception of the world, using everyday / artistic language to denote objects and phenomena of the world. For example, a man of art creates artistic images of the world on the basis of a synthesis of his subjective (emotional perception) and objective (passionless) comprehension, while a man of science focuses on extremely objective and through critical thinking removes subjectivity from research results.

With philosophical

The relationship between science and philosophy is a matter of debate. On the one hand, the history of philosophy is a humanities science , the main method of which is the interpretation and comparison of texts. On the other hand, philosophy claims to be something more than science, its beginning and end, the methodology of science and its generalization, a theory of a higher order, meta- science . Science exists as a process of putting forward and refuting hypotheses , the role of philosophy in this is to study the criteria of scientific and rational . At the same time, philosophy comprehends scientific discoveries, including them in the context of formed knowledge and thereby determining their significance. The ancient concept of philosophy as the queen of sciences or the science of sciences is connected with this.

With mixed

All of these representations can be present in humans together and in various combinations. The scientific picture of the world, although it can make up a significant part of the worldview, is never an adequate replacement, since in his individual being a person needs both emotions and an artistic or purely everyday perception of the surrounding reality, as well as ideas about what is beyond reliably known or on the border of the unknown, which has to be overcome at one time or another in the process of cognition.

Evolution of Representations

There are different opinions on how the ideas about the world in the history of mankind are changing. Since science appeared relatively recently, it can provide additional information about the world. However, some philosophers believe that over time, the scientific picture of the world should completely supersede all others.

According to Comte’s classification, the scientific picture of the world represents the third, positive (after theological and metaphysical) phase of the consistent phase of philosophical thought in the history of all mankind.

Feuerbach said so about the change of his ideas:

“God was my first thought, mind was the second, man was the third and last.”

From Feuerbach's ideas, the idea of ​​the evolution of philosophy and society also passed into Marxism .

History of the Universe

Birth of the Universe

According to cosmology , the Universe arose as a result of an explosive process called the Big Bang , which occurred about 14 billion years ago. The Big Bang theory is in good agreement with the observed facts (for example, the expansion of the Universe and the predominance of hydrogen ) and made it possible to make correct predictions, in particular, about the existence and parameters of CMB radiation .

At the time of the Big Bang, the Universe and space itself were microscopic, quantum in size.

In accordance with the inflationary model , in the initial stage of its evolution, the Universe experienced a period of accelerated expansion (inflation). It is assumed that at this moment the Universe was “empty and cold” (there was only a high-energy scalar field), and then it was filled with hot substance, which continued to expand.

Переход энергии в массу не противоречит физическим законам, например, рождение пары частица- античастица из вакуума можно наблюдать и сейчас в научных экспериментах.

О причинах Большого взрыва выдвинуто несколько гипотез. В соответствии с одной из них, взрыв порождён флуктуацией вакуума . Причина флуктуации — квантовые колебания, которые испытывает любой объект на квантовом уровне; вероятность крупной флуктуации низка, но отлична от нуля. В результате флуктуации вакуум вышел из состояния равновесия (см. туннельный эффект ) и перешёл в новое состояние с меньшим энергетическим уровнем (что привело к выделению энергии).

Другая гипотеза, оперирующая в терминах теории струн , предполагает некое внешнее по отношению к нашей Вселенной событие, например, столкновение бран в многомерном пространстве .

Некоторые физики допускают возможность множественности подобных процессов, а значит и множественность вселенных, обладающих разными свойствами. Тот факт, что наша Вселенная приспособлена для образования жизни, может объясняться случайностью — в «менее приспособленных» вселенных просто некому это анализировать (см. Антропный принцип и текст лекции «Инфляция, квантовая космология и антропный принцип» ). Ряд учёных выдвинули концепцию «кипящей Мультивселенной », в которой непрерывно рождаются новые вселенные и у этого процесса нет начала и конца.

Необходимо отметить, что сам факт Большого взрыва с высокой долей вероятности является доказанным, но объяснения его причин и подробные описания того, как это происходило, пока относятся к разряду гипотез .

Эволюция Вселенной

Расширение и остывание Вселенной в первые мгновения существования нашего мира привело к следующему фазовому переходу — образованию физических сил и элементарных частиц в их современной форме.

Доминирующие гипотезы сводятся к тому, что первые 300—400 тыс. лет Вселенная была заполнена только ионизированным водородом и гелием . По мере расширения и остывания Вселенной они перешли в стабильное нейтральное состояние, образовав обычный газ. Предположительно через 500 млн лет зажглись первые звёзды , а сгустки вещества, образовавшиеся на ранних стадиях благодаря квантовым флуктуациям, превратились в галактики .

В результате термоядерных реакций в звёздах были синтезированы более тяжёлые элементы (вплоть до углерода ). Во время взрывов сверхновых звёзд образовались ещё более тяжёлые элементы. В молодых галактиках процесс образования и гибели звёзд шёл очень бурно. Чем массивнее звезда, тем быстрее она гибнет и рассеивает бо́льшую часть своего вещества в пространстве, обогащая его разнообразными химическими элементами. После взрывов вещество сгущалось снова, в результате чего зажигались звёзды следующих поколений, вокруг которых образовывались планетные системы. Поэтическая фраза «мы состоим из пепла давно угасших звёзд» полностью соответствует действительности.

Образование звёзд и планетных систем

The formation of stars and planetary systems is studied by the science of cosmogony . Under the influence of gravity in gas-dust clouds , condensations form with the formation of rotating gas-dust disks. The bulk of the substance is concentrated in the center of the disk, where the temperature rises, as a result of which a thermonuclear reaction begins and a star flares up (births of stars in gas and dust clouds were observed with a telescope ). In the remaining parts of the disk, planets form.

Thermonuclear fusion reactions of nuclei of hydrogen atoms with the formation of helium support the burning of a star for most of its life. Then, various types of stars behave differently: from a brief “bloating” and gradual cooling in the form of a white dwarf to powerful explosions with the formation of neutron stars and black holes .

As recent studies show, planetary systems around stars are very common (at least in our Galaxy). There are several hundred billion stars in the Galaxy and, apparently, no fewer planets.

The solar system formed about 5 billion years ago. We are located in the peripheral part of our Galaxy (although far enough from its edge).

Universe Device

One of the most important properties of the Universe - it is expanding, moreover, accelerated. The farther the object is from our galaxy , the faster it moves away from us (but this does not mean that we are in the center of the world: the same is true for any point in space).

Visible matter in the Universe is structured into star clusters - galaxies. Galaxies form groups , which, in turn, enter superclusters of galaxies . Superclusters are concentrated mainly inside flat layers, between which there is a space that is practically free of galaxies. Thus, on a very large scale, the Universe has a honeycomb structure resembling the “nosmature” structure of bread. However, at even greater distances (over 1 billion light-years), matter in the Universe is uniformly distributed.

In addition to visible matter, dark matter is present in the Universe, which manifests itself through gravitational influence. Dark matter, like ordinary matter, is also concentrated in galaxies . The nature of dark matter is still unknown. In addition, there is a hypothetical dark energy , which is the reason for the accelerated expansion of the universe. According to one hypothesis, at the time of the Big Bang, all dark energy was “compressed” in a small volume, which caused the explosion (in accordance with other hypotheses, dark energy can manifest itself only at large distances).

According to calculations, more than 70% of the mass in the Universe is accounted for by dark energy (if we convert energy to mass according to Einstein's formula), more than 20% - to dark matter, and only about 5% - to ordinary matter.

Space and Time

The concepts of space and time form the basis of physics . According to classical physics, based on Newton’s laws , physical interactions unfold in an infinite three-dimensional space - the so-called absolute space, in which time can be measured by a universal clock (absolute time).

At the beginning of the twentieth century, scientists discovered some contradictions in Newtonian physics. In particular, physicists could not explain how the speed of light remains constant regardless of whether the observer is moving. Albert Einstein resolved this paradox in his special theory of relativity .

In accordance with the theory of relativity , space and time are relative - the results of measuring length and time depend on whether the observer moves or not. These effects are manifested, for example, in the need to adjust the clock on GPS navigation satellites.

Based on Einstein’s theory, German Minkowski created an elegant theory that describes space and time as 4-dimensional space-time (Minkowski space). In space-time, distances (more precisely, hyperdistances, since they include time as one of the coordinates) are absolute: they are the same for any observer.

Having created a special theory of relativity, Einstein generalized it in the general theory of relativity , including gravity in its consideration. According to the general theory of relativity, massive bodies bend space-time, which determines gravitational interactions. Moreover, the nature of gravity and acceleration is one and the same - we can feel acceleration or gravity if we make a curvilinear motion in space-time.

Modern physics is faced with the task of creating a general theory combining quantum field theory and theory of relativity. This would explain the processes occurring in black holes and, possibly, the mechanism of the Big Bang .

According to Newton, empty space is a real entity (this statement illustrates a thought experiment : if we unwind a plate of sand in an empty universe, then the sand will begin to fly apart, since the plate will spin relative to empty space). According to the interpretation of Leibniz-Mach, only material objects are real entities. It follows that the sand will not fly apart, since its position relative to the plate does not change (that is, nothing happens in the frame of reference rotating with the plate). Moreover, the contradiction with experience is explained by the fact that in reality the Universe is not empty, and the whole set of material objects forms a gravitational field, relative to which the plate rotates. Einstein initially believed the Leibniz-Mach interpretation to be true, but in the second half of his life he was inclined to believe that space-time is a real entity.

According to experimental data, the space (usual) of our Universe at large distances has zero or very small positive curvature . This is explained by the rapid expansion of the Universe at the initial moment, as a result of which the elements of space curvature are aligned (see. Inflation Model of the Universe ).

In our Universe, space has three dimensions (according to some theories, there are additional measurements at microdistances), and time is one.

Time moves in only one direction (the “ arrow of time ”), although the physical formulas are symmetrical with respect to the direction of time ^[12] , with the exception of thermodynamics . One of the explanations of the unidirectionality of time is based on the second law of thermodynamics , according to which the entropy can only increase and therefore determines the direction of time. The increase in entropy is explained by probabilistic reasons: at the level of interaction of elementary particles, all physical processes are reversible, but the probability of a chain of events in the “forward” and “reverse” directions can be different. Thanks to this probabilistic difference, we can judge the events of the past with more confidence and certainty than the events of the future. According to another hypothesis, the reduction of the wave function is irreversible and therefore determines the direction of time (however, many physicists doubt that the reduction is a real physical process). Some scientists are trying to reconcile both approaches within the framework of decoherence theory : when decoherence, information about most of the previous quantum states is lost, therefore, this process is irreversible in time.

Physical vacuum

Vacuum is not an absolute void. In accordance with quantum field theory , in a vacuum, quantum fluctuations of physical fields occur around a zero value, virtual particles are continuously born and die, which under certain conditions can turn into real ones. The presence of fluctuations in empty space is confirmed experimentally (see the Casimir effect ).

According to some theories, a vacuum can be in different states with different energy levels. According to one hypothesis, the vacuum is filled by the Higgs field (the “remnants” of the inflaton field preserved after the Big Bang), which is responsible for the manifestations of gravity and the presence of dark energy.

Some of these field theory predictions have already been successfully confirmed experimentally. Thus, the Casimir effect ^[13] and the Lamb shift of atomic levels are explained by zero oscillations of the electromagnetic field in a physical vacuum. Some other ideas about vacuum are based on modern physical theories. For example, the existence of several vacuum states (the false vacuums mentioned above) is one of the main foundations of the Big Bang inflation theory .

Elementary particles

Elementary particles - micro-objects that cannot be split into components that can exist independently.

Some elementary particles ( electron , neutrino , quarks , etc.) are currently considered structureless and are considered as primary fundamental particles ^[14] . Other elementary particles (the so-called compound particles , including particles entering the nucleus of an atom - protons and neutrons ) consist of elementary particles of a "lower order", but, nevertheless, according to modern concepts, it is impossible to separate them into separate parts due to confinement effect. For example, a neutron consists of three quarks , which do not exist in a free state, but can turn into other particles (quarks are attracted the stronger, the farther they are from each other, and it is impossible to separate them).

In total, more than 350 elementary particles are discovered together with antiparticles . Of these, the photon, electron and muon neutrino, electron, proton and their antiparticles are stable. The remaining elementary particles spontaneously decay according to an exponential law with a time constant from approximately 1000 seconds (for a free neutron ) to a negligible fraction of a second (from 10 ⁻²⁴ to 10 ⁻²² s for resonances ). Due to the wide variety of elementary particles, their sizes are very different, but far from all particles, the sizes were exactly ahead.

According to the Standard Model , all matter (including light) consists of 12 fundamental particles of matter (6 leptons and 6 quarks - not counting the corresponding antiparticles) and 12 interaction transfer particles (8 gluons , 3 gauge bosons , one photon ).

Particle -wave dualism is inherent in all elementary particles: on the one hand, particles are single indivisible objects, on the other hand, the probability of their detection is “smeared” in space (“smeared” is fundamental and is not just a mathematical abstraction, this fact illustrates for example, an experiment with the simultaneous passage of a photon through two slits at once ). Under certain conditions, such a “smearing” can even take on macroscopic dimensions.

Quantum mechanics describes a particle using the so-called wave function , whose physical meaning is still unclear. The square of its module determines not where exactly the particle is located, but where it could be located and with what probability. Thus, the behavior of particles is fundamentally probabilistic in nature: due to the “smearing” of the probability of detecting a particle in space, we cannot determine its location and momentum with absolute certainty (see the uncertainty principle ). But in the macrocosm, dualism is insignificant.

In the experimental determination of the exact location of the particle, the wave function is reduced , that is, during the measurement process the “smeared” particle turns into “unoiled” with randomly distributed one of the interaction parameters at the time of measurement, also this process is called “collapse” of the particle. Reduction is an instantaneous process (realized above the speed of light), therefore, many physicists consider it not a real process, but a mathematical method of description. A similar mechanism operates in experiments with entangled particles (see quantum entanglement ). At the same time, experimental data allow many scientists to argue that these instantaneous processes (including the relationship between spatially separated entangled particles) are of a real nature. Moreover, information is not transmitted and the theory of relativity is not violated.

The reasons why there is such a set of particles, the reasons for the presence of mass in some of them and a number of other parameters are still unknown. Physics is faced with the task of constructing a theory in which the properties of particles follow from the properties of vacuum.

One of the attempts to build a universal theory was string theory , in which fundamental elementary particles are one-dimensional objects (strings) that differ only in their geometry.

Interactions

In nature, there are four fundamental forces and all physical phenomena are caused by only four types of interactions (in decreasing order of strength):

• strong interaction connects quarks to hadrons and holds protons and neutrons in the composition of the atomic nucleus (acts at distances of the order of 10 ⁻¹⁵ m);
• electromagnetic interaction acts between particles having an electric charge , and is "responsible" for the phenomena of electromagnetism;
• weak interaction causes the majority of decays of elementary particles, the interaction of neutrinos with matter, etc. (acts at a distance of the order of 10 ⁻¹⁸ m);
• due to gravitational interaction, objects with mass are attracted to each other.

According to the latest theories, interaction occurs due to the transfer of a carrier particle of interaction between interacting particles. For example, the electromagnetic interaction between two electrons occurs as a result of the transfer of a photon between them. The nature of the gravitational interaction is still not exactly known, presumably it occurs as a result of the transfer of hypothetical particles of gravitons .

Many theoretical physicists believe that in reality there is only one interaction in nature, which can manifest itself in four forms (just as the whole variety of chemical reactions are different manifestations of the same quantum effects). Therefore, the task of fundamental physics is to develop a theory of the “great unification” of interactions. To date, only a theory of electroweak interaction has been developed, combining weak and electromagnetic interactions.

As suggested, at the time of the Big Bang there was a single interaction, which was divided into four in the first instants of the existence of our world.

Atoms

Вещество, с которым мы сталкиваемся в повседневной жизни, состоит из атомов . В состав атомов входит атомное ядро, состоящее из протонов и нейтронов , а также электроны , «мерцающие» вокруг ядра ( квантовая механика использует понятие «электронное облако»). Протоны и нейтроны относятся к адронам (которые состоят из кварков ). Следует отметить, что в лабораторных условиях удалось получить « экзотические атомы », состоящие и из других элементарных частиц (например, пионий и мюоний , в состав которых входят пион и мюон .).

Атомы каждого химического элемента имеют в своём составе одно и то же количество протонов, называемое атомным номером или зарядом ядра. Однако количество нейтронов может различаться, поэтому один химический элемент может быть представлен несколькими изотопами . В настоящее время известно свыше 110 элементов, наиболее массивные из которых нестабильны (см. также Таблица Менделеева ).

Атомы могут взаимодействовать друг с другом, образуя химические соединения . Взаимодействие происходит на уровне их электронных оболочек. Химические вещества чрезвычайно многообразны.

Наука пока не решила задачу точного предсказания физических свойств химических веществ.

В XIX веке считалось, что атомы являются первичными «кирпичиками» строения материи. Однако и сейчас остаётся открытым вопрос о том, существует ли предел деления материи, о котором говорил ещё Демокрит (см. Атомизм ).

Понятие живого

Согласно определению академика РАН Э. М. Галимова , жизнь есть материализованное в организмах явление возрастающего и наследуемого упорядочения, присущее при определённых условиях эволюции соединений углерода. Для всех живых организмов характерны обособленность от среды, способность к самовоспроизведению, функционирование посредством обмена веществом и энергией с окружающей средой, способность к изменчивости и адаптации, способность воспринимать сигналы и способность на них реагировать. ^[fifteen]

Устройство живых организмов, гены и ДНК

Живые организмы состоят из органических веществ , воды и минеральных соединений. Фенотип (совокупность внешних и внутренних признаков) организма в основном определяется набором его генов , в которых записана большая часть наследственной информации. Количество генов может варьировать от нескольких генов у простейших вирусов до десятков тысяч у высших организмов (около 30 тыс. у человека).

Носителем генетической информации является ДНК — сложная органическая молекула, имеющая форму двойной спирали. Информация на ней «записана» в виде последовательности нуклеотидов , полимером которых она является. Генетический код определяет формирование белков (из которых, в основном, состоят живые организмы) на основе информации, содержащейся в ДНК. В генетическом коде используется лишь 4 «буквы»-нуклеотида; код един для всех земных организмов. Существуют очень немногочисленные исключения из этого правила, которые являются модификациями единого кода (например, метилирование отдельных нуклеотидов).

Генетический код определяет порядок синтеза белков, из которых состоят все живые организмы.

Генетическая информация реализуется при экспрессии генов в процессах транскрипции и трансляции . Передача генетической информации от родительской клетки дочерним происходит в результате репликации (копирования ДНК комплексом ферментов).

Помимо генов в ДНК имеются некодирующие участки. Некоторые из них выполняют регуляторную функцию (энхансеры, сайленсеры); функция других пока неизвестна.

Генетика достигла впечатляющих успехов. Учёные умеют внедрять гены одних организмов в геномы других, клонировать живые существа, «включать» и «выключать» определённые гены и многое другое. Это привносит проблемы морального плана .

Эволюция живых организмов

Принципы эволюции

Развитие жизни на Земле, в том числе усложнение живых организмов происходит в результате непредсказуемых мутаций и последующего естественного отбора наиболее удачных из них. ^[16]

Развитие таких сложных приспособлений, как глаз , в результате «случайных» изменений может показаться невероятным. Однако анализ примитивных биологических видов и палеонтологических данных показывает, что эволюция даже самых сложных органов происходила через цепочку небольших изменений, каждое из которых по отдельности не представляет ничего необычного. Компьютерное моделирование развития глаза позволило сделать вывод, что его эволюция могла бы осуществляться даже быстрее, чем это происходило в реальности ^[17]

В целом, эволюция, изменение систем — есть фундаментальное свойство природы, воспроизводимое в лабораторных условиях. Для открытых систем это не противоречит закону возрастания энтропии . Процессы самопроизвольного усложнения изучает наука синергетика . Один из примеров эволюции неживых систем — формирование десятков атомов на основе лишь трёх частиц и образование миллиардов сложнейших химических веществ на основе атомов.

История жизни на Земле

Зарождение жизни на Земле представляет пока не до конца решённую проблему. Существует только две теории о зарождении жизни: самозарождение жизни — жизни предшествовала химическая эволюция , и занесение жизни из космоса. Последняя, однако, не решает проблемы происхождения жизни, поскольку оставляет открытым вопрос, где именно и как жизнь возникла в космосе ^[18] .

Согласно палеонтологическим данным, первые прокариоты ( бактерии ) появились около 4 млрд лет назад. Первые эукариоты (клетки с ядром) образовались примерно 2 млрд лет назад в результате, согласно одной из наиболее распространённых теорий, симбиоза прокариот. Первые многоклеточные организмы появились около 1 млрд лет назад в результате симбиоза эукариот. Около 600 млн лет назад появились многие знакомые нам животные (например, рыбы, членистоногие и др.). 400 млн лет назад жизнь вышла на сушу. 300 млн лет назад появились деревья (с твёрдыми волокнами) и пресмыкающиеся , 200 млн лет назад — динозавры и яйцекладущие млекопитающие , 65 млн лет назад вымерли динозавры и появились плацентарные млекопитающие, около 100 тыс. лет назад появился современный человек (см. Геохронологическая шкала и сайт «История развития жизни» ).

Уровни организации жизни

Шесть основных структурных уровней жизни:

• Молекулярный
• Клеточный
• Организменный
• Популяционно-видовой
• Биогеоценотический
• Биосферный

Расхождение предков современных человекообразных обезьян и человека произошло около 15 млн лет назад. Примерно 5 млн лет назад появились первые гоминиды — австралопитеки . Следует отметить, что формирование «человеческих» черт шло одновременно у нескольких видов гоминид (такой параллелизм в истории эволюционных изменений наблюдался неоднократно).

Около 2,5 млн лет назад от австралопитеков обособился первый представитель рода Homo — человек умелый ( Homo habilis ), который уже умел изготавливать каменные орудия. 1,6 млн лет назад на смену Homo habilis пришёл человек прямоходящий ( Homo erectus , питекантроп) с увеличенным объёмом мозга. Современный человек (кроманьонец) появился около 100 тыс. лет назад в Африке. Примерно 60 — 40 тыс. лет назад кроманьонцы перебрались в Азию и постепенно расселились по всем частям света за исключением Антарктиды, вытеснив другой вид людей — неандертальцев , вымерших около 30 тысяч лет назад. Все части света, включая Австралию и отдалённые острова Океании, Южную Америку, были заселены людьми задолго до Великих географических открытий Колумба , Магеллана и других европейских путешественников XV — XVI веков нашей эры.

У человека в гораздо большей степени, чем у других животных, развито абстрактное мышление и способность к обобщению.

Важнейшим достижением современного человека, во многом отличающего его от других животных, явилось освоение обмена информацией с помощью устной речи. Это позволило людям накапливать культурные достижения, в том числе совершенствовать способы изготовления и применения орудий труда из поколения в поколение.

Изобретение письменности , сделанное 4 — 3 тыс. лет до н. e. в междуречье Тигра и Евфрата (на территории современного Ирака) и в древнем Египте, значительно ускорило технический прогресс , так как позволило передавать накопленные знания без непосредственного контакта.

• Article by Academician V. Ginzburg on Unresolved Scientific Problems
• Encyclopedia of Science
• Frigg, Roman. Models in Science // Stanford Encyclopedia of Philosophy (Fall 2012 Version) / Ed. Edward N. Zalta. Per. from English D.V. Chirva