Science

Matrix is a special mathematical element. It is a table consisting of a certain number of rows and columns. Matrices are used in mathematics to write and conveniently solve systems of linear equations. Systems of equations using a matrix are solved using the Gauss method, Cramer's method, the method of algebraic additions, etc. The basis of working with matrices is to bring it to a standard, or triangular form. Last modified: 2025-01-23 12:01

Dangers lurk at every step, except for the gases used by man in many areas of activity. Gas poisoning is detrimental to humans in most cases, antidotes for many species have not yet been invented or found. Last modified: 2025-01-23 12:01

Magnetism is a form of interaction between moving electric charges carried out at a distance by means of a magnetic field. Along with electricity, magnetism is one of the manifestations of the electromagnetic interaction. From the point of view of quantum field theory, the electromagnetic interaction is carried by a boson - a photon (a particle that can be represented as a quantum excitation of an electromagnetic field). Last modified: 2025-01-23 12:01

Hydrogen indicator pH (lat. pondus Hydrogenii - “weight of hydrogen”; in Russian tradition it is pronounced “p-ash”) - a measure of activity (in very dilute solutions it is equivalent to concentration) of hydrogen ions in a solution, quantitatively expressing its acidity . Equal in modulus and opposite in sign to the decimal logarithm of the activity of hydrogen ions, expressed in moles per liter. Last modified: 2025-06-01 07:06

The Titius-Bode rule (also known as Bode's law) is an empirical formula that approximately describes the distances between the planets of the solar system and the Sun (mean orbital radii). The rule was proposed by J. D. Titius in 1766 and gained fame thanks to the work of J. E. Bode in 1772. Last modified: 2025-06-01 07:06

Grand Unified Theory (GUT) is a group of theoretical models in particle physics that describe the strong, weak and electromagnetic interactions in a unified way. It is assumed that at extremely high energies (above 1014 GeV) these interactions combine. Last modified: 2025-01-23 12:01

The conductometric method of analysis is based on measuring the electrical conductivity of the analyzed solution. Electrical conductivity is the reciprocal of the electrical resistance R. The unit of electrical conductivity is Ohm-1 or Siemens (Sm). Electrolyte solutions, being conductors of the second kind, obey Ohm's law. By analogy with the resistance of conductors of the first kind, the resistance of the solution is directly proportional to the distance between the electrodes l and inversely proportional to their surface area. Last modified: 2025-06-01 07:06

Surface roughness - a set of surface irregularities with relatively small steps on the base length. It is measured in micrometers (µm). Roughness refers to the microgeometry of a solid body and determines its most important operational properties. First of all, wear resistance against abrasion, strength, tightness (tightness) of joints, chemical resistance, appearance. Last modified: 2025-06-01 07:06

Goldbach's problem is one of the oldest and most hyped problems in the history of all mathematics. This conjecture has been proven to be true for all integers less than 4 × 1018, but remains unproven despite considerable efforts by mathematicians. Last modified: 2025-01-23 12:01

Naphthenic acids (NA) are a mixture of several cyclopentyl and cyclohexylcarboxylic acids with a molecular weight of 120 to 700 or more atomic mass units. The main fraction are carboxylic acids with a carbon skeleton from 9 to 20 carbon atoms. Scientists claim that naphthenic acids (NA) are cycloaliphatic carboxylic acids with 10-16 carbon atoms, although acids containing up to 50 carbon atoms have been found in heavy oils. Last modified: 2025-01-23 12:01

Temperament (lat. temperamentum - "stable mixture of components") - a stable set of individual psychophysiological characteristics of a person associated with dynamic, rather than meaningful aspects of activity. Temperament is the basis for the formation and development of character. From a physiological point of view, it is due to the type of higher nervous activity of a person and manifests itself in the nature of a person’s behavior, in the degree of his vital activity. Last modified: 2025-01-23 12:01

Silent and ultra-fast alien vehicles were of great interest to world governments in the first half of the 20th century. And one of the first UFO researchers was Sergei Korolev. Stalin called him in 1948. The Queen was provided with various materials related to the research of unidentified flying objects. The Secretary General was interested in whether a UFO could be a weapon of a potential enemy. Last modified: 2025-01-23 12:01

Radiation is a stream of energy that propagates around in the form of electromagnetic waves. Radio waves, microwave radiation, ordinary light and X-rays are all related to radiation. But natural elements can also be radioactive, which decay over decades, emitting particles of energy - electrons (beta rays), protons (alpha rays) and neutrons. Last modified: 2025-01-23 12:01

G alton's whistle is an acoustic emitter that works on the principle of cutting the air flow with a wedge located next to the acoustic resonator. Typically used to produce ultrasound, however, whistles of a similar design can also be used to produce sound in both the audible and infrasonic ranges. Last modified: 2025-01-23 12:01

Synergy (Greek συνεργία - cooperation, assistance, assistance, complicity, complicity; from Greek σύν - together, other Greek ἔργον - business, work, work, (impact) action) - enhancing the effect of interaction two or more factors, characterized by the fact that the combined effect of these factors significantly exceeds the simple sum of the actions of each of them. Last modified: 2025-01-23 12:01

The human eye is arranged in an amazing way, scientists are still making amazing discoveries by studying the abilities of our visual organ. Compared to the most advanced modern photographic equipment, our eye is a truly unique mechanism. How many megapixels are in the human eye and is it more powerful than modern cameras? Do you want to know the answer to these questions? Read the article below. Last modified: 2025-01-23 12:01

Different types of communication are an essential part of a person's daily life. Without the types of verbal communication available to us, it would be extremely difficult to contact, work together, and achieve meaningful goals. Last modified: 2025-01-23 12:01

All modern science has developed on assumptions that initially seemed mythical and implausible. But over time, having accumulated reasoned evidence, these assumptions have become a socially recognized truth. And so theories arose on which all scientific knowledge of mankind is based. But what is the meaning of the word "theory"? You will learn the answer to this question from our article. Last modified: 2025-01-23 12:01

Marine fish such as tuna, salmon and mackerel are rich in omega-unsaturated fatty acids. Their vegetable analogues include linseed and rapeseed oil, pumpkin seeds and various types of nuts. Fish oil contains omega-3 fatty acids. Its complete plant replacement is flaxseed oil. Last modified: 2025-01-23 12:01

Geographic instruments are devices that help to find out data in various areas of our environment. Such devices are literally needed to measure every single natural phenomenon, and they benefit all people on our planet. Last modified: 2025-01-23 12:01

Interaction of an alkaline earth metal with a strong acid. Substitution reaction, interaction of a metal with an acid. Qualitative reaction with gas evolution. A redox reaction that produces s alt and releases hydrogen. Last modified: 2025-01-23 12:01

Thymus or thymus gland is one of the most important organs of the immune system. It plays a special role in the normal development of the child. That is why the size of this endocrine organ in children is much larger than in an adult. Its decrease over time is called thymus involution. Read more about this phenomenon in the article. Last modified: 2025-01-23 12:01

Hormones are substances that are synthesized in the human body with the help of specialized endocrine glands. Each hormone has a specific biological activity. At the moment, there are about 60 substances that are secreted by the glands and have hormonal activity. Last modified: 2025-01-23 12:01

To determine the amount of a dissolved substance in water, the quality of an oil product, to prove the authenticity of a precious stone, etc., it is required to know the refractive index of a particular medium. Its value is determined by the formulas. In addition, a device was invented specifically for this purpose - a refractometer. Last modified: 2025-06-01 07:06

Along with the mathematical and statistical cartographic method, it studies the source information and has various ways of processing it. This is how research is carried out using the construction of geographical maps with special figurative-sign spatial models. The cartographic method is indispensable in the system of methods for studying population. Last modified: 2025-01-23 12:01

When studying the social geography of a particular country, one should distinguish between concepts that are similar at first glance. So, for example, the space and territory of Russia are considered to be somewhat different definitions. Last modified: 2025-01-23 12:01

Before we learn about the concept of a data model, its types and classifications, we need to understand the very meaning of computer science and all areas studied by it. In this article, we will consider the basic terms and pillars of this science, in particular, we will talk about data structure types and much more. Last modified: 2025-01-23 12:01

The study of such an interesting subject as chemistry should begin with the basics, namely the classification and nomenclature of chemical compounds. This will help not to get lost in such a complex science and put all new knowledge in its place. Last modified: 2025-01-23 12:01

We all know that atoms are made up of protons, neutrons and electrons. But how are they located? How is energy distributed within an atom? What is an energy level and how was it discovered? Everyone should become familiar with this in order to expand their knowledge and understand the structure of substances, having an idea of the arrangement of the smallest particles inside its atoms. Last modified: 2025-01-23 12:01

The cell is the structural unit of the living. It consists of various organelles and inclusions, each of which has its own structural features and functions. Many are familiar with some of them, but do you know what a centriole is and what is its role in a eukaryotic cell?. Last modified: 2025-01-23 12:01

A flower is a modified shoot, which is an important organ of sexual reproduction in angiosperms. The flowers are very diverse in smell, shape, size and color, but the same in structure. For example, each perianth consists of two main parts - a calyx and a corolla. Last modified: 2025-01-23 12:01

The night sky impresses with countless stars. It is especially attractive that they are all located in a certain place, as if someone specially placed them in such a way as to draw patterns in the sky. Last modified: 2025-01-23 12:01

The Need Theory, also known as the Three Needs Theory, proposed by psychologist David McClelland. Essentially, it is a motivational model that attempts to explain how needs for achievement, power, and belonging affect people's actions from a managerial context. This model was developed in the 60s of the last century, 2 decades after the discovery of Maslow's hierarchy of needs. Last modified: 2025-01-23 12:01

Modern society is unthinkable without scientific achievements, techniques and technologies that have radically changed human life and his ideas about the surrounding universe over the past 100 years. American scientists made a great contribution to the development of science, the most famous of which are discussed in the article. Last modified: 2025-01-23 12:01

Often in life we are faced with the need to assess the chances of an event occurring. Whether it is worth buying a lottery ticket or not, what will be the gender of the third child in the family, whether tomorrow the weather will be clear or it will rain again - there are countless such examples. In the simplest case, you should divide the number of favorable outcomes by the total number of events. Last modified: 2025-06-01 07:06

Speed in physics means the speed of movement of any object (material point) in space. This value is different: linear, angular, average, cosmic and even superluminal. Among all existing varieties also includes instantaneous speed. What is this value, what is its formula and what actions are needed to calculate it - this is exactly what will be discussed in our article. Last modified: 2025-01-23 12:01

Usually, when we talk about movement, we imagine an object that moves in a straight line. The speed of such movement is usually called linear, and the calculation of its average value is simple: it is enough to find the ratio of the distance traveled to the time during which it was overcome by the body. If the object moves in a circle, then in this case not a linear, but an angular velocity is already determined. Last modified: 2025-06-01 07:06

Do you know what magnets are and how the magnetic force works? An interesting fact: our planet is also the prototype of a magnet with two poles. Read more useful information in this article. Last modified: 2025-01-23 12:01

In our time, we know that the Earth revolves around the Sun and around its axis, but earlier people believed that it was motionless. There were many legends that the Earth rests on three whales and even on elephants. Let's find out the most interesting of them. Last modified: 2025-06-01 07:06

"To be with everyone" and "to remain oneself" - these are two seemingly mutually exclusive motives that underlie the driving force of the socialization of the individual. What exactly, for what and how a person uses from the inherited and acquired arsenal of his potentialities, serves as the basis for his future successes or failures, determines his unique and inimitable life path. Last modified: 2025-01-23 12:01