Basic definitions. An alternating current is an electric current whose magnitude and direction change with time.

Time is the most mysterious of all phenomena studied by science.

It is believed that time can be slowed down, speeded up, reversed ...

The most daring minds suggest the possibility of time travel.

But, alas, everything is much more prosaic,

and at the same time more interesting.

Movement, change is the basis of time.

Time is the most mysterious, most incomprehensible phenomenon that a person has encountered. For centuries, pundits have racked their brains trying to figure out what time is. In the end, science came to the conclusion that time is a kind of substance of our universe - one of the forms of existence of matter.

Alas, it is not. Science is wrong about the concept of time. Time is not a modification of matter. Time - as a phenomenon of the universe - does not exist at all. Time is an artificial term coined by man for the convenience of his orientation in a continuously changing world. This misconception has cost science dearly. The erroneous idea of time has become a powerful obstacle that has prevented science from reaching the true depths in the study of the universe.

Einstein made a mistake by combining time with space into a single space-time continuum. He was captivated by the magic of mathematical expression " E=mc 2 /√(1-v 2 /c 2)”, from which the binding of matter, energy, space - to time clearly follows. Alas, the great Einstein forgot that mathematics is just a tool of knowledge invented by man and can explain the physical meaning of phenomena, but mathematics cannot replace the laws of nature.

Our view is alternative:

time was invented by man for his convenience in a continuously changing world.

time is a characteristic of the evolution of phenomena, and it denotes the speed of this evolution.

But everything is in order. To begin with, we will consider another concept: .

Our universe is not something frozen. It changes every moment. Moreover, in the universe you will not find a single material phenomenon that in the next moment would remain the same. This guarantees: "all material phenomena in the universe, starting from an elementary particle of matter and ending with a galaxy, are continuously moving in space."

The evolution of all material phenomena is based on a single act of motion of an elementary particle of matter. For example: your body consists of countless quintillions of elementary particles of matter. All these “your” elementary particles are combined into atoms, atoms into molecules, molecules into the structures of your internal organs.

Now imagine: where, in space, were these elementary particles of yours, say, twelve billion years ago? (Our universe, according to science, was formed about fifteen billion years ago as a result of the "big bang").

“At a distance of many billions of kilometers from each other.

- And what, in the end, led them to each other, that they were close by and in the composition of your body?

- Motion. Movement and only movement in the space of the universe.

At the third stage - the stage of Dynamics - the galaxy increases the speed of its forward motion to the speed of light. Here we see the evolution of the galaxy from a hydrogen nebula - through a stellar phase - to a quasar phase.

The fourth stage is the stage of the Black Hole, at which the galaxy collapses: all the matter and energy of the galaxy come to the state of pro-matter.

At the fifth stage - the stage of Promatter - the galaxy in the form of an ultra-small monolith of promatter flies at the speed of light in the vastness of the universe.

At the Primordial Chaos stage, each elemental , is released from energy and slows down the speed of its movement. At the same time, each next quantum, at the same time, releases less energy than the previous one.

At the stage of Dynamics, it is the other way around: each elementary particle of matter in the galaxy, quantum by quantum, starting from the lightest, absorbs energy. At the same time, each next quantum, at the same time, binds more energy than the previous one. The galaxy is gradually accelerating in the space of the universe.

On the graph we get a parabola. Here we can note:

The Primordial Chaos stage is the stage of time acceleration: the galaxy slows down its movement, the number of simultaneous changes becomes less and less.

At the conditionally zero point, we see the fastest possible passage of time for the galaxy: the speed of the galaxy has dropped to almost zero, there are almost no changes.

From the beginning of the Dynamics stage, the time slowdown begins for the galaxy: the number of simultaneous changes increases, the speed of the galaxy's forward motion increases.

The slowing down of time continues at the stage of the black hole.

When the galaxy reaches the speed of light, it occurs, and the elementary particles of matter cease to absorb energy. The galaxy collapses into a monolith of promatter. A certain incomprehensible moment arises: there are no changes inside the galaxy itself, but it continues its movement in the space of the universe. Time for the galaxy seems to be the slowest: the galaxy flies through space at the speed of light. At the same time, time should not exist at all: its particles of matter do not absorb energy, no changes occur with them. This is the time transition state of the galaxy. The state of transition of time corresponds to the stage of Promatter of the galaxy. The galaxy in the form of a monolith of promatter flies in the space of the universe until it reaches its borders and flares up in the process of a big bang.

So, we have considered the concept of "time". As you can see, time is not a modification of matter - the fourth dimension of the space-time continuum. Time is an artificial quantity invented by man for the convenience of his orientation in this continuously changing world. With time, a person determines the rate of evolution of all changes occurring in the surrounding reality. The universe is much simpler than it is represented by Science.

theory of time and theory of relativity

A favorite topic of science fiction writers, and some gentlemen scientists dream of such a dream - time travel. According to the theory of relativity, time (more precisely: space-time) is an objective reality, and it can be controlled. Of course, at a fairly high level of development of technical capabilities. The most daring minds assume the possibility of turning back time - returning to the past. Alas, as we see, this is not the case. Time is not an objective reality and cannot be manipulated. Time cannot be arbitrarily "stretched" or "compressed", and even more so - "stop", and, of course, it is impossible to "reverse".

Accordingly, another dream of mankind - the possibility of interstellar travel - is also highly questionable. Imagine what will happen to the human body on board the spacecraft.

The ship is constantly picking up speed. The elementary particles of matter that make up the human body, in each next moment, fold and absorb an increasing amount of energy. Distances between elementary particles begin to decrease. The density of free energy inside the body begins to increase: both in the intratomic space and in the intramolecular and intermolecular spaces. The human body begins to shrink - in the truest sense of the word. The pressure and temperature of these spaces are growing.

This is the first obstacle: the temperature of the human body will start to rise. The temperature of the human body at which the chemical processes of metabolism normally proceed is 36.6 °. At 37°, 38°, 39° a person already feels very uncomfortable. A further increase in body temperature leads to the shutdown of a person from conscious activity, and then to the death of the body. Which is what should happen on a continuously accelerating spacecraft.

The second obstacle follows logically from the first. Let's recall the laws of formation of atoms of chemical elements (see the book "Unified Field Theory - Alternative Opinion"):

Each subsequent atom of a chemical element, according to the periodic system of chemical elements, is formed upon reaching a certain, for each atom, speed of translational movement in the space of the universe.
At a certain distance from the center of the atom, only a certain number of pair structures of elementary particles of matter can be located.

The human body is made up of carbon, oxygen and hydrogen atoms. As the speed of the forward motion of the spacecraft increases, the distances between pair structures in periods, between periods within atoms, will continuously decrease. In the end, these processes will reach a critical value, when reactions of nuclear transformations begin inside the body. Transformations of carbon, oxygen, hydrogen - into atoms of other chemical elements. Of course, no biological body can exist in such conditions.

Well, in the end, the human body (and the spacecraft along with it), at sublight speeds, will shrink to such values that there can be no talk of any molecular structure and specific spatial form of the physical body. And at the speed of light, the ship, together with the human body, collapses: it turns into an ultra-small point of pro-matter.

Although not everything is so gloomy. The only question is: how to block the way of a substance that penetrates absolutely everywhere? Theoretically, it is possible to build a screen around the ship, protecting from energy flows from outside - inside the ship. Such a screen will protect against the above processes.

What about the twin paradox? Which of the two twins, after all, will age earlier - the one who went on an interstellar journey, or the one who stayed at home? At least theoretically.

We will assume that the total number of changes that will occur with the bodies of the twins is the same for both of them: "I 1 = I 2". The number of simultaneous changes for the twin remaining on Earth will be "i earth". And for a space traveler, this value will be: "i ship". Moreover, the number of simultaneous changes on the spacecraft will be greater: "i ship > i earth", in proportion to the speed of the ship. The personal time of existence of the phenomenon is equal to the ratio of the total number of changes to the number of simultaneous changes: "T ~ I: i".

We get: T 1 ~ I: i land T 2 ~ I: i ship

In relation to the brother, the processes of evolution of the space traveler's body will accelerate, which means that the twin on the ship will live a shorter life compared to his brother on Earth.

Despite the alternativeness of the concept of four substances to the dominant concept, our approach almost does not affect the huge building of science. We changed the "foundation" and slightly "shaken" the whole building. At the same time, some of the "bricks" flew away, some - changed places. But from this the building of science has become more perfect, more harmonious and logical. Surprisingly, the concept of four substances does not even contradict the basic provisions of the theory of relativity.

The speed of light is the highest speed of translational motion in space.
Time for material phenomena slows down as they increase the speed of forward movement.
The physical dimensions of bodies decrease as the speed of their forward movement increases.
The mass of particles and bodies grows as the speed of their forward motion increases.
All material bodies have wave properties.
Rays of light are deflected by the gravitational field.

Expression:

does not correspond to reality, because such an interpretation of the Lorentz transformation is Einstein's mistake. The error of the theory of relativity lies precisely in the connection of space and time into a single space-time continuum. Hence the appearance of the concept of “four-vector”, and the growth of the mass of matter to infinity, and its disappearance at the moment of reaching the speed of light, and the paradox of twins…

Now we will introduce you to another interesting thing: you will learn how averages change over time. Imagine for a moment that we have an operator in which time is not explicitly included. This refers to an operator such as or . [What excludes, say, such things as the time-varying external potential operator.] Now imagine that we have computed in some state , i.e.

. (18.76)

How will it depend on time? But why can it depend on time at all? Well, firstly, it could happen that the operator itself explicitly depends on time, for example, if it was associated with a variable potential of type . But even if the operator does not depend on, for example, the operator , then the corresponding average may depend on time. After all, the average position of the particle can move. But how can such a motion be obtained from (18.76), if it does not depend on time? The fact is that the state itself can change over time. For non-stationary states, we often even explicitly noted the dependence on time, writing them as . We now want to show that the rate of change is given by a new operator, which we will denote . Recall that this is an operator, so the dot above does not mean time differentiation at all, but is simply a way of writing a new operator defined by the equality

. (18.77)

Our task will be to find the operator .

First of all, we know that the rate of state change is given by the Hamiltonian. In particular,

. (18.78)

This is just an abstract form of our original definition of the Hamiltonian

. (18.79)

If we complex conjugate this equation, it will be equivalent to

. (18.80)

Now let's see what happens if we differentiate (18.76) with respect to . Since each depends on , we have

. (18.81)

Finally, replacing their derivatives by expressions (18.78) and (18.80), we obtain

which is the same as writing

Comparing this equation with (18.77), we see that

. (18.82)

This is the interesting ratio we promised; and it is valid for any operator .

By the way, we note that if the operator itself depended on time, we would get

. (18.83)

Let's check (18.82) on some example to see if it makes any sense at all. Which, for example, operator corresponds to ? We claim that it must be

. (18.84)

What it is? One way to find out what it is is to change to coordinate representation and use the algebraic operator . In this representation, the commutator is

If you act on the wave function with this whole expression and calculate derivatives wherever necessary, you end up with

But it's the same as

so we find that

, (18.85)

A lovely result. It means that if the average changes over time, then the displacement of the center of gravity is equal to the average momentum divided by the mass. Just like in classical mechanics.

Another example. What is the rate of change of the average momentum of the state? The rules of the game are the same. The operator of this speed is

. (18.87)

Again, everything can be calculated in -representation. Recall that it turns into , which means that you have to differentiate the potential energy (in ), but only in the second term. In the end there is only one member left and you get

The history of this idea is also interesting. With a difference of several months in 1926, Heisenberg and Schrödinger independently found the correct laws describing atomic mechanics. Schrödinger invented his wave function and found an equation for it, and Heisenberg discovered that nature could be described by classical equations, as long as it was equal to what could be achieved by defining them using a special kind of matrix. In our current language, he used the energy representation and its matrices. Both, Heisenberg's matrix algebra and Schrödinger's differential equation, explained the hydrogen atom. A few months later, Schrödinger was able to show that both theories are equivalent—we have just seen that. But two different mathematical forms of quantum mechanics were discovered independently.

Our world and our soul change in time. The problem of time for Augustine is one of the main ones; he devotes almost the entire 11th book of the Confessions to it. He begins by asking the question: “Are not those who ask us what God did before He created the heavens and the earth, out of date?” And he tries to logically prove the point of view of the supporters of the theory, according to which if God did nothing before he created heaven and earth, then He cannot be called God in absolute measure, for He was inactive; and if He did something, then why didn't He do it?

To this Augustine responds as follows. First, those who reason themselves reason in time, so they cannot rise above time and understand God, who exists in eternity. On the other hand, while creating the world, God simultaneously creates time. Therefore, to ask what was before God created the world is unfair, incorrect, because there was no “before” - time is created along with the world. So Augustine answers this question boldly: God did nothing. Of course, writes Augustine, I could repeat the joke that one theologian got rid of intrusive opponents by dismissing the phrase that God thought up a separate punishment for those who ask this kind of questions. However, Augustine answers the question seriously.

But Augustine does not stop there and asks the question: what is time? This question is not empty and not accidental, because if we are trying to understand the variability of the world, the world and the soul (and the soul, as we remember, Augustine is primarily interested in), then we must know the time in which the soul and the world exist.

The question of the existence of time is itself unusual. After all, the existence of something is always spoken of as an existence in time, most often in the present. But what about the existence of time? Time exists in time!?

Taking it apart, Augustine reiterates that it is generally agreed that there are three parts to time: the past, the present, and the future. Here a paradox arises: the past no longer exists, the future does not yet exist, so only the present can be known. But where is the real one? First, Augustine writes that the present for us can be a year in which there is both a past and a future. Then you can narrow this concept down to a month, a day, an hour, a minute, and in the end we come to a certain point. But as soon as we try to grasp this point, the present is no more - it has become the past. We are trying to understand the future, but we also cannot grasp it in any way, it is either in the future or in the past.

Existence is spoken of only in relation to the present, so the existence of time can also be spoken of only in this aspect. Both the past and the future exist only as what we currently imagine - or remember, or foresee. Therefore, Augustine argues: it can be said that only the present exists, and one can speak of the past and the future only as the present of the past and the present of the future. Everything exists in the present: the past exists in memory, and the future in anticipation. We define this premonition based on the present. As about the coming sunrise, we judge the dawn that has appeared. We see the dawn and know that soon the sun will come. In the same way, we judge the future by the fact that there is a present. Therefore, it is more correct to speak not about the past, present and future, but about the present of the past, the present of the present and the present of the future. And they exist only in our soul: the present of the past exists in memory, the present of the present in direct contemplation, the present of the future in expectation. Augustine comes to the conclusion: time exists only in our soul, i.e. it exists subjectively.

Usually this concept in the history of philosophy is associated with the name of Immanuel Kant. But, according to Augustine, the objective world exists in time, so he tends to the point of view that time exists both in our soul and objectively, but time is a property not of the material, sensible world, but of the soul. In the "Confession" Augustine answers the question of time: time is a certain length. And to the question: “The length of what?” - he answers: "The extent of the spirit."

But what is time? Where does it come from? Some philosophers say that time is movement - in particular, the movement of the stars. Augustine does not agree with this position, because the movement is conceived in time, and not vice versa - time in motion. Therefore, with the help of time, we can measure the revolutions of stars, but not vice versa. We know that the very movement of stars can be either fast or slow, and for this there must be a criterion. Therefore, movement is not time, but movement exists in time. And what exactly is time? This remains a mystery to Augustine. The only thing he says about time is that it is a certain extension of the spirit. Augustine ends his discourse on time with the phrase: "In you, my soul, I measure time."

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More on the topic of the Teaching of Time:

Question 13. The doctrine of substance and its attributes in the philosophy of modern times (R. Descartes, B. Spinoza, G. Leibniz).
Define the concept of working time. Define the types of working time. Identify the differences between reduced working hours and part-time working hours.
8. The political and legal doctrine of Aristotle (the doctrine of the duties of a citizen; of the forms of the state, of the correct and perverted forms of the state; the doctrine of the ideal state structure).
28. Determine the content and means of expressing the category of time, the relationship of the meaning of temporary forms with the meaning of the species. The impact of context on the meaning of temporary forms. Give examples of the absolute and relative use of tense forms.
2. Political and legal teachings of Ancient China: Confucianism. Teachings of Confucius about the virtuous husband and the five virtues. The image of the ideal ruler (Huang Di - "Yellow Emperor"). The doctrine of proper social behavior and hierarchy. Foundations of the hierarchical structure of society according to Confucianism. Teaching about the correction of names.
The Doctrine of the State, the Concept of the Separation of Powers and the Doctrine of the Spirit of the Laws of Charles Louis de Montesquieu
21. Political and legal doctrine J.-J. Rousseau (On the Social Contract). The doctrine of the proper forms of the democratic structure of the state and their limitations.

- static; - dynamic.

According to the method of presentation of measurement results

- absolute (measurements of a quantity in its units);

- relative (measurements of changes in a quantity with respect to the same name, taken as the initial one). Relative measurements can be made more accurately than absolute measurements. the total error does not include the error of the quantity measure.

According to the method of obtaining the measurement result

- straight (the value of the PV is obtained directly from the experimental data).

- indirect (defining the desired value of the PV based on the results of direct measurements of other PV, functionally related to the desired value. Indirect measurements, in turn, are divided into aggregate and joint .)

Measurement characteristics.

Measuring principle - physical. phenomenon underlying the measurements.

Method of measurement - reception or co-methods of comparing the measured PV with its unit in acc. with implemented measurement principle.

Measurement result - the value of the quantity obtained by measuring it.

Measurement error - deviation of the measurement result from the true (actual) value of the measured quantity.

Measurement result accuracy is one of the characteristics of the quality of measurements, reflecting the closeness to zero of the error of the measurement result.

With mileage of measurement results - the proximity to each other of the results of measurements of the same quantity, performed under completely identical conditions.

Reproducibility - the closeness of the results of measurements of the same quantity obtained under completely different conditions, but reduced to the same ones (temperature, pressure, humidity, etc.).

Right - character of the quality of measurements, reflects the closeness to zero of systematic errors in their results.

Reliability - a characteristic of the quality of measurements, reflecting confidence in their results, which is determined by the probability (confidence) that the true value of the measured quantity is within the specified limits (confidence).

Question #5

The concept of a physical quantity and a unit of a physical quantity

FV - one of St. in physical. object (s-we, phenomenon or process), general in quality. respect for many physical. objects, but in the number of respects individual for each of them.

Qualitative character PV def. by what kind of property of the mother object and what feature of the mother world this led to har-et (hardness, strength, etc.)

To express the quantitative content of St. Islands of a particular object of use. the concept of "PV size", which is established in the measurement process.

So all bodies have mass and temperature, but for each of them these parameters are different. And in order to be able to establish differences in the quantitative content in each given object of the property displayed by the PV, the concept is introduced FV size.

PV size - the number of certainty of PV inherent in a particular material object, system, phenomenon or process.

FV are divided into:

-measurable (can be expressed quantitatively in established units of measurement);

-evaluated (for which no unit of measure can be entered).

PV is classified according to the types of phenomena:

- real (describing the physical and physico-chemical properties of the substances of materials and products from them);

- energy (describing the energy characteristics of the processes of transformation, transmission and use of energy);

Physical quantities characterizing the course of the process in time.

There are relations between the sizes of each PV, which are similar to the relations between numerical forms (integer, rational or real numbers, vectors, matrices).

Question #6

Quantitative representation of a physical quantity

The possibility of measuring the PV is substantiated by the following theorem.

Each size Q can be assigned a positive real number q, which is the smallest of the rational numbers m/n, where m and n are integers determined from the relation nQ ≤ m[Q], where [Q]- some size of the PV, called the unit of this PV. Number q is called the numerical value of the quantity Q, and its quantitative expression in the form of a certain number of units accepted for it - by the value of the PV:

Q = q[Q]

It follows from this equation that the numerical value of the PV shows how many times the value of the measured quantity is greater than a certain value taken as a unit.

This implies the following definition of measurement: “measurement is a cognitive process, which consists in comparing, by means of a physical experiment, a given quantity with some of its value, taken as a unit of comparison”

The above equation is the basic measurement equation. It shows that the numerical value of the PV depends on the size of the adopted unit.

That. quantitative assessment of a particular PV, expressed as a certain number of units of a given value, is called PV value, and the abstract number included in the value of the PV is called numerical value of PV.

There is a fundamental difference between the size and value of PV. The size of the PV exists in reality, regardless of whether we know it or not. We can express the size of the PV using any of the units of a given value, in other words, using a numerical value.

The size of the PV does not depend on the choice of the PV unit, which cannot be said about the numerical value, which is entirely determined by the choice of the PV unit.

For a numerical value, it is characteristic that when a different unit is used, it changes, while the physical size of the quantity remains unchanged. The sizes of different units of the same value are different. Thus, the size of a kilogram is different from the size of a pound, the size of a meter is different from the size of a foot, and so on.

10kg = 10 ∙ 1kg

here 10kg is the size of the PV, 10 is the numerical value of the PV, 1kg is the unit of the PV.

Question #7

The concept of the dimension of a physical quantity

The dimension of the measured value is. its qualitative characteristic and is denoted by the symbol dim, origin. from the word dimension. Dimension main PV is designated acc. capital letters. For example, for length, mass and time dim l = L; dim t = M; dim t= T.

When def. dimensions derivatives values are guided by the following. rules:

1. The dimensions of the left and right parts of the equations cannot but coincide, because only identical properties can be compared with each other. Combining the left and right parts of the equations, we can come to the conclusion that only quantities that have the same dimensions can be summed algebraically.

2. The algebra of dimensions is multiplicative, that is, it consists of a single action - multiplication.

The dimension of the product of several quantities is equal to the product of their dimensions. So, if the manager is m / d values of quantities Q, A, B, C has the form Q = A B C, then dim Q= dim BUT.· dim AT · dim WITH.

Q \u003d A / B, then dim Q= dim BUT / dim AT

If the speed def. according to the formula V = l/t then dim V= dim l / dim t = L/T= LT -1. If the force according to the 2nd Newtonian F=ma, where a=V/t is the acceleration of the body, then

dim F= dim t dim a= ML / T 2 \u003d MLT -2.

Thus, it is always possible to express the dimension of the PV derivative in terms of the dimensions of the main PV using a power monomial:

dim Q= L α M β T γ.,

where L, M, T,... - dimensions corresponding main PV;

α, β, γ, - dimensions indicators.

In measurement theory, it is generally accepted to distinguish between five types of scales:

Name scales characterized by an equivalence relation (equality). Example: classification (assessment) of color by name.

order scales arranged in ascending or descending order of the size of the measured quantity. Example: students' knowledge by points, earthquakes by 12-point system.

Scales of differences (intervals) according to them, one can judge not only that the size is larger than the other, but also how much larger; Mathematical operations are possible on them. Example: time interval scale, since time intervals can be added or subtracted,

Relationship scales An example is the length scale. Any measurement on the scale of ratios consists in comparing an unknown size with a known one and expressing the 1st through the 2nd in a multiple or fractional ratio.

Absolute scales have all the features of scales of relations, but in them additionally noun. natural unambiguous def. units measurements. Such scales, respectively. relates. values (gain, attenuation)

Question #8

Measurement classification

Measurement -

Measurements yavl. instrument of knowledge of objects and phenomena of the environment. peace. Objects of measurements yavl. physical objects and processes us of the world. All modern physics can be built on 7 basic veins, which characterize the fundamental properties of the material world. These include: length, mass, time, el. current, thermodynamic temperature, quantity in-va and light intensity. With these and two additional quantities - flat and solid angles- introduced solely for convenience, a sample of all the variety derivatives physical quantities and provides a description of St. in physical objects and phenomena

As an example, you can specify the following areas and types of measurements:

1. Measurements of geometric quantities: lengths; pairs of complex surfaces; roughness; corners.

2. Measurements of mechanical quantities: masses; strength; torques; stresses and strains; motion parameters; hardness.

H. Measurement of parameters of flow, flow, level, volume of substances: mass and volume flow of liquids; gases; fuel, fluid level.

4. Pressure measurements, vacuum measurements: excess pressure;

absolute pressure; variable pressure; vacuum.

5. Physical and chemical measurements: viscosity; density; humidity of gases, solids; electrochemical measurements.

6. Thermophysical and temperature measurements: temperature;

7. Time and frequency measurements: rev. time intervals; frequencies;
8. Measurements of electrical and magnetic quantities on direct and alternating current: current strength, amount of electricity, emf, voltage,

9. Electronic measurements: signal intensity; par-ditch form and spectrum of signals; St. in substances and materials by radio engineering methods;

10. Measurements of acoustic quantities: in the air; in the aquatic environment;

in solids; audiometry and noise level measurements.

11. Optical and optical-physical measurements: measurements of optical properties of materials in the visible region of the spectrum; spectral, frequency characteristics, polarization of laser radiation; parameters of optical components, optical characteristics of materials; characteristics of photographic materials and optical density.

12. Measurements of ionizing radiation and nuclear constants: spectral characteristics of ionizing radiation; activities of radionuclides;

AT qualimetry(a section of metrology) dedicated to measuring quality, the division of quality indicators into basic and derivative ones is not accepted, but into single and complex quality indicators. At the same time, single ones refer to one of the saints in the product, and complex ones characterize several of the saints at once.

Question #9

System of units of physical quantities

For the first time, the concept of the system of units of PV was introduced by the German scientist K. Gauss. According to his method of constructing systems of units of various quantities, first set or choose arbitrarily several values independently of each other. The units of these quantities are called main , since they are yavl. basis to build a system of units of other quantities. Units expressed in terms of basic units of PV are called derivatives . The totality of basic and derived units established in this way is PV units (NEFW) .

The choice of quantities, the units of which should become basic, is limited by considerations of rationality and optimality (the optimal choice is the min number of basic units, which would allow forming max a large number of derived units.

Standards of units of the main PV:

Length standard - meter - is equal to the length of the path traveled by light in vacuum in 1/299.792.458 of a second.

Mass standard - kg - a cylinder made of an alloy of platinum (90%) and iridium (10%), in which the diameter and height are approximately the same (about 30 mm).

Time standard - second - equal to 9.192631770 periods of radiation, respectively. transition m / d 2 hyperfine levels of the ground state of the cesium atom - 133.

current standard - ampere - force that does not change in time e. current, which, flowing in vacuum along two parallel rectilinear conductors of infinite length and an negligible area of circular cross-section, located one from the other at a distance of 1 m, creates a mutual force on each section of the conductor 1 m long. 2 10 -7 N.

Thermodynamic temperature standard - kelvin , constituting 1/273.16 of the thermodynamic temperature of the triple point of water.

Standard quantity in-va - mole – the amount of a system containing as many structural elements of particles as there are atoms in 12 g

The standard of the power of light - candela - luminous intensity in a given direction of a source emitting monochromatic radiation with a frequency of 540 10 -12 Hz, the luminous energy intensity of which in this direction is 1/683 W / sr.

Radian - angle m / d by two radii of a circle, the arc between which is equal in length to the radius.

Steradian is equal to the solid angle with the vertex at the center of the sphere, which cuts out on the surface of the sphere an area equal to the area of a square with a side along the length equal to the radius of the sphere.

Question #10

Relative and logarithmic units and quantities

In science and technology, relative and logarithmic quantities and their units are widespread, which characterize the composition and properties of materials, the ratio of energy and force quantities, for example, relative elongation, relative density, relative dielectric and magnetic permeability, amplification and attenuation of powers and etc.

The relative value is a dimensionless ratio of the PV to the PV of the same name, taken as the initial one. Relative values also include the relative atomic or molecular masses of chemical elements, expressed in relation to one twelfth (1/12) of the mass of the carbon-12 atom.

Relative values can be expressed in dimensionless units (when the ratio of two similar quantities is 1), or in percentage (when the ratio is 10 -2), ppm (the ratio is 10 -3).

The logarithmic value is the logarithm (decimal, natural or base 2) of the dimensionless ratio of two PVs of the same name. Logarithmic values are used to express the sound pressure level, gain, attenuation, expression of the frequency interval, etc.

The unit of the logarithmic value is bel (B), defined by the ratio 1B \u003d lg P 2 /P 1 at P 2 \u003d 10P 1 (where P 1 and P 2 are energy quantities of the same name: power, energy, energy density, etc.).

If a logarithmic value is taken for the ratio of two "power" quantities of the same name (voltage, current, pressure, field strength, etc.), bel is determined by the formula 1 B \u003d 2 lg F 2 / F 1 at. The submultiple of the bela is the decibel, which is equal to 0.1 B.

So, in the case of an electrical power amplification characteristic with a ratio of the received power Rg to the initial Pb equal to 10, the logarithmic gain will be one bel or 10 dB, with an increase or decrease in power by 1000 times, the logarithmic gain will be 3 B or 30 dB, etc. d.

Question #11

Measuring instruments, their classification

Measuring instrument (SI)- this is a technical device used in measurements and having certain standardized metrological characteristics.

The most important property of the SI lies in the "ability" to store or reproduce the unit of PV and in the invariance of the size of the PV.

These most important factors determine the possibility of performing a measurement i.e. "make" a technical tool a means of measurement.

SI is classified according to appointment and metrological functions.

According to metrological functions, SI are divided into:

- standards - are intended for verification of other measuring instruments, both working and standards of less high accuracy.

- working SI- are intended for measurement of the sizes of the sizes necessary in various activity of the person.

By subordination, the standards are divided into: international; primary (national); secondary (sectoral, departmental).

According to the metrological purpose, standards are divided into:

- initial - having the highest metrological properties;

- comparisons - used to compare standards that cannot be directly compared with each other.

- workers - a standard designed to transfer the size of the PV to the working SI.

Working SI (RSI) – SI used in measurement practice and not related to the transfer of PV size units to other SI.

RSI there are: main and auxiliary.

Basic SI- SI of the PV, the value of which must be obtained in acc. with a measurement task.

Auxiliary SI- MI of the PV, the influence of which on the main MI must be taken into account in order to obtain measurement results of the required accuracy.

By appointment, SI are divided into:

- measure – SI intended for reproduction and storage of PV of one or several specified sizes, the values of which are expressed in established units and are known with the required accuracy.

There are measures:

unambiguous- reproducing PV of the same size (for example, the EMF of a normal element is 1.0185 V);

polysemantic- reproducing PV of different sizes (for example, a dashed measure of length);

set of measures- a set of measures of different sizes of the same PV

measure store- a set of measures structurally combined into a single device

- Ypres - technical means with normative metrological characteristics, which is used to convert the measured value into another value, or another measured signal, convenient for processing or storage, but not amenable to direct perception by the observer.

Ypre is part of any measuring device (IU, IS, IVK), or is used together with any SI.

Basically Ypres consists of: sensors (sensing element and Ypres); communication channels (telemechanics); matching elements; measuring mechanism (reading device).

- Ypres – MI, designed to obtain the value of the measured PV in the established range (produces measuring information in a form accessible for direct perception by the observer).

Ypres are subdivided:

According to the form of registration of the measured PV: analog and digital.

By application: ammeters; voltmeters; frequency meters; phase meters, etc.

By appointment: for measuring electrical FV; for measuring non-electric FV.

By action: showing value measured PV at a given time; integrating(the measured quantity is the sum of the products of the measured quantities by small segments of another quantity, usually time); summarizing.

According to the method of indicating the values of the measured PV: showing; signaling (indicator); registering.

According to the method of converting the measured PV: direct evaluation(direct conversion, direct action); comparisons(compare the measured value with the values, the values of which are known).

According to the method of application and design: panel; portable; stationary.

- IU -a combination of functionally combined measures, Ypres, Ypres and other devices designed to measure one or more PV and located in one place.

- IP – a combination of functionally combined measures, Ypres, Ypres, computers and other technical means located at different points of the controlled object in order to measure one or more PV.

- CPI - a functionally integrated set of MI, computer and auxiliary devices, designed to perform a specific measurement task as part of the IS.

Technical devices designed to detect (indicate) physical properties are called indicators and(compass needle, litmus paper). With the help of indicators, only the presence of a measured physical quantity of a property of matter of interest to us is established. An example of an indicator is a gauge of the amount of gasoline in a car's gas tank.

Question #12

Metrological characteristics of measuring instruments

Metrological characteristic (MX) SI - a characteristic of one of the SI properties that affects the result and the error of its measurements. MX, established by regulatory and technical documents, are called normalized MX, determined experimentally - valid MH. MX includes:

Static conversion characteristic(conversion function or calibration chart). She installs a dependency y=f(x) out. signal IPre (y) from the input. signal(x). The static characteristic is normalized by setting in the form of an equation, graph or table some nominal static characteristic, which is officially attributed to this IPre at nominal values of input. signal.

The initial and final value of the scale of the reading device- the smallest and largest value of the measured value y, which are indicated on the scale of the reading device or reproduced by the digital reading device of the measuring tool: Y min , Y max (Y min ≤ y ≤ Y max)

Indication range- interval limited by the initial and final value of the reading device of the measuring tool: Δ Y = Y max - Y min

Limits (upper and lower) measurements- the largest and smallest value of the limits of the range of change of the measured value x, which can be implemented by the measuring tool: X min , X max (X min ≤ x ≤ X max)

Range of measurements (conversions)- the range of values of the measured quantity, for which the metrological characteristics of the measuring instrument used are determined: Δ X = X max - X min

Absolute error Δ at = y - x.

Relative error or .

Reduced error- the ratio of the absolute error to the range of measurements, indications, to the length of the scale or .

Basic error- MI error with normally operating factors taken as normal.

Additional error- change in the error in relation to the value of the main error (caused by deviation from the standard)

Accuracy class- passport characteristic of SI accuracy

Measuring instrument sensitivity the ratio of the change in output. measured value to the change in the input measured value .

Scale division value def. the difference in the values of quantities, respectively. two adjacent readings of the scale of the measuring instrument. The number of units of the measured value per one division of the instrument

Reaction time - the duration of the establishment of indications from the moment the measurements were started until the moment the result was presented on the reading device.

Variation(instability) of instrument readings - algebraic difference m / d max. and naming results of measurements during repeated measurement of the same quantity under unchanged conditions.

SI stability- a quality that reflects the invariance in time of its metrological characteristics.

Question #13

Rationing of metrological characteristics of measuring instruments

All measuring instruments, regardless of their execution, have a number of common properties necessary for them to fulfill their functional purpose. Specifications that describe these properties and affect the results and measurement errors are called metrological characteristics (MX) of measuring instruments.

Depending on the specifics and purpose of measuring instruments, various sets or complexes of metrological characteristics are normalized. However, these complexes should be sufficient to take into account the St. TV SI when assessing measurement errors.

Normalization is understood as setting boundaries for permissible deviations of real metrological characteristics of SI from their nominal values. Only through the standardization of metrological characteristics, it is possible to achieve their interchangeability and ensure the unity of measurements in the state. The real values of MX are determined during the manufacture of the MI and then checked periodically during operation. If at the same time at least one of the MX goes beyond the established limits, then such SI is either subjected to adjustment or withdrawn from circulation.

The norms for the values of MX are established by the standards for certain types of SI. At the same time, a distinction is made between m / d normal and working conditions for the use of SI.

Normal conditions for the use of MI are those under which the quantities affecting the measurement process (temperature, humidity, frequency and supply voltage, external magnetic fields, etc.), as well as the input parameters. and or out. signals are in the normal range of values for these SI, i.e., in a region where their influence on the MC can be neglected. The normal ranges of values of the influencing quantities are indicated in the standards or specifications for MI of this type in the form of nominal values with normalized deviations, for example, the temperature should be (20 ± 2) ° С, the supply voltage - (220 ± 10%) or in the form of value intervals ( humidity 30-80%).

The total error Δ of measuring instruments under normal operating conditions is called the basic error and is normalized by setting the limit of the allowable value Δ d, i.e., the highest value at which the measuring instrument can still be considered fit for use.

The standards for individual MX are given in the operational documentation (passport, technical description, operating instructions, etc.) in the form of nominal values, function coefficients specified by formulas, tables or graphs for the limits of permissible deviations from the nominal values of functions.

Question #14

Accuracy classes of measuring instruments

Accounting for all standardized metrological characteristics (MC) SI yavl. complex and time-consuming procedure, therefore, for SI used in everyday practice, the division into accuracy classes - generalized MX, determined by the limits of permissible basic and additional errors, as well as a number of other properties that affect the accuracy of measurements carried out with their help.

Accuracy classes are regulated by standards for certain types of measuring instruments. The designation of accuracy classes is introduced in the head of the methods for setting the limits of the permissible basic error (PDOP).

The limits of permissible absolute basic error can be specified either in the form of a one-term formula Δ = ±α, or in the form of a two-term formula

Δ = ±( α+bx), - where Δ and x are expressed in units of the measured quantity.

It is more preferable to set the limits of permissible errors in the form of a reduced or relative error.

The limits of the permissible reduced basic error (RPPOP) are normalized in the form of a one-term formula

where the number p is selected from the series p=1·10 n ; 1.5 10n: 2 10n; 2.5 10n; 4 10n; 5 10n; 6 10 n (n =1; 0; -1; -2, etc.).

Limits of permissible relative basic error (PDOOP) can be normalized either by a one-term formula,

or the two-term formula

where X k- the final value of the measurement range or the range of values of the measured quantity, and the constant numbers q, c and d are selected from the series as p.

There are 3 ways to normalize the basic error:

a) normalization by setting the limits of the permissible basic absolute or reduced error ±Δ or ±γ, constant over the entire range of measurement or conversion;

b) normalization by setting the limits of the permissible basic absolute or relative error ±Δ or ±δ as a function of the measured value according to two-term formulas;

c) normalization by setting constant limits of the permissible basic error, different for the entire measurement range and one or more normalized sections, or different for different measurement ranges (for multi-limit instruments).

Designations of accuracy classes are applied to dials, shields and SI cases, are given in regulatory and technical documents.

The designation of accuracy classes may be accompanied by additional conventional signs:

0.5, 1.6, 2.5, etc. - (PDPOP) for devices, the reduced error of which is 0.5, 1.6, 2.5% of the normalized value.

Similarly, but with X N equal to the length of the scale or its part;

0,1

0,4

1,0

etc. (PDOP) - for devices whose relative error is 0.1, 0.4, 1.0% directly from the obtained value of the measured value X;

0,02/0,01 (PDOP) - for devices for which the measured value cannot differ from the value X, shown by the pointer, is greater than

[c + d (| X to / X| - 1)]%,

where c and d are the numerator and denominator, respectively, in the designation of the accuracy class; Hk - the largest (modulo) of the measurement limits of the device.

Question #15

Measurement methods

Specific measurement methods are determined by: the type of measured quantities, their dimensions, the required accuracy of the result, the speed of the measurement process, the conditions under which measurements are carried out, and a number of other features.

Measurement - finding the value of PV empirically using special technical means.

Method of measurement- Soviet principles and means of measurement.

Measuring principle-sov-Th physical phenomena or laws on which measurements are based. For example, temperature measurement using the thermoelectric effect; measurement of gas flow by pressure drop in the narrowing device.

Each physical quantity can be measured by several methods, and at the same time, all measurement methods can be systematized and generalized according to common characteristic features. Consideration and study of these features helps not only the correct choice of method, but also greatly facilitates the development of new ones.

1. By the nature of the dependence of the measured value on time:

- static( the measured value remains constant in time, for example, measurements of body dimensions, constant pressure);

- dynamic(measured value changes in time, for example, measurements of pulsating pressures, vibrations).

2. According to the method of obtaining measurement results:

- straight(the value of the quantity is found directly from experimental data, for example, measuring the angle with a goniometer or measuring the diameter with a caliper)

- indirect(the value of the value is determined on the basis of the known dependence of m / d by this value and the values \u200b\u200bsubjected to direct measurements, for example, determining the average thread diameter using three wires)

- joint(measurements made simultaneously by several quantities of the same name, at which the PV is determined by solving systems of equations, for example, the dependence of body length on temperature)

- cumulative(measurements carried out simultaneously by several quantities of the same name to determine the relationship between them. For example, measurements in which the masses of individual weights of a set are found from the known mass of one of them and from the results of direct comparisons of the masses of various combinations of weights)

3. According to the conditions that determine the accuracy of the measurement result:

Measurements with the highest possible accuracy(reference measurements related to the maximum possible accuracy of reproduction of the established units of PV, for example, the absolute value of the acceleration of gravity, etc.).

Control and verification measurements(carried out by laboratories of state supervision over the implementation and observance of standards and the state of measuring equipment and factory measuring laboratories with an error of the set value.

Technical measurements(performed in the process of production at machine-building enterprises, on switchboards of distribution devices in electric stations.

4. According to the method of expressing the results of measurements, there are:

- absolute measurement based on direct measurements of the quantity and (or) the use of the values of physical constants, for example, measuring the dimensions of parts with a caliper or micrometer.

- relative measurement the values are compared with the same name, which plays the role of a unit or is taken as the initial one, for example, measuring the diameter of a rotating part by the number of revolutions of a certified roller in contact with it.

5. Depending on the totality of the measured parameters, there are:

- element-by-element method characterized by measuring each parameter of the product separately (for example, ovality, cutting of a cylindrical shaft).

- complex method characterized by measuring the total quality indicator (and not PV), which is influenced by its individual components.

6. According to the method of obtaining the values of the measured quantities, there are

- method of direct evaluation- a method in which the PV value is determined directly from the reading device of a direct-acting measuring device (for example, measuring length with a ruler, etc.).

- measure comparison method- a method in which the measured PV is compared with the value reproduced by the measure.

There are several types of comparison methods:

- opposition method(the measured value and the value reproduced by the measure simultaneously affect the device