1. A material point is a body whose dimensions can be neglected when solving specific problems. 2. A reference system is a coordinate system; a reference body with which it is associated and a device for measuring time. 3. Movement is a vector connecting the initial position of the body with the final position of the body 4. Trajectory is an imaginary line along which the body moves. 5. Path - the length of the trajectory 6. Average speed - the ratio of the entire path traveled at different speeds to the entire time of movement.
7. Rectilinear movement - movement along one straight line 8. Rectilinear uniform movement - this is a movement in which the body, moving in a straight line for equal periods of time, travels equal distances. 9.Speed with uniform movement - vector quantity equal to the ratio movement of the body for any period of time to this period. 10. Uniformly accelerated movement is movement with constant acceleration. 11. Acceleration-Speed, speed change. 12. Schedule
Speed-dependence of speed on the time of movement 13. Braking distance is the distance traveled by the body from the beginning of braking to its complete stop. 14. Force is a vector quantity, it is a quantitative measure of the interaction of bodies. 15. An inertial frame of reference is such a frame of reference, relative to which the body moves in a straight line and uniformly, or is at rest if no forces act on it. 16. "Newton's first law": There are frames of reference called inertial, with respect to
which the body moves uniformly, rectilinearly or is at rest if the sum of the forces acting on it is equal to zero. 17. "Newton's second law": The acceleration caused by a force acting on a body is directly proportional to the force and inversely proportional to the mass of the body 18. "Newton's third law": The reaction force is equal to the force of the action on a support or suspension. 20. Free fall is movement under the force of gravity 21."
The law of universal gravitation ": The force of mutual attraction of two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. 22. The gravitational constant is a physical quantity equal to the force, with which attracts two bodies of mass 1 kg at a distance of 1 meter. 23. The momentum of a body is a vector quantity equal to the product of the body's mass and its speed
over time for any interactions of bodies with each other. 25. Inertia is the ability of a body to continue moving after the force has ceased to act on it. 26. Mass is a measure of inertia. 27. Mechanical vibrations are any periodically repeated mechanical movements. 28. Period is the time during which the body makes one oscillation. 29. Frequency is a physical quantity equal to the number of oscillations per unit time.
30. The oscillation amplitude is a value equal to the maximum deviation from the equilibrium position. 31. Free oscillations are oscillations caused by an initial deviation from the equilibrium position. 32. Harmonic oscillations are oscillations described by the equation of sine and cosine. 33. Resonance is the phenomenon of a sharp increase in the amplitude of the system's oscillations when the frequency of the natural oscillations of the system coincides with the frequency of the external driving force.
34. Waves - Any disturbances propagating in space from the place of origin. 35. Elastic waves are perturbations propagating in an elastic medium. 36. Longitudinal waves are waves that oscillate along the direction of wave propagation. 37. Transverse waves are waves that oscillate perpendicular to the direction of wave propagation. 38. Wavelength is the distance between the nearest points that oscillate in the same phase.
39. Sound vibrations are vibrations with a frequency of 20 Hz to 20 kHz, which the human ear can perceive. 40. Infrasound is an oscillation with a frequency below 20 Hz 41. Ultrasound is a sound with a frequency above 20 kHz 42. Electric current is the ordered movement of charged particles 43. Dielectrics are substances that do not conduct electricity 44. Resistance-Physical quantity characterizing the ability of a substance to conduct electrical
current. 45. "Ohm's Law": The current in a circuit is directly proportional to the voltage and inversely proportional to the resistance. 46. Serial connection is such a connection in which all elements of the circuit are connected in series one after another. 47. Parallel connection is such a connection in which all elements of the circuit are connected in parallel to each other. 48. Magnetic field is a special kind of matter through which magnetic interactions are carried out. 49. A uniform magnetic field is a field whose lines are parallel
each other with the same frequency. 50. An inhomogeneous magnetic field is a field whose lines are curved and located at different frequencies. 51. Solenoid-coil, on which a large number of turns of current-carrying wire are wound. 52. "Rule of the Gimlet": If the direction of the translational movement of the Gimlet coincides with the direction of the current in the conductor, then the direction of rotation of the Gimlet handle coincides with the direction of the lines magnetic field.
53. "Rule of the right hand": If you grasp the solenoid with the palm of your right hand, pointing four fingers in the direction of the current in the turns, then the thumb set aside ninety degrees will show the direction of the magnetic field lines inside the solenoid. 54. "Rule of the left hand": If the left hand is positioned so that the lines of the magnetic field enter the palm perpendicular to it, and four fingers are directed to the flow, then the thumb set aside ninety degrees will show the direction
force acting on the conductor. 55. Magnetic field induction is a vector quantity that characterizes the strength of the magnetic field at each point in space. 56. One Tesla is such an induction of a magnetic field that acts on a conductor one meter long with a current of one Ampere with a force of one Newton. 57. Magnetic flux is a physical quantity that characterizes the change in the vector of magnetic induction passing through the space bounded by the circuit.
58. An electromagnetic field is a special kind of matter formed from alternating electric and magnetic fields parading each other. 59. "Basic position of Maxell's theory": Any change in the magnetic field leads to the emergence of an alternating electric field, and any change in the electric field generates an alternating magnetic field. 60. An electromagnetic wave is a system of variables generating each other and propagating in space
electric and magnetic fields. 61. Ultraviolet radiation is electromagnetic radiation with a shorter wavelength. 62. Light interference is the phenomenon of the superposition of two coherent waves, in which an interference pattern is formed. 63. Coherent waves are waves with the same frequency and constant phase difference. 64. An interference pattern is a picture of the distribution of oscillation amplitudes in space that does not change with time. 65. Alpha radiation is a stream of helium atom nuclei 66. Betta
radiation is a flow of electrons 67. Gamma radiation is a flow of photons 68. Radioactivity is the ability of an atom of a substance to spontaneously emit Alpha, Betta and Gamma rays. 69. Alpha decay is the phenomenon of radiation from one or more nuclei of a helium atom. 70. Isotopes are atoms of the same substance with different masses of the nucleus. 71. Nucleons is a general designation for protons and neutrons.
A physical quantity that characterizes the property of particles or bodies to enter into electromagnetic force interactions.There are two kinds of electric charges, positive and negative.
Charges can be transferred (for example, by direct contact) from one body to another. Unlike body mass, electric charge is not an inherent characteristic of a given body. The same body in different conditions can have a different charge.
Like charges repel, unlike charges attract. This shows the fundamental difference electromagnetic forces from gravity. Gravitational forces are always forces of attraction.
One of the fundamental laws of nature is the experimentally established law of conservation of electric charge. In an isolated system, the algebraic sum of the charges of all bodies remains constant:
q 1 + q 1 + q 3 + ... + q n= const.
The law of conservation of electric charge states that in a closed system of bodies processes of the birth or disappearance of charges of only one sign cannot be observed.
From the modern point of view, charge carriers are elementary particles. All ordinary bodies are composed of atoms, which include positively charged protons, negatively charged electrons and neutral particles - neutrons. Protons and neutrons are part of atomic nuclei, electrons form the electron shell of atoms. The electric charges of the proton and electron modulo are exactly the same and equal to the elementary charge e:
e\u003d 1.602177 10 -19 C ≈ 1.6 10 -19 C
In a neutral atom, the number of protons in the nucleus is equal to the number of electrons in the shell. This number is called the atomic number. An atom of a given substance can lose one or more electrons or gain an extra electron. In these cases, the neutral atom turns into a positively or negatively charged ion.
A charge can be transferred from one body to another only in portions containing an integer number of elementary charges. Thus, the electric charge of the body is a discrete quantity.
Physical quantities that can only take on a discrete series of values are called quantized. elementary charge e is a quantum (smallest portion) of electric charge.
It should be noted that in modern physics elementary particles, the existence of so-called quarks, particles with a fractional charge, is assumed. However, quarks have not yet been observed in the free state.
In conventional laboratory experiments, an electrometer is used to detect and measure electric charges - a device consisting of a metal rod and an arrow that can rotate around a horizontal axis. The arrowhead is insulated from the metal case. When a charged body comes into contact with the rod of an electrometer, electric charges of the same sign are distributed along the rod and the arrow. The forces of electrical repulsion cause the arrow to turn at a certain angle, by which one can judge the charge transferred to the rod of the electrometer.
State vector- a quantity that completely describes the state of a micro-object (electron, proton, atom, molecule) and in general any closed quantum system.
IN quantum theory the state vector is usually denoted by the symbol | >. If some set of data defining the system is denoted by the letter x, then the state vector will look like | x>.
wave function(WF) - a special case, one of the possible forms of representation of the state vector as a function of coordinates and time or variables associated with it. This is a representation of the system, as close as possible to the usual classical description, which assumes the existence of a common and independent space-time.
The description of the state of a microobject with the help of the WF has a statistical, that is, a probabilistic character: the square of the absolute value (modulus) of the WF indicates the value of the probabilities of those quantities on which the WF depends. For example, if the dependence of the WF of a particle on the coordinates X, at, z and time t, then the square of the modulus of this WF determines the probability of detecting a particle at the moment t at the point with coordinates X, at, z. Since the probability of a state is determined by the square of the WF, it is also called the probability amplitude.
Harmonic oscillator(GO) - a physical system that performs harmonic vibrations around a stable equilibrium. For GO, the potential energy of the system U is determined by the expression , where x- deviation of the system from the equilibrium position; k- constant coefficient. For a harmonic oscillator, the average kinetic energy of the system over the period of oscillation is exactly equal to the average potential energy.
A quantum oscillator is characterized by a discrete set of states, energy levels En which are located at equal distances 
, where n = 0, 1, 2...; h- Planck's constant; ? - own frequency of oscillations.
Hilbert space(GP) - in relation to tasks quantum mechanics, this is the space of possible states of the system, defined by a set of its own (basic, or basic) states.
GP elements must have convergence properties (i.e., consist of vectors whose "length" is finite), for which the concept of proximity between objects is established in a certain way.
Operators play a significant role in GP. The operator defined in the GP acts on one element of the GP and translates it into another.
Depending on the task, we can choose one or another set of basic states. If we are interested in the spatial coordinates of the particle, then an infinite-dimensional Hilbert space is chosen, since the coordinate is continuous quantity, and each point in space is associated with a separate state of the particle. If we are interested in the behavior of the spin of a particle, we can choose as a basis the possible spin states for the particle, for example, “spin-up” and “spin-down”.
Decoherence- a physical process, which is accompanied by a decrease in quantum entanglement as a result of the interaction of the system with the environment. Decoherence is accompanied by the appearance of its classical features: subsystems "appear" from a non-local state, acquiring visible local forms. This process can be described as the formation of quantum correlations (or entanglement) between the system and its environment, arising in the process of their interaction. In this sense, decoherence is identical to quantum measurement.
Decoherence, caused by the interaction of a quantum system with its environment, destroys quantum effects, turning them into classical ones. Because of this interaction, there is a "mixing" of the states of the system with such a large number of states environment that coherent effects are "lost" in the ongoing averaging and become unobservable.
Decoherence is a movement from the source, the center - to the periphery, a multitude of externally unrelated phenomena. A completely decohered system is heading towards chaos.
In relation to the human psyche, decoherence means a narrowing of attention on one side of the phenomenon, the object of attraction or addiction, as a result of which a person finds himself in a narrowed space of perception. He accepts one side of the phenomenon, but not the other.
Diffraction- scattering of microparticles (electrons, neutrons, atoms, etc.) by crystals or molecules of liquids and gases, in which deflected beams are formed from the initial particle beam, the direction and intensity of which depend on the structure of the scattering object.
Particle diffraction arises due to the interference of the components formed during the interaction of the initial beam with the periodic structure of the object and can only be understood on the basis of quantum theory. Particle diffraction, in terms of classical physics, is impossible.
Diffraction of light- a phenomenon observed when light propagates past the sharp edges of various bodies (for example, slits). In this case, there is a violation of the straightness of the propagation of light, that is, a deviation from the laws of geometric optics.
Entangled (quantum-correlated) states(ЗС) - a form of correlations of composite systems that does not have a classical analogue. CS is the state of a composite system that cannot be divided into separate, completely independent and independent parts, that is, it is an inseparable (inseparable) state. APs can arise in a system whose parts interacted, and then the system broke up into subsystems that did not interact with each other. For such systems, fluctuations of individual parts are interconnected through non-local quantum correlations, when a change in one part of the system at the same time affects its other parts (even those separated in space by infinitely large distances).
In the case of open systems interacting with the environment, the connection between particles will be preserved until the superposition of states turns into a mixture under the influence of interaction with surrounding objects.
Interference- addition in space of two (or several) waves, in which at different points an increase or decrease in the amplitude of the resulting wave is obtained. If the crests of one wave coincide with the crests of another wave, then amplification occurs and the amplitude increases. If the crests of one wave fall on the troughs of another, then the waves cancel each other out, and the amplitude of the resulting wave weakens.
Interference is characteristic of all waves, regardless of their nature: for waves on the surface of a liquid, elastic (for example, sound) waves, electromagnetic (for example, radio waves or light) waves.
quantum system- this term indicates not the size of the system, but the way it is described by the methods of quantum physics in terms of states.
Classical correlations- the relationship of the characteristics of any objects through ordinary interactions through the exchange of energy. The speed of establishment of classical correlations between objects is limited by the speed of light.
coherence(from lat. cohaerens- being in connection) - the coordinated flow in time of several oscillatory or wave processes, which manifests itself when they are added. Oscillations are called coherent if the difference between their phases remains constant in time and, when the oscillations are added, determines the amplitude of the total oscillation.
Correlation(from lat. correlation- interdependence) - a systematic and conditional relationship between two data series.
Density matrix- a matrix (table of elements), with the help of which both pure quantum states and mixed states that arise during the interaction of the system with the environment are described.
Nonlocality- a property of entangled states, which cannot be compared with local elements of reality. The term "non-locality" is often used to describe the extra-spatial connection of entangled states, when one particle or part of the system immediately responds to changes with another particle or subsystem, regardless of the distance between them.
Uncertainty ratio(uncertainty principle) - one of the provisions of quantum theory, stating that any physical system cannot be in states in which the coordinates of its center of inertia and momentum simultaneously take on exact values. An equivalent formulation is that the energy of any system can be measured with an accuracy not exceeding , where h- Planck's constant; ? t- measurement time. In other words, the classical concepts of position and momentum are applicable to microparticles only within the limits established by the Heisenberg relations. Thus, the law of conservation of energy during short periods of time may not be fulfilled, this makes it possible to create virtual particles (or pairs) that exist for a short time. According to quantum field theory, any interaction can be represented as a set of processes involving virtual particles.
Inseparability- the fundamental impossibility of dividing the system into independent and independent of each other component parts. Same as quantum entanglement.
Light polarization- property of optical radiation, consisting in inequality various directions in a plane perpendicular to the light beam (the direction of propagation of the light wave). This is due to the fact that the vectors of the electric field strength oscillating in the light wave E and magnetic field strength H are perpendicular to the direction of wave propagation and distinguish certain directions in space.
Energy flow characterizes the intensity of energy exchange of any object with the environment. The energy flux density is the amount of energy flowing per unit time through a unit area of a surface located perpendicular to the flow. Energy flows inside the body arise due to the uneven distribution of energy, that is, due to the presence of energy gradients that occur, for example, during accelerations. In relation to our perception, this is felt as “spirit captured”, “blood rushed to the head”, “hair stirred” or a soft feeling of what is happening in the body.
Scattering- the process of interaction of microparticles with various objects (including other particles), during which their energy, direction of movement, internal state, etc. can change.
Recoherence- a process that is the reverse of decoherence, that is, the transition from mixed (classical) states to purely quantum ones. This is the process of acquiring quantum properties by a system, including quantum entanglement, when interaction with the environment is terminated or weakened. For the system to recohere into a quantum state, it is necessary to stop or weaken the exchange of information with the environment.
In the course of recoherence, dense material shells “blur”, and the boundaries between bodies begin to disappear, the subsystems merge into a single non-local quantum system. Recoherence means movement from the periphery of flickering phenomena to the center, to their source.
In relation to the human psyche, recoherence means awareness, synthesis, getting into the source, that is, the transition to understanding what is happening from a wider spectrum of perception of the world. For recoherence, it is necessary to be able to distinguish a fairly complete set of states of a certain event space and be able to interact with them in a controlled manner.
In this case, recoherence is reduced to defocusing of attention, that is, removing the focus of attention from the object, thought or feeling that caused addiction without suppressing them.
IN subjective perception recoherence can be characterized by a state of calm, clarity, non-occupancy, an expanded vision of what is happening. In the case of "recoherence" of everyday troubles, the result can be expressed in the words: "This question no longer interests me"; “I noticed so many new and interesting things around”; “It turned out that everything is very good”; “I clearly understood what had to be done.”
mixed state- such a state of the system that cannot be described by a single state vector, it can only be represented by a density matrix. In a mixed state, the most complete set of independent variables is not specified. physical quantities, which determine the state of the system, and only the probabilities are determined w 1, w 2... detect the system in various quantum states described by the state vectors |1>, |2>...
State of the system- realization of certain potential possibilities of the system, possible under given conditions. It is characterized by a set of quantities that can be measured.
Pure state(pure quantum state) - a state that can be described by a state vector. Pure states describe closed systems.
Examination tickets in physics 2006-2007 ac. year
Grade 9
Ticket number 1.mechanical movement. Path. Speed, Acceleration
mechanical movement- change in the position of the body in space relative to other bodies over time.
Path- the length of the trajectory along which the body moves for some time. Denoted by the letter s and measured in meters (m). Calculated according to the formula
Speed is a vector quantity equal to the ratio of the path to the time for which this path has been traveled. Determines both the speed of movement and its direction at a given time. Denoted by a letter and measured in meters per second (). Calculated according to the formula
Acceleration with uniformly accelerated motion is a vector quantity equal to the ratio of the change in speed to the time interval during which this change occurred. Determines the rate of change of speed in magnitude and direction. Denoted by letter a or and is measured in meters per second squared (). Calculated according to the formula
Ticket number 2.The phenomenon of inertia. Newton's first law. Strength and composition of forces. Newton's second law
The phenomenon of maintaining the speed of a body in the absence of the action of other bodies is called inertia.
Newton's first law: there are frames of reference with respect to which bodies keep their speed unchanged if they are not acted upon by other bodies.
Frames of reference where the law of inertia is satisfied are called inert.
Frames of reference where the law of inertia is not fulfilled - non-inert.
Force- vector quantity. And it is a measure of the interaction of bodies. Denoted by letter F or and is measured in newtons (N)
A force that produces the same effect on a body as several simultaneously acting forces is called resultant of these forces.
The resultant of forces directed along one straight line in one direction is directed in the same direction, and its module is equal to the sum of the modules of the component forces.
The resultant of forces directed along one straight line in opposite directions is directed towards the greater force in absolute value, and its module is equal to the difference between the modules of the component forces.
The greater the resultant of the forces applied to the body, the greater the acceleration of the body.
When the force is halved, the acceleration is also halved, i.e.
Means, the acceleration with which a body of constant mass moves is directly proportional to the force applied to this body, as a result of which acceleration occurs.
When the body weight is doubled, the acceleration is halved, i.e.
Means, the acceleration with which a body moves with a constant force is inversely proportional to the mass of that body.
The quantitative relationship between body mass, acceleration, and the resultant of the forces applied to the body is called Newton's second law.
Second Newton's law: acceleration of the body is directly proportional to the resultant forces applied to the body and inversely proportional to its mass.
Mathematically, Newton's second law is expressed by the formula:
Ticket number 3. Newton's third law. Pulse. Law of conservation of momentum. Explanation of jet propulsion based on the law of conservation of momentum
Newton's third law: the forces with which two bodies act on each other are equal in magnitude and opposite in direction.
Mathematically, Newton's third law is expressed as follows:
body momentum- a vector quantity equal to the product of the mass of the body and its speed. It is denoted by a letter and is measured in kilograms per meters per second (). Calculated according to the formula
law of conservation of momentum: the sum of the momenta of the bodies before the interaction is equal to the sum after the interaction. Let's consider jet propulsion based on the motion of a balloon with a jet of air coming out of it. According to the law of conservation of momentum, the total momentum of a system consisting of two bodies must remain the same as it was before the start of the outflow of air, i.e. equal to zero. Therefore, the ball begins to move in the direction opposite to the air jet with the same speed that its momentum is equal to the modulus of the air jet momentum.
Ticket number 4.Gravity. Free fall. Acceleration of gravity. Law of gravity
Gravity- the force with which the Earth attracts the body to itself. Denoted or
Free fall- the movement of bodies under the influence of gravity.
In a given place on the Earth, all bodies, regardless of their masses and other physical characteristics, free fall with the same acceleration. This acceleration is called free fall acceleration and is denoted by the letter or . It
The law of universal gravitation: any two bodies are attracted to each other with a force directly proportional to the mass of each of them and inversely proportional to the square of the distance between them.
G \u003d 6.67 10 -11 N m 2 / kg 2
G - Gravitational constant
Ticket number 5. Elastic force. Explanation of the device and principle of operation of the dynamometer. Friction force. Friction in nature and technology
The force that arises in the body as a result of its deformation and tends to return the body to its original position is called elastic force. Designated . It is found according to the formula
Dynamometer- a device for measuring force.
The main part of the dynamometer is a steel spring, which is given a different shape depending on the purpose of the device. The device of the simplest dynamometer is based on the comparison of any force with the elastic force of the spring.
When one body comes into contact with another, an interaction occurs that prevents their relative motion, which is called friction. And the force that characterizes this interaction is called friction force. There is static friction, sliding friction and rolling friction.
Without the friction of rest, neither people nor animals could walk on the earth, because. When we walk, we push off the ground with our feet. If there were no friction, objects would slip out of the hands. The force of friction stops the car when braking, but without static friction, it would not be able to start moving. In many cases, friction is harmful and must be dealt with. To reduce friction, the contact surfaces are made smooth, and a lubricant is introduced between them. To reduce the friction of the rotating shafts of machines and machine tools, they are supported on bearings.
Ticket number 6. Pressure. Atmosphere pressure. Pascal's law. Law of Archimedes
The value equal to the ratio of the force acting perpendicular to the surface to the area of this surface is called pressure. It is denoted by the letter or and is measured in pascals (Pa). Calculated according to the formula
Atmosphere pressure- this is the pressure of the entire thickness of the air on the earth's surface and the bodies located on it.
Atmospheric pressure equal to the pressure of a column of mercury 760 mm high at a temperature is called normal atmospheric pressure.
Normal atmospheric pressure is 101300Pa = 1013hPa.
Every 12m the pressure decreases by 1mm. rt. Art. (or 1.33hPa)
Pascal's law: the pressure exerted on a liquid or gas is transmitted to any point equally in all directions.
Archimedes' law: a body immersed in a liquid (or gas, or plasma) is subjected to a buoyant force (called the Archimedes force)
where ρ is the density of the liquid (gas), is the acceleration of free fall, and V is the volume of the submerged body (or the part of the volume of the body below the surface). The buoyant force (also called the Archimedean force) is equal in absolute value (and opposite in direction) to the force of gravity acting on the volume of liquid (gas) displaced by the body, and is applied to the center of gravity of this volume.
It should be noted that the body must be completely surrounded by the liquid (or intersected by the surface of the liquid). So, for example, the law of Archimedes cannot be applied to a cube that lies at the bottom of the tank, hermetically touching the bottom.
Ticket number 7.Force work. Kinetic and potential energy. Law of conservation of mechanical energy
Mechanical work is done only when a force acts on the body and it moves.
mechanical work directly proportional to the applied force and directly proportional to the distance traveled. It is denoted by the letter or and is measured in joules (J). Calculated according to the formula
Energy - a physical quantity showing how much work a body can do. Energy is measured in joules (J).
Potential energy called energy, which is determined by the mutual position of interacting bodies or parts of the same body. Indicated by the letter or . Calculated according to the formula
The energy possessed by a body as a result of its motion is called kinetic energy. Indicated by the letter or . Calculated according to the formula
The law of conservation of mechanical energy:
In the absence of forces such as friction, mechanical energy does not arise from nothing and cannot disappear anywhere.
Ticket number 8.Mechanical vibrations. mechanical waves. Sound.Fluctuations in nature and technology
A movement that repeats itself after a certain period of time is called oscillatory.
Oscillations that occur only due to the initial supply of energy are called free vibrations Physics The concept of time in classical thermodynamics Abstract >> Philosophy
He puts time first major concepts physics, followed by space, place... ideas about space is introduced in physics high energy concept physical vacuum as a kind of...
Physical terms
Acoustics(from Greek. akustikos- auditory) - in a broad sense - a branch of physics that studies elastic waves from the lowest frequencies to the highest (1012–1013 Hz); V narrow sense- the study of sound. General and theoretical acoustics study the patterns of radiation and propagation of elastic waves in various media, as well as their interaction with the environment. The sections of acoustics include electroacoustics, architectural acoustics and building acoustics, atmospheric acoustics, geoacoustics, hydroacoustics, physics and technology of ultrasound, psychological and physiological acoustics, musical acoustics.
Astrospectroscopy- a branch of astronomy that studies spectra celestial bodies for the purpose of determining spectral characteristics physical and chemical properties of these bodies, including the speed of their movement.
Astrophysics the branch of astronomy that studies physical state and the chemical composition of celestial bodies and their systems, interstellar and intergalactic media, as well as the processes occurring in them. Main sections of astrophysics: physics of planets and their satellites, physics of the Sun, physics of stellar atmospheres, interstellar medium, theory internal structure stars and their evolution. Problems of the structure of superdense objects and related processes (capture of matter from the environment, accretion disks, etc.) and problems of cosmology are considered by relativistic astrophysics.
Atom(from Greek. atomos- indivisible) - the smallest particle of a chemical element that retains its properties. In the center of the atom is a positively charged nucleus, in which almost the entire mass of the atom is concentrated; electrons move around, forming electron shells, the dimensions of which (~108 cm) determine the dimensions of the atom. The nucleus of an atom is made up of protons and neutrons. The number of electrons in an atom is equal to the number of protons in the nucleus (the charge of all the electrons of the atom is equal to the charge of the nucleus), the number of protons is equal to the ordinal number of the element in periodic system. Atoms can gain or donate electrons, becoming negatively or positively charged ions. The chemical properties of atoms are determined mainly by the number of electrons in the outer shell; Atoms combine chemically to form molecules. An important characteristic of an atom is its internal energy, which can only take certain (discrete) values corresponding to the stable states of the atom, and changes only abruptly through a quantum transition. Absorbing a certain portion of energy, the atom goes into an excited state (more high level energy). From an excited state, an atom, emitting a photon, can go to a state with a lower energy (to a lower energy level). The level corresponding to the minimum energy of an atom is called the ground level, the rest are called excited. Quantum transitions cause atomic spectra absorption and emission, individual for atoms of all chemical elements.
Atomic mass is the mass of an atom, expressed in atomic mass units. The atomic mass is less than the sum of the masses of the particles that make up the atom (protons, neutrons, electrons) by an amount determined by the energy of their interaction.
LAW OF RADIOACTIVE DECAY
- the number of undecayed radioactive nuclei in any sample is halved every time interval, called the half-life. The law of radioactive decay is a statistical law and is valid for sufficiently large numbers radioactive nuclei. The half-life does not depend on external conditions and on the starting time.
THE LAW OF WINE DISPLACEMENT
- with increasing temperature, the maximum energy in the radiation spectrum of a black body shifts towards shorter waves and, moreover, in such a way that the product of the wavelength that accounts for the maximum radiation energy, and absolute temperature body is constant.
LAWS OF THE EXTERNAL PHOTO EFFECT
1st law: the number of electrons knocked out by light of a given wavelength from the surface of a metal in 1 s is directly proportional to the intensity of light;
2nd law: the maximum kinetic energy of electrons ejected by light increases linearly with the frequency of light and does not depend on its intensity;
3rd law: for each substance there is a red border of the photoelectric effect, i.e. such a minimum frequency of light (or maximum wavelength) at which the photoelectric effect is still possible, and if the light frequency is less than this critical value, then the photoelectric effect no longer occurs.
ISOTOPS
are varieties of this chemical element, which differ in the mass number of their nuclei. The nuclei of isotopes of the same element contain the same number of protons, but a different number of neutrons. Having the same structure of electron shells, isotopes have almost the same chemical properties. However, the physical properties of isotopes can differ quite sharply.
IONIZING RADIATION
- this is radiation, the interaction of which with the medium leads to the ionization of its atoms and molecules. This x-rays and γ-radiation, streams of β-particles, electrons, positrons, protons, neutrons, etc. Visible and ultraviolet radiation are not classified as ionizing radiation.
QUANTUM OF LIGHT (photon)
- a portion of the energy of electromagnetic radiation, an elementary particle, which is a portion of electromagnetic radiation, a carrier of electromagnetic interaction. A term used to describe light as a stream of neutral particles that exhibit wavelike properties in a number of experiments.
QUARKS
- these are point, structureless formations related to truly elementary particles, which were introduced to systematize numerous (more than a hundred) elementary particles discovered in the 20th century (electron, proton, neutron, etc.). A characteristic feature of quarks, which is not found in other particles, is a fractional electric charge, a multiple of 1/3 of the elementary charge. Attempts to detect quarks in the free state have not been successful.
CORPUSCULAR-WAVE DUALISM
- this is a universal property of nature, which consists in the fact that both corpuscular and wave features are manifested in the behavior of micro-objects. The term was introduced during the development of quantum physics, since, according to the ideas of classical physics, the movement of particles (corpuscles) and the propagation of waves are fundamentally different physical processes. It turned out that in the physics of the microcosm such a representation is incorrect. It was found that to explain the laws of the photoelectric effect, light must be considered a stream of particles, while for electrons and protons, interference and diffraction can be observed.
NEUTRON BREEDING RATIO
- this is a characteristic of the chain process of decay of radioactive nuclei, equal to the ratio of the number of neutrons in any generation of the chain reaction to the number of neutrons that generated them in the previous generation.
RED BORDER PHOTO EFFECT
is the minimum frequency of light ν0 or the maximum wavelength λ0 at which the photoelectric effect is still possible.
CRITICAL MASS
- this is the minimum mass of nuclear fuel at which a chain reaction of nuclear fission is possible.
LASER (optical quantum generator)
is a light source operating on the principle of stimulated emission. The name "laser" (LASER) is formed by the first letters of the words English expression Light Amplification by Stimulated Emission of Radiation, which means "light amplification by stimulated emission." High degree coherence and sharp directivity of laser radiation, as well as the ability to concentrate very high power in a pulse (with sufficient intensity, the laser beam melts and vaporizes any substance) has led to the widespread use of lasers in the most various areas technology and medicine.
LINE SPECTRA
are optical spectra consisting of individual spectral lines. Line spectra are characteristic of the radiation of heated substances that are in a gaseous atomic (but not molecular) state. The line emission spectrum is characterized by the following regularity: the atoms of a given chemical element emit waves of a strictly defined set of frequencies, therefore, each chemical element has its own line emission spectrum, which does not coincide with the spectrum of any other chemical element. Linear in individual atoms of a substance is not only the emission spectrum, but also the absorption spectrum. For the absorption spectrum, the following regularity is valid: the atoms of a substance absorb light of just those frequencies that they emit in a heated state; therefore, the lines in the absorption spectrum of a given chemical element are located in the same places in the spectrum as the lines in the spectrum of its emission.
LUMINESCENCE
- this is an electromagnetic radiation of the body (cold glow) that is excessive above the thermal one, caused either by the bombardment of the substance with electrons (cathodoluminescence), or by passing an electric current through the substance (electroluminescence), or by the action of some kind of radiation (photoluminescence).
PHOSPHORS
- these are solid and liquid substances capable of emitting light under the action of electron flows (cathodoluminophores), ultraviolet radiation (photoluminophores), etc.
MASS NUMBER
is the number of nucleons (protons and neutrons) in an atomic nucleus. The mass number is equal to the relative atomic mass of the element rounded to the nearest whole number. There is a conservation law for the mass number, which is a special case of the baryon charge conservation law.
NEUTRINO
is a light (possibly massless) electrically neutral particle participating only in weak and gravitational interactions. A distinctive property of neutrinos is their enormous penetrating power. It is believed that these particles fill the entire outer space with an average density of about 300 neutrinos per 1 cm3.
NEUTRON
is an electrically neutral particle with a mass that is 1839 times the mass of an electron. A free neutron is an unstable particle that decays into a proton and an electron. The neutron is one of the nucleons (along with the proton) and is part of the atomic nucleus.
CONTINUOUS SPECTRUM (continuous spectrum)
is a spectrum containing a continuous sequence of all frequencies (or wavelengths) of electromagnetic radiation, smoothly passing into each other. Continuous spectrum give red-hot solid bodies, luminous liquids, dense gases, and high-temperature plasmas. In the optical region, when the light from these bodies is decomposed using a spectral apparatus (spectroscope or spectrograph), the continuous spectrum appears as a rainbow-colored band in which seven primary colors can be distinguished (red, orange, yellow, green, blue, indigo and violet), smoothly passing into each other. The frequency distribution of energy in the continuous radiation spectrum of different bodies is different.
NUCLEOSYNTHESIS
is a sequence of nuclear reactions leading to the formation of ever heavier atomic nuclei from other, lighter ones.
NUCLEONES
is a common name for protons and neutrons - the particles from which atomic nuclei are built.
BASIC CONDITION
is the state of an atom, molecule, or some other quantum system with the smallest possible value internal energy. Unlike excited states, the ground state is stable.
HALF LIFE
- this is the period of time during which the initial number of radioactive nuclei, on average, is halved. For different elements, it can take values from many billions of years to fractions of a second. For each type of nucleus, the half-life is strictly constant. Experiments with radioactive substances showed that no external conditions (heating to high temperatures, high pressures, etc.) can affect the nature and rate of decomposition.
POSITRON
- an elementary particle with a positive charge equal to the charge of an electron, with a mass equal to the mass of an electron. It is the antiparticle with respect to the electron.
STRIPED SPECTRA
- These are the optical spectra of molecules and crystals, consisting of wide spectral bands, the position of which is different for different substances.
BOHR POSTULATES
- these are the basic principles of the "old" quantum theory - the theory of the atom, developed in 1913 by the Danish physicist Bohr.
Bohr's first postulate: an atom may not be in all states allowed classical physics, but only in special quantum (or stationary) states, each of which corresponds to a certain energy; in a stationary state, the atom does not radiate.
Bohr's second postulate: when an atom passes from one stationary state to another, a quantum of electromagnetic radiation is emitted or absorbed. The energy of the emitted or absorbed quantum (photon) is equal to the difference between the energies of the stationary states.
PROTON
is a positively charged elementary particle with a mass exceeding the mass of an electron by 1836 times; the nucleus of a hydrogen atom. The proton (along with the neutron) is one of the nucleons and is part of the atomic nuclei of all chemical elements.
EXIT WORK
- the minimum work that must be done to remove an electron from a solid or liquid substance into a vacuum. The work function is determined by the type of substance and the state of its surface.
RADIOACTIVITY
- this is the ability of some atomic nuclei to spontaneously transform into other nuclei, while emitting various particles: Any spontaneous radioactive decay is exothermic, that is, it occurs with the release of heat.
STRONG INTERACTION
- this is one of the four fundamental interactions of elementary particles, a particular manifestation of which are nuclear forces. Compared to other types of interactions, it is the most intense. It has a short-range character: its radius of action is only 10–15 m. Strong interaction is characteristic of particles called hadrons. The carriers of the strong interaction are gluons.
WEAK INTERACTION
- this is one of the four fundamental interactions of elementary particles, a particular manifestation of which is the beta decay of atomic nuclei. The weak interaction is less intense than the strong and electromagnetic interactions, but much stronger than the gravitational one. Weak interaction is characteristic of almost all particles, but its radius of action is extremely small: ~10–18 m. Intermediate bosons are carriers of the weak interaction.
UNCERTAINTY RELATION
- this is the fundamental relation of quantum mechanics, according to which the product of uncertainties ("inaccuracies") in the coordinate and the corresponding projection of the particle momentum, with any accuracy of their simultaneous measurement, cannot be less than a value equal to half of Planck's constant. It follows from the uncertainty relation that the more precisely the location of a particle is determined, the less accurate is the information about its momentum, and vice versa.
RADIATION SPECTRUM
is a set of frequencies or wavelengths contained in the radiation of a given substance.
ABSORPTION SPECTRUM
is a set of frequencies (or wavelengths) of electromagnetic radiation absorbed by a given substance.
SPECTRAL ANALYSIS
is a method for determining the chemical composition of a substance from its spectrum. There are qualitative spectral analysis, which determines which chemical elements are part of the substance, and quantitative spectral analysis, which allows determining its quantitative content in the test sample by the intensity of the spectral lines of a chemical element.
SPIN
is the intrinsic angular momentum of the elementary particle. It has a quantum nature and (unlike the angular momentum of ordinary bodies) is not associated with the motion of a particle as a whole.
THERMAL RADIATION
- This is electromagnetic radiation that occurs due to the internal energy of the substance emitting it. It is characterized by a continuous (continuous) spectrum with a maximum, the position of which depends on the temperature of the substance. With its increase, the total energy of thermal radiation increases, and the maximum moves to the region of higher frequencies.
THERMONUCLEAR REACTIONS
are nuclear reactions between light atomic nuclei occurring at very high temperatures (~108 K and above). In this case, the substance is in a state of fully ionized plasma. The need for high temperatures is explained by the fact that for the fusion of nuclei into thermonuclear reaction it is necessary that they approach at a very small distance and fall into the sphere of action of nuclear forces. This approach is prevented by the Coulomb repulsive forces acting between like-charged nuclei. To overcome them, the nuclei must have a very large kinetic energy. After the start of the thermonuclear reaction, all the energy spent on heating the mixture is compensated by the energy released during the reaction.
TRACK
is the trace left by a charged particle in the detector.
TRITIUM
is a superheavy radioactive isotope of hydrogen with a mass number of 3. The average content of tritium in natural waters is 1 atom per 1018 hydrogen atoms.
EINSTEIN'S EQUATION for the photoelectric effect
- this is an equation expressing the relationship between the energy of a photon participating in the photoelectric effect, the maximum kinetic energy of an electron emitted from the substance, and the characteristic of the metal on which the photoelectric effect is observed - the work function for the metal.
PHOTON
- this is an elementary particle, which is a quantum of electromagnetic radiation (in the narrow sense - light). It is a truly neutral particle (i.e., it does not have any charges). It always propagates at a fundamental speed equal to 3×108 meters per second. The energy of a photon is proportional to the frequency of oscillations of the electric field strength of the radiation, the coefficient of proportionality is a fundamental constant, called Planck's constant.
PHOTOEFFECT (external photoelectric effect)
is the emission of electrons by bodies under the action of light.
CHEMICAL ACTIONS OF LIGHT
- these are the actions of light, as a result of which chemical transformations occur in substances that absorb light - photochemical reactions. The chemical actions of light include the reactions of photosynthesis in the green parts of plants; the appearance of sunburn; fading of fabrics in the sun; decomposition into component parts of silver bromide molecules in the photosensitive layer of a photographic plate, etc.
Photochemical transformations play an important role in the mechanism of vision in humans and animals. The role of light in photochemical processes is to impart so much energy to the molecule of a substance that the molecule is split into its component parts. Chemical action of light. As with the photoelectric effect, for every photochemical reaction there is a red limit, i.e., a minimum frequency at which light is still chemically active. The existence of such a boundary can only be explained in terms of quantum concepts.
CHAIN REACTION
is a self-sustaining fission reaction heavy nuclei, in which neutrons are continuously reproduced, fissuring more and more new nuclei.
BLACK HOLE
- this is a region of space in which there is such a strong gravitational field that even light cannot leave this region and go to infinity.
ELEMENTARY PARTICLES
- this is the conventional name for a large group of micro-objects that are not atoms or atomic nuclei (with the exception of the proton - the nucleus of the hydrogen atom).
At present, about 400 such particles (along with antiparticles) have been discovered. Most of them do not satisfy the strict definition of elementarity (indecomposability into even "smaller" formations), because according to modern ideas they (in particular, the proton and neutron) are composite systems. For this reason, instead of the term "elementary" the name "subnuclear particles" is sometimes used. Those particles that claim to be the primary elements of matter are called truly elementary or fundamental particles. Leptons (for example, electron), quarks and carriers of interactions (photon, graviton, gluons and intermediate bosons) are currently considered fundamental. In contrast, all hadrons (which include mesons and baryons, including nucleons) are composite objects built from "smaller" particles called quarks.
Individual elementary particles differ in their mass, average lifetime, electric charge and other characteristics. One of the most fundamental properties of elementary particles is their interconvertibility. The particles formed as a result of various interactions are not included in the composition of the initial particles, but are born directly in the processes of their collisions or decays.
ENERGY YIELD OF NUCLEAR REACTION (reaction energy)
is the difference between the kinetic energies of the final and initial states of the particles involved in a nuclear reaction. To find the energy released in a nuclear reaction, subtract the mass of the products from the mass of the initial components and multiply by the square of the speed of light.
BINDING ENERGY OF ATOMIC NUCLEI
is the minimum energy required to completely split the nucleus into individual nucleons. When a nucleus is formed from nucleons, the energy of the nucleus decreases, which is accompanied by a decrease in mass, i.e., the mass of the nucleus must be less than the sum of the masses of the individual nucleons that form this nucleus. The difference between the sum of masses of nucleons (protons and neutrons) and the mass of the nucleus consisting of them, multiplied by the square of the speed of light in vacuum, is the binding energy of nucleons in the nucleus. The binding energy per nucleon is called the specific binding energy.
THE COMPTON EFFECT
is a decrease in the frequency of electromagnetic radiation when it is scattered by free electrons. It is observed for high frequencies of scattered radiation (in the X-ray region and above). The Compton effect reveals the quantum properties of electromagnetic radiation. The correct explanation of the effect was given on the basis of the idea that electromagnetic radiation is a stream of photons with energy and momentum associated with the radiation frequency.
NUCLEAR (PLANETARY) MODEL OF THE ATOM
- a model of the structure of the atom, proposed by the English physicist Rutherford, according to which the atom is as empty as the solar system. In the center of the atom is the nucleus, which is positively charged, and almost the entire mass of the atom is concentrated in it. The nucleus of an element with ordinal Z carries a charge that is Z times greater than the elementary one, has dimensions that are tens of thousands of times smaller than the dimensions of the entire atom. Z electrons circulate around the nucleus under the influence of Coulomb electric forces, so that the atom as a whole is neutral.
NUCLEAR REACTIONS
- this is the transformation of atomic nuclei as a result of interaction with each other or with any elementary particles. For a nuclear reaction to occur, it is necessary that the colliding particles approach at a distance of about 10–15 m. Nuclear reactions obey the laws of conservation of energy, momentum, electric and baryon charges. Nuclear reactions can proceed both with the release and absorption of kinetic energy, and this energy is approximately 106 times greater than the energy absorbed or released in chemical reactions.
NUCLEAR FORCES
is a measure of the interaction of nucleons in an atomic nucleus. It is these forces that hold like-charged protons in the nucleus, preventing them from scattering under the action of electrical repulsive forces. Nuclear forces have a number of specific properties:
1. Nuclear forces are 2–3 orders of magnitude more intense than electromagnetic ones.
2. Nuclear forces are short-range in nature: their radius of action is R ~ 10–15 m (i.e., it coincides in order of magnitude with the radius of the atomic nucleus).
3. Nuclear forces are attractive forces at distances of ~ 10–15 m, but at much shorter distances between nucleons they turn into repulsive forces.
4. Nuclear forces are non-central; in classical (non-quantum) language, this means that they are directed at some angle to the straight line connecting the interacting particles (forces of this type are called tensor forces).
5. Nuclear forces are charge independent, that is, the forces acting between a neutron and a neutron, between a proton and a proton, and also between a neutron and a proton, are the same.
6. Nuclear forces have the property of saturation: each nucleon in the nucleus attracts only a small number of its neighbors to itself, while repelling the rest of the particles.
7. Along with conventional (pair) nuclear forces, there are also so-called triple (and generally many-particle) nuclear forces, the radius of action of which is approximately half that of conventional pair forces. (Three particles mean the forces between three particles that vanish when at least one of these particles is removed to infinity.)
8. Nuclear forces, at least in part, are of an exchange nature. According to the meson theory of nuclear forces, the interaction between nucleons is carried out by emission and absorption by these particles of quanta of a special pion field - pi-mesons. A complete complete theory of nuclear forces, which would explain and predict all their properties, has not yet been created.
NUCLEAR PHOTO-EMULSIONS
are photographic emulsions used to register tracks of charged particles. When studying high-energy particles, these photographic emulsions are stacked in stacks of several hundred layers. A charged particle flying through them excites the atoms encountered on the way, leading to the formation of a latent image in the photographic emulsion. After development, the track becomes visible. Due to the high braking power of photographic emulsions, the tracks are short. For example, in a typical photographic emulsion, α-particles with an energy of 55 MV leave a track about 1 mm long. Therefore, traces left in photographic emulsions are observed using microscopes that give an increase of 200 to 2000 times.
NUCLEAR REACTOR
- a device in which a controlled chain reaction of nuclear fission is carried out. main part nuclear reactor is an active zone in which a chain reaction takes place and nuclear energy is released. The chain reaction is controlled by special control rods, which are inserted into the reactor core with the help of a remote control panel. These rods are made from materials that strongly absorb neutrons (cadmium or boron). The parameters of the core are calculated in such a way that, with the rods fully inserted, the chain reaction certainly does not proceed. The reactor starts working when the rods are extended so that the neutron multiplication factor is equal to 1.
NUCLEUS (atomic)
- This is the positively charged central part of the atom, in which 99.96% of its mass is concentrated. The radius of the nucleus is ~10–15 m, which is approximately one hundred thousand times less than the radius of the entire atom, determined by the size of its electron shell.
atomic nucleus is made up of protons and neutrons. Their total number in the nucleus is denoted by the letter A and is called the mass number. The number of protons in the nucleus Z determines the electric charge of the nucleus and coincides with the atomic number of the element in the periodic system of elements of D. I. Mendeleev. The number of neutrons in a nucleus can be defined as the difference between the mass number of the nucleus and the number of protons in it. The mass number is the number of nucleons in the nucleus.
Nucleons in the nucleus are held by special nuclear forces, which are a particular manifestation of the so-called strong interaction. The powerful nuclear forces operating in the nucleus ensure its stability. A measure of the stability of a nucleus is its binding energy.
1.A material point is a body whose dimensions can be neglected when solving specific problems. 2.A reference system is a coordinate system, a body of reference with which it is associated, and a device for measuring time. 3.Displacement is a vector connecting the initial position of the body with the final position of the body 4.A trajectory is an imaginary line along which a body moves. 5.Path-length trajectory 6.Average speed is the ratio of the entire distance traveled at different speeds to the entire time of movement. 7.Rectilinear motion - movement along one straight line 8.Rectilinear uniform motion is a motion in which a body, moving in a straight line for equal intervals time travels equal distances. 9. Speed with uniform motion is a vector quantity equal to the ratio of the movement of the body for any time interval to this interval. 10. Uniformly accelerated motion is motion with constant acceleration. 11.Acceleration-Speed, change of speed. 12.Schedule Speed-dependence of speed on the time of movement 13. The braking distance is the distance traveled by the body from the beginning of braking to its complete stop. 14.Force is a vector quantity, it is a quantitative measure of the interaction of bodies. 15.An inertial frame of reference is a frame of reference relative to which a body is moving in a straight line and uniformly or at rest if no forces act on it. 16. "Newton's first law": There are frames of reference, called inertial, relative to which the body moves uniformly, rectilinearly or at rest if the sum of the forces acting on it is zero. 17. "Newton's second law": The acceleration caused by a force acting on a body is directly proportional to the force and inversely proportional to the mass of the body 18. "Newton's third law": The reaction force is equal to the force of the action on a support or suspension. 20. Free fall is movement under the influence of gravity 21. "Law of Universal Gravitation": The force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. 22. The gravitational constant is a physical quantity equal to the force with which two bodies of mass are attracted 1 kg at a distance of 1 meter. 23. The momentum of a body is a vector quantity equal to the product of the mass of the body and its speed 24. "Law of Conservation of Momentum": The vector sum of impulses of bodies that make up a closed system does not change over time with any interactions of bodies with each other. 25. Inertia is the ability of a body to continue moving after the force has ceased. 26.Mass is a measure of inertia. 27.Mechanical vibrations are any periodically repeated mechanical movements. 28.Period is the time it takes for a body to make one oscillation. 29.Frequency is a physical quantity equal to the number of vibrations per unit of time.. 30.The oscillation amplitude is a value equal to the maximum deviation from the equilibrium position. 31.Free vibrations are vibrations caused by an initial deviation from the equilibrium position. 32.Harmonic oscillations are oscillations described by the equation of sine and cosine. 33.Resonance is the phenomenon of a sharp increase in the amplitude of system oscillations when the frequency of natural oscillations of the system with the frequency of the external driving force. 34. Waves - Any perturbation that propagates in space from the place of origin. 35.Elastic waves are perturbations propagating in an elastic medium. 36.Longitudinal waves are waves that oscillate along the direction of wave propagation. 37. Transverse waves are waves that oscillate perpendicular to the direction of wave propagation. 38. Wavelength is the distance between nearest points that oscillate in the same phase.. 39.Sound vibrations are vibrations with a frequency of 20Hz to 20kHz, which can be perceived by the human ear. 40. Infrasound is an oscillation with a frequency below 20 Hz 41. Ultrasound is sound with a higher frequency 20 kHz 42. Electric current is the orderly movement of charged particles. 43.Dielectrics are substances that do not conduct electricity. 44.Resistance is a physical quantity that characterizes the ability of a substance to conduct electricity. current. 45. "Ohm's Law": The current in a circuit is directly proportional to the voltage and inversely proportional to the resistance. 46. Serial connection is such a connection in which all elements of the circuit are connected in series one after another. 47. Parallel connection is such a connection in which all elements of the circuit are connected in parallel to each other. 48. A magnetic field is a special kind of matter through which magnetic interactions are carried out. 49.A uniform magnetic field is a field whose lines are parallel each other with the same frequency. 50. An inhomogeneous magnetic field is a field whose lines are curved and located at different frequencies. 51.A solenoid is a coil on which a large number of turns of current-carrying wire are wound. 52. "Rule of the Gimlet": If the direction of the translational movement of the Gimlet coincides with the direction of the current in the conductor, then the direction of rotation of the Gimlet handle coincides with the direction of the magnetic field lines. 53. "Rule of the right hand": If you grasp the solenoid with the palm of your right hand, pointing four fingers in the direction of the current in the turns, then the thumb set aside ninety degrees will show the direction of the magnetic field lines inside the solenoid. 54. "Rule of the left hand": If the left hand is positioned so that the lines of the magnetic field enter the palm perpendicular to it, and four fingers are directed to the flow, then the thumb set aside ninety degrees will show the direction of the force acting on the conductor. 55. Magnetic field induction is a vector quantity that characterizes the strength of the magnetic field at each point in space. 56. One Tesla is such an induction of a magnetic field that acts on a conductor one meter long with a current of one Ampere with a force of one Newton. 57. Magnetic flux is a physical quantity that characterizes the change in the vector of magnetic induction passing through the space bounded by the circuit. 58. An electromagnetic field is a special kind of matter formed from alternating electric and magnetic fields parading each other. 59. "Basic position of Maxell's theory": Any change in the magnetic field leads to the emergence of an alternating electric field, and any change in the electric field generates an alternating magnetic field. 60. An electromagnetic wave is a system of alternating electric and magnetic fields that generate each other and propagate in space. 61. Ultraviolet radiation is electromagnetic radiation with a shorter wavelength. 62. Light interference is the phenomenon of the superposition of two coherent waves, in which an interference pattern is formed. 63. Coherent waves are waves with the same frequency and constant phase difference. 64. An interference pattern is a picture of the distribution of oscillation amplitudes in space that does not change with time. 65. Alpha radiation is the flow of nuclei of the helium atom 66. Betta radiation is the flow of electrons 67. Gamma radiation is the flow of photons 68. Radioactivity is the ability of an atom of matter to spontaneously emit Alpha, Betta and Gamma rays. 69. Alpha decay is the phenomenon of radiation from one or more nuclei of a helium atom. 70. Isotopes are atoms of the same substance with different masses of the nucleus. 71. Nucleons is a general designation for protons and neutrons.
hadrons- the class of elementary particles participating in the strong interaction. Everything belongs to hadrons baryons And mesons, including resonances.
Hadron jets- directed beams of hadrons produced by the collision of high-energy particles in deeply inelastic processes.
antiparticles- particles that differ from similar ones in the sign of electric charge. The names "particle" and "antiparticle" are largely arbitrary.
"Fragrance"- characteristic of quarks, including the entire set quantum numbers(electric charge, strangeness, "charm", etc. except for "color").
baryons- a group of "heavy" elementary particles with a half-integer back and a mass not less than the mass of a proton. Baryons include proton, neutron, hyperons, part of resonances, etc.
boson- a particle with zero and integer spin, subject to Bose-Einstein statistics. The bosons are photons, gravitons(not open yet) mesons, bosonic resonances, gas molecules, gluons and etc.
Vacuum- a special kind of matter, which corresponds in quantum field theory to the lowest energy state of quantized fields. Characterized by the absence of any real particles, at the same time constantly generates short-lived virtual particles.
virtual particles- in quantum theory, short-lived particles for which the connection between energy, momentum and mass is broken: E 2 ≠p 2 c 2 + m 2 c 2 . Virtual particles are carriers of interactions.
Hypercharge (Y) is one of the characteristics of hadrons. Hypercharge is expressed through other hadron quantum numbers - baryon charge, strangeness, "charm", "beauty".
Hyperons- unstable elementary particles with a mass greater than the nucleon. Refer to hadrons and are baryons.
Gluons- hypothetical, electrically neutral particles, carriers of the strong interaction between quarks in quantum chromodynamics. Spin = 1, rest mass = 0.
Goldstone boson- a hypothetical particle with zero spin and zero mass. Introduced in quantum field theory to distinguish between vacuum states.
Gravitational collapse- astrophysical process of compression of space objects under the action of their own gravitational forces.
graviton- quantum of the gravitational field, having zero mass and electric charge, the spin is 2. Gravitons are carriers of gravitational interaction; experimentally not yet discovered.
Dirac monopole is a hypothetical particle that has one magnetic pole. Its existence was predicted in 1931 by P. Dirac.
Doppler effect- change in the frequency of oscillations when the source moves relative to the observer.
Unified field theory- a general theory designed to unite all the variety of properties of elementary particles and the features of their interaction. At present, only electric, magnetic, and weak nuclear interactions have been combined within the framework of the ETP.
Charge parity- (C-parity), a quantum number characterizing the behavior of neutral particles. In weak interactions, the symmetry associated with charge parity is broken.
Isotopic invariance- symmetry of strongly interacting particles. On the basis of isotopic invariance, multiplets are formed that make it possible to effectively classify all hadrons.
instanton- a special state of vacuum, which corresponds to a strong fluctuation of the gluon field. In the theory of self-organization, an instanton is one of the main structures generated by vacuum.
Gauge symmetry - common name class of internal symmetries in quantum field theory and quantum chromodynamics. Gauge symmetries are related to the properties of elementary particles.
Quasars- powerful extragalactic sources of electromagnetic radiation. There is an assumption that cosmic rays are the active nuclei of distant galaxies.
Quantization of space - time- the general name of generalizations of quantum field theory based on the hypothesis of the existence of fundamental length and fundamental time interval as universal physical constants.
Quantum mechanics(wave mechanics) - a theory that establishes the method of description and the laws of motion of microparticles, as well as their connection with physical quantities directly measured by experience.
quantum chromodynamics(QCD) - quantum field theory of the strong interaction of quarks and gluons, modeled on quantum electrodynamics based on "color" gauge symmetry.
Quarks- material particles, of which, according to modern concepts, all hadrons consist. To understand the dynamics various processes with the participation of hadrons, six quarks are currently considered sufficient: u, d, s, c, b, t. There are indirect confirmations of the existence of the first five quarks.
quantum numbers- whole or fractional numbers, which determine the possible values of physical quantities characterizing quantum systems. Quantum numbers include: main (n), orbital (l), magnetic (m e), spin (m s), strangeness, "charm", "beauty", etc.
Chiral symmetry- in quantum field theory, one of the fundamental dynamic symmetries, through which a good description of the processes of scattering and decay of hadrons at low energies and at very high energies becomes possible. Chiral symmetry also includes enantiomorphisms (right-left).
K-mesons(kaons) - a group of unstable elementary particles that participate in strong interaction. Charge asymmetry of decays K 0 L →π - + e + (μ +) + v e (v μ) and k 0 L →π + + e - (μ -) + v e (v μ ), where the probability of the second decay is greater than the first one by 10 ~"\ indicates the violation of one of the fundamental symmetries of nature (CP invariance).
Compton wavelength- the value of the dimension of length, characteristic of relativistic quantum processes λ 0 = h / mc .
Cosmology- the doctrine of the universe as a whole. The conclusions of cosmology are based on the laws of physics and data from observational astronomy, taking into account philosophical principles.
Mesons- unstable elementary particles belonging to hadrons. According to the quark model, matter consists of a quark and an antiquark.
Neutrino- light (possibly massless) electrically neutral particle with spin 1/2. Participates only in weak and gravitational interactions. Neutrinos have an enormous penetrating power, and their detection will make it possible to study in detail the states of the early Universe.
Reversible process- in thermodynamics and statistical physics, the process of transition of a system from one state to another, allowing the possibility of returning it to its original state.
Time reversal- mathematical operation of changing the sign of time in the equations of motion. Objectively real time as an attribute of matter, it is irreversible, and therefore the operation of changing the sign of time is possible only as an epistemological device that facilitates the solution of a physical problem.
Operators- in quantum theory, a mathematical symbol used to perform some action on a physical quantity.
orbital moment- angular momentum of a microparticle due to its motion in a force field with spherical symmetry.
Basic state quantum system - a stable state with the lowest possible internal energy.
open systems- thermodynamic systems that exchange matter, energy, momentum with the environment. Recently, open systems have been studied in chemistry and biology.
Partons are the virtual components of hadrons, which manifest themselves in deeply inelastic processes.
Plasma- one of the main types of matter, is a partially or fully ionized gas. The vast majority of the Universe is in the plasma state: stars, galactic nebulae, interstellar medium. Under laboratory conditions, plasma is formed in discharges, combustion processes, MHD generators and special installations (for example, "Tokamak").
Positron- (e+) elementary particle with a positive electric charge numerically equal to the charge of an electron. Is antiparticle with respect to the electron.
Vacuum polarization- a quantum-relativistic phenomenon, which consists in the birth of virtual pairs of charged particles-antiparticles from vacuum under the influence of an external field.
Space and time- attributive (inalienable) properties of matter. Space expresses the order of coexistence of objects, time - the order of change of events. Space and time are objective, that is, they do not depend on a person, and their characteristics are determined solely by the nature of the movement of the corresponding forms of matter.
Proton- a positively charged elementary particle, the nucleus of a hydrogen atom. It has been suggested that the proton is an unstable particle with a half-life of ~10 30 years, but experimental confirmation of this hypothesis has not yet been carried out.
Pulsars- Variable sources of cosmic electromagnetic radiation.
Resonances- short-lived excited states of hadrons (lifetime t ~ 10 -22 ÷10 -24 s). Unlike other unstable particles, resonances decay mainly due to the strong interaction. To date, more than 300 resonances have been discovered.
Relativistic effects- physical phenomena observed at speeds comparable to the speed of light. These include: slowing down time, shortening lengths, increasing body weight, etc.
Superconductivity and high-temperature superconductivity- a property of many conductors, consisting in the fact that their electrical resistance abruptly drops to zero when cooled to the temperature of liquid hydrogen and helium. At present (March 1987) a transition to the superconducting state of a number of materials at high temperatures has been discovered, which will be of exceptional national economic importance.
Symmetry- a) in physics - a kind of proportionality of laws. In a more general sense, symmetry is a kind of relationship between two objects that is characterized by both moments of identity and moments of difference. The most widely used in physics isotopic, "color", gauge and other symmetries, without which modern physical theory would be impossible; b) in philosophy, symmetry is one of the general scientific concepts, denoting the formation of moments of identity in the different. Symmetry is represented in the objective world in the form of specific forms of symmetry.
Soliton- structurally stable solitary wave in a nonlinear dispersive (scattering) medium. Solitons are intensively used in the construction of quantum nonlinear field theory.
Compliance principle- in the methodology of science, one of the principles according to which any subsequent scientific theory should include, as a limiting (special) case, the previous theory. In relation to correspondence are, for example, Newtonian mechanics and the special theory of relativity.
Spin- own moment of momentum of elementary particles, has a quantum nature, due to the internal "rotation" of the particle.
Spontaneous symmetry breaking- spontaneous violation of a stable, equilibrium, symmetrical state, provided that it is removed from the state with minimal energy. The solution of many problems of quantum field theory, including the appearance of particles with zero mass and zero spin, is associated with spontaneous symmetry breaking.
supergravity- gauge theory of supersymmetry, which allows to generalize general theory relativity. In the framework of supergravity, in principle, it is possible to combine all known types of interactions.
supersymmetry- symmetry connecting fields whose quanta are bosons with fields whose quanta are fer ions. The most interesting application of supersymmetry is supergravity.
CPT symmetry- one of the fundamental symmetries, according to which in quantum field theory the equations are invariant under the combined C (charge), P (spatial) and T (time reversal) transformations.
Unitary symmetry- approximate symmetry inherent in the strong interaction of elementary particles. In electromagnetic and weak interactions is violated. It was possible to classify hadrons on the basis of unitary symmetry.
fluctuations- random deviations of physical quantities from their average values. Fluctuations occur in any quantities as a consequence of random factors.
Fermions are particles obeying Fermi-Dirac statistics. Fermions have half-integer spin. Fermions include quarks, leptons (electron, muon, all types of neutrinos).
Photon- elementary particle, quantum of electromagnetic radiation. The rest mass of a photon is zero. Photons are bosons.
Parity- quantum mechanical characteristic of the state of a microparticle, reflecting the symmetry properties of the wave function of this particle with respect to spatial transformations.
State vector- a quantity that completely describes the state of a micro-object (electron, proton, atom, molecule) and in general any closed quantum system.
In quantum theory, the state vector is usually denoted by the symbol | >. If some set of data defining the system is denoted by the letter x, then the state vector will look like | x>.
wave function(WF) - a special case, one of the possible forms of representation of the state vector as a function of coordinates and time or variables associated with it. This is a representation of the system, as close as possible to the usual classical description, which assumes the existence of a common and independent space-time.
The description of the state of a microobject with the help of the WF has a statistical, that is, a probabilistic character: the square of the absolute value (modulus) of the WF indicates the value of the probabilities of those quantities on which the WF depends. For example, if the dependence of the WF of a particle on the coordinates X, at, z and time t, then the square of the modulus of this WF determines the probability of detecting a particle at the moment t at the point with coordinates X, at, z. Since the probability of a state is determined by the square of the WF, it is also called the probability amplitude.
Harmonic oscillator(GO) - a physical system that performs harmonic oscillations around the position of stable equilibrium. For GO, the potential energy of the system U is determined by the expression, where x- deviation of the system from the equilibrium position; k- constant coefficient. For a harmonic oscillator, the average kinetic energy of the system over the period of oscillation is exactly equal to the average potential energy.
A quantum oscillator is characterized by a discrete set of states, energy levels En which are located at equal distances , where n = 0, 1, 2...; h- Planck's constant; ? - own frequency of oscillations.
Hilbert space(GP) - in relation to the problems of quantum mechanics, this is the space of possible states of the system, specified by a set of its own (basic, or basic) states.
GP elements must have convergence properties (i.e., consist of vectors whose "length" is finite), for which the concept of proximity between objects is established in a certain way.
Operators play a significant role in GP. The operator defined in the GP acts on one element of the GP and translates it into another.
Depending on the task, we can choose one or another set of basic states. If we are interested in the spatial coordinates of the particle, then an infinite-dimensional Hilbert space is chosen, since the coordinate is a continuous quantity, and each point in space is associated with a separate state of the particle. If we are interested in the behavior of the spin of a particle, we can choose as a basis the possible spin states for the particle, for example, “spin-up” and “spin-down”.
Decoherence- a physical process, which is accompanied by a decrease in quantum entanglement as a result of the interaction of the system with the environment. Decoherence is accompanied by the appearance of its classical features: subsystems "appear" from a non-local state, acquiring visible local forms. This process can be described as the formation of quantum correlations (or entanglement) between the system and its environment, arising in the process of their interaction. In this sense, decoherence is identical to quantum measurement.
Decoherence, caused by the interaction of a quantum system with its environment, destroys quantum effects, turning them into classical ones. Due to this interaction, the states of the system are "entangled" with so many states of the environment that coherent effects are "lost" in the ongoing averaging and become unobservable.
Decoherence is a movement from the source, the center - to the periphery, a multitude of externally unrelated phenomena. A completely decohered system is heading towards chaos.
In relation to the human psyche, decoherence means a narrowing of attention on one side of the phenomenon, the object of attraction or addiction, as a result of which a person finds himself in a narrowed space of perception. He accepts one side of the phenomenon, but not the other.
Diffraction- scattering of microparticles (electrons, neutrons, atoms, etc.) by crystals or molecules of liquids and gases, in which deflected beams are formed from the initial particle beam, the direction and intensity of which depend on the structure of the scattering object.
Particle diffraction arises due to the interference of the components formed during the interaction of the initial beam with the periodic structure of the object and can only be understood on the basis of quantum theory. Diffraction of particles, from the point of view of classical physics, is impossible.
Diffraction of light- a phenomenon observed when light propagates past the sharp edges of various bodies (for example, slits). In this case, there is a violation of the straightness of the propagation of light, that is, a deviation from the laws of geometric optics.
Entangled (quantum-correlated) states(ЗС) - a form of correlations of composite systems that does not have a classical analogue. CS is the state of a composite system that cannot be divided into separate, completely independent and independent parts, that is, it is an inseparable (inseparable) state. APs can arise in a system whose parts interacted, and then the system broke up into subsystems that did not interact with each other. For such systems, fluctuations of individual parts are interconnected through non-local quantum correlations, when a change in one part of the system at the same time affects its other parts (even those separated in space by infinitely large distances).
In the case of open systems interacting with the environment, the connection between particles will be preserved until the superposition of states turns into a mixture under the influence of interaction with surrounding objects.
Interference- addition in space of two (or several) waves, in which at different points an increase or decrease in the amplitude of the resulting wave is obtained. If the crests of one wave coincide with the crests of another wave, then amplification occurs and the amplitude increases. If the crests of one wave fall on the troughs of another, then the waves cancel each other out, and the amplitude of the resulting wave weakens.
Interference is characteristic of all waves, regardless of their nature: for waves on the surface of a liquid, elastic (for example, sound) waves, electromagnetic (for example, radio waves or light) waves.
quantum system- this term indicates not the size of the system, but the way it is described by the methods of quantum physics in terms of states.
Classical correlations- the relationship of the characteristics of any objects through ordinary interactions through the exchange of energy. The speed of establishment of classical correlations between objects is limited by the speed of light.
coherence(from lat. cohaerens- being in connection) - the coordinated flow in time of several oscillatory or wave processes, which manifests itself when they are added. Oscillations are called coherent if the difference between their phases remains constant in time and, when the oscillations are added, determines the amplitude of the total oscillation.
Correlation(from lat. correlation- interdependence) - a systematic and conditional relationship between two data series.
Density matrix- a matrix (table of elements), with the help of which both pure quantum states and mixed states that arise during the interaction of the system with the environment are described.
Nonlocality- a property of entangled states, which cannot be compared with local elements of reality. The term "non-locality" is often used to describe the extra-spatial connection of entangled states, when one particle or part of the system immediately responds to changes with another particle or subsystem, regardless of the distance between them.
Uncertainty ratio(uncertainty principle) - one of the provisions of quantum theory, stating that any physical system cannot be in states in which the coordinates of its center of inertia and momentum simultaneously take on exact values. An equivalent formulation is that for any system, the energy can be measured with an accuracy not exceeding, where h- Planck's constant; ? t- measurement time. In other words, the classical concepts of position and momentum are applicable to microparticles only within the limits established by the Heisenberg relations. Thus, the law of conservation of energy during short periods of time may not be fulfilled, this makes it possible to create virtual particles (or pairs) that exist for a short time. According to quantum field theory, any interaction can be represented as a set of processes involving virtual particles.
Inseparability- the fundamental impossibility of dividing the system into independent and independent of each other component parts. Same as quantum entanglement.
Light polarization- a property of optical radiation, consisting in the inequality of different directions in a plane perpendicular to the light beam (the direction of propagation of the light wave). This is due to the fact that the vectors of the electric field strength oscillating in the light wave E and magnetic field strength H are perpendicular to the direction of wave propagation and distinguish certain directions in space.
Energy flow characterizes the intensity of energy exchange of any object with the environment. The energy flux density is the amount of energy flowing per unit time through a unit area of a surface located perpendicular to the flow. Energy flows inside the body arise due to the uneven distribution of energy, that is, due to the presence of energy gradients that occur, for example, during accelerations. In relation to our perception, this is felt as “spirit captured”, “blood rushed to the head”, “hair stirred” or a soft feeling of what is happening in the body.
Scattering- the process of interaction of microparticles with various objects (including other particles), during which their energy, direction of movement, internal state, etc. can change.
Recoherence- a process that is the reverse of decoherence, that is, the transition from mixed (classical) states to purely quantum ones. This is the process of acquiring quantum properties by a system, including quantum entanglement, when interaction with the environment is terminated or weakened. For the system to recohere into a quantum state, it is necessary to stop or weaken the exchange of information with the environment.
In the course of recoherence, dense material shells “blur”, and the boundaries between bodies begin to disappear, the subsystems merge into a single non-local quantum system. Recoherence means movement from the periphery of flickering phenomena to the center, to their source.
In relation to the human psyche, recoherence means awareness, synthesis, getting into the source, that is, the transition to understanding what is happening from a wider spectrum of perception of the world. For recoherence, it is necessary to be able to distinguish a fairly complete set of states of a certain event space and be able to interact with them in a controlled manner.
In this case, recoherence is reduced to defocusing of attention, that is, removing the focus of attention from the object, thought or feeling that caused addiction without suppressing them.
In subjective perception, recoherence can be characterized by a state of rest, clarity, non-occupancy, an expanded vision of what is happening. In the case of "recoherence" of everyday troubles, the result can be expressed in the words: "This question no longer interests me"; “I noticed so many new and interesting things around”; “It turned out that everything is very good”; “I clearly understood what had to be done.”
mixed state- such a state of the system that cannot be described by a single state vector, it can only be represented by a density matrix. In a mixed state, the most complete set of independent physical quantities that determine the state of the system is not set, but only the probabilities are determined w 1, w 2... detect the system in different quantum states described by the state vectors |1>, |2>...
State of the system- realization of certain potential possibilities of the system, possible under given conditions. It is characterized by a set of quantities that can be measured.
Pure state(pure quantum state) - a state that can be described by a state vector. Pure states describe closed systems.
