Physics
Electromagnetic Radiation and Quantum Phenomena
Electromagnetic radiation refers to the energy that is transmitted through space in the form of electromagnetic waves, such as light, radio waves, and X-rays. Quantum phenomena, on the other hand, are the behaviors and interactions of particles at the quantum level, where classical physics principles no longer apply. These phenomena are described by quantum mechanics, a fundamental theory in physics that governs the behavior of matter and energy at the smallest scales.
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10 Key excerpts on "Electromagnetic Radiation and Quantum Phenomena"
- Heinrich F. Beyer, Viateheslav P. Shevelko(Authors)
- 2016(Publication Date)
- CRC Press(Publisher)
Chapter 2 Radiation In the introduction we have addressed several radiative phenomena without explaining their physical foundations in detail. For a deeper physical understanding we are now going to recall electromagnetic wave phenomena. In this chapter we will recall basic definitions and discuss some radiation physics which will prepare the stage for the later chapters. 2.1 Light and radiation Light is a fundamental feature and has attracted philosophers since ancient times. For the Pythagoreans light was something that originated from a body and caused vision by entering the eye. Socrates and Plato reversed this idea in that the eye searches for objects by sending out light rays. In modern times, such a philosophical dispute appears strange and can only be understood by the tremendous size of the speed of light that prohibited a scientific proof in ancient times. It was at the beginning of the 19th century when it was generally agreed that light was a wave phenomenon with some similarities to water and sound waves. In 1887 Michelson and Morley established that the velocity of light was independent of the Earth’s movement. This fundamental observation was used later by Einstein to develop his theory of light. The understanding of the general properties of radiation is central to the physics of atoms. Interaction with light is also an important tool for investigating ions and atoms. Radiation is the way in which energy is transmitted through space from one point to another without the need for any connection or medium between these two places. The terms light, radiation, rays and waves characterize the same phenomenon and are often used as synonyms. Electromagnetic waves, i.e. periodically fluctuating electric and magnetic fields are matterless patterns, series of events that happen repeatedly.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Learning Press(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter- 5 Electromagnetic Radiation Electromagnetic radiation (often abbreviated E-M radiation or EMR ) is a phenomenon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what is called the visible spectrum. The photon is the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation and is also the force carrier for the electromagnetic force. EM radiation carries energy and momentum that may be imparted to matter with which it interacts. ________________________ WORLD TECHNOLOGIES ________________________ Physics Theory Shows three electromagnetic modes (blue, green and red) with a distance scale in micrometres along the x-axis. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa .
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 5 Electromagnetic Radiation Electromagnetic radiation (often abbreviated E-M radiation or EMR ) is a pheno-menon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what is called the visible spectrum. The photon is the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation and is also the force carrier for the electromagnetic force. EM radiation carries energy and momentum that may be imparted to matter with which it interacts. ________________________ WORLD TECHNOLOGIES ________________________ Physics Theory Shows three electromagnetic modes (blue, green and red) with a distance scale in micrometres along the x-axis. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa .
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Library Press(Publisher)
____________________ WORLD TECHNOLOGIES ____________________ Chapter 6 Electromagnetic Radiation Electromagnetic radiation (often abbreviated E-M radiation or EMR ) is a phenomenon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what is called the visible spectrum. The photon is the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation and is also the force carrier for the electromagnetic force. EM radiation carries energy and momentum that may be imparted to matter with which it interacts. ____________________ WORLD TECHNOLOGIES ____________________ Physics Theory Shows three electromagnetic modes (blue, green and red) with a distance scale in micrometres along the x-axis. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa .
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Learning Press(Publisher)
____________________ WORLD TECHNOLOGIES ____________________ Chapter- 6 Electromagnetic Radiation Electromagnetic radiation (often abbreviated E-M radiation or EMR ) is a phenol-menon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what is called the visible spectrum. The photon is the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation and is also the force carrier for the electromagnetic force. EM radiation carries energy and momentum that may be imparted to matter with which it interacts. ____________________ WORLD TECHNOLOGIES ____________________ Physics Theory Shows three electromagnetic modes (blue, green and red) with a distance scale in micrometres along the x-axis. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa .
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 6 Electromagnetic Radiation Electromagnetic radiation (often abbreviated E-M radiation or EMR ) is a phenol-menon that takes the form of self-propagating waves in a vacuum or in matter. It comprises electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation. Electromagnetic radiation is classified into several types according to the frequency of its wave; these types include (in order of increasing frequency and decreasing wavelength): radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. A small and somewhat variable window of frequencies is sensed by the eyes of various organisms; this is what is called the visible spectrum. The photon is the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation and is also the force carrier for the electromagnetic force. EM radiation carries energy and momentum that may be imparted to matter with which it interacts. ________________________ WORLD TECHNOLOGIES ________________________ Physics Theory Shows three electromagnetic modes (blue, green and red) with a distance scale in micrometres along the x-axis. Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave. According to Maxwell's equations, a spatially-varying electric field generates a time-varying magnetic field and vice versa .
eBook - PDF- Olsen, R.C.(Authors)
- 2007(Publication Date)
Chapter 2 Electromagnetic Basics 2.1 The Electromagnetic Spectrum The previous chapter discussed various remote sensing modalities and some characteristics of modern systems; at this point, it is necessary to review some basic physics relevant to electromagnetic waves and remote sensing. The chief things to understand are the electromagnetic (EM) spectrum and EM radiation, of which light, radar, and radio waves are examples. This section takes a brief look at the physical equations that underlie EM waves, the wave equations that result, their energy in the context of the photoelectric effect, sources of EM radiation, and some fundamental interactions of EM waves with matter. Figure 2.0 The next two chapters follow the progression of energy (light) from the source (generally the sun) to detectors that measure such energy. Concepts of target reflectance and atmospheric transmission are developed, and the problem of getting data to the ground is discussed. 27 2.1.1 Maxwell ’ s equations The principles that define electricity and magnetism were codified by James Maxwell in the late 1800s in four equations that bear his name: 1. ∯ E · d S ¼ Q ε o or ∇ · E ¼ r ε o , (2.1a) 2. ∯ B · d S ¼ 0 or ∇ · B ¼ 0 , (2.1b) 3. ∮ E · d l ¼ --t ∫∫ B · d S or ∇ E ¼ -B -t , (2.1c) 4. ∮ B · d l ¼ m o i þ m o ε o --t ∫∫ E · d S or ∇ B ¼ m o J þ m o ε o -E -t : (2.1d) These four equations respectively say • that the electric flux through a Gaussian surface is equal to the charge contained inside the surface; • that, in the absence of a magnetic point charge, the magnetic flux through a Gaussian surface is equal to zero; • that the voltage induced in a wire loop is defined by the rate of change of the magnetic flux through that loop (the equation that defines electrical generators); and • that a magnetic field is generated by a current (typically in a wire) but also by a time-varying electric field.
eBook - PDF- Liou(Author)
- 1981(Publication Date)
- Academic Press(Publisher)
Chapter 1 FUNDAMENTALS OF RADIATION 1.1 CONCEPTS, DEFINITIONS, AND UNITS 1.1.1 Electromagnetic Spectrum The most important of the processes responsible for energy transfer in the atmosphere is electromagnetic radiation. Electromagnetic radiation travels in the wave form, and all electromagnetic waves travel at the same speed, which is the speed of light. This is 2.99793 ± 1 x 10 8 m sec-1 in a vacuum and at very nearly this speed in air. Visible light together with gamma rays, x rays, ultraviolet light, infrared radiation, microwaves, television signals, and radio waves form the electromagnetic spectrum. The retina of the human eye is sensitive to electromagnetic waves with frequencies between 4.3 x 10 14 vibrations per second (usually written as cycles per second and abbreviated cps) and 7.5 x 10 14 cps. Hence, this band of frequencies is called the visible region of the electromagnetic spectrum. The eye, however, does not respond to frequencies of the electromagnetic waves higher than 7.5 x 10 1 4 cps. Such waves, lying beyond the violet edge of the spectrum, are called ultraviolet light. Moreover, if the waves have frequencies lower than 4.3 x 10 14 cps, the eye again does not respond to them. These waves, having frequencies lower than the lowest frequency of visible light at the red end of the spectrum and higher than about 3 x 10 1 2 cps, are called infrared light or infrared radiation. Just beyond the infrared portion of the spectrum are the microwaves, which cover the frequency from about 3 x 10 10 to 3 X 10 12 cps. The most significant spectral regions associated 1 2 Name of region 1 Fundamentalsof Radiation Wavelength Frequency (em) (cps) 3X10-' 10 Violet Purple Blue Green Yellow Orange Red 10' 10' 3X 1 0 3X 1 0 '• 3X10 3X 10'0 3X10· 3X 10' 3X 10· 3X 10' Fig. 1.1 The electromagnetic spectrum. 1.1 Concepts, Definitions, and Units 3 with the radiative energy transfer in planetary atmospheres lie between the ultraviolet light and microwaves.
(Remember, both visible light and ultraviolet light are forms of electromagnetic radiation, but visible light has longer wavelengths, and therefore less energy, than ultraviolet radiation.) This phenomenon, called fluorescence, provides the so-called black light effects so pop- ular in stage shows and nightclubs. We’ll examine the ori- gins of fluorescence in more detail in Chapter 8. X-RAYS X-rays are electromagnetic waves that range in wavelength from about 100 nanometers down to 0.1 nanometer, smaller than a single atom. These high-frequency (and thus high-energy) waves can penetrate several centimeters into most solid matter but are absorbed to different degrees by all kinds of materials. This fact allows X-rays to be used extensively in medicine to form visual images of bones and organs inside the body. Bones and teeth absorb X-rays much more efficiently than skin or muscle, so a detailed picture of inner structures emerges (Figure 6-27). X-rays are also used extensively in industry to inspect for defects in welds and manufactured parts. The X-ray machine in your doctor’s or dentist’s office is something like a giant lightbulb with a glass vacuum tube. At one end of the tube is a tungsten filament that is heated to a very high temperature by an electrical current, just as in an incandescent lightbulb. At the other end is a polished metal plate. X-rays are produced by applying an extremely high voltage—negative on the filament and positive on the metal plate— so electrons stream off the filament and smash into the metal plate at high velocity. The sudden deceleration of the negatively charged electrons releases a flood of high-energy electromag- netic radiation—the X-rays that travel from the machine to you at light speed. THE ONGOING PROCESS OF SCIENCE Intense X-ray Sources X-rays have become supremely important in many facets of sci- ence and industry.
eBook - PDF- Kenneth S. Krane(Author)
- 2020(Publication Date)
- Wiley(Publisher)
The inescapable conclusion of this kind of experiment is that we cannot separate the wave and particle nature of light. They are both present simul- taneously, so that a wave-type experiment reveals one aspect of the nature of light, while a particle-type experiment reveals the other. The terms “wave” and “particle” describe not the composition of light (we don’t think of light as containing waves or particles) but rather its interactions with matter. So light might be emitted by electron transitions in atoms as individual pho- tons, then might travel as a wave in encountering a double-slit apparatus, and then might be detected again as photons by triggering individual pixels on a screen. This situation is often known as particle–wave duality. Both are needed for a complete understanding of light, and the two are complementary to each other. Yet it took some time for this philosophical view to be accepted by physicists. Einstein proposed his photoelectric effect analysis in 1905 based on Planck’s ideas about quantization, but Planck was one of many who tried to hold on to 19th-century ideas about electromagnetic waves. Millikan, whose photoelectric effect experiments verified Einstein’s theory, doubted that the theory was fundamentally correct. Einstein’s later ideas about the momentum carried by photons were likewise doubted, and even Niels Bohr, one of the founders of the quantum theory, tried (unsuccessfully) to find a wave-based theory to explain Compton scattering. When photon events are recorded on a screen after the double-slit experi- ment, what guides the photons to their proper locations on the screen? What steers them toward the interference maxima and away from the interference minima? In the wave interpretation of double-slit interference, the maxima occur where the electric fields of the light passing through the two slits add together, while the minima occur where the electric fields cancel.
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