The document discusses electromagnetic radiation and its properties. It notes that EM radiation can be described as both a wave and particle. As a wave, it travels at the speed of light and is characterized by its frequency and wavelength. As a particle, it consists of individual quanta called photons. The document also discusses how spectroscopy can provide information about astronomical objects by examining the EM radiation they emit.
[1] Nuclear magnetic resonance (NMR) spectroscopy uses radio waves to alter the spin of atomic nuclei within molecules, providing information about molecular structure.
[2] When placed in a strong magnetic field, atomic nuclei such as hydrogen protons align with or against the field. Absorbing radio wave energy can excite the nuclei to a higher energy state.
[3] The energy emitted when the nuclei relax back to the lower energy state is measured by NMR. The chemical environment of each type of nucleus affects the energy level and provides details about molecular bonding and structure.
IB Chemistry on Line Emission Spectrum, Bohr Model and Electromagnetic SpectrumLawrence kok
This document provides a tutorial on electromagnetic radiation and the Bohr model of the hydrogen atom. It discusses the electromagnetic spectrum, electromagnetic wave propagation, continuous and line emission spectra, and the Bohr model. Regarding line emission spectra, it specifically examines the visible Balmer series for hydrogen. Calculations are shown for the wavelengths, frequencies, and energies of emission lines. The Bohr model is used to calculate energy levels and ionization energy through the convergence of line spectra. Videos and simulations are referenced to further explain key concepts.
This document discusses electrostatics and charging methods. It begins by reviewing atomic structure and defining electric charge. It then explains that oppositely charged particles attract while like charges repel. The three main charging methods are conduction, induction, and triboelectricity (friction). Conduction involves direct contact, induction charges objects without contact by polarization, and triboelectricity occurs when two dissimilar insulators are rubbed and exchange electrons. The document provides examples and diagrams to illustrate these electrostatic principles.
IB Chemistry on Electromagnetic Spectrum and Wave Particle DualityLawrence kok
This document provides a tutorial on electromagnetic radiation and wave-particle duality. It discusses the electromagnetic spectrum, the inverse relationship between wavelength and frequency, and how shorter wavelengths correspond to higher frequencies and energies. It also examines the wave-like and particle-like properties of light and electrons using the photoelectric effect and double-slit experiment. The results of these experiments support the principle of wave-particle duality - that light and matter can behave as both particles and waves.
This document summarizes key concepts from a chapter on atomic structure:
1. Electromagnetic radiation consists of oscillating electric and magnetic fields that propagate as waves. Light is a type of electromagnetic radiation detectable by the human eye.
2. Atoms can only absorb or emit electromagnetic radiation at specific quantized energy levels. This explains the emission spectrum of hydrogen, which shows only certain discrete wavelengths.
3. Niels Bohr's early model of the hydrogen atom proposed that electrons orbit the nucleus at fixed distances corresponding to discrete energy levels. Later, the quantum mechanical model described electron behavior as wave-like standing waves.
4. Werner Heisenberg's uncertainty principle states that the more precisely the position
Communication - Space Communication Class 12 Part-5Self-employed
This document provides an overview of space communication and satellite technology. It discusses key topics such as electromagnetic wave propagation through ground waves, sky waves, and space waves. It describes how communication satellites in geostationary orbit facilitate global communication through transponders that receive and retransmit signals. Remote sensing satellites are also summarized, including their sun-synchronous orbits and wide range of applications in areas like geology, agriculture, defense, and environmental monitoring.
Radiometry and Photometry by Sumayya NaseemSumayya Naseem
This document discusses quantitative measurement of light through radiometry and photometry. It defines key terms like radiant flux, luminous flux, radiant intensity, luminous intensity, irradiance, illuminance, radiance and luminance. It discusses how these terms are used to measure different properties of light and visual perception in both absolute and relative terms. Clinical applications including visual acuity testing, visual field testing, color vision testing and electrophysiology rely on defined levels of luminance and illumination. Surgical procedures also require precise control and measurement of light levels.
The document discusses the electromagnetic spectrum, which spans over 140 octaves from low frequencies like microwaves up to a theoretical maximum frequency called the Planck frequency of 2.95 x 1042 Hz. It follows a logarithmic spiral pattern with wavelength inversely proportional to frequency. The visible light spectrum detectable by the human eye ranges from 430-770 THz. The highest measured gamma cosmic ray had a frequency of around 1023 Hz.
[1] Nuclear magnetic resonance (NMR) spectroscopy uses radio waves to alter the spin of atomic nuclei within molecules, providing information about molecular structure.
[2] When placed in a strong magnetic field, atomic nuclei such as hydrogen protons align with or against the field. Absorbing radio wave energy can excite the nuclei to a higher energy state.
[3] The energy emitted when the nuclei relax back to the lower energy state is measured by NMR. The chemical environment of each type of nucleus affects the energy level and provides details about molecular bonding and structure.
IB Chemistry on Line Emission Spectrum, Bohr Model and Electromagnetic SpectrumLawrence kok
This document provides a tutorial on electromagnetic radiation and the Bohr model of the hydrogen atom. It discusses the electromagnetic spectrum, electromagnetic wave propagation, continuous and line emission spectra, and the Bohr model. Regarding line emission spectra, it specifically examines the visible Balmer series for hydrogen. Calculations are shown for the wavelengths, frequencies, and energies of emission lines. The Bohr model is used to calculate energy levels and ionization energy through the convergence of line spectra. Videos and simulations are referenced to further explain key concepts.
This document discusses electrostatics and charging methods. It begins by reviewing atomic structure and defining electric charge. It then explains that oppositely charged particles attract while like charges repel. The three main charging methods are conduction, induction, and triboelectricity (friction). Conduction involves direct contact, induction charges objects without contact by polarization, and triboelectricity occurs when two dissimilar insulators are rubbed and exchange electrons. The document provides examples and diagrams to illustrate these electrostatic principles.
IB Chemistry on Electromagnetic Spectrum and Wave Particle DualityLawrence kok
This document provides a tutorial on electromagnetic radiation and wave-particle duality. It discusses the electromagnetic spectrum, the inverse relationship between wavelength and frequency, and how shorter wavelengths correspond to higher frequencies and energies. It also examines the wave-like and particle-like properties of light and electrons using the photoelectric effect and double-slit experiment. The results of these experiments support the principle of wave-particle duality - that light and matter can behave as both particles and waves.
This document summarizes key concepts from a chapter on atomic structure:
1. Electromagnetic radiation consists of oscillating electric and magnetic fields that propagate as waves. Light is a type of electromagnetic radiation detectable by the human eye.
2. Atoms can only absorb or emit electromagnetic radiation at specific quantized energy levels. This explains the emission spectrum of hydrogen, which shows only certain discrete wavelengths.
3. Niels Bohr's early model of the hydrogen atom proposed that electrons orbit the nucleus at fixed distances corresponding to discrete energy levels. Later, the quantum mechanical model described electron behavior as wave-like standing waves.
4. Werner Heisenberg's uncertainty principle states that the more precisely the position
Communication - Space Communication Class 12 Part-5Self-employed
This document provides an overview of space communication and satellite technology. It discusses key topics such as electromagnetic wave propagation through ground waves, sky waves, and space waves. It describes how communication satellites in geostationary orbit facilitate global communication through transponders that receive and retransmit signals. Remote sensing satellites are also summarized, including their sun-synchronous orbits and wide range of applications in areas like geology, agriculture, defense, and environmental monitoring.
Radiometry and Photometry by Sumayya NaseemSumayya Naseem
This document discusses quantitative measurement of light through radiometry and photometry. It defines key terms like radiant flux, luminous flux, radiant intensity, luminous intensity, irradiance, illuminance, radiance and luminance. It discusses how these terms are used to measure different properties of light and visual perception in both absolute and relative terms. Clinical applications including visual acuity testing, visual field testing, color vision testing and electrophysiology rely on defined levels of luminance and illumination. Surgical procedures also require precise control and measurement of light levels.
The document discusses the electromagnetic spectrum, which spans over 140 octaves from low frequencies like microwaves up to a theoretical maximum frequency called the Planck frequency of 2.95 x 1042 Hz. It follows a logarithmic spiral pattern with wavelength inversely proportional to frequency. The visible light spectrum detectable by the human eye ranges from 430-770 THz. The highest measured gamma cosmic ray had a frequency of around 1023 Hz.
the chemical shift of the singlet.
This document provides an overview of nuclear magnetic resonance (NMR) spectroscopy. It discusses the physical principles behind NMR, including how certain atomic nuclei with spin can absorb electromagnetic radiation when placed in a magnetic field. It also describes how NMR spectra provide chemical shift, integral, and spin-spin coupling data that can be used to determine molecular structure. Interpreting NMR spectra requires considering these different types of data and relating observed signals to specific protons in a molecule.
This document discusses antennas and propagation in wireless communication systems. It covers topics such as antenna characteristics, radiation patterns, polarization, Maxwell's equations, far-field approximation, Hertzian dipole antenna model, radiated power flux density, normalized radiation intensity, antenna gain, directivity, radiation resistance, and different antenna types including dipole and Yagi antennas. Examples are provided to analyze antenna properties such as radiated power, resistance, directionality, and beamwidth for dipole antennas of different lengths.
This document provides an outline for Unit 4 Topic 2 on interactions of light and matter in VCE Physics. It lists key learning outcomes including explaining various phenomena through wave and particle models of light such as the production of incoherent light, Young's double slit experiment, diffraction, the photoelectric effect, electron diffraction, and atomic spectra. Chapter 1 covers the nature of light as electromagnetic radiation and concepts of interference, incoherent versus coherent light sources, and Young's experiment demonstrating the wave-like properties of light. Incandescent light sources produce incoherent light from the random thermal excitation of electrons.
Speaker: Michael Hippke
Affiliation: Sonneberg Observatory
Title: ''Interstellar communication: What works (not so) well and why? "
Abstract: Our nearest neighbor star, Alpha Centauri C, has a planet in the habitable zone. The Russian billionaire Yuri Milnor funds research to send an exploration probe there. Obtaining remote observational data from such a probe is not trivial because of minimal instrumentation (gram scale) and large distances (pc). Together, we follow the long journey of a photon from the transmitter beam through the interstellar dust and gas, atmospheric turbulence, and other obstacles, before finally arriving in the receiver on Earth. We discuss wavelength/frequency choices, gravitational lensing, and particles other than photons, such as Neutrinos. We conclude by asking the "big picture" question: Only when we understand how to communicate efficiently over interstellar communications, we can hope to learn how to receive such communications from other civilizations, if they exist. Are radio waves the best choice?
This document discusses the principles of nuclear magnetic resonance (NMR) spectroscopy. It explains that atoms with an odd atomic number, such as hydrogen-1, carbon-13, and nitrogen-15, have spin properties that can be analyzed using NMR. When samples containing these atoms are placed in a strong magnetic field and exposed to radiofrequency pulses, their atomic nuclei absorb energy and produce detectable signals. The signals provide information about the chemical environment and bonding of atoms in molecules. Tetramethylsilane is often used as a reference standard in NMR spectroscopy because its signals do not interfere with sample readings and allow chemical shifts to be measured in parts per million.
The document summarizes the operating principles of phototransistors and photoconductive detectors.
- Phototransistors are bipolar junction transistors that use the photocurrent generated in the base-collector junction to inject a multiplied current into the emitter circuit, similar to a common emitter transistor. The photocurrent acts as the base current.
- Photoconductive detectors have two electrodes attached to a light-absorbing semiconductor. Absorbed photons increase conductivity and the external photocurrent. With ohmic contacts, multiple electrons enter the semiconductor for each hole, producing photoconductive gain.
- The main sources of noise in photodetectors are shot noise from the dark current and photocurrent. The total noise
1. The document describes a lecture on antennas and wave propagation. It introduces different types of antennas like wire antennas, aperture antennas, reflector antennas, lens antennas, microstrip antennas, and array antennas.
2. It explains the basic radiation mechanism of antennas which involves time-varying currents and accelerated charges producing electromagnetic waves. A current only radiates if the wire is bent, curved, or the charge is oscillating.
3. Key antenna parameters like radiation resistance, directivity, gain, polarization and reciprocity are also covered briefly. Current and voltage distribution on a half-wave dipole antenna is shown.
The document provides lecture notes on antennas that cover various topics:
- A brief history of antenna development and types including electrically small, resonant, broadband, and aperture antennas.
- Analysis of fundamental antenna parameters such as radiation patterns, impedance, directivity and gain.
- Descriptions of simple radiating systems including monopoles and dipoles.
- Discussions of antenna arrays and their properties including pattern multiplication and mutual coupling effects.
- Explanations of other antenna categories like line sources, resonant antennas, and broadband antennas.
- Overviews of aperture antennas including horns, reflectors and their analysis methods.
Light is a form of electromagnetic radiation that can be described as a wave. Waves have characteristics like wavelength, frequency, amplitude, and speed. The wave equation relates these properties and shows that wave speed equals the product of frequency and wavelength. Lasers produce coherent light in a narrow wavelength range and have many applications like optical storage, surgery, manufacturing, and communication.
The document discusses lasers, including their history, characteristics, components, types, and applications. It begins with defining what a laser is, describing early developments in stimulated emission. Key points made include:
- Lasers emit highly directional, intense beams of coherent, monochromatic light.
- The first working laser was a ruby laser developed by Maiman in 1960.
- Laser light has properties of directionality, coherence, monochromaticity, and high intensity compared to other light sources.
- The main components of a laser system are the power source, active medium which is pumped to induce stimulated emission, and optical cavity.
- Common laser types include solid state, gas, liquid,
1) Optical amplifiers are needed in long-distance optical communications to compensate for signal power loss and pulse broadening.
2) There are two main types of optical amplifiers - semiconductor optical amplifiers and doped-fiber amplifiers such as erbium doped fiber amplifiers.
3) Optical amplifiers amplify signals through stimulated emission and introduce noise in the form of amplified spontaneous emission. They must have high gain, wide bandwidth, low noise figure and high saturation power to be used effectively in optical communication systems.
Here are the key differences between primary colors in light vs pigments:
- Primary light colors are red, green, and blue. These can be combined to form white light.
- Primary pigment colors are yellow, cyan, and magenta. These absorb one primary light color and reflect the other two.
- Secondary light colors are formed by combining two primary light colors: orange (red + green), violet (red + blue), and yellow (green + blue).
- Secondary pigment colors are formed by absorbing two primary light colors: red (absorbs yellow and cyan), blue (absorbs yellow and magenta), and green (absorbs cyan and magenta).
So in summary, primary
Wave-particle duality postulates that all particles exhibit both wave and particle properties under different experimental conditions. Historically, debates centered around whether light was a wave or particle. Key experiments and theorists helped establish the dual nature of light and matter, including:
- Einstein showing light has particle-like photons; Compton effect confirming this.
- De Broglie proposing electrons and matter have wave properties like wavelength and frequency. Davisson and Germer experimentally verified the wave nature of electrons.
- The double slit experiment demonstrated the wave behavior of electrons through an interference pattern, shocking as electrons were considered particles. This supported matter having wave-particle duality.
The document discusses the wave properties of particles. Some key points:
1) Louis de Broglie hypothesized in 1924 that matter has an associated wave-like nature with a wavelength given by Planck's constant divided by momentum.
2) A particle can be represented as a localized "wave packet" resulting from the interference and superposition of multiple waves with slightly different wavelengths and frequencies.
3) Davisson and Germer's electron diffraction experiment in 1927 provided direct evidence of the wave nature of electrons and supported de Broglie's hypothesis by measuring electron wavelengths matching those expected.
The document summarizes key concepts in optics and optical properties of materials. It discusses topics like electromagnetic radiation spectrum, optical classifications of materials as transparent, translucent or opaque. It also covers concepts like reflection, refraction, absorption, transmission and how they relate to the band structure and band gaps of materials. Specific phenomena like fluorescence, phosphorescence, photoelasticity and their working principles are defined. Applications of optics like lasers, optical data storage are also briefly mentioned.
Mass spectroscopy is an analytical technique used to identify unknown compounds and elucidate molecular structures. It involves ionizing molecules and separating the resulting ions based on their mass-to-charge ratio. Key components include an ion source, mass analyzer, and detector. Common ionization techniques are electron impact and chemical ionization. Mass spectrometers can be classified based on the type of mass analyzer used, such as magnetic sector, quadrupole, time-of-flight, Fourier transform ion cyclotron resonance, and tandem instruments. Tandem MS allows preselected ions to be fragmented and analyzed.
Quantum Mechanics: Electrons, Transistors, & LASERS. Paul H. Carr
Quantum Mechanics, QM, has enabled new technologies that impact our daily lives. Yet, there have been at least 14 different QM interpretations in the last century. “If you think you understand QM, you don’t,” said Richard Feynman. Our macroscopic language is inadequate to describe the wave-particle duality of microscopic QM particles. Mathematics works better. This talk illuminated the production of the play Copenhagen, in which German physicist Werner Heisenberg, who directed the German attempt to make an atom bomb, visited Niels Bohr in Denmark during WWII.
Quantum theory provides a framework to understand phenomena at the atomic scale that cannot be explained by classical physics. It proposes that energy is emitted and absorbed in discrete units called quanta. This explains observations like the photoelectric effect where electrons are only ejected above a threshold frequency. Light behaves as both a wave and particle - a photon. Similarly, matter exhibits wave-particle duality as demonstrated by electron diffraction. At the quantum level, only probabilities, not definite values, can be predicted. Quantum mechanics is applied to describe atomic structure and spectra.
The photoelectric effect provides evidence that light behaves as particles. When light shines on a metal surface, electrons can be emitted. This is explained by assuming that light is made up of particles called photons, with each photon having an energy determined by its frequency. The kinetic energy of the emitted electrons depends on the frequency of the incident light, not its intensity. This is consistent with a particle model where each photon transfers its energy to an electron. The wave-particle duality of light is evidenced by both its particle-like properties in the photoelectric effect and its wave-like properties demonstrated in phenomena such as interference and diffraction.
Quantum theory describes the behavior of matter and energy at the microscopic scale. Some key ideas are:
- Light and matter can behave as both particles and waves (wave-particle duality).
- Planck's constant relates the energy of a system to its frequency or wavelength.
- Einstein's photon model explained the photoelectric effect.
- The Heisenberg uncertainty principle limits the precision with which certain pairs of physical properties can be known.
- Schrödinger's equation describes how quantum systems evolve over time.
This document discusses interference and diffraction of light waves. It begins by introducing Young's double slit experiment and discussing how it demonstrates the wave nature of light through superposition. It then discusses why two slits are used, explaining that single light sources cannot maintain a constant phase difference due to thermal agitation. It also discusses how diffraction occurs when a plane wave passes through a slit and produces an interference pattern on a screen. The document compares interference and diffraction, and discusses how diffraction can be used to prove the uncertainty principle of quantum mechanics. It concludes by discussing how gravity can cause decoherence in double slit experiments and briefly summarizing G.P. Thomson's experiment using electron diffraction through thin metal films.
This document discusses the photoelectric effect and the dual nature of matter and radiation. It begins by defining photons and the photoelectric effect. It then describes experiments that demonstrate:
- Photoelectric current increases with light intensity but not frequency.
- Kinetic energy of emitted electrons increases with frequency.
- There is a threshold frequency below which no electrons are emitted.
Einstein's equation for the photoelectric effect is presented along with verification of its predictions. Applications of the effect are listed. The document concludes by discussing the dual wave-particle nature of both radiation and matter, including de Broglie's proposal of matter waves and the Davisson-Germer experiment demonstrating them.
the chemical shift of the singlet.
This document provides an overview of nuclear magnetic resonance (NMR) spectroscopy. It discusses the physical principles behind NMR, including how certain atomic nuclei with spin can absorb electromagnetic radiation when placed in a magnetic field. It also describes how NMR spectra provide chemical shift, integral, and spin-spin coupling data that can be used to determine molecular structure. Interpreting NMR spectra requires considering these different types of data and relating observed signals to specific protons in a molecule.
This document discusses antennas and propagation in wireless communication systems. It covers topics such as antenna characteristics, radiation patterns, polarization, Maxwell's equations, far-field approximation, Hertzian dipole antenna model, radiated power flux density, normalized radiation intensity, antenna gain, directivity, radiation resistance, and different antenna types including dipole and Yagi antennas. Examples are provided to analyze antenna properties such as radiated power, resistance, directionality, and beamwidth for dipole antennas of different lengths.
This document provides an outline for Unit 4 Topic 2 on interactions of light and matter in VCE Physics. It lists key learning outcomes including explaining various phenomena through wave and particle models of light such as the production of incoherent light, Young's double slit experiment, diffraction, the photoelectric effect, electron diffraction, and atomic spectra. Chapter 1 covers the nature of light as electromagnetic radiation and concepts of interference, incoherent versus coherent light sources, and Young's experiment demonstrating the wave-like properties of light. Incandescent light sources produce incoherent light from the random thermal excitation of electrons.
Speaker: Michael Hippke
Affiliation: Sonneberg Observatory
Title: ''Interstellar communication: What works (not so) well and why? "
Abstract: Our nearest neighbor star, Alpha Centauri C, has a planet in the habitable zone. The Russian billionaire Yuri Milnor funds research to send an exploration probe there. Obtaining remote observational data from such a probe is not trivial because of minimal instrumentation (gram scale) and large distances (pc). Together, we follow the long journey of a photon from the transmitter beam through the interstellar dust and gas, atmospheric turbulence, and other obstacles, before finally arriving in the receiver on Earth. We discuss wavelength/frequency choices, gravitational lensing, and particles other than photons, such as Neutrinos. We conclude by asking the "big picture" question: Only when we understand how to communicate efficiently over interstellar communications, we can hope to learn how to receive such communications from other civilizations, if they exist. Are radio waves the best choice?
This document discusses the principles of nuclear magnetic resonance (NMR) spectroscopy. It explains that atoms with an odd atomic number, such as hydrogen-1, carbon-13, and nitrogen-15, have spin properties that can be analyzed using NMR. When samples containing these atoms are placed in a strong magnetic field and exposed to radiofrequency pulses, their atomic nuclei absorb energy and produce detectable signals. The signals provide information about the chemical environment and bonding of atoms in molecules. Tetramethylsilane is often used as a reference standard in NMR spectroscopy because its signals do not interfere with sample readings and allow chemical shifts to be measured in parts per million.
The document summarizes the operating principles of phototransistors and photoconductive detectors.
- Phototransistors are bipolar junction transistors that use the photocurrent generated in the base-collector junction to inject a multiplied current into the emitter circuit, similar to a common emitter transistor. The photocurrent acts as the base current.
- Photoconductive detectors have two electrodes attached to a light-absorbing semiconductor. Absorbed photons increase conductivity and the external photocurrent. With ohmic contacts, multiple electrons enter the semiconductor for each hole, producing photoconductive gain.
- The main sources of noise in photodetectors are shot noise from the dark current and photocurrent. The total noise
1. The document describes a lecture on antennas and wave propagation. It introduces different types of antennas like wire antennas, aperture antennas, reflector antennas, lens antennas, microstrip antennas, and array antennas.
2. It explains the basic radiation mechanism of antennas which involves time-varying currents and accelerated charges producing electromagnetic waves. A current only radiates if the wire is bent, curved, or the charge is oscillating.
3. Key antenna parameters like radiation resistance, directivity, gain, polarization and reciprocity are also covered briefly. Current and voltage distribution on a half-wave dipole antenna is shown.
The document provides lecture notes on antennas that cover various topics:
- A brief history of antenna development and types including electrically small, resonant, broadband, and aperture antennas.
- Analysis of fundamental antenna parameters such as radiation patterns, impedance, directivity and gain.
- Descriptions of simple radiating systems including monopoles and dipoles.
- Discussions of antenna arrays and their properties including pattern multiplication and mutual coupling effects.
- Explanations of other antenna categories like line sources, resonant antennas, and broadband antennas.
- Overviews of aperture antennas including horns, reflectors and their analysis methods.
Light is a form of electromagnetic radiation that can be described as a wave. Waves have characteristics like wavelength, frequency, amplitude, and speed. The wave equation relates these properties and shows that wave speed equals the product of frequency and wavelength. Lasers produce coherent light in a narrow wavelength range and have many applications like optical storage, surgery, manufacturing, and communication.
The document discusses lasers, including their history, characteristics, components, types, and applications. It begins with defining what a laser is, describing early developments in stimulated emission. Key points made include:
- Lasers emit highly directional, intense beams of coherent, monochromatic light.
- The first working laser was a ruby laser developed by Maiman in 1960.
- Laser light has properties of directionality, coherence, monochromaticity, and high intensity compared to other light sources.
- The main components of a laser system are the power source, active medium which is pumped to induce stimulated emission, and optical cavity.
- Common laser types include solid state, gas, liquid,
1) Optical amplifiers are needed in long-distance optical communications to compensate for signal power loss and pulse broadening.
2) There are two main types of optical amplifiers - semiconductor optical amplifiers and doped-fiber amplifiers such as erbium doped fiber amplifiers.
3) Optical amplifiers amplify signals through stimulated emission and introduce noise in the form of amplified spontaneous emission. They must have high gain, wide bandwidth, low noise figure and high saturation power to be used effectively in optical communication systems.
Here are the key differences between primary colors in light vs pigments:
- Primary light colors are red, green, and blue. These can be combined to form white light.
- Primary pigment colors are yellow, cyan, and magenta. These absorb one primary light color and reflect the other two.
- Secondary light colors are formed by combining two primary light colors: orange (red + green), violet (red + blue), and yellow (green + blue).
- Secondary pigment colors are formed by absorbing two primary light colors: red (absorbs yellow and cyan), blue (absorbs yellow and magenta), and green (absorbs cyan and magenta).
So in summary, primary
Wave-particle duality postulates that all particles exhibit both wave and particle properties under different experimental conditions. Historically, debates centered around whether light was a wave or particle. Key experiments and theorists helped establish the dual nature of light and matter, including:
- Einstein showing light has particle-like photons; Compton effect confirming this.
- De Broglie proposing electrons and matter have wave properties like wavelength and frequency. Davisson and Germer experimentally verified the wave nature of electrons.
- The double slit experiment demonstrated the wave behavior of electrons through an interference pattern, shocking as electrons were considered particles. This supported matter having wave-particle duality.
The document discusses the wave properties of particles. Some key points:
1) Louis de Broglie hypothesized in 1924 that matter has an associated wave-like nature with a wavelength given by Planck's constant divided by momentum.
2) A particle can be represented as a localized "wave packet" resulting from the interference and superposition of multiple waves with slightly different wavelengths and frequencies.
3) Davisson and Germer's electron diffraction experiment in 1927 provided direct evidence of the wave nature of electrons and supported de Broglie's hypothesis by measuring electron wavelengths matching those expected.
The document summarizes key concepts in optics and optical properties of materials. It discusses topics like electromagnetic radiation spectrum, optical classifications of materials as transparent, translucent or opaque. It also covers concepts like reflection, refraction, absorption, transmission and how they relate to the band structure and band gaps of materials. Specific phenomena like fluorescence, phosphorescence, photoelasticity and their working principles are defined. Applications of optics like lasers, optical data storage are also briefly mentioned.
Mass spectroscopy is an analytical technique used to identify unknown compounds and elucidate molecular structures. It involves ionizing molecules and separating the resulting ions based on their mass-to-charge ratio. Key components include an ion source, mass analyzer, and detector. Common ionization techniques are electron impact and chemical ionization. Mass spectrometers can be classified based on the type of mass analyzer used, such as magnetic sector, quadrupole, time-of-flight, Fourier transform ion cyclotron resonance, and tandem instruments. Tandem MS allows preselected ions to be fragmented and analyzed.
Quantum Mechanics: Electrons, Transistors, & LASERS. Paul H. Carr
Quantum Mechanics, QM, has enabled new technologies that impact our daily lives. Yet, there have been at least 14 different QM interpretations in the last century. “If you think you understand QM, you don’t,” said Richard Feynman. Our macroscopic language is inadequate to describe the wave-particle duality of microscopic QM particles. Mathematics works better. This talk illuminated the production of the play Copenhagen, in which German physicist Werner Heisenberg, who directed the German attempt to make an atom bomb, visited Niels Bohr in Denmark during WWII.
Quantum theory provides a framework to understand phenomena at the atomic scale that cannot be explained by classical physics. It proposes that energy is emitted and absorbed in discrete units called quanta. This explains observations like the photoelectric effect where electrons are only ejected above a threshold frequency. Light behaves as both a wave and particle - a photon. Similarly, matter exhibits wave-particle duality as demonstrated by electron diffraction. At the quantum level, only probabilities, not definite values, can be predicted. Quantum mechanics is applied to describe atomic structure and spectra.
The photoelectric effect provides evidence that light behaves as particles. When light shines on a metal surface, electrons can be emitted. This is explained by assuming that light is made up of particles called photons, with each photon having an energy determined by its frequency. The kinetic energy of the emitted electrons depends on the frequency of the incident light, not its intensity. This is consistent with a particle model where each photon transfers its energy to an electron. The wave-particle duality of light is evidenced by both its particle-like properties in the photoelectric effect and its wave-like properties demonstrated in phenomena such as interference and diffraction.
Quantum theory describes the behavior of matter and energy at the microscopic scale. Some key ideas are:
- Light and matter can behave as both particles and waves (wave-particle duality).
- Planck's constant relates the energy of a system to its frequency or wavelength.
- Einstein's photon model explained the photoelectric effect.
- The Heisenberg uncertainty principle limits the precision with which certain pairs of physical properties can be known.
- Schrödinger's equation describes how quantum systems evolve over time.
This document discusses interference and diffraction of light waves. It begins by introducing Young's double slit experiment and discussing how it demonstrates the wave nature of light through superposition. It then discusses why two slits are used, explaining that single light sources cannot maintain a constant phase difference due to thermal agitation. It also discusses how diffraction occurs when a plane wave passes through a slit and produces an interference pattern on a screen. The document compares interference and diffraction, and discusses how diffraction can be used to prove the uncertainty principle of quantum mechanics. It concludes by discussing how gravity can cause decoherence in double slit experiments and briefly summarizing G.P. Thomson's experiment using electron diffraction through thin metal films.
This document discusses the photoelectric effect and the dual nature of matter and radiation. It begins by defining photons and the photoelectric effect. It then describes experiments that demonstrate:
- Photoelectric current increases with light intensity but not frequency.
- Kinetic energy of emitted electrons increases with frequency.
- There is a threshold frequency below which no electrons are emitted.
Einstein's equation for the photoelectric effect is presented along with verification of its predictions. Applications of the effect are listed. The document concludes by discussing the dual wave-particle nature of both radiation and matter, including de Broglie's proposal of matter waves and the Davisson-Germer experiment demonstrating them.
The document discusses various physics concepts related to the wave-particle duality of light, including interference, diffraction, polarization, and the photoelectric effect. It provides examples of these concepts, such as thin film interference seen in soap bubbles and discusses experiments like the Michelson-Morley experiment and LIGO that study properties of light and gravity waves. The key point is that light must be understood as both a wave and particle based on experimental evidence.
The document summarizes key concepts about the particle and wave properties of light. It discusses (1) Newton's corpuscular theory of light and the establishment of the wave theory by Huygens, (2) wave phenomena such as reflection, refraction, diffraction and interference, (3) the photoelectric effect and how Einstein's photon theory explained experimental observations, and (4) provides an example calculation of determining the work function of a metal from photoelectric emission data.
The document discusses the photoelectric effect and provides details on several key topics:
1. It outlines 5 main subtopics to be covered in the chapter, including how the intensity and frequency of light affects photoelectrons and the quantitative equations involved.
2. It describes the photoelectric effect as the emission of electrons from a metal surface when light shines on it. Experimental results showed inconsistencies with the wave theory of light.
3. Einstein's photon theory predicted the kinetic energy of ejected electrons would increase linearly with frequency, in agreement with experiments, resolving discrepancies with the wave theory.
The document summarizes key concepts about the photoelectric effect from the chapter on photoelectricity. It discusses 5 main topics to be learned: how intensity and frequency of light affect photoelectrons, photoelectric current graphs, quantitative equations for work function and threshold frequency, the photon theory of light, and why wave theory fails to explain the photoelectric effect. It provides definitions and examples of photoelectric terms and experiments. The document contrasts predictions of wave and photon theories, and shows photon theory agrees with experimental results that kinetic energy increases linearly with frequency.
This document discusses the wave-particle duality of light and matter. It explains how experiments demonstrating the photoelectric effect and electron diffraction show that electromagnetic radiation and electrons exhibit both wave-like and particle-like properties depending on the situation. De Broglie hypothesized that all particles can behave as waves, and he formulated an equation showing that particles are associated with a wavelength determined by their momentum and Planck's constant.
This document summarizes Louis de Broglie's hypothesis of wave-particle duality and its applications. It discusses de Broglie's proposal that particles have wave-like properties with a wavelength given by Planck's constant divided by momentum. The photoelectric effect and Compton effect provide evidence of wave and particle behavior of light and electrons. Wave-particle duality is exploited in technologies like electron microscopy and neutron diffraction to examine structures smaller than visible light wavelengths. While useful, wave-particle duality does not fully explain quantum phenomena like the Heisenberg uncertainty principle.
This document summarizes key concepts about particle-wave duality and electromagnetic waves. It discusses how electrons can be interpreted as both particles and waves, and how electromagnetic waves exhibit both wave and particle properties depending on the circumstances. Maxwell showed that electromagnetic waves travel at the speed of light. The photoelectric effect and blackbody radiation are discussed, which classical physics could not explain, leading to developments in quantum theory including Planck's hypothesis of quantized energy levels of oscillators.
The document discusses various types of ionizing radiation and their interactions with matter. It describes electromagnetic radiation as composed of photons that can interact via photoelectric effect, Compton scattering, pair production, and other processes. Compton scattering results in energy transfer between photons and recoil electrons. The probability of interaction depends on photon energy and material properties like atomic number. Higher energy photons have a greater chance of depositing energy through secondary electrons.
1. The document discusses optical properties of semiconductors when exposed to electromagnetic radiation like light.
2. It explains concepts like absorption, reflection, transmission and emission spectra that can be obtained from materials and how they provide information about electronic band structures.
3. Key optical phenomena discussed include photon absorption promoting electrons from the valence to conduction band if the photon energy exceeds the semiconductor bandgap, and the interaction of light with materials leading to processes like reflection, refraction, scattering and dispersion.
This document discusses the photoelectric effect and the dual nature of matter and radiation. It provides details on:
1) The photoelectric effect including experimental setup, laws, and Einstein's photoelectric equation which relates the maximum kinetic energy of emitted electrons to the frequency of incident light.
2) Verification of the laws of the photoelectric effect based on Einstein's equation including the threshold frequency.
3) Applications of the photoelectric effect such as automatic alarms, scanners, and photometry.
4) The dual wave-particle nature of both radiation and matter as proposed by de Broglie, including his equation relating the momentum of a particle to its wavelength.
The document summarizes key information about the atmospheres of Venus, Earth, and Mars:
- Venus has a dense, 96% carbon dioxide atmosphere with a surface pressure of 90 bars and average temperature of 850°F, caused by a runaway greenhouse effect. Its clouds are composed of sulfuric acid.
- Earth has an atmosphere composed primarily of nitrogen and oxygen with a pressure of 1 bar and average temperature of 59°F. It hosts water clouds.
- Mars has a thin, 95% carbon dioxide atmosphere with a surface pressure of 0.007 bars and average temperature of -67°F, caused by a runaway refrigerator effect that stripped it of gases over time. It can host clouds of
The document summarizes key information about the geology of Venus. It states that Venus' surface is only about 500 million years old, as evidenced by impact craters, yet erosion rates are very low. Notable surface features include pancake-shaped volcanoes, coronae, and tectonic ridges and cracks. Venus has a slow 243-day rotation period that results in low wind speeds and erosion. Its atmosphere is extremely hot and dense.
The document provides information about Earth's moon, Luna. It discusses Luna's interior structure, including its crust, mantle, and core. It also describes Luna's surface features such as impact craters, maria (large dark plains), and regolith (loose rock and soil). Additionally, it discusses Luna's origin from a giant impact event about 4.5 billion years ago and its surface ages, with the highlands being the oldest at 4.4 billion years. The document also summarizes the Earth-Moon system, particularly how the Moon causes Earth's tides and is tide-locked in its orbit.
The document discusses the geology and evolution of Earth. It describes Earth's interior structure with a core, mantle, and crust. It explains tectonic plates, geological features like impact craters, and extinction events from impacts and climate change. It also summarizes the composition and evolution of Earth's atmosphere from early outgassing to today, including the role of greenhouse gases and life in transforming the atmosphere.
Early astronomers discovered and described key facts about the shape and size of the Earth and the structure of the solar system:
- Aristotle discovered that the Earth is round in 350 BC based on observations of lunar eclipses and changes in stars viewed from different locations.
- Eratosthenes estimated the circumference of the Earth to be about 25,000 miles in 240 BC by comparing shadows cast at different locations.
- Ptolemy proposed the geocentric model in 140 AD to explain the apparent retrograde motion of planets based on their orbits around the Earth.
- Copernicus proposed the heliocentric model in 1543 AD, placing the Sun at the center of the solar system with planets in
The document discusses factors involved in estimating the number of technological civilizations that may exist among stars using the Drake Equation. It examines each variable in the equation - R* (rate of formation of suitable stars), fp (fraction with planets), ne (number of planets suitable for life), fl (fraction where life appears), fi (fraction where intelligent life emerges), fc (fraction emitting detectable signals), and L (length of time signals emitted). It provides estimates and considerations for each variable based on current astronomical and biological understandings.
The document discusses the birth of the universe through several key topics:
1) Olber's Paradox - The question of why the night sky is dark if the universe contains an infinite number of stars. Explanations include a finite age universe and the expansion of space stretching light wavelengths.
2) Hubble's Law - The observation that more distant galaxies are moving away faster, indicating an expanding universe.
3) The Big Bang Theory - Proposed to explain the expansion of the universe and supported by evidence like the cosmic microwave background radiation. It provides an explanation for how the universe began from an extremely dense and hot initial state.
Galaxies are organized into clusters and superclusters that are separated by immense voids, creating a vast foam-like structure known as the "cosmic web". The largest known structure is the Sloan Great Wall, which is nearly 1.5 billion light years in length. Dark matter seems to come in standard clumps of about 30 million solar masses and 300 parsecs across, with a temperature of about 10,000 K. The cosmological principle assumes the universe is uniform on large enough scales, both homogeneous meaning no preferred locations and isotropic meaning no preferred directions.
Active galaxies can be categorized into three main types: Seyfert galaxies, radio galaxies, and quasars. Seyfert galaxies are active spiral galaxies with non-stellar spectra. Radio galaxies are active elliptical galaxies that also have non-stellar spectra and are strong radio emitters. Quasars are the most luminous active galaxies known, far brighter than normal galaxies, with non-stellar spectra. Centaurus A is the closest active galaxy and provides a unique laboratory for studying these powerful objects, showing evidence of a past merger that fuels activity at its center.
The document discusses different methods for measuring distances to galaxies. The Cepheid variable method can be used for galaxies in our Local Group. The Tully-Fisher relation uses the correlation between luminosity and rotational velocity of spiral galaxies to estimate distances to more distant spirals. Galaxy clusters and superclusters like the Local Supercluster provide context on larger scales of structure in the universe.
The document discusses the discovery of the Milky Way galaxy. It describes how in the early 20th century, Shapley and Curtis debated whether spiral nebulae were inside or outside our galaxy. Hubble later proved with Cepheid variables that they were actually other galaxies. The Milky Way is now understood to be a barred spiral galaxy about 30,000 light years wide, with a bulge, disk containing spiral arms, and halo of globular clusters. It formed from a cloud of gas that contracted under gravity and began rotating to form the spiral structure seen today.
The document summarizes key concepts about high mass stars and binary systems from sections 22.1, 22.2, and 23.5 of the textbook. It notes that high mass stars (>10 solar masses) end their lives as Type II supernovae, sometimes gamma-ray bursters. Binary systems produce novae, Type Ia supernovae, x-ray binaries, and x-ray bursters. All stars enrich the interstellar medium with heavier elements through their evolution and deaths. The goal is to answer fundamental questions about the universe and our origins.
Typical stellar evolution proceeds through several stages:
1. Red Giant Branch: Stars expand and cool as hydrogen fuses to helium in a shell around the core.
2. Horizontal Giant Branch: A helium flash occurs, followed by helium fusing to carbon in the core while hydrogen fuses in a shell.
3. Asymptotic Giant Branch: Helium and hydrogen shells alternately fuse heavier elements, causing the star to further expand and cool before ejecting its outer layers as a planetary nebula.
The document discusses the distance ladder, which is an attempt to determine astronomical distances by using a series of methods that build on one another. Within the Solar System, distances are measured using radar ranging. Within the galaxy, distances are measured using stellar parallax, main sequence fitting, and properties of Cepheid variable stars. Further out in the universe, distances are measured using the Tully-Fisher relation, Type Ia supernovae, brightest cluster galaxies, and Hubble's law. The document aims to answer fundamental questions about what exists in the universe and how large it is.
The document discusses the Hertzsprung–Russell diagram, which plots stars' spectral classifications and luminosity classes to show overall trends of stellar properties. It notes that spectral class indicates a star's temperature from hot (OBA) to cool (KM), while luminosity class reflects size from supergiants to dwarfs. The distribution of stars in the diagram relates their masses and lifetimes, with high-mass blue main sequence stars having short lives versus low-mass red main sequence stars with long lives. The diagram aims to understand what types of stars exist.
The document discusses the solar interior and surface features. It explains that nuclear fusion in the core powers the sun, generating energy through the p-p chain reaction of converting hydrogen to helium. It also describes the solar neutrino problem, where fewer neutrinos are detected than models predict. The interior has different zones - the core, radiative zone, and convection zone. Surface features include sunspots, the 11-year sunspot cycle, prominences, and filaments.
The document provides information about outer solar system objects including Trans-Neptunian objects, Centaurs, Kuiper Belt objects, asteroids, comets, and dwarf planets. It discusses their classification, composition, formation processes, and what they reveal about the early solar system. Images show various outer solar system bodies like Pluto, Eris, asteroids, and comets, helping to illustrate their characteristics and relative sizes.
The document discusses asteroids and meteorites. Asteroids are remnants of planetary formation in the solar system. They are classified based on composition and location in relation to gravitational resonances with Jupiter. Ceres is the largest asteroid and is now classified as a dwarf planet. Meteorites provide information about early solar system conditions. They are classified based on composition as iron, stony, or stony-iron meteorites. Carbonaceous chondrites contain organic compounds and water, indicating the early solar system environment allowed these to form. Meteorites can also originate from the Moon or Mars.
The document discusses ring systems of the gas giant planets. It explains that ring systems are shaped by processes like the Roche limit and shepherding moons. It then provides details on the ring systems of Jupiter, Saturn, Uranus, and Neptune. Saturn's rings are the most extensive and are composed primarily of ice particles. The rings of the other planets are thinner and less is known about their compositions. Over time, ring systems evolve and may be temporary structures unless replenished.
The document discusses the moons of the gas giants Jupiter and Saturn, focusing on Jupiter's large Galilean moons (Io, Europa, Ganymede, and Callisto) and Saturn's moon Titan. It provides information about the surface conditions and geological features of these moons, including active volcanoes on Io, evidence that oceans may exist under the icy crusts of Europa and Ganymede, and liquid hydrocarbon seas on Titan. The document uses images from spacecraft like Galileo and Cassini to illustrate these characteristics and how they have been shaped by tidal interactions with the giant planets.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
RPMS TEMPLATE FOR SCHOOL YEAR 2023-2024 FOR TEACHER 1 TO TEACHER 3
A1 03 EM Radiation
1. Electromagnetic Radiation
LACC §4.2, 4.3, 4.5
• Electromagnetic (EM) Radiation as a wave
• Electromagnetic (EM) Radiation as a particle
• Interactions between EM Radiation
(e.g. light) and Matter
All we know about objects beyond our solar
system comes (almost) solely from examining
the radiation (e.g. light) they emit.
Wednesday, February 17, 2010 1
2. Electromagnetic Radiation
is a wave
• EM radiation is pure energy (it has no mass)
• EM radiation results from the motion of
charged objects
• EM radiation travels at the speed of light
through a vacuum (and at lesser speeds
through matter)
• EM radiation is completely described by its
frequency, intensity, and direction of travel.
Wednesday, February 17, 2010 2
3. Waves: Diffraction
If the wavelength is of a If the wavelength does
similar size to a gap ... not match the size of
then the wave will the gap, then only a little
diffract as shown diffraction will occur
below. at the edge of the wave.
http://www.gcsescience.com/pwav37.htm
Wednesday, February 17, 2010 3
4. Waves: Interference
http://www.twow.net/ObjText/OtkCaLdQmB.htm
Wednesday, February 17, 2010 4
5. Waves: Interference
The diffraction pattern of light The same when the beam passes
observed on a distant screen through two identical closely
when a He-Ne beam passes spaced slits.
through a single narrow slit;
http://www1.union.edu/newmanj/lasers/Light%20as%20a%20Wave/
light_as_a_wave.htm
Wednesday, February 17, 2010 5
6. EM Radiation as a Wave
v = fλ
v = velocity
f = frequency
λ = wavelength
Q: What is v for light?
A: c, the speed of light
= 3x108 m/s
= 186,400 miles/s
http://www.bbemg.ulg.ac.be/UK/2Basis/freqlength.html
Wednesday, February 17, 2010 6
7. E.g. Light
http://www.uark.edu/ua/pirelli/html/color_freq_wavelength.html
Wednesday, February 17, 2010 7
8. Electromagnetic Radiation
is a particle
• atoms and molecules absorb and emit photons
• a photon is a single packet of EM energy
Wednesday, February 17, 2010 8
9. Atoms Emit Photons
E = hf
E = energy
h = Plank’s constant
f = frequency
h = 6.626x10-34 J•s
This makes Plank’s constant
the smallest(?) constant in
physics.
http://www.astrosociety.org/education/publications/tnl/35/light3.html
Wednesday, February 17, 2010 9
10. Atoms Absorb and Emit
Individual Photons
http://steve.files.wordpress.com/2006/03/Absorption%20emission.jpg
Wednesday, February 17, 2010 10
11. The EM Spectrum
•
Credit: Philip Ronan who has
given permission to copy,
distribute and/or modify this
document under the terms of
the GNU Free Documentation
License, Version 1.2 or any
later version.
•
Download site: Wikipedia:
Image:EM spectrum.svg.
http://www.nhn.ou.edu/~jeffery/course/c_energy/energyl/lec001.html
Wednesday, February 17, 2010 11
12. EM Radiation:
Wave or Particle?
Waves Particles
• interactions between • interactions between
waves results in particles result in
interference patters collisions
• radiate out from a • are “shot” out in
source specific directions
• can bend around • travel in straight
corners lines
• can bend around • are blocked by
obstacles obstacles
Wednesday, February 17, 2010 12
13. Electromagnetic Radiation
LACC §4.2, 4.3, 4.5
• Electromagnetic (EM) Radiation as a wave
(v = fλ)
• Electromagnetic (EM) Radiation as a particle
(i.e. photons, E=hf)
• Interactions between EM Radiation
(e.g. light) and Matter: absorption/emission
of EM radiation by atoms/molecules
All we know about objects beyond our solar
system comes (almost) solely from examining
the radiation (e.g. light) they emit.
Wednesday, February 17, 2010 13
14. LACC HW: Franknoi, Morrison, and
Wolff, Voyages Through the Universe,
3rd ed.
• Ch. 4, pp. 106-107: 11. Choose your answers from: radio |
microwave | infrared | visible | ultraviolet | X-ray | gamma ray.
Due at the beginning of next week’s first class.
Wednesday, February 17, 2010 14
15. Spectroscopy
LACC §4.2, 4.3, 4.5
• Thermal Spectra: Wien’s Law, Stefan-
Boltaman Law
• Types of Spectra: there are 3 types of spectra
• Spectroscopy: what can it tell us?
All we know about objects beyond our solar
system comes (almost) solely from examining the
electromagnetic radiation (e.g. light) they emit.
Wednesday, February 17, 2010 15
16. Thermal Radiation
http://astro.unl.edu/classaction/animations/light/meltednail.html
Blackbody Curves or Melting
http://cse.ssl.berkeley.edu/bmendez/
ay10/2002/notes/pics/bt2lf0612_a.jpg
http://astro.unl.edu/classaction/animations/light/bbexplorer.html
Blackbody Curves (NAAP)
Wednesday, February 17, 2010 16
17. Thermal Radiation
T = Temperature
λ = peak wavelength
Wein’s law
http://feps.as.arizona.edu/outreach/bbwein.html
Wednesday, February 17, 2010 17
18. Thermal Radiation
F= T 4
F = energy flux
σ = Stefan-Boltzmann
constant
T = temperature
Stefan-Boltzmann
law
http://csep10.phys.utk.edu/astr162/lect/light/radiation.html
Wednesday, February 17, 2010 18
19. Types of Observed Spectra
http://instruct1.cit.cornell.edu/courses/astro101/lectures/images/lec07_04.jpg
http://astro.unl.edu/classaction/animations/light/threeviewsspectra.html
Three Views Spectrum Demonstrator
Wednesday, February 17, 2010 19
20. Atomic Energy Levels
of Hydrogen
http://www.daviddarling.info/
encyclopedia/H/
hydrogen_spectrum.html
http://astro.unl.edu/classaction/animations/light/hydrogenatom.htmlBlackbody Curves (NAAP)
Hydrogen Atom Simulator (NAAP)
Wednesday, February 17, 2010 20
21. EM Rad. & Space--Our Sun
http://www.weasner.com/etx/guests/2004/guests_spectra.html
Wednesday, February 17, 2010 21
22. EM Rad. & Space--Orion N.
http://mais-ccd-spectroscopy.com/Planetary%20Nebula.htm
Wednesday, February 17, 2010 22
23. EM Rad. & Space--M.W.
Wednesday, February 17, 2010 23
24. Images vs. Spectra
Which is better, the image of an astronomical
object, or the spectrum of an astronomical
object?
What about photometry?
Wednesday, February 17, 2010 24
25. Spectroscopy
LACC §4.2, 4.3, 4.5
• Types of Spectra: Continuous, Emission Line,
Absorption Line
• Thermal (or Blackbody) Spectra: Wien’s Law
(Temperature), Stefan-Boltaman Law (Power)
• Spectroscopy: Temperature, Composition,
Doppler Shift, Density
All we know about objects beyond our solar
system comes (almost) solely from examining the
electromagnetic radiation (e.g. light) they emit.
Wednesday, February 17, 2010 25
26. LACC HW: Franknoi, Morrison, and
Wolff, Voyages Through the Universe,
3rd ed.
• Ch. 4, pp. 106-107: 23, 24.
• Ch 5: Tutorial Quizzes accessible from:
www.brookscole.com/cgi-brookscole/course_products_bc.pl?
http://
fid=M20b&product_isbn_issn=9780495017899&discipline_number=19
Due at the beginning of next class period.
Wednesday, February 17, 2010 26