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Chapter 1

The Nature of Light

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Summary

The part of optics dealing with the ray aspect of light is called geometric optics The index of refraction of a material is n = c / v , where v is the speed of light in a material and c is the speed of light in a vacuum The ray model of light describes the path of light as straight lines. When a light ray strikes a smooth surface, the angle of reflection equals the angle of incidence

Key terms

refraction
changing of a light ray’s direction when it passes through variations in matter
geometric optics
part of optics dealing with the ray aspect of light
ray
straight line that originates at some point
Brewster’s law
tan θ b = n 2 n 1 , where n 1 is the medium in which the incident and reflected light travel and n 2 is the index of refraction of the medium that forms the interface that…
corner reflector
object consisting of two (or three) mutually perpendicular reflecting surfaces, so that the light that enters is reflected back exactly parallel to the direction from which it came
Huygens’s principle
every point on a wave front is a source of wavelets that spread out in the forward direction at the same speed as the wave itself; the new wave front is a plane tangent to all of…

Chapter 2

Geometric Optics and Image Formation

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Summary

Spherical aberration occurs for spherical mirrors but not parabolic mirrors; comatic aberration occurs for both types of mirrors The image and object are the same distance from a flat mirror, the image size is the same as the object size, and the image is upright A plane mirror always forms a virtual image (behind the mirror) The focal length of a spherical mirror is one-half of its radius of curvature: f = R / 2

Key terms

image and object
the same distance from a flat mirror, the image size is the same as the object size, and the image is upright
coma
similar to spherical aberration, but arises when the incoming rays are not parallel to the optical axis
spherical aberration
distortion in the image formed by a spherical mirror when rays are not all focused at the same point
virtual image
image that cannot be projected on a screen because the rays do not physically go through the image, they only appear to originate from the image
object
observed through a plane interface between two media, then it appears at an apparent distance h i that differs from the actual distance h o : h i = ( n 2 / n 1 ) h o
ray tracing
technique that uses geometric constructions to find and characterize the image formed by an optical system
focal length
distance along the optical axis from the focal point to the optical element that focuses the light rays
aberration
distortion in an image caused by departures from the small-angle approximation

Chapter 3

Interference

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Summary

An interference pattern is obtained by the superposition of light from two slits As the number of slits is increased, the intensity of the principal maxima increases and the width decreases When light reflects from a medium having an index of refraction greater than that of the medium in which it is traveling, a 180 ° phase change (or a λ / 2 shift) occurs Thin-film interference occurs between the light reflected from the top and bottom surfaces of a film.

Key terms

number of slits
increased, the intensity of the principal maxima increases and the width decreases
thin-film interference
interference between light reflected from different surfaces of a thin film
interference pattern
obtained by the superposition of light from two slits
coherent waves
waves are in phase or have a definite phase relationship
Newton’s rings
circular interference pattern created by interference between the light reflected off two surfaces as a result of a slight gap between them
order
integer m used in the equations for constructive and destructive interference for a double slit
secondary maximum
bright interference fringes of intensity lower than the principal maxima

Chapter 4

Diffraction

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Summary

Missing orders occur when an interference maximum and a diffraction minimum are located together A diffraction grating consists of a large number of evenly spaced parallel slits that produce an interference pattern similar to but sharper than that of a double slit Diffraction can send a wave around the edges of an opening or other obstacle The intensity pattern for diffraction due to a single slit can be calculated using phasors as I = I 0 ( sin β ) 2 , where β = ϕ 2 = π a sin θ λ , a is the slit width, λ is the wavelength, and θ is the angle from the…

Key terms

diffraction
bending of a wave around the edges of an opening or an obstacle
missing order
interference maximum that is not seen because it coincides with a diffraction minimum
diffraction grating
large number of evenly spaced parallel slits
hologram
three-dimensional image recorded on film by lasers; the word hologram means entire picture (from the Greek word holo , as in holistic)
Rayleigh criterion
two images are just-resolvable when the center of the diffraction pattern of one is directly over the first minimum of the diffraction pattern of the other
two-slit diffraction pattern
diffraction pattern of two slits of width D that are separated by a distance d is the interference pattern of two point sources separated by d multiplied by the diffraction…
X-ray diffraction
technique that provides the detailed information about crystallographic structure of natural and manufactured materials

Chapter 5

Relativity

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Summary

The second postulate of special relativity is that the speed of light c is the same in all inertial frames of reference, independent of the relative motion of the observer and the light source Relativity is the study of how observers in different reference frames measure the same event An inertial frame of reference is a reference frame in which a body at rest remains at rest and a body in motion moves at a constant speed in a straight line unless acted upon by an outside force The first postulate of special relativity is that the laws of physics are the same in all inertial frames of reference.

Key terms

first postulate of special relativity
laws of physics are the same in all inertial frames of reference
event
occurrence in space and time specified by its position and time coordinates ( x , y , z , t ) measured relative to a frame of reference
inertial frame of reference
reference frame in which a body at rest remains at rest and a body in motion moves at a constant speed in a straight line unless acted on by an outside force
second postulate of special relativity
light travels in a vacuum with the same speed c in any direction in all inertial frames
speed of light
ultimate speed limit for any particle having mass
classical (Galilean) velocity addition
method of adding velocities when v < c ; velocities add like regular numbers in one-dimensional motion: u = v + u ′ , where v is the velocity between two observers, u is the…
Galilean relativity
if an observer measures a velocity in one frame of reference, and that frame of reference is moving with a velocity past a second reference frame, an observer in the second frame…
length contraction
decrease in observed length of an object from its proper length L 0 to length L when its length is observed in a reference frame where it is traveling at speed v

Chapter 6

Photons and Matter Waves

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Summary

Planck’s hypothesis of energy quanta led to the theoretical Planck’s radiation law, which agrees with the experimental blackbody radiation curve; it also explains Wien’s and Stefan’s laws The classical approach does not explain the blackbody radiation curve To explain the blackbody radiation curve, Planck assumed that the exchange of energy between radiation and cavity walls takes place only in discrete quanta of energy. The experimental Stefan’s law states that the total power of radiation emitted across the entire spectrum of wavelengths at a given temperature is proportional to the fourth power of the Kelvin temperature of the…

Key terms

Planck’s hypothesis of energy quanta
energy exchanges between the radiation and the walls take place only in the form of discrete energy quanta
given temperature
proportional to the fourth power of the Kelvin temperature of the…
blackbody radiation
radiation emitted by a blackbody
blackbody
perfect absorber/emitter
nuclear model of the atom
heavy positively charged nucleus at the center is surrounded by electrons, proposed by Rutherford
Compton effect
the change in wavelength when an X-ray is scattered by its interaction with some materials
inelastic scattering
scattering effect where kinetic energy is not conserved but the total energy is conserved

Chapter 7

Quantum Mechanics

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Summary

In quantum mechanics, the state of a physical system is represented by a wave function In Born’s interpretation, the square of the particle’s wave function represents the probability density of finding the particle around a specific location in space The expectation value is the average value of a quantity that requires a wave function and an integration Wave functions must first be normalized before using them to make predictions

Key terms

energy-time uncertainty principle
energy-time relation for uncertainties in the simultaneous measurements of the energy of a quantum state and of its lifetime
expectation value
average value of the physical quantity assuming a large number of particles with the same wave function
wave function
function that represents the quantum state of a particle (quantum system)
probability density
square of the particle’s wave function
product of experimental uncertainties
always larger than or equal to ℏ / 2
state of a physical system
represented by a wave function
Copenhagen interpretation
states that when an observer is not looking or when a measurement is not being made, the particle has many values of measurable quantities, such as position
field emission
electron emission from conductor surfaces when a strong external electric field is applied in normal direction to conductor’s surface

Chapter 8

Atomic Structure

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Summary

The quantum numbers of an electron in a hydrogen atom can be used to calculate the magnitude and direction of the orbital magnetic dipole moment of the atom A hydrogen atom can be described in terms of its wave function, probability density, total energy, and orbital angular momentum The state of an electron in a hydrogen atom is specified by its quantum numbers ( n , l , m ) In contrast to the Bohr model of the atom, the Schrödinger model makes predictions based on probability statements

Key terms

orbital magnetic dipole moment
measure of the strength of the magnetic field produced by the orbital angular momentum of the electron
spin-flip transitions
atomic transitions between states of an electron-proton system in which the magnetic moments are aligned and not aligned
transition metal
element that is located in the gap between the first two columns and the last six columns of the table of elements that contains electrons that fill the d subshell
selection rules
rules that determine whether atomic transitions are allowed or forbidden (rare)
braking radiation
radiation produced by targeting metal with a high-energy electron beam (or radiation produced by the acceleration of any charged particle in a material)
spin-orbit coupling
interaction between the electron magnetic moment and the magnetic field produced by the orbital angular momentum of the electron
stimulated emission
when a photon of energy triggers an electron in a metastable state to drop in energy emitting an additional photon

Chapter 9

Condensed Matter Physics

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Summary

Molecules form by two main types of bonds: the ionic bond and the covalent bond. An ionic bond transfers an electron from one atom to another, and a covalent bond shares the electrons Energy differences between adjacent vibrational energy levels are larger than those between rotational energy levels The energy change associated with ionic bonding depends on three main processes: the ionization of an electron from one atom, the acceptance of the electron by the second atom, and the Coulomb attraction of the…

Key terms

hybridization
change in the energy structure of an atom in which energetically favorable mixed states participate in bonding
ionic bond
bond formed by the Coulomb attraction of a positive and negative ions
covalent bond
bond formed by the sharing of one or more electrons between atoms
vibrational energy level
energy level associated with the vibrational energy of a molecule
rotational energy level
energy level associated with the rotational energy of a molecule
absorption spectrum
inversely related to the moment of inertia
repulsion constant
experimental parameter associated with a repulsive force between ions brought so close together that the exclusion principle is important
body-centered cubic (BCC)
crystal structure in which an ion is surrounded by eight nearest neighbors located at the corners of a unit cell

Chapter 10

Nuclear Physics

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Summary

The atomic mass of an element is the weighted average of the masses of its isotopes The mass defect of a nucleus is the difference between the total mass of a nucleus and the sum of the masses of all its constituent nucleons The binding energy (BE) of a nucleus is equal to the amount of energy released in forming the nucleus, or the mass defect multiplied by the speed of light squared The atomic nucleus is composed of protons and neutrons

Key terms

mass defect of a nucleus
the difference between the total mass of a nucleus and the sum of the masses of all its constituent nucleons
mass defect
difference between the mass of a nucleus and the total mass of its constituent nucleons
binding energy (BE)
energy needed to break a nucleus into its constituent protons and neutrons
isotopes
nuclei having the same number of protons but different numbers of neutrons
atomic mass
total mass of the protons, neutrons, and electrons in a single atom
atomic nucleus
tightly packed group of nucleons at the center of an atom
nucleons
protons and neutrons found inside the nucleus of an atom
atomic mass of an element
the weighted average of the masses of its isotopes

Chapter 11

Particle Physics and Cosmology

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Summary

Quarks interact via the strong force, but leptons do not. Both quark and leptons interact via the electromagnetic, weak, and gravitational forces Elementary particles are classified into fermions and boson. Quarks and leptons belong to particle families composed of three members each.

Key terms

cosmology
study of the origin, evolution, and ultimate fate of the universe
fermion
particle with half-integral spin that is antisymmetric on exchange
boson
particle with integral spin that are symmetric on exchange
fundamental force
one of four forces that act between bodies of matter: the strong nuclear, electromagnetic, weak nuclear, and gravitational forces
quark
a fermion that participates in the electroweak and strong nuclear force
lepton
a fermion that participates in the electroweak force
baryon number
baryon number has the value B = + 1 for baryons, - 1 for antibaryons, and 0 for all other particles and is conserved in particle interactions
lepton number
electron-lepton number L e , the muon-lepton number L μ , and the tau-lepton number L τ are conserved separately in every particle interaction

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