11 ;;Quote: quantum mechanics is about matter and light on an atomic scale

11+;;Quote: the "particle waves" of quantum mechanics are unlike anything else

11+;;Quote: uncertainty principle: any apparatus that can detect the path of an electron will disturb it sufficiently to destroy any interference patterns

11 ;;Quote: compare quantum behavior to bullets without interference and to waves with interference; if no detection, electrons are like waves but with detection, electrons are like bullets

19 ;;Quote: bullets behave as waves but the wavelengths are so tiny that detectors can not detect them; instead see their average behavior

110 ;;Quote: an event in an ideal experiment is a specific set of initial and final conditions

110+;;Quote: the probability of an event in an ideal experiment is the square of the probability amplitude of the event

110+;;Quote: if there are alternative events, the probability amplitudes sum and there is interference; if can detect which alternative, the probabilities sum and there is no interference

110 ;;Quote: with quantum mechanics the only thing that can be predicted is the probability of different events; the events themselves can not be predicted

111 ;;Quote: uncertainty principle of Heisenberg: the product of the uncertainties in the position and momentum of a particle is greater than Planck's constant

111+;;Quote: uncertainty principle, general form: one can not build equipment to distinguish two alternatives without at the same time destroying the pattern of interference

21 ;;Quote: the idea of a particle is limited; if we know the wavelength exactly, the location is unknown; if we know the location exactly, the momentum is unknown

26 ;;Quote: the resistance of atoms to compression is a quantummechanical effect

26+;;Quote: classically, the minimum energy for positive and negative charges in a collection of atoms is all on top of each other; this was a puzzle

128 ;;Quote: waves in a confined space exist only at definite frequencies, e.g. sound in an organ pipe

128+;;Quote: the probability amplitudes of electrons in an atom are constrained, they exist at definite energies

29 ;;Quote: the basis of science is to predict what will happen in an experiment, to stick out one's neck; experiment is the only way to find out that we are wrong

39 ;;Quote: if you could in principle distinguish the alternative final states, their probabilities sum; if you can not, their probability amplitudes sum

41 ;;Quote: for identical particles, the order of arrival can not be distinguished and the alternatives will interfere with each other

41+;;Quote: the arrival order of Bose particles interfere with a positive sign while Fermi particles interfere with a negative sign; e.g., photons and electrons respectively

41+;;Quote: identical particles interfere only if they have identical spin states

41+;;Quote: for composite objects, halfintegral spin imitates a Fermi particle while integral spin imitates a Bose particle

47 ;;Quote: when there are n identical Bose particles present, the probability of adding another particle is enhanced by n+1

49 ;;Quote: the condition of n, noninteracting, identical Bose particles acts the same as a harmonic oscillator

49+;;Quote: the number of photons in a particular state is the same concept as the number of the energy level associated with a particular mode of oscillation of the electromagnetic field

412 ;;Quote: two Fermi particles, e.g., electrons, can not be in the same state; much of the material world hinges on this fact

413 ;;Quote: in helium the electrons can have opposite spins; in lithium, one electron must be at a lower energy level with different chemical properties

413+;;Quote: the three electrons in lithium are identical; so the picture of electron shells is only an approximate one

414 ;;Quote: the protons of multiple hydrogen atoms can not approach each other because their electrons must be in different states

414 ;;Quote: the strongest chemical bond is two atoms with two electrons between them; the nuclei are mutually attracted to the electrons; spins must be opposite

58 ;;Quote: any atomic system can theoretically be separated by filters into a set of base states where the future behavior depends only on the base state

59 ;;Quote: a filter for a different set of quantummechanical base states removes the history about previous filters

511 ;;Quote: with a base state of a quantummechanical system, the future is independent of the past

511+;;Quote: the amplitude to get between quantummechanical states is the sum of the amplitudes to go between their base states

511+;;Quote: all base states of a quantummechanical system are completely different

511+;;Quote: the amplitude to go from one quantummechanical state to another is the complex conjugate of the amplitude to go in the opposite direction

512 ;;Quote: a quantum mechanical state is described by the amplitudes to be in each of some selected set of base states

512+;;Quote: an apparatus is described by the amplitudes to go from one base state to another; from these numbers anything can be calculated

512+;;Quote: the base states of a quantum mechanical system are generally infinite

78 ;;Quote: barrier penetration by a quantum mechanical amplitude to cross a narrow region where kinetic energy is negative; e.g., alphaparticle decay of uranium

710 ;;Quote: in the classical limit, the quantum mechanics of a system will agree with Newtonian mechanics

131 ;;Quote: in a perfect lattice, electrons can easily travel through a crystal without scattering; allows metals to conduct electricity and transistors to imitate the radio tube

131 ;;Quote: connected harmonic oscillators and atoms in a crystal will convey an irregularity as a wave

134 ;;Quote: use exponential functions to solve linear differential equations with constant coefficients

136 ;;Quote: a solid conducts electricity by propagating a wave packet of probability amplitudes from atom to atom

144 ;;Quote: dope a semiconductor with donors and acceptors of electrons; the electrons and electron holes are free to wander

144+;;Quote: the average density of electrons in a semiconductor must equal the density of donor sites; otherwise electrical charge does not balance

1411 ;;Quote: a transistor consists of two semiconductor junctions with a very thin region between them; holes, or electrons, can diffuse across the gap

1411+;;Quote: a transistor is an amplifier: a small current at the base electrode gives a 100fold larger current at the collector electrode

164 ;;Quote: Shrodinger's equation for a electron moving in a line through free space is the same as the limiting case of an electron moving along a line of atoms

168 ;;Quote: the amplitude to find an electron with some momentum has the same form as the amplitude to find an electron at some location; only the width of the Gaussian is different

168+;;Quote: the width of the Gaussian distributions of an electron's probability amplitude leads to a quantitative statement of the Heisenberg uncertainty principle

1613 ;;Quote: Schrodinger's equation of an electron moving freely in space provided a theory for calculating atomic phenomena accurately and in detail

1613+;;Quote: the mathematics of Schrodinger's equation soon becomes too complicated to solve exactly any but the simplest problems

1614 ;;Quote: Dirac discovered the correct relativistic equation for the motion of an electron a year after Schrodinger's discovery; needed for magnetism

1616 ;;Quote: if a particle is to be bound in a potential well, it can do so only if it has a very definite energy; otherwise get exponential growth of the amplitude to be outside of the potential well

173 ;;Quote: a physical system is symmetric with respect to an operation if the operation commutes with the passage of time

173+;;Quote: symmetries are the basis of all conservation laws of quantum mechanics; e.g., conservation of energy, momentum, angular momentum, parity

183 ;;Quote: light scatters when a photon is absorbed and then reemitted

183+;;Quote: the quantum theory of light scattering gives the same result as the classical theory where an electron acts as a linear oscillator
