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QuoteRef: feynRP_1965

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ThesaHelp:
references e-f
Topic:
quantum mechanics
Topic:
events
Topic:
science as experiment
Topic:
probability
Topic:
quantum electrodynamics
Topic:
scientific method
Topic:
atoms and molecules
Topic:
Newtonian physics
Topic:
electricity and magnetism
Group:
mathematics
Topic:
electromagnetic field
Topic:
symmetry

Reference

Feynman, R.P., Leighton, R.B., Sands, M., The Feynman Lectures on Physics, Quantum Mechanics, 3, Reading, Massachusetts, Addison-Wesley Publishing, 1963. Google

Other Reference

chapters 1 and 2 are near duplicates of chapters 37 and 38 in (QuoteRef: feynRP_1963).

Quotations
1-1 ;;Quote: quantum mechanics is about matter and light on an atomic scale
1-1+;;Quote: the "particle waves" of quantum mechanics are unlike anything else
1-1+;;Quote: uncertainty principle: any apparatus that can detect the path of an electron will disturb it sufficiently to destroy any interference patterns
1-1 ;;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
1-9 ;;Quote: bullets behave as waves but the wavelengths are so tiny that detectors can not detect them; instead see their average behavior
1-10 ;;Quote: an event in an ideal experiment is a specific set of initial and final conditions
1-10+;;Quote: the probability of an event in an ideal experiment is the square of the probability amplitude of the event
1-10+;;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
1-10 ;;Quote: with quantum mechanics the only thing that can be predicted is the probability of different events; the events themselves can not be predicted
1-11 ;;Quote: uncertainty principle of Heisenberg: the product of the uncertainties in the position and momentum of a particle is greater than Planck's constant
1-11+;;Quote: uncertainty principle, general form: one can not build equipment to distinguish two alternatives without at the same time destroying the pattern of interference
2-1 ;;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
2-6 ;;Quote: the resistance of atoms to compression is a quantum-mechanical effect
2-6+;;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
12-8 ;;Quote: waves in a confined space exist only at definite frequencies, e.g. sound in an organ pipe
12-8+;;Quote: the probability amplitudes of electrons in an atom are constrained, they exist at definite energies
2-9 ;;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
3-9 ;;Quote: if you could in principle distinguish the alternative final states, their probabilities sum; if you can not, their probability amplitudes sum
4-1 ;;Quote: for identical particles, the order of arrival can not be distinguished and the alternatives will interfere with each other
4-1+;;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
4-1+;;Quote: identical particles interfere only if they have identical spin states
4-1+;;Quote: for composite objects, half-integral spin imitates a Fermi particle while integral spin imitates a Bose particle
4-7 ;;Quote: when there are n identical Bose particles present, the probability of adding another particle is enhanced by n+1
4-9 ;;Quote: the condition of n, non-interacting, identical Bose particles acts the same as a harmonic oscillator
4-9+;;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
4-12 ;;Quote: two Fermi particles, e.g., electrons, can not be in the same state; much of the material world hinges on this fact
4-13 ;;Quote: in helium the electrons can have opposite spins; in lithium, one electron must be at a lower energy level with different chemical properties
4-13+;;Quote: the three electrons in lithium are identical; so the picture of electron shells is only an approximate one
4-14 ;;Quote: the protons of multiple hydrogen atoms can not approach each other because their electrons must be in different states
4-14 ;;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
5-8 ;;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
5-9 ;;Quote: a filter for a different set of quantum-mechanical base states removes the history about previous filters
5-11 ;;Quote: with a base state of a quantum-mechanical system, the future is independent of the past
5-11+;;Quote: the amplitude to get between quantum-mechanical states is the sum of the amplitudes to go between their base states
5-11+;;Quote: all base states of a quantum-mechanical system are completely different
5-11+;;Quote: the amplitude to go from one quantum-mechanical state to another is the complex conjugate of the amplitude to go in the opposite direction
5-12 ;;Quote: a quantum mechanical state is described by the amplitudes to be in each of some selected set of base states
5-12+;;Quote: an apparatus is described by the amplitudes to go from one base state to another; from these numbers anything can be calculated
5-12+;;Quote: the base states of a quantum mechanical system are generally infinite
7-8 ;;Quote: barrier penetration by a quantum mechanical amplitude to cross a narrow region where kinetic energy is negative; e.g., alpha-particle decay of uranium
7-10 ;;Quote: in the classical limit, the quantum mechanics of a system will agree with Newtonian mechanics
13-1 ;;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
13-1 ;;Quote: connected harmonic oscillators and atoms in a crystal will convey an irregularity as a wave
13-4 ;;Quote: use exponential functions to solve linear differential equations with constant coefficients
13-6 ;;Quote: a solid conducts electricity by propagating a wave packet of probability amplitudes from atom to atom
14-4 ;;Quote: dope a semiconductor with donors and acceptors of electrons; the electrons and electron holes are free to wander
14-4+;;Quote: the average density of electrons in a semiconductor must equal the density of donor sites; otherwise electrical charge does not balance
14-11 ;;Quote: a transistor consists of two semiconductor junctions with a very thin region between them; holes, or electrons, can diffuse across the gap
14-11+;;Quote: a transistor is an amplifier: a small current at the base electrode gives a 100-fold larger current at the collector electrode
16-4 ;;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
16-8 ;;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
16-8+;;Quote: the width of the Gaussian distributions of an electron's probability amplitude leads to a quantitative statement of the Heisenberg uncertainty principle
16-13 ;;Quote: Schrodinger's equation of an electron moving freely in space provided a theory for calculating atomic phenomena accurately and in detail
16-13+;;Quote: the mathematics of Schrodinger's equation soon becomes too complicated to solve exactly any but the simplest problems
16-14 ;;Quote: Dirac discovered the correct relativistic equation for the motion of an electron a year after Schrodinger's discovery; needed for magnetism
16-16 ;;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
17-3 ;;Quote: a physical system is symmetric with respect to an operation if the operation commutes with the passage of time
17-3+;;Quote: symmetries are the basis of all conservation laws of quantum mechanics; e.g., conservation of energy, momentum, angular momentum, parity
18-3 ;;Quote: light scatters when a photon is absorbed and then re-emitted
18-3+;;Quote: the quantum theory of light scattering gives the same result as the classical theory where an electron acts as a linear oscillator


Related Topics up

ThesaHelp: references e-f (168 items)
Topic: quantum mechanics (100 items)
Topic: events (44 items)
Topic: science as experiment (38 items)
Topic: probability (21 items)
Topic: quantum electrodynamics (34 items)
Topic: scientific method (40 items)
Topic: atoms and molecules (47 items)
Topic: Newtonian physics (73 items)
Topic: electricity and magnetism (50 items)
Group: mathematics   (23 topics, 554 quotes)
Topic: electromagnetic field (63 items)
Topic: symmetry (11 items)

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