Quantum physics (quantum theory, quantum mechanics)
Quantum physics (quantum theory, quantum mechanics) Quantum physics (quantum theory, quantum mechanics)
wave-particle duality: Summary • objects behave like waves or particles, depending on experimental conditions • complementarity: wave and particle aspects never manifest simultaneously Spin: • results of Stern - Gerlach experiment explained by introduction of “spin” • later shown to be natural outcome of relativistic invariance (Dirac) Copenhagen interpretation: • probability statements do not reflect our imperfect knowledge, but are inherent to nature – measurement outcomes fundamentally indeterministic • Physics is science of outcome of measurement processes -- do not speculate beyond what can be measured • act of measurement causes one of the many possible outcomes to be realized (“collapse of the wave function”) • measurement process still under active investigation – lots of progress in understanding in recent years 42
Problems: Homework set 3 HW3.1: test of correspondence principle: • consider an electron in a hypothetical macroscopic H – atom at a distance (radius of orbit) of 1cm; • (a) o according to classical electrodynamics, an electron moving in a circular orbit will radiate waves of frequency = its frequency of revolution o calculate this frequency, using classical means (start with Coulomb force = centripetal force, get speed of electron,..) • (b) o Within the Bohr model, calculate the n-value for an electron at a radius of 1cm (use relationship between R n and Bohr radius a o ) o Calculate corresponding energy E n o calculate energy difference between state n and n-1, i.e. ΔE = E n - E n-1 o calculate frequency of radiation emitted in transition from o state n to state n-1 compare with frequency from (a) 43
- Page 1 and 2: Quantum physics (quantum theory, qu
- Page 3 and 4: Homework from 2 nd lecture Calcula
- Page 5 and 6: QUANTUM MECHANICS new kind of physi
- Page 7 and 8: Uncertainty principle • Uncertain
- Page 9 and 10: Quantum Mechanics of the Hydrogen A
- Page 11 and 12: Multi-electron Atoms Similar quantu
- Page 13 and 14: Photon properties Relativistic rel
- Page 15 and 16: Compton (1923) measured intensity o
- Page 17 and 18: Before Incoming photon p Compton s
- Page 19 and 20: WAVE-PARTICLE DUALITY OF LIGHT Ein
- Page 21 and 22: Fringe spacing in double slit exper
- Page 23 and 24: Double slit experiment: low intensi
- Page 25 and 26: Double slit experiment - QM interpr
- Page 27 and 28: double slit expt., wave function
- Page 29 and 30: Electron Double-Slit Experiment C.
- Page 31 and 32: Which slit? Try to determine which
- Page 33 and 34: Wave - particle - duality So, ever
- Page 35 and 36: The Copenhagen Interpretation Bohr
- Page 37 and 38: Splitting of atomic energy levels B
- Page 39 and 40: Stern-Gerlach experiment (1921) Ove
- Page 41: The concept of spin Stern-Gerlach
Problems: Homework set 3<br />
<br />
HW3.1: test of correspondence principle:<br />
• consider an electron in a hypothetical macroscopic H –<br />
atom at a distance (radius of orbit) of 1cm;<br />
• (a)<br />
o according to classical electrodynamics, an electron moving in<br />
a circular orbit will radiate waves of frequency = its<br />
frequency of revolution<br />
o calculate this frequency, using classical means (start with<br />
Coulomb force = centripetal force, get speed of electron,..)<br />
• (b)<br />
o Within the Bohr model, calculate the n-value for an electron<br />
at a radius of 1cm (use relationship between R n and Bohr<br />
radius a o )<br />
o Calculate corresponding energy E n<br />
o calculate energy difference between state n and n-1,<br />
i.e. ΔE = E n - E n-1<br />
o calculate frequency of radiation emitted in transition from<br />
o<br />
state n to state n-1<br />
compare with frequency from (a)<br />
43
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