Presentation on theme: "Keith P. Madden, PhD. Ivy Tech Community College South Bend, IN"— Presentation transcript:
1Keith P. Madden, PhD. Ivy Tech Community College South Bend, IN Using Magnetic Resonance to Connect Newtonian Mechanics and Quantum BehaviorKeith P. Madden, PhD. Ivy Tech Community College South Bend, IN
2The Nature of the Problem Nanotechnology revolution is here!Transition from macroscopic to microscopic systems.New materials and processes operating at molecular size scale.The behavior of these systems is not well explained using classical concepts.
5What Do Students Learn Now? Mostly mechanical /thermal systems, with the traditional development. My PHYS 101 topic list: 1 Introduction, Technical Measurements, Vectors, Translational Equilibrium, Friction (Measurements) 2 Torques & Rotational Equilibrium (Equilibrium) 3 Uniformly Accelerated Motion & Projectile Motion (Gravitational Acceleration) 4 Newton’s Second Law (Newton’s Second Law)
6What Do Students Learn Now? 5 Work, Energy and Power 6 Impulse and Momentum 7 Uniform Circ. Motion (Centripetal Acceleration) 8 Rotation of Rigid Bodies (Density of Materials) 9 Elasticity (Hooke’s Law & Hysteresis) 10 Fluids (Fluid Flow) 11 Temperature & Expansion Quantity of Heat 12 Heat Transfer (Specific Heat) 13 Thermal Properties, Thermodynamics, & Nanotechnology
7When and How Are Quantum Concepts Usually Introduced? When math is considered sufficient Calculus, Systems of Linear EquationsAfter Physics 101 – 102, Classical Mechanics, and Electricity and MagnetismA long time to wait in a two-year program!We need to show the inadequacies of classical concepts – and the way past that problem.
8The Traditional Introduction: Paradoxical Nature of Light Dr. Thomas Young (1802) – light is a wave
9The Traditional Introduction: Paradoxical Nature of Light R.A. Millikan (1916) – light is a particleThe electrons were emitted immediately - no time lag!2. Increasing the intensity of the light increased the number of photoelectrons, but not their maximum kinetic energy!3. Red light will not cause the ejection of electrons, no matter what the intensity!4. A weak violet light will eject only a few electrons, but their maximum kinetic energies are greater than those for intense light of longer wavelengths!
10The Traditional Introduction The particle in a boxAdvantages: Mathematically simpleDisadvantage: Correct solution to problem is not completely plausible.
13What Does it Mean? What kind of bowling alley is this?? We have discrete energies for each state of the particle.We have discrete positions for the particle.If the barriers are not infinite, we have a finite probability of finding the particle outside the box.What kind of bowling alley is this??
21S2 Total angular momentum squared In the Quantum RegimeThe operators that are used to elucidate the proton system are:S2 Total angular momentum squaredSz Parallel angular momentum componentSy Perpendicular a.m. componentSx Perpendicular a.m. component
23The ExperimentBuild an NMR Pound box (only three transistors, and three diodes!)Mix a sample of water (with a little copper sulfate to make it blue).Insert sample in ~3300 Gauss magnetic field (permanent magnet or small electromagnet)Observe absorption of R.F. energy ~13 MHz.
24The Experiment (con’t) Vary magnetic field, observe proportional change in RF frequency.Students can see quantum behavior in the most familiar substance – water.Students can then experiment with gyroscopeto see quite analogous behavior between the classical and quantum versions of angular momentum.
25ConclusionQuantum concepts can be made accessible early in the physics curriculum, but a quantum system with strong parallels to classical behavior is needed.The gyroscope and the proton of water (H2O) fulfill this criterion.A lab can be provided with simple (home- built) equipment to show the proton’s quantum transition (magnetic resonance).
26ReferencesPauling, L.; Wilson, E.B. Jr. Introduction to Quantum Mechanics, McGraw-Hill (1935).astr.gsu.edu/hbase/quantum/pbox.html (and linked pages).Wertz, J.E.,Bolton, J.R., Electron Spin Resonance, McGraw-Hill (1972).