Lab Activity This Week: B3 EOL

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• Lab Activity This Week B3 - (EOL)
• Electricity and Ohms Law
• Extra Credit or Make-up Lab B4 - (CLE)
• Coulombs Law of Electrostatics
• Chapter 8 quiz end of class Today 04/15
• Chapter 9 quiz end of class Tuesday 04/22
• Chapter 9 Mallard HW quiz
• Due by 12 AM Tuesday 04/22
• Exam 4 (Chapters 8 and 9) on THU 04/24

Tuesday, April 15 Spring 2008
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Quantum Mechanics

• Chapter 9

Great Idea At the subatomic scale, everything is
quantized. Any measurement at that scale
significantly alters the object being measured
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Chapter Outline

• The World of the Very Small
• Probabilities
• Wave-Particle Duality
• Wave-Particle Duality and the Bohr Atom

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The World of the Very Small

• Quantum mechanics
• Motion of quanta
• Bundles vs. continuous
• Does not match our intuition

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Measurement Observation in the Quantum World

• 3 components to measurement
• Sample
• Source of energy
• Detector
• Quantum World
• Measurement alters object

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Heisenberg Uncertainty Principle

• At the quantum scale, any measurement
  significantly alters the object being measured.
• Dx Dv gt h / m
• uncertainty in position uncertainty in velocity
  gt h / m

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Probabilities

• Newtonian View
• Determine velocity and position
• Quantum View
• Cannot determine both velocity and position
• Use probability

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The Double-Slit Test

• Energy
• Particles
• Waves
• Photons
• Emit photon
• Flood of photons

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Double-Slit cont.

• Single photon or particle over time
• Results depend on experimental design
• Visualizing
• Not wave or particle

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Technology

• Photoelectric Effect
• Einstein, Nobel Prize 1921
• CAT Scans

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Wave-Particle Duality and the Bohr Atom
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Wave-Particle Duality the Bohr Atom

• Wave
• Uniform vibration at certain frequencies
• Faster speedshorter wavelength
• Particle
• Precise velocity gt stable orbit
• Combine wave particle?
• Only orbits allowed are those where both particle
  and wave work
• http//zebu.uoregon.edu/js/ast123/lectures/lec06.
  html

Bending wave into circular orbit, fit only
certain standing waves into orbit
Wavelength determines frequency
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Quantum Weirdness

• Richard Feynman- I can safely say that nobody
  understands quantum mechanics. Do not keep
  saying to yourself, But how can it be like
  that? Nobody knows how it can be like that.
• Be Careful!
• Quantum mechanics is still a marvelous and
  necessary tool for understanding and visualizing
  the quantum world

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Quantum Weirdness

• Erwin Schrödinger I don't like it, and I'm
  sorry I ever had anything to do with it.
• Albert Einstein I cannot believe that God plays
  dice with the universe.
• Neils Bohr Albert, stop telling God what to do.

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Quantum Entanglement

• Quantum Entanglement
• Dice example
• Photons emitted at the same time
• Despite distance, remain entangled
• Quantum teleportation
• Re-creation of photons from interactions with an
  entangled pair