Chabot College ISLS - Six Easy Pieces - Richard Feynman - Structured Analysis
Scott Hildreth
Spring 2006
"Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry." Feynman, The Character of Physical Law
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Page 1 - Studying Physics
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| It is possible…to find laws which summarize all our
knowledge. Examples: Law of Gravity Laws of Inertia, Force, Reaction Law of Conservation of Energy
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Questions: What is a scientific LAW? How does it differ from a theory, model, or hypothesis?
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Links: Scientific Hypotheses, Theories, & Laws. University of Waikato, NZ. The Nature of Science. UC Berkeley Museum of Paleontology. |
| Page 2 - The test of all knowledge is experiment
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Why can't we state the laws quickly and simply?
So we learn piece by piece, but: Each piece…is always merely an approximation to the complete truth, or the complete truth as far as we know it. And we judge truth how? Experiment is the sole judge of scientific "truth".
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Questions: What is the role of imagination in science? How can experiments be wrong?
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Experiment in Physics, Stanford University Scientific Laws and Theories, Kennesaw State Univeristy. |
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Page 3 - We are completely wrong with the approximate law
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| Inaccurate experimental results leads to inaccurate or approximate
laws: Mass is conserved (neither created nor destroyed) - not true. Special Relativity shows how mass increases with velocity. Even a very small effect sometimes requires profound changes in our ideas.
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Questions: How were you taught physics, if at all? Fun? Rigorous? Matters of Fact? What the qualities that make for good physicists?
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Conserving Momentum: The Relativistic Mass Increase. University of Virginia. |
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Pages 4/5 - Matter is made of atoms
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| All things are made of atoms - little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. | Questions: What does Feynman do here that is interesting? Is this style of writing important to his purpose, of teaching physicists?
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Angstrom = 1 ten-billionth of a meter; dimensions of atoms are typically measured in angstroms, while the nuclei in those atoms are at least another 1000 times smaller still. |
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Page 6/7 - Atoms in Motion
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| The behavior of water molecules as a liquid, and as steam. Let us see what some of the properties of steam vapor or any other gas are. Deriving properties based on logic and the understanding of principles of motion and forces.
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Questions: How does Feynman make the physics of the very small "intelligible" to us here?
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Key terms: Pressure = A force applied against a surface, measured as force/area with typical units of pounds/sq. inch or pounds per square foot or Newtons/sq. meter. Air pressure is 14.7 lb./sq. in. at sea level.
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| Page 8 - The Behavior of a Gas; temperature is a measure of atomic speeds in a gas
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| Pressure is proportional to density (for low numbers
of atoms in a container) Pressure increases with temperature of the gas Atoms pick up speed with compression, and the temperature increases!
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Questions: What are some normal examples that support these statements?
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Pressure example |
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Page 9 - The Behavior continued; low temperatures
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| Solids, Liquids, & Gases: The difference between solids and liquids is…that in a solid the atoms are arranged in some kind of array, and they do not have a random position at long distances.
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Questions: Why don't atoms stop at absolute zero?
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Key terms: Absolute Zero = the temperature at which all macroscopic atomic motion will cease; -273 Centigrade degrees, or about -457 Fahrenheit degrees. Physics Team studies atomic life at 'absolute zero.' University of Wisconsin.
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Page 10/12 - Atomic Processes
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Feynman's writing style:
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Questions: Why does evaporation increase with wind or fans? Why does blowing on soup cool it? If soup didn't have any evaporating water molecules, would blowing on it still cool it?
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Page 13/14 - Ions
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| Electrons enter into our picture… An ion is an atom which either has a few extra electrons or has lost a few electrons. (We'll find that all of chemistry (both physical and organic) is understood in terms of the physics of electron interactions between atoms, and the behavior of particles themselves within atoms, including the neutrons, protons, and electrons.)
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Barium ions frozen in laser beam (IBM) | |
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Page 15/16 - Chemical Reactions
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| Burning - getting heat from the combination of oxygen and
carbon, in the form of molecular motion of the hot gases. Every substance is some type of arrangement of atoms.
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Key terms: Kinetic energy = energy something has because it is in motion. Your car has kinetic energy; at 60 miles per hour, a 3,000-lb. Car would have 500,000 Joules of Kinetic Energy, or the equivalent of about 120 Calories from normal food!
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Page 17/19 - Physics Smells…
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| A chemical formula is merely a picture of … a molecule. This is one of the most fantastic pieces of detective work that has every been done - organic chemistry. How do we know there are atoms? Brownian Motion, X-ray crystallography.
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Questions: If the molecule representing the odor of violets is identifiable, how is it that we smell, physiologically? What could be happening? Create some hypotheses that are testable guesses.
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Nanosight Video Gallery. |
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Pages 20 - Matter is made of atoms
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| How much more is possible? …. How much more marvelously is it possible that this thing might behave? … such that the sheer complexity of it staggers the imagination as to what it can do?
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Questions: Feynman describes more of typical "chemistry" than physics here. What is your sense of the relative importance to humanity of chemistry and physics as sciences? Why are medical students not required to take much (if any) physics?
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See Holographic Optical Tweezers! (New York University) |
Last Modified - 3/8/06 - SH