[Paleopsych] SciAm: Michael Shermer: The Feynman-Tufte Principle
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Michael Shermer: The Feynman-Tufte Principle
http://www.sciam.com/print_version.cfm?articleID=00033494-443B-1237-81CB83414B7FFE9F
March 28, 2005
The Feynman-Tufte Principle
A visual display of data should be simple enough to fit on the side of
a van
By Michael Shermer
I had long wanted to meet Edward R. Tufte--the man the New York Times
called "the da Vinci of data" because of his concisely written and
artfully illustrated books on the visual display of data--and invite
him to speak at the Skeptics Society science lecture series that I
host at the California Institute of Technology. Tufte is one of the
world's leading experts on a core tool of skepticism: how to see
through information obfuscation.
But how could we afford someone of his stature? "My honorarium," he
told me, "is to see Feynman's van."
Richard Feynman, the late Caltech physicist, is famous for working on
the atomic bomb, winning a Nobel Prize in Physics, cracking safes,
playing drums and driving a 1975 Dodge Maxivan adorned with squiggly
lines on the side panels. Most people who saw it gazed in puzzlement,
but once in a while someone would ask the driver why he had Feynman
diagrams all over his van, only to be told, "Because I'm Richard
Feynman!"
Feynman diagrams are simplified visual representations of the very
complex world of quantum electrodynamics (QED), in which particles of
light called photons are depicted by wavy lines, negatively charged
electrons are depicted by straight or curved nonwavy lines, and line
junctions show electrons emitting or absorbing a photon. In the
diagram on the back door of the van, seen in the photograph above with
Tufte, time flows from bottom to top. The pair of electrons (the
straight lines) are moving toward each other. When the left-hand
electron emits a photon (wavy-line junction), that negatively charged
particle is deflected outward left; the right-hand electron reabsorbs
the photon, causing it to deflect outward right.
Feynman diagrams are the embodiment of what Tufte teaches about
analytical design: "Good displays of data help to reveal knowledge
relevant to understanding mechanism, process and dynamics, cause and
effect." We see the unthinkable and think the unseeable. "Visual
representations of evidence should be governed by principles of
reasoning about quantitative evidence. Clear and precise seeing
becomes as one with clear and precise thinking."
The master of clear and precise thinking meets the master of clear and
precise seeing in what I call the Feynman-Tufte Principle: a visual
display of data should be simple enough to fit on the side of a van.
As Tufte poignantly demonstrated in his analysis of the space shuttle
Challenger disaster, despite the 13 charts prepared for NASA by
Thiokol (the makers of the solid-rocket booster that blew up), they
failed to communicate the link between cool temperature and O-ring
damage on earlier flights. The loss of the Columbia, Tufte believes,
was directly related to "a PowerPoint festival of bureaucratic
hyperrationalism" in which a single slide contained six different
levels of hierarchy (chapters and subheads), thereby obfuscating the
conclusion that damage to the left wing might have been significant.
In his 1970 classic work The Feynman Lectures on Physics, Feynman
covered all of physics--from celestial mechanics to quantum
electrodynamics--with only two levels of hierarchy.
Tufte codified the design process into six principles: "(1)
documenting the sources and characteristics of the data, (2)
insistently enforcing appropriate comparisons, (3) demonstrating
mechanisms of cause and effect, (4) expressing those mechanisms
quantitatively, (5) recognizing the inherently multivariate nature of
analytic problems, (6) inspecting and evaluating alternative
explanations." In brief, "information displays should be documentary,
comparative, causal and explanatory, quantified, multivariate,
exploratory, skeptical."
Skeptical. How fitting for this column, opus 50 for me, because when I
asked Tufte to summarize the goal of his work, he said, "Simple
design, intense content." Because we all need a mark at which to aim
(one meaning of "skeptic"), "simple design, intense content" is a
sound objective for this series.
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