Friday, May 21, 2010
On May 28, 585 B.C. the swath of a total solar eclipse passed over the
Greek island of Miletus. The early Greek philosopher, Thales of Miletus,
alone understood what was happening. The world's first recorded
freethinker, Thales rejected all supernatural explanations, and used the
occasion to state the first law of science: every observable effect has a
physical cause. The 585 B.C. eclipse is now taken to mark the birth of
science, and Thales is honored as the father. What troubles would be
spared the world if the education of every child began with causality? We
might, for example, have been spared the absurd cell phone/cancer myth:
No link to brain cancer was found in a 10 year, $14 million epidemiological
study of cell phone use in 13 countries (the US was not among them); the
study was led by the World Health Organization (WHO). So is it safe to use
cell phones? Uh, the report doesn't exactly say, instead it concludes
that "more study is needed." On the contrary, the WHO study itself was not
needed. I remind you that flawed epidemiology led to the great power-line
scare more than 20 years ago. Publicized by a series of ignorant articles
in the New Yorker
http://bobpark.physics.umd.edu/WN89/wn082589.html , it
was a costly diversion that morphed into the cell-phone scare on Larry King
Live
http://bobpark.physics.umd.edu/WN93/wn012993.html . Epidemiology is a
useful tool for identifying possible environmental hazards, but it is not
science, or a substitute for science. The science of electromagnetic
radiation is clear: photons with energies below the photoelectric threshold
(extreme blue-end of the visible spectrum) are not cancer agents. The
energy of the photoelectron threshold is about 1 million times the energy
of a microwave photon. Blueberry consumption would have a greater chance of
being linked to cancer. Even as I send this off, however, my mail is full
of warnings from nonscientists about the dangers of cell phones.
Currently President of the Memorial Sloan-Kettering Cancer Center, the
former director of NIH has been named to head the National Cancer
Institute. Some are surprised that a former head of NIH would agree to
direct one of its institutes, but Varmus never seems limited by the
expected. Perhaps he believes, as many others do that we are on the
threshold of major progress in preventing cancer. In this battle, the cell
phone myth is a tragic diversion.
Opportunity arrived on Mars 25 Jan 04. In the 6 Earth-years since,
Opportunity has never once complained about the cold nights, and it lives
on sunshine. It has now operated on Mars longer than the 1976 Viking 1
lander, which ceased transmission in November of 1982. Meanwhile, Spirit,
Opportunity's twin, is stuck in a sand trap. Not a lot happens on Mars for
a stationary observer to report on, so Opportunity is trekking to a large
crater. It should be there in a couple of years. Long before an astronaut
could get there.
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