Number 709, November 17, 2004
by Phil Schewe, Ben Stein
What Propels A Book To The Top Of Online Sales
Is the latest bestseller simply the product of clever marketing or
has it truly permeated society? Will its popularity wane as quickly
as it appeared or will the book be a classic for future generations?
Though these questions seem to lay outside the realm of science, scientists
can actually obtain deep insights into these issues by using the tools
of statistical physics, which can predict the rates at which certain
events occur, such as the number of aftershocks following a major earthquake
or the number of large avalanches in a given sandpile.
Using a unique database of the Amazon.com rankings of book sales,
scientists (Thomas Gilbert, UC-Berkeley, 510-642-5295, email@example.com)
followed the chart histories of books that reached the top 50 in sales.
The researchers found that the bestsellers generally reach their sales
peaks in one of two ways, which they classify as "exogenous shocks"
(e.g., a rave review in the New York Times) and endogenous shocks
(e.g., word of mouth). An endogenous shock appears slowly but results
in a long-lived growth and decline of sales owing to small but very
extensive interactions in the network of buyers.
For example, "The Divine Secrets of the Ya-Ya Sisterhood,"
reached the bestseller lists two years after it came out (and without
a major marketing campaign) by making the rounds of book-discussion
clubs and inspiring women to form "Ya-Ya Sisterhood" groups
of their own. In contrast, an exogenous shock (rave review) appears
suddenly and propels a book to bestseller status; however, these sales
typically decline rapidly, much more quickly than those that made the
charts via word-of-mouth.
In either case, single triggering events (e.g., a mention on Oprah)
appear to have much less effect on the sales history of a book than
the actions of interconnected groups of people, who may pick up the
book after multiple conversations with acquaintances or by hearing about
the book secondhand or by remembering a friend's recommendation months
or even years after the book comes out.
According to the researchers, marketing agencies could apply their
method of classifying and analyzing bestsellers to measure and to maximize
the impact of their publicity on the network of potential buyers. (Sornette,
Deschatres, Gilbert, and Ageon, Physical Review Letters, 26 November
Atom lithography, shooting sculpted beams of atoms at a substrate,
can create lines of deposited atoms with widths as narrow as 50 nm.
Two groups in Holland have separately carried out experiments in which
atoms, heated in an oven, released through a baffle, cooled
by laser rays striking the beam at right angles, and then focused in
optical microlenses consisting of opposing laser beams.
In the case of physicists at Eindhoven University of Technology (contact
Ton van Leeuwen, 31-40-2474094, firstname.lastname@example.org) the best resulting
grid of iron atoms had lines only 50 nm wide and spaced consistently
186 nm apart. The researchers expect to achieve 10-nm lines, but their
chief aim is to move from producing simple grid patterns to making more
elaborate patterns with holographic and other techniques. They are also
pursuing a "single-point writer" option, in which the full
atomic beam will be focused to a single, very intense spot.
What is the advantage of such slow atom-beam approach to lithography?
Mainly it is the directness of the method for inscribing microcircuitry
(no etching or use of masks) and exercising great control over line
width and spacing. The researchers also admit that there are imposing
technological hurdles to using this approach on an industrial scale.
Short-term applications would most likely be for making MEMS-like structures
(te Sligte et al.,
Applied Physics Letters, November 8, 2004; lab website at http://www.phys.tue.nl/aow).
The other Dutch group, at Radboud University Nijmegen, has laid down
their own grid of iron atoms with lines 95 nm in width, 186 nm apart,
and covering an area of 1.6 x .4 mm2. (Myszkiewicz
et al., Applied Physics Letters, October 25, 2004; contact
Theo Rasing, 31-24-3653102) The two groups are now working together
on some joint ventures.
An Avalanche Spin-Valve Transistor
An avalanche spin-valve transistor switches a current "on"
or "off" depending on whether the magnetizations of two thin
films are parallel (large current) or anti-parallel (small current).
Such a spintronic transistor is somewhat like the giant magnetoresistance
(GMR) read heads in hard drives, but is 10 to 100 times more sensitive.
The usual drawback of spin-valve transistors, a weak output current,
is, in the Harvard lab of Venkatesh Narayanamurti, overcome by using
an avalanche process much like the one used in photodetectors---an incoming
electron ionizes several secondary electrons, each of which ionizes
still more electrons, adding up in the end to a sizable current.