Physics Tip Sheet #50 - July 21, 2005

Contact: James Riordon
riordon@aps.org
301-209-3238
American Physical Society

Highlights in this issue: The science of selling Harry Potter, and understanding how spaghetti breaks.

Shocking Analysis of Book Sales
F. Deschâtres and D. Sornette
Phys. Rev. E 72, 016112 (2005)
http://link.aps.org/abstract/PRE/v72/e016112

Rave reviews and ad blitzes are important for a new book's sales, but it's the buzz among readers that will really get a book moving off the shelves, according to a paper published this month in the journal Physical Review E. Researchers at the Université de Nice-Sophia Antipolis in France and the University of California, Los Angeles studied sales of books on Amazon.com. They found that sudden bursts of publicity (exogenous shocks) are less important than informal chatter among book readers (endogenous shocks) in the overall sales numbers. At least that is the case for books like the best seller "The Devine Secrets of the Ya Ya Sisterhood." "Harry Potter and the Half-Blood Prince," however, is setting new sales records following one of the largest first printings ever. Only time will tell if the sales model holds true for such eagerly anticipated blockbusters as J.K. Rowling's latest work.

Why Does Spaghetti Break into More than Two Pieces?
B. Audoly and S. Neukirch
Phys. Rev. Lett. (upcoming article)

When dry spaghetti snaps, it usually breaks into several fragments, not just two equal pieces. Pasta-eaters and scientists alike have been puzzled by this, but now researchers at the CNRS/Universite Paris VI in France have explained the phenomenon. They experimented with several different thicknesses of dry spaghetti, which they clamped at one end, then bent and suddenly released, causing the strand to break. According to their analysis, after release, the rod's curvature initially increases near the just-released end. Then a wave travels along the pasta. The first break occurs somewhere along the rod when the curvature exceeds a critical limit. The shock of the initial break then causes more bending waves to travel along the two newly formed pieces of the spaghetti, where they locally increase the curvature further and cause more breaks, leading to a cascade of cracks.

Journal articles are available to journalists on request.

For media assistance with these or other physics stories, contact:

James Riordon
Head of Media Relations
American Physical Society
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Email: riordon@aps.org