Ask The Experts

Social Selling Sumo

Get Instant Access

What do butterflies do when it rains? Michael Raupp, professor of entomology at the University of Maryland, enlightens.

Subscribe to Scientific American Digital 13-year archive with more than 150 issues Visit www.sciamdigital.com

Save $5 (use code Web21)

Offer ends September 30

SCIENTIFIC

Established 1845

i Letters

[email protected]

THE MAY ISSUE underscored the maxim that scientific research typically raises more questions than it answers. For instance, in the cover story "The First Few Microseconds," Michael Riordan and William A. Zajc described collider experiments that slammed gold nuclei together at nearly light-speed to replicate the quark-gluon plasma that existed only in the microseconds-old universe. Pondering the mysteries ofthose microseconds, readers sent some mind-bending questions.

The biggest mail magnet was "When Slide Rules Ruled," by Cliff Stoll, which brought responses, silly and serious, as well as nostalgic recollections from those who lived and ciphered in the primitive times before electronic calculators. Kevin Dixon-Jackson of Macclesfield, England, observed: "As a user of both a Faber-Castell 2/83N and a Hewlett-Packard HP-35, I believe that the slide rule wasted less lab time, because, unlike a calculator, there was no display to turn upside down to show 'funny' words, nor could you play 'get all the integers using only the top three rows of buttons.' Also, it was a straightedge, a T-square and a reach-extender for flicking distant switches and manipulating live electrical wires!"

EDITOR IN CHIEF: John Rennie EXECUTIVE EDITOR: Mariette DiChristina MANAGING EDITOR: Ricki L. Rusting NEWS EDITOR: Philip M. Yam SPECIAL PROJECTS EDITOR: Gary Stix SENIOR EDITOR: Michelle Press SENIOR WRITER: W. Wayt Gibbs EDITORS: Mark Alpert, Steven Ashley, Graham P. Collins, Steve Mirsky, George Musser, Christine Soares CONTRIBUTING EDITORS: Mark Fischetti, Marguerite Holloway, Michael Shermer, Sarah Simpson

EDITORIAL DIRECTOR, ONLINE: Kate Wong ASSOCIATE EDITOR, ONLINE: David Biello

ART DIRECTOR: Edward Bell

SENIOR ASSOCIATE ART DIRECTOR: Jana Brenning ASSOCIATE ART DIRECTOR: Mark Clemens ASSISTANT ART DIRECTOR: Johnny Johnson PHOTOGRAPHY EDITOR: Emily Harrison PRODUCTION EDITOR: Richard Hunt

COPY DIRECTOR: Maria-Christina Keller COPY CHIEF: Molly K. Frances COPY AND RESEARCH: Daniel C. Schlenoff, Michael Battaglia, Smitha Alampur, Michelle Wright, John Matson

EDITORIAL ADMINISTRATOR: Jacob Lasky SENIOR SECRETARY: Maya Harty

ASSOCIATE PUBLISHER, PRODUCTION: William Sherman MANUFACTURING MANAGER: Janet Cermak ADVERTISING PRODUCTION MANAGER: Carl Cherebin PREPRESS AND QUALITY MANAGER: Silvia De Santis PRODUCTION MANAGER: Christina Hippeli CUSTOM PUBLISHING MANAGER: Madelyn Keyes-Milch

ASSOCIATE PUBLISHER, CIRCULATION: Simon Aronin CIRCULATION DIRECTOR: Christian Dorbandt RENEWALS MANAGER: Karen Singer FULFILLMENT AND DISTRIBUTION MANAGER: Rosa Davis

VICE PRESIDENT AND PUBLISHER: Bruce Brandfon WESTERN SALES MANAGER: Debra Silver SALES DEVELOPMENT MANAGER: David Tirpack SALES REPRESENTATIVES: Jeffrey Crennan, Stephen Dudley, Stan Schmidt

ASSOCIATE PUBLISHER, STRATEGIC PLANNING:

Laura Salant

PROMOTION MANAGER: Diane Schube RESEARCH MANAGER: Aida Dadurian PROMOTION DESIGN MANAGER: Nancy Mongelli GENERAL MANAGER: Michael Florek BUSINESS MANAGER: Marie Maher MANAGER, ADVERTISING ACCOUNTING AND COORDINATION: Constance Holmes

DIRECTOR, SPECIAL PROJECTS: Barth David Schwartz

MANAGING DIRECTOR, ONLINE: Mina C. Lux OPERATIONS MANAGER, ONLINE: Vincent Ma SALES REPRESENTATIVE, ONLINE: Gary Bronson MARKETING DIRECTOR, ONLINE: Han Ko

DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey

PERMISSIONS MANAGER: Linda Hertz

MANAGER OF CUSTOM PUBLISHING: Jeremy A. Abbate

CHAIRMAN EMERITUS: John J. Hanley

CHAIRMAN: Brian Napack

PRESIDENT AND CHIEF EXECUTIVE OFFICER:

Gretchen G. Teichgraeber VICE PRESIDENT AND MANAGING DIRECTOR, INTERNATIONAL: Dean Sanderson VICE PRESIDENT: Frances Newburg

STICKING IT TO CALCULATORS In "When Slide Rules Ruled," Cliff Stoll mentioned that it took a 19-year-old French artillery lieutenant to popularize the slide rule. He went on to say that it now "serves as an icon of computational obsolescence." Well, I—a 24-year-old artillery lieutenant—would like to inform you that the slide rule is alive and well in the artillery community in the form of the graphical firing table. Despite having $40,000 fire-direction computers to calculate data, we still use our trusty "sticks" to double-check the solutions. And should our high technology fail, we retain the ability to deliver accurate and timely fire support, all thanks to a few dollars' worth of wood and plastic. Instead of multiplication and logarithms, our sticks have functions like quadrant elevation and time-fuze setting, but the mechanics are the same as those two generations ago. I'm happy we can do our part to keep a little piece of scientific history out of the museum and in the field.

1st Lt. Christopher Lusto, USMC Fire Direction Officer Battery G, 2nd Battalion, 11th Marines Regimental Combat Team 5 Camp Fallujah, Iraq

Stoll did not mention one of the radical effects of replacing slipsticks with cal culators: all the answers in engineering and science textbooks needed correction or revision. Their authors, usually professors, had commonly given the problems to a group of their better students to solve.

The consensus answer (ideally) or the median was taken to be correct. The slipstick's solutions of three places with rounding errors could not stand against calculators' eight-place displays, let alone 12-place readouts of 13-place computations. Indeed, current scientific calculators are more precise than the available data.

David F. Siemens, Jr.

Mesa, Ariz.

QUARKY QUERIES

In "The First Few Microseconds," Michael Riordan and William A. Zajc explain what happened in the first 10 microseconds after the big bang. The article also shows a timeline of the universe's history from its birth to 380,000 years after. According to relativity theory, mass and energy create gravity, and time passes slower in stronger gravity fields. Also, in the first moments after the big bang, the matter and energy density of the universe was ultrahigh. If so, the gravity field must have been very strong, and time must have passed very slowly. My ques

I Letters tion: Are the first 10 microseconds after the big bang equal to 10 microseconds today? Is the big bang's timeline the same time duration as in today's universe?

Fuat Bahadir Omaha, Neb.

Riordan and Zajc claim that colliders can replicate the conditions of the early universe. Might such a claim be premature, or at least overly broad, because cosmol-ogists now believe that most of the matter in the universe is "dark matter" of unknown composition? Could the infant universe have consisted primarily of precursors to exotic types of matter that we do not understand, or do most physicists believe that the dark matter arose from particles accounted for in the current theory of the big bang?

Ronald Hodges Palo Alto, Calif.

RIORDAN AND ZAJC REPLY: Bahadir is correct—gravity can affect the passage of time relative to an observer who is distant from the strong gravitational field. That was not the case in the early universe, where there were no observers far removed from the source of gravity, the very dense matter that uniformly filled the entire universe. Perhaps the best way to answer the question is this: if some hypothetical timekeeper could survive both within the fantastically hot and dense quark-gluon matter of the early universe and within the present, the 10 microseconds her clock registered in the first moments of time would be identical to the 10 microseconds measured today.

To answer Hodges's question, colliders with enough energy might be able to produce some of the dark matter particles now believed to contribute most of the matter in the universe. When the Large Hadron Collider starts operations next year at the European laboratory CERN, physicists there will search for "supersymmetric"particles predicted by certain theories. The lightest of these is the leading candidate for the mysterious dark matter. Supersymmetric particles are thought to be too heavy to be created in significant quantities at the energies of the Rel-ativistic Heavy Ion Collider (RHIC). The infant universe could indeed have consisted of precursors to such exotic types of matter, which we do not completely understand today.

POLITICAL SCIENCE The Bush administration has to learn that science is different. At first blush, the suppression of scientific voices outlined by Paul Raeburn in "Legislating

Integrity" [News Scan] seems like just another case of the administration ignoring expert opinion when it conflicts with policy; they know the answers they want and will ignore contrary evidence or judgment.

But scientific opinions are different. Elected officials and their appointees have the right to decide policy, but scientific opinions are a matter of information. Let government researchers report what they find, even if it isn't what the White House wants to hear.

Frank Palmer Chicago

Regarding "Legislating Integrity" and the accompanying sidebar, "Arm Twisting?": When a Democratic administra tion comes to power, will you be as diligent in exposing examples of the suppression of scientific opinion that is skeptical of the human contribution to global warming? I doubt it.

John H.Howe Fulton, N.Y.

HELP YOURSELF

Michael Shermer's column "SHAM Scam" [Skeptic] about self-help books quotes extensively from Steve Salerno's book SHAM: Hotv the Self-Help Movement Made America Helpless. That book does not pass muster as a serious, well-reasoned critique of the self-help industry. The tone is vitriolic, and the arguments are often based on faulty logic. There are ample critiques of the book available out there. The fundamental argument of SHAM, and the impulse to write it, seems to spring from the question: "If self-help books work, why do people have to buy them over and over again?" It is a very weak, simple-minded objection, and it does not justify labeling an entire industry insincere or deluded or evil. Replace "self-help books" with "insulin" or "church services" or even "cookbooks," and you'll see the point. As Dr. Samuel Johnson said, "People need to be reminded more often than they need to be instructed."

Name withheld via e-mail

CLARIFICATION "Eyeing Redness," by Charles Q. Choi [News Scan], stated that two of the three kinds of color photoreceptors in humans and primates are most sensitive to 550-nanometer-wavelength light, which optimizes them for detecting subtle changes in skin tone from varying concentrations of oxygenated hemoglobin. It should have noted that 550-nanometer light is green-yellow and that skin is greenish-blue when underlying veins contain deoxygenated blood; if there is a high concentration of oxygenated blood, it is reddish-blue.

BANG-UP RESEARCH: ALICE detector slated to operate at CERN in 2008 will analyze lead nuclei collisions occurring at about 50 times the energy of RHIC's mini big bangs.

50, 100 & 150 Years Ago

Was this article helpful?

0 0
Solar Stirling Engine Basics Explained

Solar Stirling Engine Basics Explained

The solar Stirling engine is progressively becoming a viable alternative to solar panels for its higher efficiency. Stirling engines might be the best way to harvest the power provided by the sun. This is an easy-to-understand explanation of how Stirling engines work, the different types, and why they are more efficient than steam engines.

Get My Free Ebook


Post a comment