Scientific American-September 2007 - Ann Hetzel Gunkel

97 Pages·2007·9.75 MB·English

by  Scientific American, Inc.

SPECIAL ISSUE: Diet, Health and the Food Supply
The
Threat of
TAINTED
FOODS
page 112
September 2007 www.SciAm.com
FEAST FAMINE
and
The Global Paradox of Obesity and Malnutrition
N ot Just Calories
C omplex Causes
o f Weight Gain
G ene Tech
C an It Help End
W orld Hunger?
Chocoholic
N euroscience of
Food Addictions
P ounds of Cure
Healthier to Be Overweight?
© 2007 SCIENTIFIC AMERICAN, INC.
FEATURES ■
SCIENTIFIC AMERICAN September 2007 ■ Volume 297 Number 3
SPECIAL ISSUE
Feast and Famine
INTRODUCTION
54 A Question of Sustenance
By Gary Stix
Globalization ushered in a world in which more
than a billion are overfed. Yet 800 million or so
still suffer from hunger’s persistent scourge.
NUTRITION
60 Eating Made Simple
By Marion Nestle
How do you cope with a mountain of confl icting
diet advice? Also: Paul Raeburn reviews the best
scientifi c guidance on weight loss.
HEALTH
70 Can Fat Be Fit?
60
By Paul Raeburn
Popular books have questioned the ill effects of
being overweight. They are probably wrong.
PHYSIOLOGY
72 What Fuels Fat
By Jeffrey S. Flier and
70
Eleftheria Maratos-Flier
Understanding obesity as a breakdown in
the body’s weight regulation could yield new
ways to fi ght fat.
OBESITY AND ADDICTION
84 This Is Your Brain on Food
Interview with Nora D. Volkow
by Kristin Leutwyler Ozelli
Neuroimaging reveals what chocoholics have
in common with drug addicts.
72 88
EMERGING PROBLEMS
88 The World Is Fat
By Barry M. Popkin
Cover by Kenn Brown (illustration), James Porto (photography
How can the poorest countries fi ght obesity?
and photocomposition) and Brett Kurzweil (food styling).
SPECIAL ISSUE PODCASTS SHARE YOUR THOUGHTS
Listen to interviews with contributing authors Post your comments about articles in this
from this special issue each week in September special issue on our Editors’ Blog.
at www.SciAm.com Go to www.SciAm.com/ontheweb
5
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© 2007 SCIENTIFIC AMERICAN, INC.
MORE FEATURES ■
MALNUTRITION 112
96 Still Hungry
By Per Pinstrup-Andersen and Fuzhi Cheng
One eighth of the world does not have enough to eat.
BIOTECHNOLOGY
104 Sowing a Gene Revolution
By Terri Raney and Prabhu Pingali
A new green revolution based on genetically modifi ed
96
crops could help reduce poverty and hunger, but only
if formidable institutional challenges are met.
SECURITY
112 Is Your Food Contaminated?
Safe to Grow—and Eat?
By Mark Fischetti
Transgenic crops could help feed a hungry world, but they are
New approaches to protect the food supply. controversial. Why? Go to www.SciAm.com/ontheweb
SciAm.com
Rebuilding Ecosystems
CULTURED NEURONS (below) grown atop a polymer panel
studded with electrodes were induced to encode persistent
memories for
the first time
Europe may be a better candidate for rewilding than
ever. The North America, given the existence of close living
results augur relatives of its extinct megafauna.
a future in
which neu- HNaecwkesr:s W, Pinhdoonwe CFailmlls ,K EeMepPss Out OTO ()lion
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NICO S
Scientifi c American (ISSN 0036-8733), published monthly by Scientifi c American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2007 by Scientifi c
American, Inc. All rights reserved. No part of this issue may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying
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8
SCIENTIFIC AMERICAN September 2007
© 2007 SCIENTIFIC AMERICAN, INC.
DEPARTMENTS ■
12 From the Editor 20
14 Letters
18 50, 100 and 150 Years Ago
20 Updates
120
N S
EWS CAN
22
■ Psychosocial effects of Katrina.
■ A genetic basis for speaking Chinese?
■ Muons to detect smuggled nuclear material.
■ Growing nerve cells for spinal cord repair.
■ Hacking HD DVD and Blu-ray disks.
■ COROT’s search for Earth-like planets.
■ Data Points: “Green Man” is not so green.
O
PINION
38 SciAm Perspectives
■
Can you trust food studies?
40 ■ Sustainable Developments OHER 50
O
TBayr gJeeftefdre iyn vDes.t Smaecnhtss can trump a region’s ATHLEEN D
K
geographic disadvantages.
50 Insights
42 Forum
■ Lene Vestergaard Hau can bring light to a stop,
By C. Konrad Gelbke extinguish it and revive it—thereby
Full speed ahead for an accelerator. bringing quantum information a new look.
44 ■ Skeptic 118 Working Knowledge
By Michael Shermer Desalination of seawater.
An open letter on faith to Messrs. Dawkins,
120 Reviews
Dennett, Harris and Hitchens.
Cyclic universe.
48 Anti Gravity
■ The language conundrum.
By Steve Mirsky Nuclear terror.
What’s the big idea?
124 Ask the Experts
Why did humans lose
their body hair?
126
How can opera singers
be heard over orchestras?
126 Fact or Fiction?
Do living people
outnumber the dead?
42 124
10
SCIENTIFIC AMERICAN
© 2007 SCIENTIFIC AMERICAN, INC.
Page Intentionally Blank
SCIENTIFIC AMERICAN Digital
FROM THE EDITOR ■
A ll You Can’t Eat
The paradoxes of the modern diet need to be tamed
If our civilization should weight-loss diets work and how many ex-
someday collapse, then— tra pounds we can pack without risk. The
with apologies to McDon- traditional advice in favor of exercise and
ald’s—let this be its epitaph: moderation still applies: take the stairs,
“Billions and billions served.” leave the cannoli.
Humanity has come a long way from its At the physiological level, we are al-
hunter-gatherer roots. Thanks to indus- most unchanged from our hunter-gather-
trial-age agricultural production, global er ancestors. We carry elaborate regulato-
commerce and the 20th century’s green ry circuits in our heads and guts that
revolution in farming, the world can sup- helped us survive back when periodic fam-
port billions of people who once would ine was common and sweet, fatty desserts
not have found enough to eat. But good- were not. The article from Jeffrey S. Flier
ness, look what we’re feeding them. and Eleftheria Maratos-Flier (“What Fu-
Modern culinary extravagances in- els Fat,” on page 72) and the interview
clude high caloric fantasies lacking even a with Nora D. Volkow (“This Is Your
twig’s worth of nutrients, and poor na- Brain on Food,” on page 84) explain what
tions are among their most avid consum- those holdovers mean for us today.
ers. Widespread obesity and malnutrition Barry M. Popkin, in “The World Is Fat”
exist side by side—sometimes even within (page 88), and Per Pinstrup-Andersen and
Among Our
the same people. The world has become a Fuzhi Cheng, in “Still Hungry” (page 96),
Contributors
place simultaneously of overabundance describe the nutritional Scylla and Cha-
and aching starvation: the cornucopia and rybdis through which developing nations
JEFFREY S. FLIER
the empty cupboard in one. now navigate. Populations that escape
Biomedical researcher
Harvard Medical School In this special issue, Scientifi c Amer- famine by fi lling their bellies with cheap
After serving as professor of medicine ican explores the relation between human snacks and soda set themselves up for dif-
for many years, he was recently appointed
dean of Harvard’s Faculty of Medicine. health and food, which has never been ferent sets of health concerns in the future.
more complicated and paradoxical. A controversial remedy for hunger might
MARION NESTLE
After gobbling down mountains of be to embrace genetically modifi ed crops;
Professor of food studies
New York University chips, rivers of cream, stampedes of beef Terri Raney and Prabhu Pingali suggest as
Her books Food Politics, Safe Food and and poppin’ fresh boxcars of baked goods, much in their piece (“Sowing a Gene Rev-
What to Eat explore the scientifi c and social
infl uences on diet. many of us fret over which best-selling olution,” on page 104).
diet book can salvage our health and help The public has become acutely aware
PRABHU PINGALI
Agricultural economist us see our toes again. Are we expecting too that the food supply is increasingly vulner-
Food and Agriculture Organization much? Nutritionist Marion Nestle able, both to terrorist actions and to acci-
(FAO)
says yes. In “Eating Made Simple” dental contamination. Check out “Is
Earlier this year he was elected to the
U.S. National Academy of Sciences as (beginning on page 60), she lays out Your Food Contaminated?”—Mark
a foreign associate.
why the state of nutritional science Fischetti’s sobering overview of the situ-
BARRY M. POPKIN is still too incomplete to make de- ation and of the technological fi xes
Nutritional epidemiologist tailed prescriptions for individual that might help restore a measure of
Uatn Civhearpsietly H oifl lNorth Carolina well-being. Journalist Paul Rae- security, starting on page 112. N ()food
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aSahnnend u iAsa gcl rhpiicueubfl lteiucdraietto.ior no,f T thhee SFtAaOte’s o f Food 7p0ec)t, aatilosnos daebfoluatt ehso wex w- ell eJdOiHtoNr RinE NchNiIeEf FLYNN LARSE
12
SCIENTIFIC AMERICAN September 2007
© 2007 SCIENTIFIC AMERICAN, INC.
LETTERS �
[email protected]
®
Martian Molecules Cancer Quantum Theory
� �
Established 1845
EDITOR IN CHIEF: John Rennie
EXECUTIVE EDITOR: Mariette DiChristina
MANAGING EDITOR: Ricki L. Rusting
CHIEF NEWS EDITOR: Philip M. Yam “If the science of a body of work is
SENIOR WRITER: Gary Stix
SENIOR EDITOR: Michelle Press solid, it deserves publication
EDITORS: Mark Alpert, Steven Ashley,
regardless of who produced it.”
Graham P. Collins, Mark Fischetti, Steve Mirsky,
George Musser, Christine Soares
—Ethan Gutierrez EMBUDO, N.M.
CONTRIBUTING EDITORS: W. Wayt Gibbs,
Marguerite Holloway, Michael Shermer,
Sarah Simpson
EDITORIAL DIRECTOR, ONLINE: Kate Wong MAY 2007
NEWS EDITOR, ONLINE: Lisa Stein
ASSOCIATE EDITORS, ONLINE: David Biello, � Dubious Disclaimer? scorn for his HIV denial. We therefore chose to make
Christopher Mims
NEWS REPORTERS, ONLINE: JR Minkel, I applaud Scientifi c American’s deci- our positions clear in the Perspectives column.
Nikhil Swaminathan sion to publish Peter Duesberg’s article on
cancer [“Chromosomal Chaos and Can- � Cancer and Complexity
ART DIRECTOR: Edward Bell
cer”] despite consensus against his belief Duesberggives an informative and dif-
ASSOCIATE ART DIRECTOR: Mark Clemens
ASSISTANT ART DIRECTOR: Johnny Johnson that HIV is not linked to AIDS. I was dis- ferent perspective of aneuploidy as a pos-
PHOTOGRAPHY EDITOR: Emily Harrison appointed, however, to fi nd the editors sible cause of cancer, but in the process he
PRODUCTION EDITOR: Richard Hunt
apologizing for doing so in “When Pari- makes unwarranted attacks on the theory
COPY DIRECTOR: Maria-Christina Keller ahs Have Good Ideas” [Perspectives]. of gene mutation as a cause. Although
COPY CHIEF: Daniel C. Schlenoff The beauty of science is that it is not gene mutation alone cannot explain can-
COPY AND RESEARCH: Michael Battaglia,
predicated on trust. Repeatable experi- cer fully, its role in many cancers cannot
John Matson, Aaron Shattuck, Smitha Alampur,
Michelle Wright ments render the messenger irrelevant. If be overlooked. Cancers are robust, hetero-
the science of a body of work is solid, it geneous systems with multiple causes and
EDITORIAL ADMINISTRATOR: Jacob Lasky
deserves publication regardless of who in general involve the complex interplay
SENIOR SECRETARY: Maya Harty
produced it. Further, it is my understand- between the immune system, the aging
ASSOCIATE PUBLISHER, PRODUCTION: ing that Duesberg’s cancer research re- process, epigenetics, gene mutation and
William Sherman
mains reputable. Do we consider Michael aneuploidy. Any simplistic theory like the
MANUFACTURING MANAGER: Janet Cermak
ADVERTISING PRODUCTION MANAGER: Carl Cherebin Jordan any less a basketball player be- gene mutation theory that Duesberg paints
PREPRESS AND QUALITY MANAGER: Silvia De Santis cause his performance at baseball was cannot possibly explain all the observed
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sometimes less than stellar? Although I characteristics of cancers, and his alterna-
CUSTOM PUBLISHING MANAGER:
Madelyn Keyes-Milch may disagree with Duesberg’s premise re- tive aneuploidy theory is no exception.
garding HIV, I believe no one’s work (For example, Duesberg asserts that the
should be discounted simply because he or gene mutation theory cannot explain the
BOARD OF ADVISERS
she has held an unpopular opinion. long latency in carcinogen-caused cancers,
RITA R. COLWELL
Ethan Gutierrez but aneuploidy evolves faster than gene
Distinguished Professor, University of Maryland
Embudo, N.M. mutation, making his theory even less like-
College Park and Johns Hopkins University
Bloomberg School of Public Health ly.) Gene mutation and aneuploidy can
THE EDITORS REPLY: We do not apologize for pub- work hand in hand in carcinogenesis. One
VINOD KHOSLA
Founder, Khosla Ventures lishing “Chromosomal Chaos and Cancer.” But as does not have to discredit the prevailing
considerable mail and online commentary have dem- theory to fi nd the cause of the disease.
M. GRANGER MORGAN
Professor and Head of Engineering and Public Policy, onstrated, not all readers are as fair-minded as Wai Wong
Carnegie Mellon University Gu tier rez in separating Duesberg’s work on cancer Mitcham, Australia
LISA RANDALL from his denial of the realities of HIV. We did not
Professor of Physics, Harvard University want anyone to misinterpret—or misuse—his Sci- � Oxygen Link?
GEORGE M. WHITESIDES entific American article on the former as a tacit I believe that the two possible sources
Professor of Chemistry, Harvard University endorsement of the latter. Conversely, we also did of methane on Mars presented in “The
not want anyone to skip Duesberg’s article out of Mystery of Methane on Mars and Titan,”
14
SCIENTIFIC AMERICAN September 2007
© 2007 SCIENTIFIC AMERICAN, INC.
LETTERS �
by Sushil K. Atreya, should release three seem to ultimately result in three oxygen atoms and by paying close attention to its surface material. strained by Heisenberg’s uncertainty principle,
atoms of oxygen for every molecule of one methane molecule. This is somewhat misleading, which tells us that better knowledge of one thing
methane, but Atreya does not mention however, because oxygen atoms form oxygen mole- � Quantum Query automatically implies poorer knowledge of some- ®
oxygen. Has thought been given to testing cules and also destroy methane and other organics. According to “A Do-It-Yourself Quan- thing else. Further, the intrinsic wave nature of all ASSOCIATE PUBLISHER, STRATEGIC PLANNING:
Established 1845 Laura Salant
for a corresponding amount of oxygen to Thus, on Mars oxygen most likely partitions into tum Eraser,” by Rachel Hillmer and Paul particles does imply that no object has a true “hard
CHAIRMAN: Brian Napack PROMOTION MANAGER: Diane Schube
corroborate these sources? formaldehyde, methanol, peroxides, carboxylic acid Kwiat, the interference pattern created edge.” (Even in a simple hydrogen atom, the loca- VICE PRESIDENT AND MANAGING DIRECTOR, RESEARCH MANAGER: Aida Dadurian
Stephen R. Troy or another form on reactions with ambient minerals, when a photon can travel through either of tion of the electron is smeared out around the nucle- INTERNATIONAL: Dean Sanderson PROMOTION DESIGN MANAGER: Nancy Mongelli
Arnold, Md. gases and fluids. Unless the source of these oxygen- two slits is destroyed by knowledge of us, with an exponentially decreasing likelihood of VICE PRESIDENT: Frances Newburg GENERAL MANAGER: Michael Florek
CHAIRMAN EMERITUS: John J. Hanley BUSINESS MANAGER: Marie Maher
containing molecules is continuous or they are which path it took. But if only one observ- finding it the farther away it is from the proton.) MANAGER, ADVERTISING ACCOUNTING AND
ATREYA REPLIES: Production of sequestered in the soil or rocks, the detection of er gains this knowledge, is the effect the ASSOCIATE PUBLISHER, CIRCULATION: Simon Aronin COORDINATION: Constance Holmes
CIRCULATION DIRECTOR: Christian Dorbandt
methane requires a react ion these molecules would be difficult because of their same for other observers? ERRATUM “Medieval Quasicrystals,” by JR Min- RENEWALS MANAGER: Karen Singer DIRECTOR, SPECIAL PROJECTS: Barth David Schwartz
between carbon and hy - short life span. Nevertheless, the mass spectrometer Also, as nothing can be measured with kel [News Scan], includes a photograph of tile work FULFILLMENT AND DISTRIBUTION MANAGER:
drogen. Oxygen, though on the Sample Analysis Suite of the 2009 Mars Sci- total accuracy, is everything in quantum from a Turkish mosque incorrectly identified as an Rosa Davis MANAGING DIRECTOR, ONLINE: Mina C. Lux
DIRECTOR, WEB TECHNOLOGIES, ONLINE: Vincent Ma
unnec essary, can be in - ence Laboratory can detect very small amounts of fl ux, without defi nite size or shape? example of a quasicrystal, a complex pattern that VICE PRESIDENT AND PUBLISHER: Bruce Brandfon SALES REPRESENTATIVE, ONLINE: Gary Bronson
volved if it is incorp- gases, either directly or after releasing them from sol- John S. Somerset never repeats. Tile work from the Darb-i Imam shrine SALES DEVELOPMENT MANAGER: David Tirpack
SALES REPRESENTATIVES: Jeffrey Crennan, DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey
orated into the reacting ids by pyrolysis. Birmingham, Ala. in Isfahan, Iran, which forms a pattern that repeats Stephen Dudley, Stan Schmidt PERMISSIONS MANAGER: Linda Hertz
molecules. A key reac- On Titan, extremely low temperatures in the but could be extended to make a quasicrystal, can
tion between four car- interior, surface and atmosphere allow only very KWIAT REPLIES: Quantum interference does not be seen at www.SciAm.com/ontheweb
bon monoxide and two basic oxygen reactions. The best hope of finding actually depend on any observer. To lose interfer- How to Contact Us
PERMISSIONS
water molecules would oxygen-bearing molecules—discounting small ence in the two-slit experiment, it is sufficient that Letters to the Editor SUBSCRIPTIONS FDoerp paertrmmeisnstio, Snc tioe nctoipfi yc oArm reeuriscea nm, aterial: Permissions
amounts of carbon monoxide and carbon dioxide the “which path?” information could be obtained by For new subscriptions, renewals, gifts, payments, and 415 Madison Ave., New York, NY 10017-1111;
CREATING AN changes of address: U.S. and Canada, 800-333-1199; out- www.SciAm.com/permissions or 212-451-8546 for
ATMOSPHERE: Mars’s in the air—is on the surface. The Huygens probe’s some hypothetical observer, even if none existed. Send letters to [email protected] or to side North America, 515-248-7684 or www.SciAm.com procedures. Please allow three to six weeks for processing.
methane derives either gas chromatograph mass spectrometer was able As to the second question, there are some things Scientifi c American, 415 Madison Ave., New REPRINTS ADVERTISING
callefrdo sfmreo rapm reo lnicvtkii-nnwigza abttaeicort nree.raiac toior n Astoun rmyf aefucaetsu,u rrewe mhthiicesh sgi oaansrese s t coeuv Tarirpteaonnrta lwtye idlbl efbrioen mgw Teailntl aasnel’yrszv ieecddy . wwnuehm iccabhne crm aoenfa abstueor mec owsu imtnhat eckodinm. gOp ultehpte ear a pqcacuuratrinactcuiytl,ai esrsu m cahor elae scc tuohlnee- , NASA/JPL/MSSS Yoleofn rSgkct,i heN naYtn i1fid 0 cc0 lA1am7r.i teLyre.i tctaenr sa nbde cmoamye b teh ee dpirtoepde frotry TA2o1m 2oe-r4rdi5ce1ar -nr8e, 8p47r1i75n, t Mfsa oaxfd: a2isr1ot2inc- 3lAe5vs5e: -.R0, eN4p0erw8in; t Yr Deoperkrpi,na NrtstYm@ 1e0Snc0ti1,A 7Sm-c1i.1ec1no1tmi;fi c stwhawele Uws .r.SSe.cp airAnemsde .inncto oamtthi vheears sc ooeflu eSnccttirreioennst.ii cfi cc oAnmtaecrtic iannfo irnm aallt rioeng ifoonr s of
16 17
SCIENTIFIC AMERICAN September 2007 www.SciAm.com SCIENTIFIC AMERICAN
© 2007 SCIENTIFIC AMERICAN, INC.
LETTERS �
by Sushil K. Atreya, should release three seem to ultimately result in three oxygen atoms and by paying close attention to its surface material. strained by Heisenberg’s uncertainty principle,
atoms of oxygen for every molecule of one methane molecule. This is somewhat misleading, which tells us that better knowledge of one thing
methane, but Atreya does not mention however, because oxygen atoms form oxygen mole- � Quantum Query automatically implies poorer knowledge of some- ®
oxygen. Has thought been given to testing cules and also destroy methane and other organics. According to “A Do-It-Yourself Quan- thing else. Further, the intrinsic wave nature of all ASSOCIATE PUBLISHER, STRATEGIC PLANNING:
Established 1845 Laura Salant
for a corresponding amount of oxygen to Thus, on Mars oxygen most likely partitions into tum Eraser,” by Rachel Hillmer and Paul particles does imply that no object has a true “hard
CHAIRMAN: Brian Napack PROMOTION MANAGER: Diane Schube
corroborate these sources? formaldehyde, methanol, peroxides, carboxylic acid Kwiat, the interference pattern created edge.” (Even in a simple hydrogen atom, the loca- VICE PRESIDENT AND MANAGING DIRECTOR, RESEARCH MANAGER: Aida Dadurian
Stephen R. Troy or another form on reactions with ambient minerals, when a photon can travel through either of tion of the electron is smeared out around the nucle- INTERNATIONAL: Dean Sanderson PROMOTION DESIGN MANAGER: Nancy Mongelli
Arnold, Md. gases and fluids. Unless the source of these oxygen- two slits is destroyed by knowledge of us, with an exponentially decreasing likelihood of VICE PRESIDENT: Frances Newburg GENERAL MANAGER: Michael Florek
CHAIRMAN EMERITUS: John J. Hanley BUSINESS MANAGER: Marie Maher
containing molecules is continuous or they are which path it took. But if only one observ- finding it the farther away it is from the proton.) MANAGER, ADVERTISING ACCOUNTING AND
ATREYA REPLIES: Production of sequestered in the soil or rocks, the detection of er gains this knowledge, is the effect the ASSOCIATE PUBLISHER, CIRCULATION: Simon Aronin COORDINATION: Constance Holmes
CIRCULATION DIRECTOR: Christian Dorbandt
methane requires a react ion these molecules would be difficult because of their same for other observers? ERRATUM “Medieval Quasicrystals,” by JR Min- RENEWALS MANAGER: Karen Singer DIRECTOR, SPECIAL PROJECTS: Barth David Schwartz
between carbon and hy - short life span. Nevertheless, the mass spectrometer Also, as nothing can be measured with kel [News Scan], includes a photograph of tile work FULFILLMENT AND DISTRIBUTION MANAGER:
drogen. Oxygen, though on the Sample Analysis Suite of the 2009 Mars Sci- total accuracy, is everything in quantum from a Turkish mosque incorrectly identified as an Rosa Davis MANAGING DIRECTOR, ONLINE: Mina C. Lux
DIRECTOR, WEB TECHNOLOGIES, ONLINE: Vincent Ma
unnec essary, can be in - ence Laboratory can detect very small amounts of fl ux, without defi nite size or shape? example of a quasicrystal, a complex pattern that VICE PRESIDENT AND PUBLISHER: Bruce Brandfon SALES REPRESENTATIVE, ONLINE: Gary Bronson
volved if it is incorp- gases, either directly or after releasing them from sol- John S. Somerset never repeats. Tile work from the Darb-i Imam shrine SALES DEVELOPMENT MANAGER: David Tirpack
SALES REPRESENTATIVES: Jeffrey Crennan, DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey
orated into the reacting ids by pyrolysis. Birmingham, Ala. in Isfahan, Iran, which forms a pattern that repeats Stephen Dudley, Stan Schmidt PERMISSIONS MANAGER: Linda Hertz
molecules. A key reac- On Titan, extremely low temperatures in the but could be extended to make a quasicrystal, can
tion between four car- interior, surface and atmosphere allow only very KWIAT REPLIES: Quantum interference does not be seen at www.SciAm.com/ontheweb
bon monoxide and two basic oxygen reactions. The best hope of finding actually depend on any observer. To lose interfer- How to Contact Us
PERMISSIONS
water molecules would oxygen-bearing molecules—discounting small ence in the two-slit experiment, it is sufficient that Letters to the Editor SUBSCRIPTIONS FDoerp paertrmmeisnstio, Snc tioe nctoipfi yc oArm reeuriscea nm, aterial: Permissions
amounts of carbon monoxide and carbon dioxide the “which path?” information could be obtained by For new subscriptions, renewals, gifts, payments, and 415 Madison Ave., New York, NY 10017-1111;
CREATING AN changes of address: U.S. and Canada, 800-333-1199; out- www.SciAm.com/permissions or 212-451-8546 for
ATMOSPHERE: Mars’s in the air—is on the surface. The Huygens probe’s some hypothetical observer, even if none existed. Send letters to [email protected] or to side North America, 515-248-7684 or www.SciAm.com procedures. Please allow three to six weeks for processing.
methane derives either gas chromatograph mass spectrometer was able As to the second question, there are some things Scientifi c American, 415 Madison Ave., New REPRINTS ADVERTISING
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50, 100 & 150 YEARS AGO ■
In Scientific American
Crick’s Progress Flight Incentive Flame Tamer
■ ■
Compiled by Daniel C. Schlenoff
SEPTEMBER 1957
submits a most valuable and scientific and presented to the Aero Club of Ameri-
DNA—“ It is diffi cult to resist the conclu- work in which are detailed exhaustive ex- ca. The trophy commemorates Langley’s
sion that DNA is genetic material. If that periments done through six years by him aerodrome, which was the first motor-
is the case, our problem is to learn how and his colleagues at Yale. He concludes driven model aeroplane to make a success-
DNA reproduces itself. The double-helical that the dietary standards are much too ful fl ight of over half a mile.”
structure of DNA suggests a possible an- high; and that better health, increased ef-
swer, which I have discussed in a previous fi ciency, and greater chances of longevity SEPTEMBER 1857
article. The basic idea is that the two would certainly follow upon our reducing
chains of the DNA, which fi t together as a our proteids at least fi fty per cent.” COUNTING WATER—“ Liberal supplies of
hand fi ts into a glove, are separated in water in cities are a blessing which cannot
some way and the hand then acts as a be too highly appreciated. To prevent
mold for formation of a new glove while waste, however, there is a necessity of
the glove acts as a mold for a new hand. some method of recording the quantity
Thus we fi nish up with two gloved hands used in each household or establishment.
where we had only one before. In chemical The meter represented in the accompany-
terms we imagine that monomers supplied ing engravings is so arranged as to require
by the cell align themselves along the mold no packed parts, to work practically inde-
chain with complementary bases pairing pendent of friction, and to afford a means
up. —F.H.C. Crick” of measuring with great accuracy whether
the fl ow be rapid or extremely slow.”
PUGWASH CONFERENCE—“ For six days last
July, 22 scientists from 10 countries met in TELEGRAPH CONTROL—“The news burst on
the hamlet of Pugwash in Nova Scotia to India like a thunderclap that the native
talk about ‘the perils to humanity posed regiments at Meerut and Delhi had muti-
by the development of weapons of mass nied, murdered their offi cers, massacred
destruction.’ Financed by the Cleveland all the English inhabitants of Delhi, placed
industrialist Cyrus Eaton, a native of Pug- the King of Delhi on the throne and threat-
wash, the conference was the culmination ened the empire. All this happened on the
of an appeal for such a meeting made two 11th of May. On the 13th it was known by
years ago by Albert Einstein and Bertrand WATER METER (needs miniaturization), 1857 telegraph to Europeans only throughout
Russell. The group includes scientists India—I say to Europeans only, for imme-
from the U.S., the U.S.S.R., China and Ja- AERO TROPHY—“ Nearly four years ago the diately the post was stopped, and an em-
pan. They began by agreeing to ‘say noth- Wright brothers, in this country, an- bargo placed on all native correspondence.
ing which might seem to favor one rather nounced the successful application by It is not too much to say that the telegraph
than the other of the two great groups of them of a gasoline motor to an aeroplane. saved India. —London Times”
powers into which the world is divided.’” No public demonstration has ever been
made by them, however; and although, THE HOTTEST STYLES—“ Many ladies have
[EDITORS’ NOTE: The latest on Pugwash according to their own statements and been burnt to death by their light gauze
Conferences is at www.pugwash.org] tthheo sper oobfl eemye,w stiitlnl emssaensy, ptheoeyp lhe advoeu bsot ltvheids. ianngd u cpa bmebforirce dthreerses ews atsa tkiimnge tfio r eex atnindg buliashz- MBER 12, 1857
SEPTEMBER 1907 Athte a nnye wra stec,i eitn icse p wroiblla bbele m thaadte p broyg orethsse rins, tmhoe sflt alimabel.e Atoc tthreiss,s aesn da nthde dtaalnenseteuds eCs laarrae O. 1, SEPTE
GceLnOtRuIrOyU aSg FoO—OtDh—e “t iTmhee o df itehtee ttihcr eveic-be ootft lae aonf dh etahvaite irn- tthimane- tahire rme awcihlli nbees s peveerrfeacl tkeidn.d Ist Wwaeyb.s Itte ro uagnhdt ,o tthheerres f olorset, ttoh ebire lgievnese rtahlliys N, VOL. XII, N
men—was alcoholic; now, we Americans, is with the idea of encouraging inventors known that by steeping the dress, or ma- CA
at least, eat too much, especially too much in this line by giving them a valuable ob- terial com posing it, in a diluted solution MERI
A
C
meat. It is the concomitant of our prosper- ject of art worth winning, that the Scien- of chloride of zinc, it will be rendered per- NTIFI
ity. And to this effect Prof. Chittenden tifi c American trophy has been completed fectly fi re-proof.” CIE
S
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SCIENTIFIC AMERICAN September 2007
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