Scientific American November 2008 299 5

112 Pages·2008·25.2 MB·English

by  Editors of Scientific American Magazine

GeoenGineerinG: How to Cool the earth—at a Price (page 46)
Special RepoRt
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PoSSiBLe?
PLUGGinG
page 68
BrAin
into the
Download new memories?
Control machines by thought?
Can this be the ultimate
computer interface?
order from Chaos
How nature “Breaks”
the Second Law
of Thermodynamics
Scan Anywhere
Mri-like Machine
Becomes Portable
DnA Logic
Program Molecules
for Work and Play
© 2008 SCIENTIFIC AMERICAN, INC.
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feAtureS n
Scientific AmericAn november 2008 n Volume 299 number 5
56
neurOScience
Jacking into the Brain
By Gary Stix
Science-fiction writers and futurists routinely
describe a day when advances in neuroscience
and information technology will make it possible
to treat the human brain like an outsize flash
drive: memories could be uploaded or down -
loaded, and complicated devices could
be controlled with no more than a thought.
But how close is any of that to reality?
Images by Kenn Brown
(wired head and metallic globe)
GeOenGineerinG 46
46 A Sunshade for Planet Earth
By Robert Kunzig
To avert global warming, some experts are willing to
consider partly shielding the earth from the sun’s rays.
PhYSicS
62 The Long Arm of 62
the Second Law
By J. Miguel Rubí
Seemingly in defiance of the second law of
thermodynamics, nature is filled with examples 68 00
of order emerging from chaos. A new theoretical
framework resolves the apparent paradox.
SPeciAL rePOrt
hiV 25 YeArS LAter:
The Big Challenges
68
69 The Vaccine Search Goes On
By David I. Watkins
The unfinished quest for an AIDS vaccine has become
a search for new approaches to the problem.
78 Can HIV Be Cured? On the cOVer
By Mario Stevenson Brain signals now can control a cursor or
Eliminating HIV from the body would require a prosthetic arm. How far will the human-machine
flushing the virus out of its hiding places. interface go? Image by Kenn Brown.
3
www.SciAm.com © 2008 SCIENTIFIC AMERICAN, INC. SCIENTIFIC AMERICAN
mOre feAtureS n
infOrmAtiOn Science
84 DNA Computers for 84
Work and Play
By Joanne Macdonald, Darko Stefanovic and
Milan N. Stojanovic
DNA logic gates may one day make medical decisions
from within your blood stream. For now, they play
a mean game of tic-tac-toe.
innOVAtiOnS
92 The Incredible
Shrinking Scanner
By Bernhard Blümich
A portable MRI-like machine can probe
the chemistry and structure of objects anywhere.
GO tO . cOm
fOcuS On ALternAtiVe enerGY q
8
SciAm.com reporters walk through the various options news
in the alternative energy landscape: geothermal power, The Key to Smaller, More Powerful Gadgets
solar power, offshore wind, wave farms, thin film, As memory demands grow and devices shrink,
current storage techniques won’t cut it.
hydrogen fuel-cell cars, electric cars, and more.
8
More at www.SciAm.com/nov2008 mind matters
Borderline Personality Disorder: No Man Is an Island
A new study provides an illuminating look into
the brains of sufferers.
8
news
A Deep Thaw: How Much Will Vanishing Glaciers
Raise Sea Levels?
Some say high, some say low, some say fast,
some say slow.
8
Science talk
Return of a Killer: Tuberculosis in Russia
Veteran journalist Merrill Goozner of the Integrity in
Science project at the Center for Science in the Public
Interest discusses the rise of tuberculosis in Russia.
mages 8 Ask the experts
Getty I What Is Histoplasmosis?
w
ne The U.S. Food and Drug Administration is ordering
mc stronger warnings on a particular class of medications
D
avi because of patient deaths from fungal infections.
D
Scientific American (ISSN 0036-8733), published monthly by Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2008 by Scientific
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
and recording for public or private use, or by any information storage or retrieval system, without the prior written permission of the publisher. Periodicals postage paid at
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ON L3P 8A2. Subscription rates: one year $34.97, Canada $49 USD, International $55 USD. Postmaster: Send address changes to Scientific American, Box 3187, Harlan,
Iowa 51537. Reprints available: write Reprint Department, Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111; [phone];
fax: [phone]. Subscription inquiries: U.S. and Canada [phone]; other [phone]. Send e-mail to [email protected] Printed in U.S.A.
4
SCIENTIFIC AMERICAN © 2008 SCIENTIFIC AMERICAN, INC. November 2008
Just understanding HIV and AIDS was challenge
enough in the earliest days of the epidemic.
Today, we know more.
But, even with progress in prevention and treatment,
we stand short of our goal – a world without HIV
and AIDS.
In medical research and public health, the path
is never easy, never a straight line from hypothesis
to solution.
Every step forward is important.
At Merck, we are just as proud of how we have advanced understanding of
HIV through our research on medicines and vaccines as we are of how our
work with partners around the world has improved access to medicines and
care for people with HIV and AIDS.
And we are not done.
Merck will continue to press forward,
working shoulder to shoulder with the global HIV community and scientific
and public health leaders to help find a way to achieve our shared goal.
The battle must be won.
For more information visit www.merck.com
dePArtmentS n
10 From the Editor 16
12 Letters
16 50, 100 and 150 Years Ago
18 Updates
18
N s
ews caN
20
100
n B acksliding on biodefense?
n L essons from failed cancer vaccines.
n D ebunking the media bias myth.
n R esetting the morning line on extinction.
ne
nn ST aovwinagrd t hthe ew ionrsltda,- fornideg teo.wel at a time. nia, irvi
n O ut on a limb to sequence the salamander. alifor
n D ata Points: Recreational injuries add up. of c
y
versit
OpiNiON ns, uni
o
38 SciAm Perspectives ati
n c
ni
Geoengineering: the wrong way to save the earth. mu
m
o
40 n Sustainable Developments versity c
By Jeffrey D. Sachs ni
u
Don’t pit today against tomorrow.
100 Insights
42 Skeptic
n Ordained as a Dominican priest, geneticist and
By Michael Shermer
evolution advocate Francisco J. Ayala sees no conflict
Stage theories of human behavior have between the sacred and the scientific.
little evidentiary support.
104 Working Knowledge
44 Anti Gravity
n Microwave ovens.
By Steve Mirsky
Hungry for science. 106 Reviews
Quantum drama. Insect societies.
The unification of forces.
108 Ask the Experts
What is touch DNA? Why do our eyelids get
so heavy when we are tired?
38 44
108
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SCIENTIFIC AMERICAN © 2008 SCIENTIFIC AMERICAN, INC. November 2008

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