Scientific American - USA (2020-04)

Illustration by Nick Higgins April 2020, ScientificAmerican.com 3

FROM

THE EDITOR

BOARD OF ADVISERS

Leslie C. Aiello

President, Wenner-Gren Foundation

for Anthropological Research

Robin E. Bell

Research Professor, Lamont-Doherty

Earth Observatory, Columbia University

Emery N. Brown

Edward Hood Taplin Professor

of Medical Engineering and of

Computational Neuro science, M.I.T.,

and Warren M. Zapol Prof essor of

Anesthesia, Harvard Medical School

Vinton G. Cerf

Chief Internet Evangelist, Google

Emmanuelle Charpentier

Scientific Director, Max Planck Institute

for Infection Biology, and Founding

and Acting Director, Max Planck Unit

for the Science of Pathogens

George M. Church

Director, Center for Computational

Genetics, Harvard Medical School

Rita Colwell

Distinguished University Professor,

University of Maryland College Park

and Johns Hopkins Bloomberg School

of Public Health

Kate Crawford

Director of Research and Co-founder,

AI Now Institute, and Distinguished

Research Professor, New York University,

and Principal Researcher,

Microsoft Research New York City

Drew Endy

Professor of Bioengineering,

Stanford University

Nita A. Farahany

Professor of Law and Philosophy,

Director, Duke Initiative for

Science & Society, Duke University

Edward W. Felten

Director, Center for Information

Technology Policy, Princeton University

Jonathan Foley

Executive Director, Project Drawdown

Jennifer Francis

Senior Scientist,

Woods Hole Research Center

Kaigham J. Gabriel

President and Chief Executive Officer,

Charles Stark Draper Laboratory

Harold “Skip” Garner

Executive Director and Professor, Primary

Care Research Network and Center for

Bioinformatics and Genetics, Edward Via

College of Osteopathic Medicine

Michael S. Gazzaniga

Director, Sage Center for the Study of

Mind, University of California,

Santa Barbara

Carlos Gershenson

Research Professor, National

Autonomous University of Mexico

Alison Gopnik

Professor of Psychology and

Affiliate Professor of Philosophy,

University of California, Berkeley

Lene Vestergaard Hau

Mallinckrodt Professor of Physics and

of Applied Physics, Harvard University

Hopi E. Hoekstra

Alexander Agassiz Professor of Zoology,

Harvard University

Ayana Elizabeth Johnson

Founder and CEO, Ocean Collectiv

Christof Koch

President and CSO,

Allen Institute for Brain Science

Morten L. Kringelbach

Associate Professor and

Senior Research Fellow, The Queen’s

College, University of Oxford

Robert S. Langer

David H. Koch Institute Professor,

Department of Chemical Engineering,

M .I.T.

Meg Lowman

Director and Founder, TREE Foundation,

Rachel Carson Fellow, Ludwig Maximilian

University Munich, and Research

Professor, University of Science Malaysia

John Maeda

Global Head, Computational Design +

Inclusion, Automattic, Inc.

Satyajit Mayor

Senior Professor,

National Center for Biological Sciences,

Tata Institute of Fundamental Research

John P. Moore

Professor of Microbiology and

Immunology, Weill Medical College

of Cornell University

Priyamvada Natarajan

Professor of Astronomy and Physics,

Yale University

Donna J. Nelson

Professor of Chemistry,

University of Oklahoma

Robert E. Palazzo

Dean, University of Alabama at

Birmingham College of Arts and Sciences

Rosalind Picard

Professor and Director,

Affective Computing, M.I.T. Media Lab

Carolyn Porco

Leader, Cassini Imaging Science Team,

and Director, CICLOPS,

Space Science Institute

Lisa Randall

Professor of Physics, Harvard University

Martin Rees

Astronomer Royal and Professor

of Cosmology and Astrophysics,

Institute of Astronomy,

University of Cambridge

Daniela Rus

Andrew (1956) and Erna Viterbi Professor

of Electrical Engineering and Computer

Science and Director, CSAIL, M.I.T.

Eugenie C. Scott

Chair, Advisory Council,

National Center for Science Education

Terry Sejnowski

Professor and Laboratory Head of

Computational Neurobiology Laboratory,

Salk Institute for Biological Studies

Meg Urry

Israel Munson Professor of Physics

and Astronomy, Yale University

Michael E. Webber

Co-director, Clean Energy Incubator,

and Associate Professor,

Department of Mechanical Engineering,

University of Texas at Austin

George M. Whitesides

Professor of Chemistry and Chemical

Biology, Harvard University

Amie Wilkinson

Professor of Mathematics,

University of Chicago

Anton Zeilinger

Professor of Quantum Optics, Quantum

Nanophysics, Quantum Information,

University of Vienna

Curtis Brainard is acting editor in chief of Scientific American.

Follow him on Twitter @cbrainard

We Are Here

Anyone living in Manhattan can tell you that of all the wonders

the urban lifestyle affords, great vistas of the city itself are not one

of them. Sweeping views of this American metropolis are avail-

able only from the outside, from places like New Jersey or Queens.

Researchers who study the Milky Way have the same problem.

They cannot see the entirety of our galaxy, because, along with

the rest of us, they’re right in the thick of it. And yet there is no

cosmic equivalent of hopping the next train to Hoboken or Long

Island City to gain the panoramic perspective they so desire.

Thankfully, radio telescopes offer a solution, as astronomers

Mark  J. Reid and Xing-Wu Zheng explain in this month’s cover

story ( page  28 ). Using thousands of hours of observations from

several projects, they and their colleagues were able to map the

spiral structure of the Milky Way in unprecedented detail and

better pinpoint our solar system’s location therein. The result is

a stunning new picture of the whirlpool of stars we call home.

Vying for the title of most amazing image in this issue is a

magnificent portrait of Tullbergia mediantarctica, an animal

smaller than a sesame seed. This so-called extremophile makes

its unlikely home on the slopes of the Transantarctic Mountains,

hemmed in by crushing ice on one side and toxic soils on the

other. First glimpsed in 1964 but only rediscovered two years ago,

it belongs to a group of primitive, wingless relatives of insects

called springtails.

They have survived more than 30 ice ages, yet so delicate are

these creatures that they shrivel and die almost as soon as the

rocks under which they live are overturned. Thus, we had no idea

what the outcome would be when the biologists who found them

generously agreed to ship a few of the prize specimens to be pho-

tographed. But Igor Siwanowicz, a neurobiologist at the Howard

Hughes Medical Institute, who specializes in capturing images

of tiny creatures with a laser-scanning microscope and other

tools, pulled it off with aplomb. And as journalist Douglas Fox

reports, Tullbergia is now rewriting the history of Antarctica.

Turn to “Extreme Survivor,” on page 50, to explore more.

Here’s something else to chew on: paleontologist Peter  S.

Ungar’s fascinating tale ( page 44 ) about the evolution of human

teeth and the shocking revelation that we in the modern world

have many more dental problems than our ancient ancestors. As

he explains, “Although teeth endure for millions of years in the

fossil record, ours cannot seem to last a lifetime in our mouths.”

That is because our chompers are “a miracle” of evolutionary

design at the both macroscopic and microscopic levels, forged in

the oral crucible over hundreds of millions of years. But begin-

ning with the transition from foraging to farming during the

Neolithic period 10,000 years ago and continuing through the

Industrial Revolution, humans began eating softer, more carbo-

hydrate-rich foods to which our dental environment is ill adapted.

The consequences are the impacted molars, cavities and gum dis-

ease that are so common today.

Stories like these help us to understand our place in the cos-

mos, the history of our planet and its beguiling denizens, as well

as the rather astonishing reason so many people have bad teeth.

Moreover, I hope they all instill a respect for life at the grandest

scales of space and time.

© 2020 Scientific American