Scientific American - USA (2022-06)

4 Scientific American, June 2022 Illustration by Nick Higgins

FROM

THE EDITOR Laura Helmuth is editor in chief of Scientific American.

Follow her on Twitter @laurahelmuth

BOARD OF ADVISERS

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

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

Nita A. Farahany

Professor of Law and Philosophy, Director,

Duke Initiative for Science & Society, Duke University

Jonathan Foley

Executive Director, Project Drawdown

Jennifer A. Francis

Senior Scientist and Acting Deputy Director,

Woodwell Climate Research Center

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

Co-founder, Urban Ocean Lab, and

Co-founder, The All We Can Save Project

Christof Koch

Chief Scientist, MindScope Program, Allen Institute for Brain Science

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

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.

Meg Urry

Israel Munson Professor of Physics and Astronomy, Yale University

Amie Wilkinson

Professor of Mathematics, University of Chicago

Transition Times

Our ancestors’ big break came 66 million years ago, on the worst
day in Earth’s history. An asteroid slammed into our planet, set off
tsunamis and volcanoes and wildfires, and darkened the skies for
years. The disaster was the end of the dinosaurs (aside from birds)
but a new beginning for mammals—or at least the mammals that
survived. In our cover article, starting on page 28, paleontologist
Steve Brusatte fills out this origin story with fascinating new details
about the mammals that thrived in the Before Times and a deep-
er understanding of how some survived into the After.
Childhood development is one of the richest and most produc-
tive fields of research today—there’s just so much happening from
birth through the first several years of life. The brain expands rap-
idly and builds a million connections per second, as children learn
languages and social connections and how to explore the world.
As childhood-learning researcher and physician Dana Suskind and
writer and Scientific American contributing editor Lydia Denworth
explain on page 48, research has identified two crucial factors that
encourage healthy cognitive development: protection from stress
and nurturing interactions with caregivers. The work they share
has urgent implications for policies that help children thrive.
Going deeper into how the brain learns to understand the
world, neuroscientist György Buzsáki on page 36 presents an
“inside-out” theory of brain functioning. The classic “outside-in”
conception holds that the brain starts as a blank slate and gets
inscribed by perceptions and experience. But the brain has its
own ideas about how to organize, generalize and respond to exter-
nal stimulation. Studies in people and animals and AI research
show how the brain’s internal algorithms can be used to shape
our experiences, plan ahead and learn efficiently.

Powerful flares called fast radio bursts erupt with as much

energy in an instant as our sun emits in a month. Astronomers

aren’t sure what causes the flashes, but they made a lot of prog-

ress when an especially energetic fast radio burst in 2020 was

traced back to a magnetar, an enormous remnant of a superno-

va. Not all fast radio bursts seem to come from magnetars,

though, and some may be repeaters rather than single explo-

sions. It’s a hot area of astronomy, as science writer Adam Mann

describes on page 44, and it’s poised to get hotter—fast radio

bursts might help reveal what matter they traveled through from

their origins to our telescopes.

A fundamental injustice of modern times is that privileged peo-

ple live longer, healthier lives than people who face discrimination,

disempowerment and systemic bias. Our special package on health

equity ( page S1 ) explains what we know about disparities in our

health systems and, more important, how to fix them. Heart dis-

ease, the leading killer worldwide, is even more deadly in disad-

vantaged groups. The world’s oldest pandemic, tuberculosis, has

been largely eliminated in the wealthy world but persists in pov-

erty. Mental health care should be a right, not a privilege. And you

will meet people who are finding solutions to health inequalities

across the globe and who are drawing still relevant lessons from

the HIV/AIDS epidemic.

All of us at Scientific American thank Curtis Brainard, our man-

aging editor, for leading the health equity package in this issue and

so many other innovations and projects. Curtis joined our publi-

cation in 2014 as the blogs editor and soon began overseeing all

our online content. He became managing editor in 2017 and act-

ing editor in chief in 2019 and got us through the beginning of the

COVID pandemic. Curtis is leaving Scientific American (reluctant-

ly, he says) for a sweet new job in Paris, and we all wish him well,

but gosh, we’re going to miss him!