科学美国人 Scientific American 2021年5月英文版 PDF电子版百度网盘下载

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Appreciation

It seems like every conversation these days quickly turns to
COVID vaccines: Which of your dear ones have gotten a shot,
when are you due for your booster, did you have any side effects?
Social media is filling up with selfies of people showing off their
“I got vaccinated” stickers in the post-vax observation rooms,
bursting with a mix of joy and relief and gratitude that you can
see in their eyes above their masks. (Another newly relevant pan-
demic word: “smizing,” or smiling in a way that’s visible in your
eyes.) Our Scientific American publisher, Jeremy Abbate, asked
his mom if she felt any side effects from her second shot, and she
said, “An acute appreciation for science.” He shared the exchange
on Twitter, and about a quarter of a million people hit the heart-
shaped “like” button. I’m sure I’m not the only one who would
like to safely elbow-bump Jeremy’s mom and every single scien-
tist who worked on the vaccines, as well as everyone who pro-
duced, transported and delivered them, all the volunteers who
are helping with outreach and recruitment, and everyone who
has socially distanced and masked up and abided by the latest
research and public health recommendations. Thanks to you,
people are alive today who would have died.
Some of the people who have sacrificed the most during the
pandemic are schoolkids and college students. Their COVID iso-
lation has hit while they are developing social and emotional intel-
ligence, finding a sense of purpose and understanding their place
in the world. New research on the adolescent brain, shared
by writer and Scientific American contributing editor Lydia
Denworth on page 56, emphasizes that this is a time of opportu-
nity for helping young people flourish, despite the challenges.
Our photo-essay on page 66 may make you recall the smell
of classroom chalk dust. Photographer Jessica Wynne has trav-
eled the world (at least until COVID) to document mathemati-
cians’ blackboards, which, as space and physics editor Clara
Moskowitz narrates, attempt to “reveal universal truth.”
The universe, by the way, is big. “Vastly, hugely, mind-bog-
glingly big,” as sci-fi humorist Douglas Adams wrote and astron-
omers Kyle Dawson and Will Percival have shown with their
work on the largest map of the cosmos ever made, starting on
page 34. It’s a three-dimensional map of four million galaxies
over billions of light-years that may help solve the mysteries of
dark energy and the shape of the universe (which is big).
For another mind bender, turn to page 62 to find out from
researcher Kelly Jaakkola whether dolphins are left- or right-
handed (even though they don’t have hands) and why it’s been so
tricky for people to agree on which direction they’re spinning.
Dolphins and about a quarter of all ocean species spend part
of their lives near coral reefs, which are suffering. Marine scien-
tists led by Raquel Peixoto are trying to find beneficial microbes
that can help reefs withstand heat, disease and other pressures,
and the work is now being tested in open waters. It’s a risky strat-
egy, but as science writer Elizabeth Svoboda explains on page 48,
some experts say it’s time to start taking risks.
The blood-brain barrier is basically a filter that lets sugar and
oxygen in blood vessels into the brain but keeps proteins and
pathogens out. Neuroscientists Daniela Kaufer and Alon Fried-
man ( page 42 ) have found that the barrier breaks down under var-
ious kinds of stress, and its leaks could be a sign or possibly a con-
tributing cause of Alzheimer’s disease and other pathologies. If so,
reversing the damage could protect people from brain disorders.
In our cover story beginning on page 26, anthropological
geneticist Jennifer Raff shares new discoveries about who the
first people were to reach the Americas and how and when they
arrived. (And do take a second look at the opening illustration
of the aurora borealis.)