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BOOKSHELF
Einstein’s Shadow explores what it takes to snap a black hole’s picture
BOOKSHELF
Under the Knife
Arnold van de Laar
A surgeon uses wit
and his expertise to
describe 28 of his-
tory’s most interest-
ing operations and
to offer insights into the future of
medicine. St. Martin’s Press, $29.99
Innumerable Insects
Michael S. Engel
This coffee-table
book offers entomol-
ogy enthusiasts a
chance to explore
insects’ evolution and
diversity through more than 180
detailed illustrations. Sterling, $27.95
Right now, a ragtag
team of astrono-
mers, assembled
from institutes
across the globe,
may be peering in
wonder at the first
picture of a black
hole’s shadow. The
quest to create
such an image has
involved a massive
level of scientific coordination, com-
bining data from telescopes at eight
observatories scattered from the South
Pole to Hawaii to the Atacama Desert
in Chile. In Einstein’s Shadow, journal-
ist Seth Fletcher provides a twisting
narrative of the project’s inception and
how it grew into a worldwide effort.
Called the Event Horizon Telescope,
or EHT, the project is “the biggest
telescope in the history of humanity,” EHT director Shep Doeleman of
the Harvard-Smithsonian Center for
Astrophysics says in the book. EHT uni-fies far-flung radio telescopes through
a technique called very long baseline
interferometry, which involves combining the light waves spotted by each
telescope to determine how the light
adds up, through a process called interference. Using this technique, EHT can
achieve resolution equivalent to picking out a doughnut on the moon. That
extreme capability is what’s needed to
capture a picture of EHT’s main target:
the gigantic black hole at the center of
the Milky Way.
EHT captured its first data in 2006,
but has yet to produce an image of a
Einstein’s Shadow
Seth Fletcher
ECCO, $26.99
black hole. After adding more telescopes and improving the technology, in
April 2017, EHT took data aimed at capturing the silhouette of the Milky Way’s
central black hole (SN Online: 4/5/17).
Those data are still being analyzed.
No one has ever directly seen a
black hole, so scientists still debate the
details of what black holes are like. A
boundary known as an event horizon
is thought to exist at the edge of each
black hole. This border, beyond which
nothing can escape (SN: 5/31/14, p. 16),
is what EHT is attempting to image.
Close to the event horizon, physics
becomes utterly strange, with space
and time warped by intense gravity.
There, Einstein’s general theory of relativity, which describes gravity, clashes
with quantum mechanics, the theory of
physics on small scales. Scientists are
still unsure how to reconcile the two
theories (see Page 23), but an image of
the black hole’s boundary could provide hints.
Einstein’s Shadow gives a feel for what
it takes to image a black hole, thanks
to Fletcher’s accounts of researchers
scrounging for funding, pleading for
telescope time and wishing for good
weather. Leaders of the collaboration
squabble over power and responsibilities. Observations fail due to technical
difficulties. Astronomers bite their fingernails as delicate equipment is driven
up a bumpy mountain road.
Telescope upgrades and malfunc-
tions get detailed explanations in the
book. Astronomy buffs will probably
enjoy those passages, but others may
find them a bit dull. That feeling, how-
ever, may put readers in astronomers’
shoes — science sometimes can be slow.
We won’t know what EHT saw until
the team releases its results. According
to Doeleman, that should happen early
next year. If EHT eventually unveils a
black hole portrait, the dirty and dull
work that was necessary to get the project off the ground will likely be glossed
over in media coverage. Einstein’s
Shadow reveals parts of the scientific
process that, like the Milky Way’s
gigantic black hole, are usually left in
the dark. That process is worth bringing to light. — Emily Conover
Scientists hope to image a black hole’s shadow
(simulations shown) to reveal secrets of gravity.