Biologist Nicky Creux rises at
3:30 a.m. some mornings to study the
growth and development of sunflowers.
Sometimes the pursuit of data clashes with
a researcher’s own circadian rhythms
By Sam Kean
All Rodrigo Medellín wanted was a nap. A biologist at the National Autonomous University of Mexico in Mexico City, he had been trap- ping bats for several nights in a row in the Lacandon rainforest near Guatemala, and was exhausted. “So I lay on the ground,” he says, and blithely fell asleep. Forty winks
later, he awoke uneasily. One of the deadliest
snakes in Mexico, a tawny fer-de-lance, was
slithering by his head, 30 centimeters away.
“I did not move and let her pass,” he recalls.
Even after the coast cleared and he set
about his bat hunt again, fear wouldn’t
loosen its grip on his sleep-deprived mind.
That entire night, “I kept hallucinating more
snakes,” he says. Every twitching shadow concealed another serpent, every rustling leaf
had fangs. Although a veteran of the night
shift, Medellín greeted that dawn frazzled.
Working nights is unavoidable, or at least
commonplace, in certain scientific fields.
If you want to study bat behavior or stellar
nebulae or sleep physiology, you may have to
become half-nocturnal yourself, and scientists who sign up for the night shift encounter problems that just don’t arise during the
day. They tumble down embankments in the
pitch black, nod off midexperiment, and grow
paranoid in the witching hours. It’s a tough
gig, and for these and other reasons psychologists and sleep experts take a dim view of
night work, which can disrupt sleep, throw
hormones out of whack, and make you measurably dumber. “Human beings are meant
to be regulated by light,” says Candice Alfano,
a psychologist at the University of Houston
in Texas who’s leading a study for NASA that
includes a focus on circadian rhythm disruptions. “We still have that biology, even though
our social culture has changed dramatically.”
And yet, few of the nocturnal researchers
Science talked to would give up their work.
Amid the misery and exhaustion, science
after hours can still produce moments of serenity, even euphoria. “Either you’re getting
to know more about the natural world, or
you’re getting to know more about yourself,”
Medellín says. “It’s always a source of happiness to me.”
THE CHALLENGES faced by researchers on the
night shift vary significantly by discipline.
Biologists, for instance, sometimes upend
their whole lives to match the nondiurnal
schedules of certain plants and animals.
Nicky Creux, a postdoc at the University
of California (UC), Davis, studies sunflowers,
whose buds open up just before dawn. That
means getting up at 3:30 a.m. for weeklong
stretches to set up cameras and dissecting
equipment, in order to track the minute-by-minute emergence and growth of anthers and
styles, plant reproductive organs. Although
she’s naturally a morning lark, “Cycling out
to the fields in the dark is pretty miserable,”
she laughs. At the end of one recent 6-day
stretch, her fine motor skills basically broke
down from exhaustion: She kept dropping
the tiny flower parts and losing them in the
grass. She’s hoping the lost data won’t submarine the whole week.
Creux’s social life suffered as well, because
she essentially lived those weeks in a different time zone from everyone around her.
“Friends want to go to dinner and I can’t,”
she says. “I have to be in bed by 8 p.m.” She
also found it hard to abandon the lab to rest
while others nearby were still hard at work.
“As a scientist, you’re used to working 12-hour
shifts, and staying until 7 p.m. I had to get
my head around the fact that it’s okay to go
home at 3.” Alfano says that like traditional
night workers, such as hospital staff, janitors, and truckers, scientists can feel tempted
to “cheat” and attend daytime events with
friends and family. That can compromise an
NIGHT SHIF T
SPECIAL SECTION CIRCADIAN PHYSIOLOGY