2019-05-01_Discover

ON THE COVER

Einstein: 100 Years Later.

What’s Next? p.

The Future of Fertility p.

How to Repair Embryos p.

Babies in Space p.

Genetic Matchmaker? p.

Cover credit:

koya979/Shutterstock

CONTENTS

100

19

19

-^2
0
19
11
years of
relativity

4 DISCOVERMAGAZINE.COM

COLUMNS & DEPARTMENTS

6 EDITOR’S NOTE

Spaced-Out Kids

As our species explores

beyond Earth, plans to

colonize other planets will

have to get creative about

procreating.

7 INBOX

Readers share their thoughts

on fighting Alzheimer’s,

treating the terminally ill and

the pros and cons of labeling

genetically modified food.

18 VITAL SIGNS

Growing Pains

A child’s stomachache and

high blood pressure lead to

a life-altering diagnosis.

BY AMITHA KALAICHANDRAN

22 NOTES FROM EARTH

Mining the

Minuscule

Tiny grains of perfect

quartz sand, crucial to

hydraulic fracking, are

big business across the

American Midwest.

BY GEOFFREY GILLER

64 HISTORY LESSONS

The Grim Origins

of ‘Gluten-Free’

In the wake of famine, a

pediatrician discovers why

consuming the protein is,

for some, a life-and-death

matter. BY DOUGLAS G. ADLER

68 OUT THERE

The Fight for

First Exoplanet

Pseudo-star or a landmark

find that never got its due?

Astronomers rethink a

decades-old designation.

BY NOL A TAY LOR REDD

74 20 THINGS YOU

DIDN’T KNOW ABOUT ...

Rainbows

Everyone sees their own

rainbow, and the number

of colors in yours may be

different from mine. Also,

this thing? Not a rainbow.

BY GEMMA TARLACH

FEATURES

42

Einstein’s Eclipse

Worlds aligned in 1919 — and forever changed

how we understand gravity. BY DEVIN POWELL

48

It’s All Relative

Einstein’s revolutionary theory may be

complicated, but it’s our best way of grasping

the universe. BY DEVIN POWELL

50

Ripple Effect

Spotting them was merely the first step:

Gravitational waves can help unravel some of

the greatest mysteries of the cosmos. BY STEVE NADIS

58

Talk to Me

Get to know why Siri, Alexa and their digital rivals

are who they are. BY JAMES VLAHOS

9 THE CRUX

Gene editing speeds

up selective breeding

for popular produce;

recording the sounds of

the rainforest to save it; a

crater cache of water ice

on Mars; when a stone

tool is not, in fact, an

artifact; teaching robots a

gentle touch; and more.

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