12 May/June 2022LYNDONFRENCH(SAKAMOTO);COURTESYVORTEXOPTICS;^ COURTESY^ DISSTONMembers Only
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// THE LATEST NEWS AND OTHER HAPPENINGS FROM POPMECH PRO //SUPER SCOPE
a close look at the U.S. Army’s new rif le
scope, which can predict the path
of a bullet before soldiers even pull
the trigger. The “Next-Generation
Squad Weapons—Fire Control” adds
a ballistic computer to combat rif les
that automatically adjusts for bullet
drops and wind conditions, which
increases long-distance accuracy.It’s easy to lose track of all the perks that come
with your PopMech Pro membership, like exclusive
features, detailed plans for DIY projects, and a weekly
members-only newsletter. Here are some of the
best recent Pro stories you might have missed.
(Not a member? Head to join.popularmechanics.com.)Expert Q&ATHE
BATTERY
GURU
To fe e d o u r me mb e r s’
obsession with solid-state
batteries, we called up a
guy who knows everything
about them: Jeff Sakamoto,
a mechanical engineering
professor at the University of
Michigan. Here’s one of our
favorite questions from the
interview.
What will safety be like for
solid lithium metal versus
lithium-ion batteries in
electric vehicles?
The solid electrolytes that
would replace the flammable
liquid electrolyte in Li-ion
batteries should dramatically
improve safety. But a typical
solid-state battery using
lithium metal would use many
kilograms of pure lithium
metal, which is reactive when
exposed to moisture. Is this a
matter of trading one safety
issue with another? I’m not
so sure. Just because lithium
metal reacts with moisture
doesn’t mean it’s moreTHE HOURGLASS RIDDLE
This simple puzzle in a recent news-
letter seriously stumped members.
Can you crack it? (See the solution at
popularmechanics.com/hourglass.)Already
a print
subscriber?
Scan the
QR code to
upgrade to
PopMech Pro.OUR WILD UNIVERSE
A trippy study suggests the universe can
bend the laws of physics all by itself.
As the universe sought stability over
time, the basic physics it relied on in the
beginning evolved to become much more
sophisticated, scientists believe. Think of
it like this: Why are there still dogs today,
but not dinosaurs? Because pups proved
best-adapted to their environment and
successfully passed on their genes to their
progeny, and dinos didn’t. The same could
be true for our cosmos.
You have an 11-minute hourglass and a
7-minute hourglass. You need to measure
exactly 15 minutes. How do you do it?POPMECH PRODISPATCH FROM
THE TEST ZONE
“It’s not that people want to own
another tool; what they want
is a hole,” says test editor Roy
Berendsohn, who has been dropping
gear reviews just for members.
Enter the Disston QuickCore, which
Roy recently named the best hole-
saw ever made. The cutting edges
on the saw body and drill bits are
made from M42, a high-speed, ultra-
tough tool steel. This allows you to
cut construction lumber and various
steels, and helps the saw withstand
any nails it might encounter.