5G’s Society-Changing Promise Carries ‘Forever Chemicals’ Price

Hank Schwedes was driving in heavy traffic near his Morrisville, Pa., home when the car ahead of him suddenly stopped—and to Schwedes’ surprise, so did his.

“I wasn’t stopping quickly enough, so my car reacted before I did,” said Schwedes, who hadn’t known until that moment that his new Subaru Outback was equipped with a futuristic crash prevention system. “It’s a good safety feature.”

The feature relies on information traveling instantaneously to the car’s braking system, the type of data-transfer speed that will allow nascent 5G wireless networks to transform how we work, play, and make money.

But key to ...