Dennis Nagle, Free Spirit With an Engineer’s Mind, Dies at 78.

This obituary is part of a series about people who have died in the coronavirus pandemic. Read about others here.

In his youth, Dennis Nagle resembled Dennis Hopper’s character in “Easy Rider”: same bushy counterculture mustache and long hair, same pirate’s smile and wild glint in his eyes. And like the film character, Mr. Nagle embraced 1960s-style hedonism full on.

He was a big proponent of marijuana and psychedelics. He spent the ’70s living in England, where he ran with a fast crowd in London and, his oldest son, Alex, said, made his living in the illegal drug trade. By the time the ’80s rolled around, he had fathered four children with four women.

As disorganized as his personal life was, Mr. Nagle had the focused technical mind of an engineer. He could fix anything. He loved visual art, and throughout his life he built light boxes, attaching LEDs to tiny motors to create hypnotic patterns of light. A wellspring of knowledge lived within him.