Joseph Greenstein was born into deep poverty in northeastern Poland in 1893, and, because of tuberculosis, he was supposed to be dead by age 18. In a certain sense, that’s what happened.

Sickly, weak and scared of following his father into an early grave, Greenstein was looking for an escape when the circus came to town while he was a teenager. Badly beaten for trying to sneak in without a ticket, he caught the attention of a strongman and wrestler who just happened to be Jewish and took sympathy on his plight.

Greenstein left with the circus the next day and, while traveling through Russia, down to India and as far east as Japan over the next year, that weakling disappeared, to be replaced by a young man devoted to strength, fitness, nutrition, good health and the power of mind over matter.

After immigrating to Texas and having a chance meeting with Harry Houdini and his manager at the gas station he owned — lifting Houdini’s car with one hand and changing a flat tire with the other — Greenstein became the traveling strongman known as “The Mighty Atom.”

Steven Greenstein, his grandson, has made a documentary of that name to tell the story of a man who pulled airplanes with his hair, twisted horseshoes, nails and steel bars with his bare hands, and chewed through steel chains and spikes — performing unbelievable stunts well into his 70s.

Joseph Greenstein was a legendary showman.

He did it all as a proud Jew, wearing a Star of David on his singlet and once beating up an entire meeting of German American Bundists in New York.

Steven Greenstein takes the story beyond his grandfather by exploring the continuing art of “the steel game” and the body’s potential for great feats when the mind doesn’t act as a brake.

He produces a loving, moving, entertaining and powerful tribute through interviews with family members and strongmen, newsreel clips, photos, and other artifacts, all bonded with excerpts from a radio interview with the Atom himself.

(Atlanta Jewish Film Festival screenings: Jan. 28, 1:20 p.m., Perimeter Pointe; Feb. 10, 3:20 p.m., Springs Cinema)