He was little known, yet he changed the world. He often worked alone in his laboratory, yet he battled the Goliath of his time, RCA. His inventions made possible the sublime, educational, inspirational programming that comes directly into our living rooms – and the dreck that gave rise to the expression “boob tube.”

Philo T. Farnsworth did all of this in his simple lab at 200 Green St. in San Francisco, where a historical landmark today declares: “On September 7,1927 the 21-year-old inventor and several dedicated assistants successfully transmitted the first all-electronic television image, the major breakthrough that brought the practical form of this invention to mankind.”

Farnsworth, who died in 1971, managed to send his first image – a simple horizontal line – without use of wheels, motors and other mechanical devices that previously had been the basis for experimental television. Without his brilliant application of vacuum tubes and phosphors, the clear, sharp and, ultimately, colorful images that we take for granted could not have come about.

His contribution to society is recognized in this Open Forum article in the San Francisco Chronicle. Author Philip Kipper argues that, despite television’s shortcomings, the medium “has such remarkable communicative powers and such distinctive artistic qualities that a world without it is almost unimaginable today.”

Evan I. Schwartz, author of “The Last Lone Inventor,” characterizes Farnsworth as a “ball of nervous energy” who “looked like an inventor.” Schwartz describes Farnsworth’s costly and frustrating legal dispute with “the villain in this story,” RCA’s David Sarnoff, in this Q&A on SFGate.com.

On Sept. 7, 2002, the Chronicle commemorated the 75th anniversary of Farnsworth’s first simple broadcast in an interview with his wife, Pem, who was 94 at the time and was present in 1927 for the great moment.

“It was a very small screen, about the size of a postage stamp, an inch and a half square,” she said. “At first, we were stunned. It was too good to be true. Then Phil said, ‘There you have it — electric television.’ “