Once, maybe, everyone more or less understood everything and how it worked. But society pushed past that point long ago, into a realm where we are dependent on devices and structures we couldn’t possibly make ourselves and whose origins we don’t even know. As you realize if you’re reading this on a cellphone.

“How We Invented the World,” a four-part series that begins on Tuesday on the Discovery Channel, tries to fill some of this gap, and that very cellphone is the subject of the first installment. The program is intent on being entertaining and thus keeps the history simple and accessible, but hey, a little bit of appreciation of how our present came to be is better than none.

The cellphone episode begins on the Titanic, where the primitive state of radio communication contributed to the disaster: The ship could not send and receive at the same time, which led the Titanic’s wireless operator to tell the Californian, a nearby steamship that was warning of ice, to “shut up.”

The program examines how the outcry after the sinking led to technological improvements, then checks in on the actress Hedy Lamarr , who was also an inventor and came up with a way to stymie those who would eavesdrop on wireless communications, like the Nazis in World War II. Then we meet Martin Cooper , the Motorola executive who, trying to compete with the giant AT&T in the early 1970s, initiated the project that would produce the first cellphone.

“When I described this dream, the image of people walking around and talking on their own phones, everybody got excited,” he recalls.

The program’s main interest is history, though it does at least nod to the implications of the cellphone revolution after tracing how phones came to have cameras, a story that involves a new father eager to share pictures. That innovation on an innovation has of course led to the citizen journalism that has played a part in revolutions and coverage of natural disasters like the 2004 tsunami. And it’s an example of how one invention can eat another.

“When you look at the cellphone and you think about what it’s done in our society, think of the technologies that it’s completely killed,” says Becky Worley, a technology broadcaster and blogger. “No. 1 on that list: cameras. Sure, we have our big DSLRs, the long-lens cameras, the professional cameras, but when it comes to the point-and-shoot, they’re dead.”

Subsequent installments of the program will take up airplanes, cars and skyscrapers. Considering all the other ubiquitous things in our lives ? computers, televisions, microwaves, bar codes, security cameras ? you wonder why this series is stopping at four.