Happy 40th Birthday, Cell Phone

That's right, cut the cake and fetch a set of 40 candles, because back on April 3, 1973, Marty Cooper--then an engineer with Motorola--placed the first ever public call from a cell phone, thus kicking off decades of growth and innovation that lead all the way up to the present day. The cell phone has turned 40 this year, and it's causing plenty of looks back as well as looks forward.

Cooper placed the first call via a cell phone to Joel Engel, who was then head of Bell Labs' research department, a rival company of Motorola's. Cooper's first words to go out over the device were "Joel, this is Marty. I'm calling you from a cell phone, a real handheld portable cell phone." The device in question was a far cry from the devices of the present era, a DynaTac 8000x, which weighed in at a hefty 2.5 pounds. Considering that most smartphones today weigh in the neighborhood of four ounces--with some differences across the many models of handset available--this is a pretty big drop over the course of 40 years.

Cooper didn't stop developing with the DynaTac, either; most recently he went on to work with his wife to develop the Jitterbug line of phones geared toward senior citizens. The Jitterbug offers an experience specifically geared toward seniors, with large displays, large buttons and simple operation while still offering an app-based experience for those who want it. But according to an interview Cooper staged with The Verge, he currently favors not a Jitterbug but rather a Droid RAZR, and refuses to use a phone with anything less than a four-inch screen.

Cooper also is somewhat awed by the rapid development of the cell phone overall, surprised by the sheer number of additions to the device as well as its rapid scaling down. Indeed, in the interview with The Verge, Cooper confessed to some amazement, saying, "So how could you ever imagine that in my lifetime there would be tens of millions of transistors in a cell phone?"

Cooper sees both troubles with the current mobile landscape--including being initially opposed to the merger of AT&T and T-Mobile--and plenty of room to grow, as suggested by the law named for Cooper, Cooper's Law of Spectral Efficiency. Cooper's Law suggests that, so far, the number of "conversations," either voice- or data-based, doubles approximately every 30 months. Given that that rate has been observed over the course of the past 104 years, suggesting that it will continue in such a fashion is not out of line.

Cooper even weighed in on the concept of Windows Phone, suggesting that every market really needs three players to be a full market. The leader is the biggest success, the second place finisher is, usually, also quite successful, the third place finisher struggles and beyond that, the market gets sufficiently fractured that anyone below third may or may not stick around. Windows Phone, according to Cooper, may well be that third that helps "keep the first two guys honest," though chances are BlackBerry won't take that lying down.

The market has come a long way since Cooper placed that first call 40 years ago. Cell phones have gone from blocky, brick-like affairs to slim devices that make even some older computers look out of date by comparison, and for some people, have even replaced the PC outright. Where the cell phone will go in another 40 years is anyone's guess, but where ever it happens to go, it owes a certain debt to Marty Cooper, and a call made to Bell Labs in 1973.