Everything but the humor was overlooked last week when Motorola Inc. rolled out its plans for a network of go-anywhere telephones linked by 77 satellites ringing the Earth. We're calling it ''Iridium,'' the company said, because the iridium atom has 77 electrons orbiting its nucleus -- just like our plan to put up precisely enough satellites to ensure that one orbiter is always above the horizon from any corner of the Earth.

In fact, there is a deeper significance to the word iridium in these circumstances that can't -- or at least oughtn't -- have been lost on the framers. And in the telling of the story is a lesson about the astonishing rate of technical and industrial changes in global telecommunications -- and about the high-stakes competition among American and Japanese companies that will chart the way.

For in the current circumstances in the telecommunications industry, calling your new low-orbit phone setup iridium is a little like naming the burglar alarm system you plan to introduce in Germany ''Overlord.'' Or selling new ''Tora-Tora'' brand home mortgages in the United States.

The only question is, did Motorola do it accidentally, or on purpose?

The story begins with the late Luis Alvarez, a University of California at Berkeley physicist who began a second career late in life in 1979 when his geologist-son presented him with an interesting striped rock.

The stripe consisted of a layer of clay that had been laid down in a relatively brief span 65 million years before, and turned out to contain unusually high levels of iridium. And armed with that surprising fact, within a relatively brief time, Alvarez cobbled up an impact theory of mass extinctions that has been convincing the relevant scientific communities ever since.

What Alvarez concluded was that the dinosaurs were the victim of a colossal collision. When a big asteroid hit Earth 65 million years ago it threw up a dust cloud that rendered the sky dark for several years, blocking photosynthesis -- and so killing through starvation the dinosaurs and every other animal bigger than 50 pounds.

How do we know it wasn't a volcano? Well, it turns out that meteorites and other extraterrestrial materials have 10,000 times more iridium and other platinum group metals than Earth. Only a vaporizing giant meteor, six miles across, could have put into the air the iridium-rich dust that fell to form the stripe of clay.

Thus, the central connotation of iridium, at least to scientists who have followed the controversy in the professional and popular press, is not its atomic weight, fundamental though that may be. The really interesting thing about iridium is that a cloud of it around the Earth is what occasioned the dinosaur Great Wipeout.

Cut now to the telecommunications industry. Ever since William McGowan took advantage of a new technological wrinkle to start selling long-distance telephone services in competition with AT&T in 1969, the industry has been changing mighty fast.

The federal consent decree that broke the Bell System into several operating companies in 1981, the entry of a large number of new equipment suppliers into the business, the emergence of rival technologies in cable and wireless transmission, the rapid internationalization of trade -- all have played a part in furthering this ''information revolution.''

But for the last few years, no part of it has been hotter than the exploding market for cellular telephones. These mobile telephones were said to be America's great new growth industry, and investors thrilled to the race to build a great new cellular company between Craig McCaw and the several rival Bell operating companies seeking the same markets.

Meanwhile, an entirely different business is starting up in England, aimed at doing the same thing. Dubbed PCN, for personal communications network, the new technology is supposed to equip consumers with lightweight ''Dick Tracy''-style telephones that permit them to carry their business and the same phone number wherever they go. Like cellular companies, PCN companies operate essentially by putting up little transmitters on telephone poles all over the cities they serve -- but the technologies are otherwise significantly incompatible.

It was precisely these cellular companies that Motorola sought to reassure last week in New York when it rolled out its plans for a new system of putting the transmitters up in space. After all, Motorola probably is the single biggest supplier in the world to the infant cellular telephone industry. Along with Japan's NEC, it offers a completely integrated line of the vital components: The base stations that companies strew around their license areas in cells, switches that fling signals from one cell to another and the telephones themselves.

No wonder, then, that Motorola spokesmen seemed to bend over backward to say their new service would be a complement to the cellular industry, not a substitute. Satellites would be useful for serving ships at sea, for airplanes, for the occasional traveler on Interstate 80 between Cheyenne and Cody, or in the Gobi desert.

But the system would cost too much for everyday use, said Motorola -- $3 a minute, say, against 30 cents for cellular traffic. It would be difficult to engineer high volumes. And then there were the little 3-inch dish antennae that users of the phones would require.

But would cost and complexity really prevent Iridium from ultimately becoming the global telephone delivery system of choice? Given the enormous technical problems to be solved, it is all but impossible to say. For now, Motorola says the research and development necessary to pursue the plan is nothing more than the company would spend anyway. And in the end, as Stephen Galle, a partner at Boston's TA Associates says, ''It all depends on how they price it. Conceivably, it wouldn't even be a 'cellular' system anymore -- if the calls don't drop out when you switch from one cell to another, that could be a higher level of service."

So if you wanted to reassure your customers, all those big firms striving to become still bigger ones, the better to dominate the surface of the Earth, why would you call your new project Iridium?

Did Motorola mean it?

Remember that these are very sophisticated people. They've been in space since the race to the moon began. They've been on the fringes of the Strategic Defense Initiative with its ''brilliant pebbles'' concept of a network of decentralized satellites.

They know just how quickly technology can twist and turn in unexpected directions. They have competed very successfully toe-to-toe with the Japanese. They know the difficulties of raising capital in a fickle stock market. And they stand at the pinnacle of the telecommunications and computer industries, which are already the most profitable and powerful in the world -- and are likely to become even more so in the next century.

Motorola spokesmen say they were completely unaware of the second, the ''Great Wipeout,'' connotation of iridium, beyond its atomic weight, until the last moment, when somebody brought it up.

''There is no hidden meaning to it,'' says Lawrence Moore, public relations manager of its government communications division.

Are Motorola's engineers cocky enough to have called attention to the strategic possibilities of their project on purpose? It will be years before we really know. The story of the Iridium project is either a rare glimpse into the innermost workings of a world-class technology firm, or a public relations flub of memorable proportions. Quite possibly it is both.

David Warsh is a columnist for the Boston Globe.