Engineering may be a numbers-driven profession, but it’s the context surrounding the numbers that makes all the difference. NASA learned that the hard way in September 1999. Engineers at the Jet Propulsion Laboratory programmed thrusters on the Mars Climate Orbiter, which was designed to take up a permanent orbit around the Red Planet, to expect data in metric units. But as the craft approached Mars, engineers from contractor Lockheed Martin sent final navigation instructions in English units, causing the thrusters to fire with 4.45 times too much force. The $327 million craft went off course and burned up in the Martian atmosphere.
If the raw thruster-firing data supplied by Lockheed had been inherently tied to a unit of measurement—pounds of force in this case, as opposed to the newtons that the software expected—then flight controllers, or the software itself, might have detected the confusion before it was too late. But ten years ago, the concept of metadata, or associating numbers or other data in their raw form with external data about that data, was still fairly new. Only in the era of the semantic Web have a few people started to think about ways to indelibly couple numerical data to contextual data, thus providing every individual number with a kind of credential or pedigree.
Allen Razdow is one of those people. The creator of Mathcad, a software package widely used by engineers to display equations and perform calculations, Razdow has started a new company called True Engineering Technology to promote the idea that numbers in digital documents should be “live” and “connected”—that is, they should be illuminated by adding a bit of semantic information, in much the same way that text snippets are associated with URLs in hyperlinks.
True Engineering, based in Cambridge, MA, came out of stealth mode today, debuting a Web-based system that can turn a plain number into what Razdow calls a “truenumber.” Just like a hyperlink with an embedded URL, a truenumber includes an ID pointing to a record stored elsewhere, along with tags pertaining to properties of the number such as units. But unlike a hyperlink, a truenumber can do more than just send you off to another document. The metadata contained in a truenumber can also be grabbed and used by local applications—browsers, spreadsheets, e-mail clients, or presentation software, for example—to make the raw number more informative.
Here’s an actual truenumber, representing the approximate driving range of the Nissan EV-11 electric car: 150 mi. To get a sense of how a truenumber works, hover over the quantity, then click on it (then come back here).
The original goal of the project, says Razdow, was “to create a technology for numbers that allowed engineers, as they type numbers into things, to get some assistance formatting them and getting the units right, doing unit conversion, and making sure the number is correct and traceable back to the original number, whatever format it was in.” He says he sees the rise of markup languages like HTML and the semantic Web as the restoration, in a sense, of human language to a computing universe long ruled by graphical interfaces. “But it struck me that there was no special treatment for numbers,” Razdow says. “We have formatted text for headings and tables and everything else, but numbers are still just strings of characters. I began to think about what it would take to create a technology of numbers that would be sufficiently semantic that it wouldn’t be just digits, but would show what this number is, and where it came from, and how we can describe it.”
All of which sounds like it will appeal to the thousands of professionals who use programs like Mathcad—and would certainly have helped the engineers on the Mars Climate Orbiter mission avert their fiasco.
But Razdow believes truenumbers will quickly develop another use. “I think the bigger reason people will use it is for a kind of visibility,” he says. “What we’ve heard from [beta] customers is that a lot of numbers that are critical to their projects are just ‘hanging in the air’—all of the engineers are thinking about them but they don’t live anywhere, they just get
