These days, in developed countries, you can't so much as rent a car or buy a shirt without setting in motion a burst of digital information spanning hundreds of kilometers. Data stream toward a waiting credit card database through the air, over cables, and back again, bouncing and meeting interference, and encountering other signals along the way. And yet the right bits get to their destination not just usually, but virtually without fail, statistically speaking. They emerge from the noise with the seeming magic of a rabbit coming out of a hat.
Just as in a magic show, however, there's a lot going on behind the scenes: in this case, algorithms that electrical engineers, computer scientists, and mathematicians have been refining for decades. And the roots of many of those algorithms go back to one master magician, Thomas Kailath.
Kailath, a professor emeritus at Stanford University, has worked for four decades on algorithms that detect signals distorted by bouncing off objects in the environment, separate wireless signals by determining their direction using antenna arrays, and compensate for the distortion of optical systems used in semiconductor processing. And, though Kailath spent most of his career in academia, his efforts to see his algorithms make a difference led him to cofound no fewer than four start-up companies.
Along the way, he established new ways of structuring complex problems to speed up their calculation. This work has improved the efficiency of much of the technology that makes modern life possible--not only paying for gas and clothing by credit card but also sending text messages and video images to cellphones. It is for this body of work that Kailath was awarded the 2007 Medal of Honor, the IEEE's highest commendation.
Kailath didn't seem destined for a technical career. Growing up in Pune, India, he so dreaded math class that in sixth grade he would duck behind the student in front of him so a sarcastic teacher wouldn't call on him. He passed exams that year by memorizing the solutions to all the homework problems. However, a rather good thing happened that year, too. The scary math teacher introduced the class to geometry, and for the first time, Kailath realized that math could be engaging. Maybe even more than engaging. He started getting together with classmates to work on proofs. For fun.
Still, he didn't think much about math as a career. He assumed he would go into the civil service, a typical route for a middle-class kid in India. However, the civil service had strict vision requirements, and the myopic Kailath didn't meet them. Plan B was to work for All India Radio, a state-owned broadcast monopoly. He enrolled at the University of Poona (now called the University of Pune).
In 1950, his first year at Pune's Ferguson College, he was blissfully perusing magazines in the stacks of the school library, when he came upon an article in a 1949 issue of Popular Science explaining the basic idea of a new field called information theory. The article speculated about how it would be applied to the then-emerging technology of television broadcasting, pointing out that you could use less bandwidth by sending only the changes between television frames, not each frame in its entirety. It was but one use for information theory, but the article predicted that there would be many others.
For the young Kailath, standing in the quiet, wood-paneled, high-ceilinged room, it was a revelation. Not only was the idea appealing, but he found the name itself, "information theory," attractive. It involved the concepts of mathematical proofs that he had so loved in geometry and also offered the possibility of practical applications, such as improving telecommunications. He began to read more about the subject, including Claude Shannon's and Norbert Wiener's pioneering books; this reading was a relief from his less theoretical engineering courses. Kailath had found his calling, and in 1956, approaching graduation, he sent letters to MIT and Harvard asking to be considered as a graduate student in the field. Both accepted him.
On 30 August 1957, after a long journey, mostly by ship, he unpacked his bags at MIT. He was to become the first India-born student, but certainly not the last, to earn a doctorate in electrical engineering from that institution. And to Kailath's delight, Shannon had just become a professor there.