Dr. Mills was a professor at the University of Delaware for more than 30 years and was active in designing key parts of the World Wide Web in the late 1970s and 1980s. He was a lifelong contributor to open source software, building tools that are used and modified by engineers and technology companies to this day.
His main contribution was teaching computers how to tell time.
In the 1970s, researchers were building the early government-backed Arpanet. A web version connecting various nodes of universities across the country. As the Net grew and more machines were connected to it, the lack of a system to ensure that all machines had the same concept of time began to cause problems.
There is always an unpredictable time lag when one machine communicates with another, so simply timestamping pieces of code passed between computers was not enough to keep things sane. . This was a problem that had to be solved if the Internet was to be used for financial transactions, real-time communications, and millions of other potential uses.
As a researcher at Comsat, a company created by the government to develop satellite communications networks, Dr. Mills had the opportunity to work on Arpanet, which was built by the Defense Advanced Research Projects Agency. Dr. Mills began working on ways to synchronize the time on computers. Part of that was because no one else was doing it, so he was able to move forward with the project on his own terms, Dr. Mills told The New Yorker in 2022. He invented the network protocol in the late 1970s. , to programmers he will forever be known as NTP.
Part of Dr. Mills’ insight was to build a system that would rank different computers in a network by how reliable their concept of time was. Computers connected directly to an atomic clock are considered the most reliable, and other computers in the network use a combination of complex mathematics and clever programming to interact with each other to determine an agreement about the current time. Communicate quickly.
“I remember being completely amazed,” Vint Cerf, a computer scientist who led the early development of the Internet and worked closely with Dr. Mills, said in an interview. “It was black magic.”
According to The New Yorker, David Lennox Mills was born on June 3, 1938 in Oakland, California. His father was an engineer who founded a company that manufactured oil seals for car engines.
The young Mills was born with glaucoma, had poor eyesight for most of his adult life, and went blind several years before his death. Ms. Cerf recalled Dr. Mills using a telescope to look at the whiteboard. “He wasn’t shy about the fact that he was visually impaired,” Cerf said. “He’s a very down-to-earth, cards-on-the-table kind of guy.”
Dr. Mills holds five degrees from the University of Michigan and received his PhD in Computer and Communication Science in 1971. He joined Comsat in 1977, then he taught computer science at the University of Edinburgh in Scotland and the University of Maryland.
In addition to his daughter of Lebanon, Pa., survivors include his wife of 59 years, the former Beverly; Shizumadia in Newark. a son, Keith Mills of Jackson, Mississippi; And a brother.
Beyond the Network Time Protocol, Dr. Mills contributed significant parts of the original Internet structure. His “Fuzzball” software was used to run his first Internet router. Cerf said the name was also an invention of Mills, who thought of them as useful little creatures.
This is just one example of what computer scientists have come to call “milspeak.” Reliable clocks were called “truechimers” and unreliable clocks were called “falsetickers.” Computers that overwhelmed his NTP hub with too many requests were silenced with “kiss-or-death packets.”
“It is an open secret among correspondents that I occasionally have trouble speaking English in email messages and publications,” Dr. Mills wrote on his website. “If you read my papers or emails, you know what resonates with me. If not, you can calibrate my naughty meter from children’s books, outdoor walls, and old English slang.”
He taught at the University of Delaware from 1986 to 2008 and continued to update the NTP code for decades, even as the Internet became central to human civilization. Every day, millions of computers seamlessly synchronize their clocks billions of times and are constantly communicating to enable financial transactions, Zoom meetings, and power grid surges.
The system can synchronize clocks to the microsecond, or one millionth of a second, Julian Onions, a postdoctoral researcher at the University of Nottingham, said in a 2022 YouTube video explaining NTP.
Eventually, other contributors other than Dr. Mills took over more responsibility for upgrading the NTP system. Additionally, Big Tech companies such as Google and Amazon are making their own updates to the standard NTP due to their influence on the Internet.
“This is still one of the fundamental protocols of the Internet,” Cerf said, and is part of the technology that cemented Dr. Mills’ status as an Internet pioneer. “He was part of that temple.”
