Felix Marin

Physics PhD (UCSD 1983). PostDoc (Paris-Sud University).

[Felix Marin @fpmarin]

#math

[Felix Marin @fpmarin]

@a____s___m11 #math

[Felix Marin @fpmarin]

@microfusio91945 In 2, it needs some missing ()’s.

[Fermat's Library @fermatslibrary]

On this day 150 years ago William Sealy Gosset was born. He spent his whole career as a brewer at Guinness, working on a problem the textbooks ignored: how to draw conclusions from tiny samples, like four plots of barley or a handful of hops. The statistics of the day assumed large samples so Gosset invented the statistics of small ones.

Guinness barred its employees from publishing after one of them leaked trade secrets, and did not want competitors knowing it used science to brew beer so when Gosset published his method in 1908 he signed it with a pseudonym: Student.

Every clinical trial, lab experiment and A/B test that runs a t-test today is using the work of Student. The most famous name in statistics is a fake one.

[Felix Marin @fpmarin]

@Anthony_Bonato a) 1 is not prime because mathematicians want to keep/save the Fundamental Theorem of Mathematica. b) it’s not prime because the definition enforce “greater or equal to 2”. c) Another point of view is that “it must have, at least, two different divisors”.

[Felix Marin @fpmarin]

#math

[Felix Marin @fpmarin]

@psicoalfanista #math

[Felix Marin @fpmarin]

#math

[Felix Marin @fpmarin]

@Diarytells #math

[Felix Marin @fpmarin]

@a____s___m11

[Felix Marin @fpmarin]

#math

[Felix Marin @fpmarin]

@microfusio91945 #math @microfusio91945

[Felix Marin @fpmarin]

@a____s___m11 I found it. It’s 8Pi^2 instead of 8Pi^3 in the denominator.

[Felix Marin @fpmarin]

@a____s___m11 Maybe, you need a factor 3 somewhere. Good job anyway.

[Felix Marin @fpmarin]

@Eva_flag 16

[Felix Marin @fpmarin]

@Eva_flag @wydjasonX 16

[Felix Marin @fpmarin]

@Beno10_MFC 105

[Ihtesham Ali @ihtesham2005]

Dennis Ritchie invented C in 1972, co-built Unix in 1969, and his code is running inside every device you are reading this on right now and the colleague who announced his death had to do it through a Google+ post because no journalist thought to check.

He worked at Bell Labs in New Jersey for 44 years. He never gave a keynote. He never ran a company. He never appeared on a magazine cover. He just wrote code that became the invisible foundation everything else is built on.

Here is what he actually built, and why it matters more than almost anything that happened in tech.

In 1969, Bell Labs had just walked away from one of the most ambitious computing projects in history. The Multics project, a joint effort between MIT, Bell Labs, and General Electric, had collapsed under its own weight. Too complex. Too expensive. Too slow. Bell Labs pulled out.

Ken Thompson and Dennis Ritchie refused to let the ideas die.

Working in a small office in Murray Hill, New Jersey, Thompson wrote the first version of Unix in three weeks during the summer of 1969. One week for the file system. One week for the process management. One week for the command shell. Ritchie was working alongside him, and when the system needed a language that could express what they were building, he built one.

In 1972 he completed C.

C was not just another programming language. It was a different philosophy about what a programming language should be. Before C, most systems code was written in assembly, which meant every program was tied to the specific hardware it ran on. You could not move code between machines. You rewrote it from scratch every time.

C changed that. It sat close enough to the hardware to be fast, but abstract enough to run on anything. When Thompson rewrote the Unix kernel in C in 1973, it became the first operating system that could be picked up and moved to a completely different machine without starting over. Portability was a new idea. Ritchie made it real.

The branching that followed is almost impossible to overstate.

Unix spread from Bell Labs to universities. At Berkeley, it became BSD. BSD became the foundation of macOS and iOS. Unix influenced Linus Torvalds, who built Linux in 1991. Linux now runs every Android phone, every major web server, every supercomputer on the Top500 list, and the overwhelming majority of cloud infrastructure at AWS, Google, and Microsoft.

C became the parent language of C++, Java, JavaScript, Python, and Objective-C. Rob Pike, who worked across the hall from Ritchie at Bell Labs for 20 years, said it plainly: "The browsers are written in C. The Unix kernel that the entire internet runs on is written in C. Web servers are written in C, and if they're not, they're written in Java or C++, which are C derivatives, or Python or Ruby, which are implemented in C."

Ritchie won the Turing Award in 1983. He won the National Medal of Technology in 1998, presented by President Clinton. He was head of System Software Research at Bell Labs for decades.

He answered emails from strangers with technical questions until the end of his life. His home address stayed listed in the phone book. His colleague Brian Kernighan, who co-authored the definitive C textbook with him, said Ritchie was a private person who did no self-salesmanship. That was not false modesty. It was just who he was.

He died on October 12, 2011, at his home in Berkeley Heights, New Jersey. He was 70. He had been ill for some time. The world did not notice until Rob Pike posted a quiet announcement on Google+, and the news spread through the programming community in hushed tones.

No front pages. No tributes from heads of state. No candlelight vigils outside corporate campuses.

The device you are reading this on runs code that traces directly back to what he built. So does the server that delivered it to you. So does the browser or app you opened to get here.

Most people will never know his name.

The ones who built everything you use every day do.

[Felix Marin @fpmarin]

@psicoalfanista @Uranmexican_ @CPierre67 Si, es cierto. Había uno en especial ( el francés Did ) que no perdía oportunidad para criticar a mucha gente. Hace años que no aparece por allí.

[Felix Marin @fpmarin]

#math