Carl Hewitt has died [pdf]

Carl Hewitt has died [pdf](ee380.stanford.edu)

158 points by drallison 3 years ago | 33 comments

j-pb 3 years ago |

This is sad news, he invented not only the actor model, but also planner and did a lot of groundwork for deductive and parallel systems.

One of the more obscure things he pursued as a result of his early actor model work was unbounded nondeterminism as a potential source for hyper-computation.[1]

I'll always remember fondly that he pointed me to some papers via twitter when I asked him some questions about unbounded nondeterminism as an undergrad.

[1]: https://programme.hypotheses.org/files/2019/06/cardone_dayli...

082349872349872 3 years ago | |

If I am reading the footnoted slides properly, do they mean that we are willing to use unbounded determinism when we can take the property that "actions eventually complete" as an axiom (so we prove the rest of the system based on that hypothesis, and make the statistical argument that for those almost never cases where actions don't complete, the process is so unlucky that it "has already been run over by a bus"* anyway, to justify admissability of the hypothesis)?

* thank you Jim Gray (1944-?2007). compare the difference in liveness provability between token ring and ethernet. (but also compare their pragmatic adoption)

napsterbr 3 years ago |

May he RIP.

I first heard about Hewitt after watching this[0] conversation about the actor model. It's truly a masterclass. For those who want to learn more about the actor model, or simply have a fond memory of ProfHewitt, I highly recommend it.

[0] - https://youtube.com/watch?v=7erJ1DV_Tlo

peoplefromibiza 3 years ago |

That's very sad.

I've met him at Code Mesh in London in 2018 where he gave a keynote on ultraconcurrency for globally connected intelligent systems [1]

Joe Armstrong was present too, he had a talk later that day and I witnessed a conversation between Armstrong and prof. Hewitt about the actor model after the keynote, it was brilliant.

Unfortunately they're both gone now.

[1] paper: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3428114

zelphirkalt 3 years ago | |

Another video with Carl Hewitt about actors: https://invidio.xamh.de/watch?v=1zVdhDx7Tbs

abecedarius 3 years ago |

Sad news. Some of the early papers on actors are listed at http://erights.org/history/actors.html (with a bunch of broken links, unfortunately, but they should be findable).

Another really stimulating paper: https://www.researchgate.net/publication/3115052_The_Scienti... proposing that powerful problem-solvers could be organized like a model of the human scientific community.

smallstepforman 3 years ago |

Dang it, we lost 2 of the biggest champions of the Actor model, Carl and Joe a couple of years ago. Who is left to carry the torch to illuminate millions of developers who have no idea or have never heard of the Actor model? Sadly, we will see thousands or poorly thought out replacement models (eg. C++ futures, thread pools etc), which only offer a subset of Actor functionality instead of implementing the whole she-bang. E

dangets 3 years ago | |

I wouldn't say that the actor model is going away. There are several new-ish projects built around it or retrofitting it in more common languages.

- Elixir (and Erlang) https://elixir-lang.org/

- Akka - JVM and .NET frameworks - https://akka.io/ https://getakka.net/

- Actix - Rust framework - https://actix.rs/docs/actix/getting-started

- MS Orleans - https://learn.microsoft.com/en-us/dotnet/orleans/overview

- Pony - https://www.ponylang.io/

justin66 3 years ago | |

> Who is left to carry the torch to illuminate millions of developers who have no idea or have never heard of the Actor model?

Douglas Crockford.

https://www.youtube.com/watch?v=R2idkNdKqpQ

KerrAvon 3 years ago | |

All Mac and iOS developers will eventually be exposed to it. Swift's concurrency support is based on the actor model and has a construct named "actor," which does what it says on the tin.

acje 3 years ago | |

Wasmcloud community? https://wasmcloud.dev/

sn41 3 years ago |

If I am not mistaken, he is the researcher behind the actor model. He was also active on HN, I remember.

gpderetta 3 years ago | |

He is and he was: https://news.ycombinator.com/threads?id=ProfHewitt .

Probably deserves the black bar?

inopinatus 3 years ago | | |

I love how many of these remarks seem to have been piped through

a fmt(1)-ish filter, or perhaps simply manually folded. In conjunction

with the formal clarity he often expresses, they develop

a poetic, almost dreamlike quality.

agumonkey 3 years ago | |

actor model who was the reason behind the scheme lisp dialect, and contextually, underlying the arc language which runs this website

ps: j-pb above mentions planner, also linked to the logic programming world. damn

gumby 3 years ago |

This is a real loss. I learned a lot from him, ironically more from late night trips to Chinatown than formally in the lab. He had a wide ranging intellect that did not diminish with age.

drallison 3 years ago | |

It is a real loss, Gumby. Carl and I were friends and spent hours on the telephone solving the problems of the world and playing polymath math. Hardly a day would go by without an hour or so chat with Carl.

drallison 3 years ago | |

It is a real loss, Gumby. Carl and I were friends and spent hours on the telephone solving the problems of the world.

ngc248 3 years ago |

The actor model is simply magnificent. Once i encountered the actor model, concurrency just clicked for me. Even writing concurrent programs in a non-actor context became simple and easy. It is that amazing.

TowerTall 3 years ago | |

This is one of my favorite tech talks.

Hewitt, Meijer and Szyperski: The Actor Model (everything you wanted to know but are afraid to ask)

https://www.youtube.com/watch?v=7erJ1DV_Tlo

discreteevent 3 years ago | |

Every so often when thinking about a system I find I need a default model to go back to. Like when a system seems to be complex or someone is claiming that it has some new property that makes it exceptional or whatever. It's probably possible to pick a few different models but I find the actor model usually covers it. e.g. "Well when you really look at it, it's just a bunch of actors sending messages to each other's addresses/mailboxes"

mtraven 3 years ago |

Sad news. I had the honor of participating in a workshop he organized on Inconsistency Robustness in 2011, that was an interesting gathering.

https://www.amazon.com/Inconsistency-Robustness-Studies-Logi...

tempodox 3 years ago |

@dang, I move to show the black bar for this sad event. It has been almost a month, but it's the first mention on HN.

radiowave 3 years ago | |

Seconded. I hadn't heard that he'd gone.

amalgamated_inc 3 years ago | | |

Yes please. Saw an interview with him and Joe Armstrong I believe. What a gentleman.

eternalban 3 years ago | |

I just heard about this as well. Black bar please, dang.

eternalban 3 years ago |

RIP Carl Hewitt.

A mind that was never confined to a box. Always fresh, adventurous, and insightful, to the end.

shaunxcode 3 years ago |

Hugely inspirational. Wish I could have attended one of his lectures or talks.

PaulCarrack 3 years ago |

My very first computer as an HP. My dad came home with one from CompUSA back in the mid-90s. I think this was shortly after Packard Bell rebranded themselves. I don't know what involvement Carl had with the company by that point in time, but he indirectly had an impact on me as it got me started in computers very early in life. RIP.

jjtheblunt 3 years ago | |

are you thinking Hewlett not Hewitt ?

PaulCarrack 3 years ago | | |

That's odd, I'm having a Mandella Effect here, I thought the company name was Hewitt-Packard.