> I propose to consider the question, "Can machines think?" This should begin > with definitions of the meaning of the terms "machine" and "think." The > definitions might be framed so as to reflect so far as possible the normal use > of the words, but this attitude is dangerous, If the meaning of the words > "machine" and "think" are to be found by examining how they are commonly used > it is difficult to escape the conclusion that the meaning and the answer to the > question, "Can machines think?" is to be sought in a statistical survey such as > a Gallup poll. But this is absurd. Instead of attempting such a definition I > shall replace the question by another, which is closely related to it and is > expressed in relatively unambiguous words.

Many people who want to argue about AGI and its relation to the Turing test would do well to read Turing's own arguments.

I tried teaching Raft one year instead of Paxos but ended up switching back. While it was much easier to understand how to implement Raft, I think my students gained deeper insight when focusing on single-decision Paxos. There is a lightbulb moment when they first understand that consensus is a property of the system that happens first (and they can point at the moment it happens) and then the nodes discover that it has been achieved later. Exploring various failure modes and coming to understand how Paxos is robust against them seems to work better in this setting as well.

I think this paper by Heidi Howard and Richard Mortier is a great way to move on to Multipaxos:

https://arxiv.org/abs/2004.05074

They present Multipaxos in a similar style to how Raft is laid out and show that Multipaxos as it is commonly implemented and Raft are almost the same protocol.

Raft was a great contribution to the engineering community to make implementing consensus more approachable, but in the end I don't think the protocol itself is actually more understandable. It was presented better for implementers, but the implementation focus obscures some of the deep insights that plain Paxos exposes.

https://datatracker.ietf.org/doc/html/rfc2550

Of course, everyone will have a different opinion on such aesthetic matters. I taught an undergrad comp theory course for a decade or so and I wrote my own similar package[1] for generating diagrams using Metapost that built on the standard boxes package. Students were able to learn the system pretty quickly and the results were usually good, though it was pretty easy to pick out which students did/did not care about how things look.

[1] - https://github.com/russross/automata/

What influence has Forth had?

Climate change is 99% solved. The last 1% is the hardest.

We are 99% of the way to ending all wars. The last 1% will be the hardest.

Scientists are 99% of the way to curing cancer. The last 1% will be the hardest.

etc.

* The system assumes a fixed amount of RAM and a fixed memory layout, so there is no discovery process and no adaptive code to go with it

* The process table is just a small array--no dynamic allocation necessary, and the system can just do a linear search to find an unused entry

* The userspace is simplified. There is a single stack (no threads) of fixed size, mapped memory starts at address 0, and memory is layed out so that only a single number is required to track the size of the entire address space: the size is the top of mapped memory.

Simple data structures are used everywhere, and the emphasis is always on clarity, not efficiency or flexibility.

Basically, they created a disk that could accept writes everywhere except a certain sector, something you could not replicate with even a perfect copy.