There are several ways to map the IPv4 address space into the IPv6 address space, going right back to the first IPv6 addressing architecture RFC. Every compatibility protocol added a new one.

IPv6 added IPSEC which was backported to IPv4.

IPv6 tried to add easy renumbering, which did’t work and had to be discarded.

IPv6 added scoped addresses which are halfbaked and limited. Site-scoped addresses never worked and were discarded; link-scoped addresses are mostly used for autoconfiguration.

IPv6 added new autoconfiguration protocols instead of reusing bootp/DHCP.

Inmos? Transputers were inspired by Hoare’s CSP.

“Inspired by” is an understatement of the century lol. David May and Sir Tony worked very closely together to enable the architecture to be as pure a runtime for CSP as you could get - at least in early versions of the architecture and accompanying Occam language. It expanded and deviated a bit later on iirc.

Source: David loved to tell some of these stories to us as students at Bristol.

It’s also worth highlighting that the mathematical purity of the designs were also partly the problem with them. As a field, we’re still developing the maths of Effects and Effectful Algebras that are needed to make these systems both mathematically ‘pure’ (or at least sound to within some boundary) and ALSO capable of interfacing to the real world.

Transputer and Occam were, in this sense, too early. A rebuild now combining more recent developments from Effect Algebras would be very interesting technically. (Commercially there are all sorts of barriers).

Further Reading for the curious:

On specifically the relationship between Occam and Transputer architecture: http://people.cs.bris.ac.uk/~dave/transputer1984.pdf

Wider reading: http://people.cs.bris.ac.uk/~dave

Yes.

Yeah. There’s also the issue that the earth’s rotation is slowing down, so over the long term leap seconds would become more and more frequent. There’s a point when the earth is slow enough that leap seconds need to happen nearly every month, and by that point they are no longer a workable solution to the problem. That is expected to take a few thousand years, comparable to the point where a leap hour would be needed if there were no leap seconds.

So some future generations might get 23 hour days? That’s gonna be an interesting problem to solve for calendar implementations

25-hour days.

As another poster already said, there will be 25-hour days at some time.

The dinosaurs had days with fewer hours than us.

Where there fewer hours or were those hours just different length?

Now we have locked in second extremely hard underpinning all of our measurements. But you could consider that you have same number of hours in a day and length of those hours has changed...

You could look at it either way. I couldn't say which system the dinosaurs actually used.

I have it on good authority they just used unixtime for everyone but put all the leapseconds in the tz table.

A Martian sol (day cycle/rotation) is > 24 hours (by about 40 minutes). Locked in seconds seems to be the easiest for general use mathematically. 24 hours in a day is a bit of a leftover from sundials and 12 being one of the easiest large fractions of a circle and the Earth day was never really a universal anyway, just an accident of where and roughly when we lived. On the other hand, the modern metric second is now defined at exactly 9,192,631,770 periods of Cesium-133 for atomic clocks and other reasons, so a locked second is useful for a lot of reasons.

The vtable vs switch dichotomy was called the “expression problem” by Philip Wadler https://en.wikipedia.org/wiki/Expression_problem

Scientific publishers do not pay for peer review. Reviews are done by researchers as part of their jobs which are paid for by their research grants.

`info foo | less` is a better info reader than `info foo`

There is an English dictionary of fuck called The F Word

https://en.wikipedia.org/wiki/The_F-Word_(book)

The BSDs use nvi which is a clone of vi from about 1990.

You might encounter Bill Joy’s vi on a Solaris or illumos machine.

Kessler satellites

> there's basically no reason you'd ever want an alkaline battery except cost

Rechargeable batteries are much cheaper than disposable single-use batteries.