epydemic hits 100,000 downloads

epydemic hits 100,000 downloads

Downloads of epydemic, my library for epidemic (and other) process simulation on networks (and hopefully other combinatorial structures soon…) recently passed 100,000.

That number comes from the project’s PePy page, which tracks downloads from the main PyPi page as used by pip. I can’t say whether or not that number is accurate. Quite honestly it’s at least 98,000 more than I ever expected, but 100,000 feels like something of a milestone to be pleased about.

epydemic came about because of a lack of standard tooling for doing epidemic simulation. This involves a lot of stochastic simulation, which is quite tricky code to write and to make efficient. Testing the system actually involved us thinking more deeply about the effectiveness of unit testing for stochastic code, which then led to a presentation at UK Systems in 2021 explaining the problems we’d had.

TIL: The loudest Lisp program in the world

TIL: The loudest Lisp program in the world

Today I learned about a program that generates the sounds that help people navigate as they exit long tunnels when an emergency such as a fire has destroyed the visibility.

The World’s Loudest Lisp Program to the Rescue

This describes the challenges of building a software system that has to work unmonitored once deployed, for years, as well as withstanding a fairly rugged environment where, for example, the installedc hardware will be periodically sprayed with a high-pressure hose as the walls get cleaned. Overall the system is soft real-time, but has to cope with component failure, network partitions, consensus, and all the usual distributed systems challenges, while be guaranteed to work when needed.

The developers built the system in Common Lisp, which wouldn’t be the normal go-to choice for an embedded system. But their argument was that they could better handle complex and changing requirements by retaining a high level of abstraction, and that development was overall far faster than using C. Modern Common Lisp compilers are so efficient that there’s no significant performance hit at deployment. They made use of complicated components like planners (for which Lisp is an ideal choice), and built a set of macros to wrap-up the handling of industrial control and robust communications.

It’s a great read.

How to Win an Information War: The Propagandist Who Outwitted Hitler

Peter Pomerantsev (2024)

Part biography and part assessment of the modern media landscape in the face of prolonged and well-funded disinformation. Sefton Delmer crafted a lot of British propaganda against the Nazis, drawing on his own childhood in Germany.

As with How to Lose the Information War: Russia, Fake News and the Future of Conflict – another take on the same issues, with less of an historical driver – Pomerentsev focuses on the importance of the perceived messenger as well as the message: the idea that “truth will prevail” simply isn’t true when untruth is being cleverly promoted. Delmer pioneered this approach by creating radio-based characters crafted to appeal to particular segments of German society and seed disquiet amongst them.

(I was reminded at one point of a character in The Day of the Triffids who works as a professional agitator able to meet anyone on their own ground, changing his voice, dress, and presentation style to suit the audience, and arguing that the way you deliver a message is at least as important as its content. Delmer would have approved.)

One can see Delmer as the origin of the modern approach to “flood the zone” and undermine belief in all media and information. He was constantly criticised by his opponents (both those making moral arguments and those simply wanting to be in control) to demonstrate the efficacy of his techniques. That misses the point somewhat. He wasn’t looking to bring about concrete, short-term changes, but rather was trying to influence the medium-term attitudes his listeners had to their information sources: marketing rather than sales. It’s hard to measure the successes of this, other than to point out that now, eighty years later, his approach seems to have been refined and re-applied by people who are, in many cases, closely aligned to the politics he himself fought against.

4/5. Finished Friday 3 May, 2024.

(Originally published on Goodreads.)

Beyond

Stephen Walker (2021)

The space race from the American perspective is well-known: this book presents the same race from the Soviet perspective.

The differences are profound, of course, mainly driven by the Soviet programme occurring in complete secrecy to duck the risks that failure would have on the programme’s image. The American programme by contrast was conducted in the open at least as far as the actual “shots” were concerned – and their public failures did indeed endanger their ability to continue, at least in part because neither public nor politicians understood the process of engineering or just how hard each shot was. The deep irony is that the Soviet successes appeared so sudden and dramatic they led directly to the deepening of the American programme and commitment or more money and effort than the Soviets seemed able to maintain to capitalise on their early lead.

There are plenty of revelations even for those with a detailed interest in space history. I remember hearing all through the 1970s that the Soviet spacecraft landed on land, but it turns out that in many cases the cosmonauts were bailing-out and parachuting to earth instead, with this being intensively covered-up even to the extent of falsifying reports to the international organisation responsible for certifying “firsts” in space.

While the achievements of both programmes were profound, they were perhaps doomed in the long term by a lack of vision for what they were actually for. The benefits of space technology are now obvious; those of exploration perhaps less so, although it doesn’t (in my opinion) require much suspension of disbelief to feel that science-driven activities lead almost inevitably to enormously valuable spin-offs. The fact that we can’t quantify these a priori shouldn’t (in my opinion, again) stop us keeping the faith in the value of experiments that advance our science and engineering in ways that wouldn’t otherwise happen.

5/5. Finished Sunday 21 April, 2024.

(Originally published on Goodreads.)

The Emergence of Numerical Weather Prediction: Richardson’s Dream

Peter Lynch (2006)

A very technical examination of the world’s first numerical weather “prediction” – although in fact it was really a “postdiction”, taking detailed data and using it to compute a scenario that could be compared against a known ground truth. It was an incredible achievement anyway, performing manually and at low resolution the calculations now routinely performed by computers.

Richardson was the person who saw that this would be possible, realising that the physics and mathematics could be solved even though the computational capabilities didn’t exist. In this he foresaw the emergence of the modern power of data, where the existence of more and better data transforms both the way we do science and the sciene that we do. It’s something that should put him alongside Turing and Von Neumann as visionaries of what computation could achieve.

4/5. Finished Sunday 21 April, 2024.

(Originally published on Goodreads.)