Home

This is a nice trick for running your 30 minute meetings. I found it during listening to the latest episode of The Engineering Commons. 30 minutes are the standard slot for a meeting it seems. So plan for a 30 minute slot, but plan to run the meeting in 22 minutes. Why? Because if you are in a series of meetings, chances are that you’re going to be on time only in the first one (and even that is debatable). So delays accumulate and you can forget ever making it to the last meeting.

So why 22 minutes? My guess is that if you have planned for 5 meetings in a row, this 22 minute window slides enough within each 30 minute slot so that you can make it in all of them.

For longer meetings you can always multiply appropriately.

APL

2016/11/13

Today it was my fourth (I believe) encounter with APL:

  • First, too many years ago when skimming through Tim Budd’s “The Kamin Interpreters in C++” (and the Kamin book afterwards). For the hardcore fans, Tim Budd has a book on implementing an APL compiler.
  • Next was a Dr Dobbs issue about the J programming language.
  • Some years a ago a comment on this blog about Dyalog.

Today it was Functional Geekery’s Episode 65 where I found out about the most interesting (to me) implementation of Conway’s Game of Life.

Live

2016/10/24

Here is an experiment: today instead of watching the news for the night, I picked up a record I had not listened to for years, Live by Jean Michel Jarre.

jarre_live

Live, 1989

I had gifted it to a friend who passed away 10 years ago and I do not believe I had listened to it since then.

Rendezvous Houston - Houston Festival Light show in downtown Houston

The kids were impressed by the music τo the point that they wanted to learn more about Jarre. So I headed over to YouTube and played the whole of the Huston 1986 concert (another album which I had not listened for years since I only have it on cassette). They were really fascinated by what they saw also. The laser harp and the circular keyboard made an impression.

jarre_clavier

Dad, he must be a super cool engineer!

I do not know about engineering, but design-wise he won their hearts out. We even got to listen to Ron’s piece (from Ronald McNair who was supposed to play this in space) which led to discussing about the Challenger.

Funny what feelings, forgotten memories and processes a forgotten CD can spark.

[ Mostly saving this post for posterity ]

I had heard of the language long before it was made Open Source. In order to get access to the implementation I had Timos Sellis sign an NDA with Ericsson. I had fun with Mnesia (the distributed DBMS) and started thinking of whether it could be applied to stuff I was good at at the time (namely SMTP and DNS). In fact it was. Because most of the Erlang team formed a company named Bluetail that was making software based load balancers with Erlang and got sold at $152M.

Nowadays I occasionally have “fun” with the Erlang VM whenever I have a RabbitMQ instance go mad.

But this? This is something only someone like the guy who writes RabbitMQ could discover:

Donald Knuth was the first Erlang programmer

The Fields Medal. A genius Mathematician racing against time. Will he make it before he’s 40? The journal of his adventure is what this book is about. Along with his fears, the way he measures himself against other giants (does he really have to? To the reader it may seem he does not, but to him is matters a lot; the top is the top). And yes, it is written as a diary.

I will not pretend that I knew, or still understand anything about Landau damping. Or even the Boltzmann equation. In fact I know only of a handful of people who could recognise the complete notation used. Interestingly, this does not make the book less enjoyable. It took me over a year since I first found out about the book, started reading it and then finishing it. And you know what? It was not the Mathematics that put it to a pause. It was a long chapter on music, on stuff that I could follow in complete detail. When I reached there I paused in order to find the proper time to enjoy the written soundtrack. Well that time came about a year later.

Far too many top Mathematicians and Mathematical Physicists parade in the book. Perelman‘s antics and perseverance get explained. Luckily some simpler (to grasp, not solve) problems too, the Collatz for example. As it happens I too use it sometimes to block my mind from interference. But that’s where the similarities with the author stop. The other thing that felt close to heart was Coq. I always had ideas about using it in ways not expected by its creators, but my academic limited attention per suject blocked this.

All in all a fascinating read about a man, his passion and his target. You can safely ignore the Mathematics. It is hard enough for the professionals and is there to show what he dealt with. The pain is described not in algebraic notation but with plain alphabet.

 

addressing

2016/09/26

I’ve started reading John Day’s Patterns in Network Architecture and during the first pages it makes strong references to Saltzer’s 1982 paper. Why would I bring this up? Well, I just heard Surprisingly Awesome‘s episode on Postal codes where they deal with two countries (Lebanon and Mongolia) with almost non-existent addressing plans. Here is what an addressing plan should give you:

  • a name identifies what you want,
  • an address identifies where it is, and
  • a route identifies a way to get there

Day makes the case that we usually use that address of a network element in the same way that we use its name also which is an error, since by moving an element elsewhere in the network, we need to change its name also.  You on the other hand do not change your name when you change your home address. You used to change your phone number, but even that has become equally portable.

In places where no stable addressing system exists the courier is required to build a mental representation of the routes in their area of delivery, based on landmarks, trees, neon signs, whatever can help to make the delivery. In Mongolia this is solved differently: When something arrives at the post office, they call you back and you go and pick it up.

Enter the NAC. What is it exactly? It is an effort to map longitude and latitude to a more memorable representation using the base 30 number system using digits and capital letters. Borrowing from Wikipedia, the NAC for the centre of the city of Brussels is HBV6R RG77T. Compact, accurate, but not quite memorable.

what3words seems to be a service set to solve this since with their solution a unique combination of just 3 words identifies a 3m x 3m square anywhere on the planet. For example, roughly the same place as above is described as october.donor.outlined. I admit, this is much easier to type in a GPS (or tell Siri).

However, I am still surprised that nobody ever thought of using IPv6 for this (maybe somebody has? Please tell me). Given the abundance that the 128bits give us, we could have indexed every square meter on the surface of the planet and make it addressable. Oh, the directories we could have built on top of that. But I have no fear. It is quite probable that much of the inhabited First World’s surface will be pingable in the foreseeable future. The IoT will make sure of that.

 

The Last Lecture

2016/09/16

Randy, it’s such a shame that people perceive you as being so arrogant, because it’s going to limit what you’re going to be able to accomplish in life.

I will admit to never having seen The Last Lecture. Over the years I’ve started watching it, only abandoning it after the first couple of minutes. The only thing that I’ve seen, and this only by chance, is the part where Randy Pauch describes how his parents let him paint his room. Somehow this stuck with me and in our house the kids are allowed to draw on the walls of their room, only in contrast to his parents, the room gets painted from time to time and the drawings are thus erased.

Somehow I decided to read the book. Mostly because it contains one of the most annoying phrases I’ve ever heard offered as consolation: “We cannot change the cards we are dealt, just how we play the hand”. Well, you cannot argue with a dead guy, and Pauch, if alive, would not let you win the argument.

It takes tremendous self discipline to write a book like that (even though technically he did not write it, he dictated it on tape and a writer undertook the polishing). I was told though by a good friend that similar efforts (like keeping a journal) help coping with the situation. And this is visible in the writing. As is visible that we are not the main audience of the book, his three kids are (lately I pick authors with three kids). He even admits that at the end of the book. The man has little time left and a lot of guidance to give. So what is this book? A self-help book? A career-advice book? A parenting one, drawing mostly from the example his parents set for him? All of that?

Time is all you have. And you may find one day that you have less than you think

It is a time-management book. Because here is a guy that was on the path to success, that had a lot to give to his field and his family, who is suddenly told that long-term plans do not matter any more. This is what you’ve got at best, squeeze whatever you can inside. So through his book (and the lecture I suppose) he basically delivers a lesson in time management (which explains how he managed to do so many things until he was diagnosed terminally ill), planning, team building, mentoring and correcting one’s behaviour.

This is not a book that made me feel relaxed or even good about myself after reading it. Nor is a book that I agree 100% with what is written. More likely close to 60% of the advice. But am I happy I read it? Yes. Should you read it? Only if you can handle enumerating all your mistakes so far.