33C3: Works for me

Rocket Science
Rocket Science
The calm days between christmas and new year are best celebrated with your family (of choice), so I went to Hamburg where the 33rd edition of the Chaos Computer Congress opened the door to 12.000 hackers, civil rights activists, makers and people interested in privacy and computer security. The motto of this congress is “works for me” which is meant as a critical nudge towards developers who stop after technology works for them, while it should work for everyone. A demand for a change in attitude.

33C3's ballroom
33C3’s ballroom

The congress is a huge gathering of people to share information, hack, talk and party, and the past days have been a blast. This congress strikes an excellent balance between high quality talks, interesting hacks and electronics and a laid back atmosphere, all almost around the clock. (Well, the official track stops around 2 a.m., but continues around half past eleven in the morning.) The schedule is really relaxed, which makes it possibly to party at night, and interrupt dancing for a quick presentation about colonizing intergalactic space — done by domain experts.

The conference also has a large unconference part, hacking spaces, and lounge areas, meaning that the setup is somewhere in between a technology conference, a large hack-fest and a techno party. Everything is filled to the brim with electronics and decorated nicely, and after a few days, the outside world simply starts to fade and “congress” becomes the new reality.

No Love for the U.S. Gov

I’ve attended a bunch of sessions on civil rights and cyber warfare, as well as more technical things. One presentation that touched me in particular was the story of Lauri Love, who is accused of stealing data from agencies including Federal Reserve, Nasa and FBI. This talk was presented by a civil rights activist from the Courage foundation, and two hackers from Anonymous and Lulzsec. While Love is a UK citizen, the US is demanding extradition from the UK so they can prosecute him under US law (which is much stricter than the UK’s). This would create a precedent making it much easier for the US to essentially be able to prosecute citizens anywhere under US law.

What kind of technoparty^W congres is this?
What kind of technoparty^W congres is this?
This, combined with the US jail system poses a serious threat to Love. He wouldn’t be the first person to commit suicide under the pressure put on him by the US government agencies, who really seem to be playing hardball here. (Chelsea Manning, the whistleblower behind the videos of the baghdad airstrikes, in which US airforce killed innocent citizens carelessly, among others) who suffered from mental health issues, was put into solitary confinement, instead of receiving health care. Against that background, the UK would send one of their own citizens into a jail that doesn’t even respect basic human rights. On particularly touching moment was when the brother of Aaron Swartz took the microphone and appealed to the people who asked how they could prevent another Aaron, that helping Lauri (and Chelsea) is the way to help out, and that’s where the energy should be put. Very moving.

The media team at this event is recording most of the sessions, so if you have some time to spare, head over to media.ccc.de and get your fix. See you at 34C3!

to not breathe

I’ve always loved diving down while snorkeling or swimming, and it’s been intriguing to me how long I can hold my breath, how far and deep I could go just like that. (The answer so far, 14m.)

Last week, I met with Jeanine Grasmeijer. Jeanine is one of the world’s top freedivers, two times world record holder, 11 times Dutch national record holder. She can hold her breath for longer than 7 minutes. Just last month she dove down to -92m without fins. (For the mathematically challenged, that’s 6.6 times 14m.)

Diving with Jeanine Grasmeijer
Diving with Jeanine Grasmeijer
Jeanine showed me how to not breathe properly.
We started with relaxation and breathing exercises on dry land. Deep relaxation, breathing using the proper and most effective technique, then holding  breath and recovering.
In the water, this actually got a bit easier. Water has better pressure characteristics on the lungs, and the mammalian diving reflex helps shutting off the air ways, leading to a yet more efficient breath hold. A cycle starts with breathing in the water through the snorkel for a few minutes, focusing on a calm and regular, relaxed breathing rhythm. After a few cycles of static apnea (breath holding under water, no movement), I passed the three-minute-mark at 3:10.
We then moved on to dynamic apnea (swimming a horizontal distance under water on one breath). Jeanine did a careful weight check with me, making sure my position would need as little as possible correction movements while swimming. With a reasonable trim achieved, I swam some 50m, though we mainly focused not on distance, but on technique of finning, arms usage and horizontal trim.
The final exercise in the pool was about diving safety. We went over the procedure to surface an unconscious diver, and get her back to her senses.

Freediving, as it turns out, is a way to put the world around on pause for a moment. You exist in the here and now, as if the past and future do not exist. The mind is in a completely calm state, while your body floats in a world of weightless balance. As much as diving is a physical activity, it can be a way to enter a state of Zen in the under water world.

Jeanine has not only been a kind, patient and reassuring mentor to me, but opened the door to a world which has always fascinated and intrigued me. A huge, warm thanks for so much inspiration of this deep passion!

Harbor porpoise Michael
The cutest whale in the world!

In other news on the “mammals that can hold their breath really well” topic: I’ve adopted a cute tiny orphaned whale!

Ocean Warrior

The Ocean Warrior
The Ocean Warrior

The Ocean Warrior, the newest vessel in Sea Shepherd‘s fleet docked in Amsterdam before beginning its voyage to the Southern Ocean around Antarctica to prevent poachers from killing whales. Sea Shepherd is a marine conservation society that employs direct action to protect marine wildlife. The Ocean Warrior is a 54m custom-built vessel, hosting a crew of 16. It’s very fast, reaching almost 30 knots at top speed. It is powered by 4 3000 horse power engines, and features an open deck at the stern with a hefty water cannon.

Inspecting the bridge
Inspecting the bridge

The Ocean Warrior is an incredibly slick and strictly functional master-piece of ship engineering.  Its solid build makes it a tool suitable for the extreme conditions around Antarctica.

View towards the stern from the bridge
View towards the stern from the bridge
Powerful water cannon to keep poachers at bay
Powerful water cannon to keep poachers at bay

Its unusually high top-speed will give the Sea Shepherd fleet a huge strategic advantage in the vast wideness of the Southern Ocean.

Stern deck
Stern deck



I’ve done a facelift to my website. The new version is more mobile-friendly, modern-looking and quite a departure visually from its original look. I’ve chosen for a newpaper-like, typography-based responsive layout. My site finally also supports SSL, thanks to let’s encrypt.

Going to Akademy
Next week, I’ll be going to Akademy, which is co-hosted with QtCon. As usual, my focus will be around Plasma-related topics. I’ll also hold a presentation about a KDE software store.

Inside the Particle Accelerator

IMG_20160311_164446We visited the CMS today, the Compact Muon Solenoid, one of the “experiments” that are part of the LHC, the large hadron collider, which is a research project aiming to find out more about the basic structures that make up our universe, like how gravity works, which particles make up our universe, and so on.

In order to do that, researchers accelerate elementary particles to almost the speed of light, make them crash into each other and record this process. There’s a 27km long circular tunnel 100m below the ground near Geneva, Switzerland (the tunnel actually extends into France, so the CMS experiment is located in France).


As we’re currently at a KDE Plasma sprint at CERN, the European Research center for nuclear energie, we were invited to a tour through the CMS. We got to learn a lot about physics and also descended down into the chamber holding the giant CMS machine. (It’s switched off currently, since energy costs during winter are too high to run it — it takes a lot of power to accelerate particles to almost the speed of light, in the range of 200 Megawatt). There’s some maintenance work going on right now before this monster is switched on again towards the end of the month.

CERN staff were friendly and patient and answered all our questions. The tour was interesting and a lot of fun.

Here are some more pictures I took during the visit. You may notice that some of the computers in the control room are running Plasma on their desktops.

More photos of my visit can be found here.

Cuba Diving.

Spectacular sunset at Maria la Gorda
Spectacular sunset at Maria la Gorda
I recently went on a vacation to Cuba. As I wanted to go scuba diving there, I researched a bit beforehand. The information I could dig up was spotty at times, so I decided to share my notes in order to add it as anecdotal information when planning their diving trips.

During the 3 week trip to Cuba, I visited three locations in the south-western part of the island. In total, I did 19 dives along the Cuba coast, all of them very enjoyable. On the list were shallow (10-18m) coral reef dives, wall dives, some of them deep. I clocked my max depth at 34.1m. One of the things I wanted to do was a cave dive in a Cenote. Cenotes are underwater cave systems found around the geological area.

General Considerations

Dive boat at Maria la Gorda
Dive boat at Maria la Gorda
Cuba, being a Carribean island has a tropical climate with warm waters around it, and climatically a wet and a dry season. As the wet season may make the sea choppy, reduce visibility and carries the risk of hurricanes, it’s advisable to pick the dry seasons, months from November to May for diving activities. The South coast, which is where I have been diving had warm waters 27°C at the surface, and 26°C as depths down to about 35m. Visibility was generally excellent, commonly around 30m, with sometimes up to 50-60m in calm water. In several spots, there are large and well-preserved coral reefs. The South coast usually has calmer waters than the North coast, so I picked locations in the South-West: Maria La Gorda at the far southwestern point of the island, Playa Girón at the Bay of Pigs, and Playa Ancón near Trinidad. All turned out to be worth visiting and made for some amazing dives. (We also visited Cayo Levisa on Cuba’s Northern shore, which has a nice beach, but was mediocre at best for snorkeling from the shore. Go to Cayo Jutia instead, if you want good snorkeling, or book the boat to go diving at Cayo Levisa.)
Cuba is a communist country, instead of Coca Cola advertisements you’ll find some billboard reminding you that “the revolution is invincible”. Economic trade embargoes make acquiring scuba diving gear a problem (although I haven’t seen any shortcomings in this area myself). There’s usually just one dive center running the diving operations, so not much choice, but on the other hand, you’ll rarely encounter crowded dive sites, or reduced visibility due to other divers silting up the waters.

Touristic activities such as diving are usually possible through government-owned dive centers. There’s a network of official travel agents across the country, which can help you with booking trips and getting in contact with dive centers. Many of them are not easily reachable by phone, but you can sometimes book in advance of your trip online. In my experience, it would have been fine to just show up at the dive center at the right time of the day with your certification card and dive logs to prove your experience, and you’ll be almost good to go. I decided to bring my own gear, regulator, jacket BCD, 3mm wetsuit, fins, mask and torch in order to avoid any annoyances or unsafe situations due to flaky equipment.

My personal experience has been very positive, I loved the different dive sites, guides were generally skilled, and I had a whole bunch of amazing dives in Cuba. Would recommend.

Maria la Gorda

Maria la Gorda's beach
Maria la Gorda’s beach
Maria la Gorda is a bit off the beaten path in Cuba, one of the more remote locations on the main land. We travelled there from Vinales in 3 hours by car. The location itself is comprised of a hotel, two restaurants, and dive centre on a beautiful beach that also makes for some very nice snorkeling, you can basically walk in and enjoy lots of fish, even those not often discovered while scuba diving. Kim spotted barracuda, jacks, parrot fish, a moray and even an octopus just a few meters off the beach.
Diving there is done by boat 3 times a day. Almost all of the diving spots are within a 15min boat ride. The dive boat goes to 3 different sites a day, at 8:30, 11:00 and 15:00. It’s possible to also do a night dive, but has to be arranged with the staff. If you’re doing a day trip from Vinales just for diving, you’ll arrive in time to do two dives before leaving, the dive center does consider day guests. The surface time in between was enough to not dip too deep into nitrogen levels with 3 daily dives, the first two of them deep. Dives are usually limited to 45′ bottom time. If in general, you can’t get enough of scuba diving, that’s a lot of diving there.
The sites I’ve visited were all amazing in their own rights. Beautiful walls littered with coral, dropping down to 2000m right below you, really nice tunnels to dive through, large fan corals, barrel sponges of 3m and more, large groupers, jacks, and the usual variety of coral reef fish (parrot, box fish, angelfish, jacks, butterfly fish, etc.). Fish of more than 50cm in size were no exception, which seems like a sign that at least this part of the Carribean is comparably less overfished than other areas, there and especially in Asian countries.
The procedures on the boat were a bit unclear, I had liked to get better introduction there. Other people were happy to help, so this wasn’t much of a problem. The guides’ briefings were too short for my taste, especially knowing a bit about the navigation planned underwater would help to keep the group together more closely and in the end improves safety. I’ve asked the guide to tell me about the planned route under water, which he did in the following dives. That allowed me to take some responsibility myself (I really like to know under water that everybody who went into the water comes out of it as well). That said, there’s always room for improvement, and it didn’t lead to any dangerous situations. Taking responsibility for your buddies is part of diving, and as long as everybody takes it seriously, no problem.

Bahía de Cochinos (Bay of Pigs)

Museum in Playa Giron
Museum in Playa Giron
The Bay of Pigs is historically known for an attempt by the CIA to invade Cuba with US-friendly troops and overthrow the then-young communist government. Lack of political support from the US government, underestimation of the Cuban revolutionary troops and insufficient secrecy lead to an utter failure of the invasion attempt. Nowadays, the bay of pigs is a rather calm area, with excellent scuba diving. Basically, the eastern shore of the bay is lined with a coral reef wall very close to the shore. Commonly, one would do a shore entry here, swim out about 100m and then drop into the wall.
I dove with Ronel’s local dive operation. A tweaked bus would pick us up in the morning, go to the dive center (next to the government run hotel in Playa Giron) to gear up, and then drive up North for 10 – 20 minutes to one of the dive spots along the bay, then do two shore dives from there. We’d return around 1 o’clock in the afternoon, so there’s plenty of time for other activities (which, to be fair there aren’t that many apart from the beach and a “not-quite-neutral” museum about the failed invasion attempt).

The Cenote Dive

Entering the Cenote
Entering the Cenote
Cenotes are sinkholes in the shallow limestone ground near the coast. Small pools filled with fresh surface waters lead to extended cave systems flooded with salt water, so one enters a fresh water pool in the woods, then descends through a haloclyne. This haloclyne is the border between fresh and salt water. The caves were usually filled with salt water seeping in from the sea, but as there are almost no currents, rain water that comes in from above stays on top as fresh water. The haloclyne produces a weird disturbed visual effect when one dives through it, but above and underneath it, visibility is clear. These sink holes are often quite deep, the one we entered was 26m deep at entry point, the deepest points of the cave system went down to 60m. We entered into a tunnel, a vertical crack in the limestone about 1m wide, so wide enough to comfortably swim through. During the dive, we made our way about 350m into the cave to a maximum depth of 32m. As the shape of the cave determines the dive profile, I ended up having to add an extra decompression stop before surfacing.
We went through a lower tunnel into a larger cave, which had some beautiful sunlight shining in through cracks above in blue-green colors. Visibility was excellent, and the sunrays produced an almost magical ray of sunlight in the water of the deeper cave.
Descending into the Cenote
Descending into the Cenote
Through the haloclyne above us, the sunlight was broken by the different densities of air, fresh and salt water until they hit the particles drifting in the water or the walls and bottom and of the cave. This dive was guided by a specialized cave diving guide. Briefings were thorough, and after a first reef dive to check everyone’s buoyancy and general diving skills, we did our second dive of the day in the Cenote. I’ve found this video, which gives an impression how such a dive looks like. If you’re an advanced diver, comfortable with overhead environments and experienced enough, I’d definitely recommend doing a Cenote dive, For me, it’s been an unforgettable experience.

Playa Ancón

Playa Ancón is the beach village close to Trinidad. It’s a peninsula at about 7km from Trinidad. I’ve found it a bit complicated to book the diving there. Tour operator in Trinidad would tell me that everything’s fully booked, but inquiring at the dive center in Playa Ancon, I was told to just show up before 9am and I should be fine. That’s what I did, and it was indeed no problem to go diving there. We’d enter the boat from the beach and would go out a few hundred meters, just too much to swim there comfortably.
Even with a bit of a choppy sea that day, the diving was excellent. Good guides lead me over an interesting seascape with sandbed-“roads” in between coral fields, and much life in between. Highlights of these dives were a wreck, which lay across two large rocks and created a swimthrough this way, a school of tuna (about 40 fish), and a 1.2m large eagle ray. Water was warm and visibility in the range of 15m (considered quite bad for the location, so expect better when you get there). The dive shop was run professionally, but be prepared for a “laid-back scheduling”, which means depending on the day, two boat dives with a surface interval on shore might run into the early afternoon. (I’m mentioning it here, since every other dive center I dove with in Cuba was exceptionally punctual, contrary to what I had read before.)

Spring dive.


Spring is just showing its first rays of sun, so we went diving today. We did a shallow dive in the morning in a lake close by, which is known for decent diving. The water was 4°C, so really chilly for a recreational dive, visibility under water about 5-7m, which is quite good for this kind of water. During our dive, we had really nice light as we didn’t go very deep and it’s been a really sunny day.

I’ve used Lycra undergarment and a 2mm neoprene bodywarmer under a 5mm wetsuit, 5mm neoprene gloves, hood and boots. My coldest dive so far was in 18 degrees water (in the same lake, late summer), so water that cold was quite something new. Richard, my buddy has a lot of experience also in these conditions, so I was in excellent hands.

After an initial bit of a shock when we entered the water, and a quick weighting / buoyancy check I gained back my serene diving breathing rhythm and started trusting the suit enough to become comfortable that it would keep me warm enough to take it for a swim. We went under for almost half an hour, but also took first signs of hypothermia seriously, in order to keep it safe and healthy. During the dive, we saw some fun fresh water lobsters, but also a fairly dormant ecosystem. I wanted to test out my new equipment, wireless integrated tank pressure gauge, jacket BCD, fins, regulator and an air tank I’ve borrowed from a neighbor, aside from the different layers of the suit.

I’m really happy with the new gear, everything functions perfectly, and there’s nothing that doesn’t have a clear purpose. I’ve taken a couple of notes for the next dive with this equipment, though those are only small adjustments, such as strapping on the tank a bit lower for a better weight distribution (which translates to a more hydrodynamic body position, meaning less exertion, lower air consumption and a more relaxed dive).

My next dive will be in 26°C water. Phew.

Trusty Old Router

Linksys WRT54G
I decommissioned a fine piece of hardware today. This access point brought the first wireless connectivity to my place. It’s been in service for more than 11 years, and is still fully functional.

In the past years, the device has been running OpenWRT, which is a really nice and very powerful little Linux distribution specifically for this kind of routers. OpenWRT actually sprang from the original firmware for this device, and was extended, updated, improved and made available for a wide range of hardware. OpenWRT lately has made this piece of hardware useful, and I’m really thankful for that. It also a shows how much value releasing firmware under an Open Source license can add to a product. Aside from the long-term support effect of releasing the firmware, updated firmware would add features to the router which were otherwise only available in much more expensive hardware.

The first custom firmware I ran on this device was Sveasoft. In the long run, this ended up not being such a good option, since the company producing the software really stretched the meaning of the GPL — while you were technically allowed to share software with others, doing so would end your support contract with the company — no updates for you. LWN has a good write-up about this story.

Bitter-sweet gadget-melancholy aside, the replacement access point brings a 4 times speed increase to the wifi in my home office: less finger-twiddling, more coding. :)

Looking back, looking ahead.

Dragon- and Jackfruit, coffee, cocoa, tobacco, chocolate, palm sugar and tahoe from JavaThis year’s general assembly of KDE e.V. during Akademy will be my last one as a member of the KDE e.V.‘s Board of Directors. I had been elected during Akademy 2006 in Dublin, and since then served the KDE community by working on organisational bits necessary to support a Free Software project. We’ve seen times where our environment wildly changed, times of growth, consolidation, growing pains. Looking back fills me with satisfaction how we have developed KDE e.V. as an organisation. I think KDE e.V. is exemplary in many ways for other Free Software, and Free Culture projects. One of the cornerstones here is continuity, we simply had the time to learn a lot, to define and implement necessary processes around administration, fund-raising, legal questions, conference organisation and many more. As it stands today, KDE e.V. is an organisation that provides the continuity necessary for a community to think ahead, and the necessary infrastructure to foster and support those next steps. KDE e.V. is also an organisation that constantly evolves, reacting, but also foreseeing and preparing for the next steps. We have a well-functioning team in place to guide this, and I’m confident that the current and coming board members will keep developing KDE e.V. as an organisation towards its goal of supporting KDE.

The Merapi volcano, as seen from the BorobodurEarlier this year, I had also resigned from my role as one of KDE’s release managers. When I joined the release time, around KDE 3.5 (our software compilation was still called KDE back then), our release process was becoming dysfunctional. In KDE 3 times, coolo (to some known as Stephan Kulow) was the release dude, and it was all in his hands. He did a great job, but, just like in many other areas of KDE, embodied a single point of failure. Not that he, or others we relied on, ever failed, but it’s usually more a matter of statistics than personal skills, attitude and motivation. For critical tasks (and actually releasing all the work of such a community for others to use is a pretty critical one!), you want a team in place that can fall back on each other, both to spread workload and risks. Afin, KDE needed release managers, and after a detour through a more official body (the KDE e.V.-elected Technical Working Group, for those who remember this episode), it became clear that only a self-motivated group of people that want to get the job done will work. In hindsight, this sounds completely natural and closely aligned to KDE’s way of achieving things, but I think this way had to be walked, we have learned from it, and in the end, there’s a competent team in place which can deliver our software in time and quality. As being on the release team is work, and at times quite a lot, I wanted to get rid of this eventually. I managed to pull out, I think without leaving too much of a hole. A few releases have been done without me actively particating. Probably, most people won’t even have noticed. Perfect.

So am I on the way out? Most certainly not! I’ve been consistently shifting from organisational tasks to more technically oriented work, which to me personally, is a good development. I simply get more kicks out of writing code than reading emails. In that regard, I think I’m in good company.

The sun rising over BaliOn a professional level, I’ve been working for Blue Systems on Plasma’s upcoming version for a while now. I’m spending most of my time on Plasma and our Frameworks 5 effort, and enjoy that a lot. It gives me both the time to intimately understand more parts of our codebase, and much opportunity to learn new things and improve and develop existing skills. The work happens entirely within KDE infrastructure and community, and I’ve got a bunch of great colleagues who are equally eager to take big steps, technologically with our codebase. My role has now shifted a bit to also include team coordination tasks, which is an interesting exercise. On the one hand, a geographically spread team is harder to keep track of, but this is offset by the great motivation, skills and attitude of my colleagues (within both Blue Systems and KDE).

Incense in a buddhistic templeLuckily, my life’s not all KDE and the serious business of software development. In May, Kim and me travelled to Indonesia. We spent a few nights in the jungle of Borneo, took a walk with Orang Utans. We planted trees, and slept the nights on the deck of our boat acompanied by jungle noises and clear skies. On Java, we visited the Borobodur, a giant buddhistic temple, one of the 7 wonders of the world, we learnt about the roots (literally and figuratively) of many conveniences such as coffee, rice, tobacco and latex. We climbed up a Volcano. From Java, we set off to Bali, travelled along its North coast and then spent some time on Gili Trawangan, which is part of a group of sandy, tropical islands just off the coast of Lombok. The time in Bali and on the Gilis did my scuba diving skills really well. The area is excellent for diving with warm waters and amazing marine life. My finning technique has improved vastly and I’ve got dehydration under control much better now. During our dives we spotted lots of coral, soft and hard, vast amounts of colourful reef fish, turtles, reef sharks, morays, sea snakes. The abundance of colour and life was enchanting, though fragile.

With all that said, some of you will meet me later this week in Bilbao for Akademy. I will arrive on Wednesday already, going to see Depeche Mode and The Editors at BKK festival. If you want to talk Frameworks5, Plasma2 or anything else which lies in my line of interest: Talk to me.