Software

Don’t take this too seriously. As part of my coping mechanisms, I try to understand the latest (Dutch) COVID-19 figures. I documented where to get the raw data and what they mean in an earlier post. Please note I am not trying to make any kind of point with this data, not positive, not negative. I have no agenda, please do not read this as me trying to argue things aren’t that bad or that they are terrible.

Around a million years ago (it feels like) but actually 9 months ago I delivered a brief talk on end to end encryption for the European Internet Forum at the European Parliament. Update: in February 2024, the European Court of Human Rights ruled in rather strong words that forcing providers to break end to end encryption violates human rights. Sorry, your browser doesn't support embedded videos. If you can spare 9 minutes, I recommend watching the video.

The European Global Navigation Satellite System Galileo has recently been suffering from frequent "almost disruptions", most likely partially due to Corona, and possibly also due to Brexit, but in any case due to some historical stinginess. Before I explain what is going on, I should hasten to say that most days of the week, Galileo is working well for most users. But for example, Monday the 28th of September, one satellite was off by a stunning 5 meters.

Welcome to part 3 of my series on OSNMA, the proposed Galileo Navigation Message Authentication protocol. This part can be read independently from part 1 and part 2, but it might be useful to read the introduction to part 1. This post attempts to explain GPS (GNSS) jamming and spoofing, so it might be a useful read even if you don’t care about Galileo or its authentication. As usual, I’ve been helped tremendously by Daniel Estévez & many other researchers and Galileo professionals, and again I am very greatful for all the links, corrections, suggestions and knowledge you provided.

We horen veel over hoeveel mensen er nu besmet raken met COVID-19. Tegelijk viel het tot begin oktober erg mee met de ziekenhuisopnames en sterfgevallen. Ik kan ook niet verklaren hoe dat precies komt (het is niet alleen leeftijd), maar ik wil het in dit artikel wel hebben over “de zonlichtvitamine”, vitamine D. Want nu in september hebben we net een zomer lang zon gehad, en in maart kwamen we vers uit de winter.

Recapping from part 1: Galileo will soon add cryptographic signatures to the navigation messages. These cryptographic signatures are made with symmetric cryptography, which means clever techniques are required to prevent receivers from impersonating the network. The key to the technique is first signing messages, and only later disclosing the key used for the signatures, thus invalidating it for further use. Receivers can however verify that earlier signatures were indeed made with that key.

Position, velocity and time (PVT) information can be a ’nice to have’, but in other circumstances knowing place and time has legal or military importance as well. Heavy vehicles for example are typically outfitted with tachographs that track driver speed and/or location. This has importance for rest regulations, but also to check if loads are actually from where they say they are. Our Global Navigation Satellite Systems so far are broadcasting unauthenticated data, at least to civilian users.

Toch weer een kleine Corona-update, vrij snel na de vorige van 1 juli. Want poeh, gaat het nou ineens weer mis in Nederland? Of valt het mee? Moeten we allemaal aan de maskers en komt het dan goed? En gaan de vaccins en medicijnen ons redden voor de winter? In tegenstelling tot vele roeptoeters heb ik daar ook allemaal geen zekere antwoorden op, maar hier toch een set updates over de meest recente ontwikkelingen.

GPS, GLONASS, Galileo, BeiDou (Global Navigational Satellite Systems, GNSS) are miracles of engineering. And within any complex system hide surprises and unsuspected complications. In this post I go over how we resolved an odd observation: that everyone (including major institutions) reported that one of the Galileo satellites (E24) appeared to be off by 1.5 meters, while actual positioning equipment (like phones) showed no problems at all. Through the explanation, we’ll casually learn a thing or two about the cool concept of multi-frequency GNSS.

Hi everyone, Disclaimer: this is a review of a free sample I got sent by Uputronics. I recently spotted on Twitter that Uputronics had launched a GPS/RTS Raspberry Pi Expansion Board, and that they were looking for worthy projects to test it. I thought our Galileo/GPS/BeiDou/GLONASS monitoring project galmon.eu might be worthy and Uputronics agreed. Relevant for our purposes, this is an actual ’timing receiver’. Any GNSS chip will get you a location, but some of them go the extra mile to also deliver a very stable clock signal.

I have a longer story brewing, but in this post I want to briefly announce the “Galmon.eu unofficial Weekly Performance Report”. This is a blog post version of an earlier Twitter thread. I’m very proud to present the first full Galmon.eu Weekly Galileo Report! And the good news is: it was a good week with very little to report. The email has just gone out, but you can also find it here.

Nu het RIVM gestopt is met dagelijkse updates vond ik dat het tijd was dat gat dan maar te vullen, al is het maar voor een dag. Een nieuwe Corona Update “hoe gaat het nu met”. De vorige was alweer van 21 april! De “Ik ben geen expert, maar toch”-factor Een boel dansleraren en opiniepeilers zijn inmiddels COVID-19 experts. In deze post heb ik erg mijn best gedaan alleen dingen te melden die we heel zeker weten.

When COVID-19 burst on to the scene, tests quickly showed that the everyone was susceptible - no pre-existing antibodies were found that bound to the SARS-CoV-2 virus. This led to dire predictions that over 80% of the population might eventually fall ill. Now more than six months in, this has not happened, and it does not appear to be close to happening. A few months ago, noted virologist Christian Drosten mused in his (German) podcast that some people might have a level of immunity after all, but he wasn’t yet sure.

Welcome to this post, in which we’ll be taking a trip through the wild and bumpy ride that has been Vitamin D & sunlight research over the past few decades, and what it might mean for COVID-19. As with my previous post, before any non-specialist attempts to write something on COVID-19, we should wonder: are any actual experts already writing on this, and if not, why not. Enough badly informed stuff has already been published by amateurs that before posting we should be certain we are actually being helpful.

It turns out that so far, I have written over 44000 words on COVID-19. I’ve tried very hard to only report the best and most trustworthy science, but I did strive to include interesting new insights that were not yet mainstream. As an example, I spoke about vitamin D and sunlight real early, which now indeed appears to be a thing. No guarantees yet, but it definitely is a thing.

This post is dedicated to lab technicians everywhere doing the difficult work institutes and hospitals rely on to investigate disease and keep us healthy. Lab work requires high precision, deep understanding, is physically demanding, and can even be dangerous. Although our healthcare systems & universities would come to a grinding halt without lab technicians, they are often almost literally invisible somewhere far away. Thank you all for your hard work!

Before any non-specialist attempts to write something on COVID-19, we should wonder: are any actual experts already writing on this, and if not, why not. Enough badly informed stuff has already been published by amateurs that before posting we should be certain we are actually being helpful. October 2022 UPDATE: I've removed the rest of this post. Turns out everyone (including me) was wrong, and we didn't understand pandemics of respiratory diseases very well.

Een spontane wetenschapsupdate, omdat het Moederdag is, en speciaal voor iedereen die het nu zonder zijn of haar moeder moet doen. Want, we dragen allemaal letterlijk een beetje onze moeder bij ons! Deze post is dankbaar geïnspireerd door deze Twitter thread van Efra Rivera-Serrano, PhD. Bron: Efra Rivera-Serrano, link Ons DNA is een mix van dat van onze beide ouders. Maar, in vrijwel al onze cellen leeft een wonderlijk wezentje wat we echt alleen van onze moeder geërfd hebben.

Het RIVM, het “Outbreak Management Team” en het kabinet werken samen aan gedegen adviezen. Uiteindelijk worden dit ook wel de juiste adviezen, al blijft men soms lang aan oude dingen hangen: mensen zonder symptomen zijn niet besmettelijk (oeps, toch wel), maskers hebben geen zin (oeps, ze helpen wel voorkomen dat je andere mensen besmet). Uiteindelijk maakt men de draai wel, maar het kost even. Nu de scholen weer opengaan vroeg ik me af, wat weten we eigenlijk over hoe mensen besmet raken met COVID-19?

Ik blog al maanden over SARS-CoV-2 aka COVID-19 aka “het coronavirus”, waarbij ik grotendeels dingen uitleg en verwijs naar positieve ontwikkelingen. Ook zijn er stukjes over medische experimenten, over ons immuunsysteem en recent iets korts over het vermoedelijke belang van goede ventilatie om COVID-19 besmettingen tegen te gaan. Ik houd van de wetenschap en ben trots op het mooie onderzoek wat hier in internationale samenwerking verricht wordt. Maar nu dan toch een zeurstuk: waarom weten we niet waar en hoe mensen in Nederland besmet raken?