Tagged with tech


You probably have not noticed, but this site was offline for twelve days. And so was I.

This is because the glass fiber link that leads to our home in the forest was broken in connection with some work further down the road. Then the usual fuckups of privatized and distributed responsibilities ensued. Meaning that I had to lean hard on our network provider (ISP) to finally refer the issue to the network operator after 5 days. And then another week to get the technician to diagnose, and talk to the other company that caused the fault.

This is the kind of thing that would have easily annoyed the hell out of younger me - things not working as they should! The world is mean to me!!

This time, though, I was quite fine with it. I am on holidays anyway and can in fact build a new shed for firewood without internet access (pics will follow!). The notifications for emails had been turned off anyway and for urgent stuff we still had the 4G of our phones - so there really only remained the inconvenience that we imagined ourselves.

Still, it's good to be back online.

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Our World In 80,000 Hours

I usually don't consider myself a "fan" of anything, but when it comes to the work of @MaxCRoser at Our World in Data, and @robertwiblin as an interviewer, the term applies quite well.

So imagine what a treat for my ears the podcast with them both has been! Lots of background on one of the best sites on the interwebs. If you know it only for its statistics about the CoVid19-pandemic, make sure to check out their other topics as well!


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Disk Magic

A while back, my installation of HomeAssistant broke down and that caused some minor inconveniences, like lamp switches no longer working. Nevertheless, I only this week looked into what happened and whether I could recover the setup. The pairing of the lamps and switches is not something that one wants to repeat unnecessarily.

The most likely cause turned out to be it: The microSD-card in the RaspberryPi4 broke. They are known to do that, unfortunately. So I bought a new one, pulled an image from the old card and after a bit of fiddling, I was able to restore a snapshot that I had taken not long ago. All good.

I bought an additional microSD out of concern for the same thing happening to the other RasPi, the one that runs this very website.

ssh berr "dd if=/dev/mmcblk0" > berry.img
losetup --find --show -P berry.img

I had not known about the option -P before and it is exactly what I needed in this case: additional device files for the partitions within the disk image, not just a loop device for the iamge itself. So I could go on and check the filesystems' integrity:

fsck.vfat /dev/loop25p1
e2fsck -f /dev/loop25p2

Not surprisingly, there were several errors to be fixed in the main partition. After all, I was pulling the image from a running system that was continuously writing logs and stuff to the disk.

Then I tried to write the image to the new microSD-card.

dd if=berry.img of=/dev/mmcblk0 bs=2048

But this did not work because the new card was slightly smaller than the old one. Apparently 32GB are not what they used to be. Annoying!

So I had to figure out the number of sectors that remained on the new card for the Ext4-filesystem.

cfdisk /dev/loop25
cfdisk /dev/mmcblk0 # compare numbers in cfdisk
resize2fs /dev/loop25p2 61083647s
losetup --detach /dev/loop25
dd if=berry.img of=/dev/mmcblk0 bs=2048

Take out the card and re-insert.

fsck.ext4 /dev/mmcblk0p2 # passes the test now!
cfdisk /dev/mmcblk0 # mark first partition as bootable

And that's it. I did not test whether the card actually boots up because it would cause unnecessary downtime. I am reasonably confident it will work, should the need arise.

I quite enjoyed this whole small exercise. It had been a while and one always learns something new in the process.


Alias Nano=Vim

Some long time ago, probably around 2005, I got convinced that I should use vi for quick edits in the terminal, instead of nano which I had been using for this purpose, for historical reasons.

So I added this simple line to my .bash_aliases:

alias nano='vim'

And to this day I type nano when I just quickly want to edit a file, just out of muscle memory, and I would be very surprised if I would end up in actual nano, not vim.


Green Fundamentalism

From this book review:

Three hundred years ago, we burned wood for energy. Then there was coal and the steam engine, which gave us the Industrial Revolution. Then there was oil and gas, giving us cars and airplanes. Then there should have been nuclear fission and nanotech, letting you fit a lifetime's worth of energy in your pocket. Instead, we still drive much the same cars and airplanes, and climate change threatens to boil the Earth.

"Where is my Flying Car?", by J. Storrs Hall, is an attempt to answer that question. His answer is: the Great Stagnation was caused by energy usage flatlining, which was caused by our failure to switch to nuclear energy, which was caused by excessive regulation, which was caused by "green fundamentalism".

Counterfactuals are fun! I think I dismissed them too quickly as unknowable for a long time, but as with mot things, there can be better and worse arguments for how things could have turned out differently.

The environemntal movement is an interesting case, because what is considered good or bad in that context depends very much more on culture than on a problem solving strategy. The underlying conviction that human activity is inherently destructive leads to moralizing calls to give up things, that are not very effective. Whereas the obvious alternative is to improve technology to do more with less environmental impact. But that does not fit the narrative; to berate people and make them feel quilty lets one feel more morally superior and pure.

Would climate change never have become a problem, if the environmental movement would have empraced nuclear power instead of crippling it? No one knows for sure, but it certainly is interesting to think about.

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What Bird Or Plant Is That?

Have you heard of PlantNet and BirdNET? Their phone apps allow you to take a picture of a flow or plant, or record bird song, and instantly get an answer on what species it is.

They are not perfectly accurate and often give several probable choices, but very impressive and fun nonetheless. I especially like the visualization of the spectrum of bird songs, because I remember more easily how they look than from sound alone.

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Another picture of pennywort flowers, I know. But they are very photogenic and make good subjects for macro photography. So let me tell you how this picture was taken.

This is my gear, the same that I had for the last 15 years, from the time when digital photography was all the hype and everyone wanted to be a photographer.


The Nikon D300, 105mm macro lens and the external flash would cost you around 350€ used today (disregard the 18-200m zoom lens). They work great together and can give very sharp and beautiful results.

There are however a few things to do before pressing the shutter release.

  • I use the internal flash in master mode to control the external flash. This makes lighting very flexible. I often hand-hold the flash 90-180 degrees from the sun because the goal is making the light less harsh by filling in the shadows.
  • The camera is set to shutter mode with the shortest flash-sync time dialed in, 1/250s in this case. This is because the flash needs to compete with the bright sunlight and the short shutter time lets less of that in.
  • Exposure compensation at -1/2 stops, flash -1 or -3/2 stops. The violet and highlights easily get saturated at default exposure. And we want the flash to be less bright than the sun, again just evening out the light somewhat but not completely flattening the scene.
  • The two previous points have a welcome side-effect: The camera needs to choose the largest aperture it can in the current light condition, thereby rendering the background very much out of focus.
  • Then I compose the image and focus, first auto-focus to get close, then I hold focus and put it at the right spot by moving the camera ever so slightly.
  • I take several pictures before moving on. Not all will be a success with this quick method, not using a tripod, and I rigorously throw away all but the best one in a series.

This way I usually get the picture that I had in mind with quite little effort.

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Seeing Faces


I was recently reminded of thispersondoesnotexist.com which is a site that displays a new computer-generated face every time you reload it. There are still some artefacts that give away the artificial origin (I chose two examples with few glitches for the picture above) but I think it is fair to say that these faces look convincingly real.

This means that they trigger the same reactions in our minds that pictures of real people do. I found myself reloading the page for at least ten minutes, becoming more and more mesmerized, reacting to facial expressions, sometimes falsely recognizing someone I know, and generally unable to convince the automatic parts of the brain that these are not people.

Do I have a point? Should we become even more sceptical of media than we already are? I don't know. But being a somewhat aware of the way we cannot help but react to faces, real or not, cannot be such a bad thing, a kind of meta awareness that hopefully contributes to resilience against manipulation.

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I like to fix things when they break, and also to use them until they really no longer work. Replacing something that does its job well enough, just because there exists a "nicer" version of it out in the world, is an itch that I am able to resist scratching most of the time. The aesthetics of objects has value, sure, but I generally rank it lower than the enviromental impact of consumerism and the sheer hassle of buying things. Deciding what to get and then doing so is effort that has to be priced in.

All that is to say that I broke our coffee pot when I took it out of the dishwasher yesterday. A large corner is missing and while it still works for now, I am quite sure the rest of the glass will disintegrate very soon.


That machine came with the house when we bought it more than six years ago and who knows how old it was by then already. Not a chance that I find a replacement pot! I fixed/modified the electrical part twice already and the plastic is starting to disintegrate, so I admit it is time to give it up.

We have a Moccamaster at work and I like its no-nonsense approach and that it brews very quickly. That they are so popular should help with future repairs and replacement parts, so I am leaning in that direction for now.

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Nuclear And Bioweapons

This recent 80,000 hours podcast is a great listen! Fascinating stories on how they secured nuclear material from former Soviet states, and a perspective on weapons of mass destruction that one does not hear very often.

Just a small excerpt:

North Korea has an advanced biological weapons program. What worries me about North Korea is they’re more likely to use biological weapons than nuclear weapons, because if they used a nuclear weapon, it’s over, right? If they used a biological weapon and delivered it covertly through secret operatives, anywhere in the world… In Malaysia, where they used VX against a Kim Jong-un’s brother in a successful assassination attempt. Now that was a chemical weapon, but wherever North Koreans have a diplomatic presence, they could launch biological weapons attacks covertly. And in a way, perhaps that’s a little bit deniable, maybe they would never get caught for doing it. So I think they’re more likely to do that than to use a nuclear weapon, which would have a home address.

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