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Sheogorath's Blog


Depending on the time of the day a friend, a colleague, a wise guy. The beauty of the world is its sense of humor to show humans their way by letting them search their own.


  1. About zip files and floppy disks

    Today I learned that zip files keep their metadata at the end of the file for historical reasons. This originates from the times of floppy disks. The disk space on floppy disks was rather limited and there was a lot of variation, resulting in the inability of a program to estimate how many floppy disks would be needed to store the zipped data. The solution to this problem was to simply write data to floppy disks, count them and as soon as all data was written, to write the metadata, including the count of the used floppy disks, on the last floppy disk and call it a day. …


  2. A hand full of sugar

    Today I learned that there is the rule of thumb that one should only eat a hand full1 of candies/sweets per day. For your average sweet that’s enough to satisfy your daily sugar needs (which range from 45-60 gram of sugar in all your food for a grown up person). The nice thing about the rule is, that everyone can understand them. The measurement device is literally always at hand and it grows with you. Making it super easy to explain it to any age group. A hand full means the amount one can hold in one hand, but without cheating as in making a huge pile or alike. ↩ …


  3. Event-based Sudoku

    Today I learned that one can write an event-based Sudoku solver. Means a solver that selectively re-evaluates the state of the Sudoku based on changed fields rather than iterating over the whole Sudoku over an over again to solve it. …


  4. Root DNS garbage

    Today I learned that roughly 50% of the all DNS queries to the root DNS servers are garbage produced by a single function in chromium and (all) browsers based on it.1 This function tries to detect NXDOMAIN hijacking by internet providers by generating 3 random, non-existing top-level domains (TLD) and request them as part of a regular http request. This important because Chromium-based browsers have a unified search and URL bar, which search feature can be defeated by NXDOMAIN hijacking as suddenly everything becomes a valid domain name. With all that said, when a recursive DNS server doesn’t know the answer to a DNS request it’ll ask the next DNS tier, which in case of a TLD is simple the root DNS servers. As Chromium runs this test on each startup and network change and there are literally more than 70% of chromium(-based) browsers on the internet that from time to time switch their networks2. This results in a ton of nonsense DNS requests on the root DNS servers. According to a study published on the APNIC’s blog it’s roughly 50% of all DNS traffic that hits the root DNS servers. 50%. Half of the traffic to the that hits one of the most important parts of the internet’s infrastructure is literal garbage created by a single function in a browser that is only needed because 2 input boxes, for 2 different functionalities is too complicated for users. And in 10 years they haven’t made it to find a better solution for the problem. Chromium, for those unaware, is the open source base, published by Google, for the popular Google Chrome browser as well as the majority of other browsers such as Vivaldi, Opera but also the newest version of Microsoft Edge or Brave. The only really competitors these days are Apple with WebKit/Safari and Mozilla with Firefox ↩ Like your phone joining and leaving your Home network ↩ …


  5. CSS Variables

    Today I learned that CSS variables exist. CSS variables are basically CSS properties that can be applied generically like every other CSS definition to elements. But they start with two dashes -- and a case-sensitive variable name, like --my-variable: 10px;. To read them as value for another property, you use the var() function. For example: font-size: var(--my-variable); This allows to apply them almost as easy as SASS or SCSS variables to around your web pages, just that they are actual CSS and replaced by the CSS rendering process at runtime and not like the SASS compiler at build time. …


  6. Domestication syndrome

    Today I learned about the domestication syndrome, which describes the visual changes one can observe when comparing wild animals with domesticated animals from the same species. Like wolfs compared to dogs. It describes that as part of the domestication process usually certain attributes, like the shape of the nose, the floppiness of the ears and the colour of the fur changes. Discovered by Charles Darwin, it is still not fully understood or even proven that it actually exists, but there is work going on to explain it. A paper from July 2014 links the attributes to so-called “Neural Crest Cell” which are also in charge of regulating the adrenalin and therefore the aggression level of mammals. …


  7. Foxes have a compass

    Today I learned that foxes probably use the earth’s magnetic field to judge the distance to their prey. A scientist of the University Duisburg-Essen in Germany noticed, while watching foxes in the Czech Republic, that foxes hunting for hidden prey (such as mice underneath the snow cover) facing the north-east directory were successful in 72 percent of the cases. While other directions were only successful in 18 percent of the cases. After some discussions with other scientists they developed the theory that it might be related to the earth’s magnetic field as other animals use it as well but usually for travelling and orientation. Therefore foxes are the first animals “known” be the using the earth’s magnetic field to measure distances. …


  8. Servus - the young tradition

    Today I learned that the cultural phenomenon of saying “Servus” as a greeting in Bavaria and the rest of Germany is rather young. While many people associate it with “old Bavarian traditions” the greeting wasn’t used for most of history. It’s originating in the Latin language and is short for “I’m your servant”. It made its first appearance in Germany when the Roman empire expanded to the north. But it disappeared soon afterwards again until the 19th century where Latin was used as a military language by foreign armies. At that time words like “Ade” were more commonly used, but due to the war with France got out of the trends quickly and was replaced by “Servus”. Over time it made it’s way into more sayings and replaced various words to make things sound less direct. In the 20th century it got more and more popular due to pop culture and similar trend setting events. Nowadays basically everyone in Germany knows the greeting and a lot of people use it on a regular basis as a greeting. …


  9. Breaking bad habits

    Today I learned that habits are made of 4 key phases, according to the book “Atomic habits” by James Clear: cue, craving, response and reward. Taking one of them away or making it much more difficult, breaks the habit. From my personal experience the easiest thing is to take the cue away. Those are notifications on your phone, your notebook or simply a label in your room. Want to eat less chips, put them behind solid doors. Another way is to make the response harder. To stay with the chips example, this can be done, by putting a lock on the door or simply putting them in another room, especially when you have to pass by with your flatmate. And of course the reward can be taken away by only eating them with a sauce you dislike. Obviously for the chips example you can also just take them an not buy them at all, but watch out for shop designers, they play with our cravings and they put the hints exactly where they need to be. …


  10. "The Eighth Wonder Of the World"

    Today I learned that in 1910 at the International Exposition in Brussels a mechanical instrument was presented called the “Phonoliszt Violina”. It’s a mechanical machine that plays music by itself, like a barrel organ, but instead of using pipes or plates to make sounds, this machine was playing an actual piano along with the most impressive instrument to automate at that time: The violin. Due to the complexity of the play of a violin it was considered to be impossible to automate, but as the existence of this machine shows, it’s possible and very impressive. The machine basically contains three violins where each of them only plays one string. Mechanical “fingers” then make sure the accords are hit. Generally speaking very impressive. …