Technology

there are many different methods of file compression. one of the simplest methods is run length encoding (RLE). the idea is simple: say you have a file like this:aaabbbbaaaaayou could store it as:a3b4a5to represent that there are 3 a’s, 4 b’s, etc. you would then simply need a program to… Read More »Lynne Teaches Tech: Why does compressing a JPEG make it look worse, even though putting in a ZIP file makes it look the same?

an operating system (OS), such as windows or macOS, handles a lot of low-level stuff. this means that developers don’t have to worry about details like “how to scroll a page” or “how to read text from a file”, because the OS handles it for you. a computer can’t do… Read More »Lynne Teaches Tech: why don’t windows programs work on a mac, and vice versa?

the “analogue loophole” (or the analog loophole) refers to the idea that no matter how hard you try to make sure nobody can make illegal copies of videos, music, or text, there’s always a “hole” in the protection that occurs when it’s no longer digital. digital content can be protected… Read More »Lynne Teaches Tech: what is the “analogue loophole”?

after downloading the image, OCRbot uses tesseract-ocr to extract the text. this is a free (as in libre and gratis) program that uses neural networks to do the job. it’s been trained on a massive dataset of text and has “learned” what letters usually look like. it knows that a… Read More »Lynne Teaches Tech: How does OCRbot work?

the ebooks bots (the ones i using the code i made, anyway) use something called markov chains. markov chains are a mathematical concept, and in computer science (computers are the only thing i know about), they are generally used for predictive text. when you type “how are” on your phone… Read More »Lynne Teaches Tech: How do mstdn-ebooks bots work?

Let’s use twitter and mastodon for our examples.Twitter is centralised, while Mastodon is not. This means that it’s possible for Twitter to disappear at any time – the CEO could (theoretically) shut it down and delete anything at a moment’s notice. The company behind twitter has complete control over everything… Read More »Lynne Teaches Tech: What does “decentralised” mean?

when you see a website that’s HTTPS rather than HTTP, it means the connection is secure. most popular browsers will display a green padlock in the URL bar to symbolise that (and colour it yellow or red if something’s wrong). to verify that a connection is secure (and not just… Read More »Lynne Teaches Tech: What does HTTPS mean?

There are a lot of ways you could define “free software”. For example, you could say Candy Crush or CCleaner is free software, because you can install it for free. When people say that software is “free as in freedom”, or “libre”, they mean something else. Under these definitions, neither… Read More »Lynne Teaches Tech: What is “free software”? Why do people say software isn’t free, even though you can download it for free from the app store?

paraphrased Wikipedia quote:In 1991, the Linux kernel appeared. Combined with the operating system utilities developed by the GNU project, it allowed for the first operating system that was free software, commonly known as Linux. in other words, the linux kernel and GNU utilities work together to form the linux operating… Read More »Lynne Teaches Tech: Why do people say GNU/Linux or GNU+Linux?