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A large part of our civilisation rests on the shoulders of one medieval monk: Thomas Aquinas. Amid the turmoil of life, riddled with wickedness and pain, he would insist that our world is good. And all our success is built on this belief. Note: Before we start, let’s get one thing out of the way: Thomas Aquinas is clearly a Christian thinker, a Saint even. Yet he was also a brilliant philosopher. So even if you consider yourself agnostic or an atheist, stay with me, you will still enjoy his ideas. What is good? Thomas’ argument is rooted in Aristotle’s concept of goodness: Something is good if it fulfills its function. Aristotle had illustrated this idea with a knife. A knife is good to the extent that it cuts well. He made a distinction between an actual knife and its ideal function. That actual thing in your drawer is the existence of a knife. And its ideal function is its essence—what it means to be a knife: to cut well. So everything is separated into its existence and its ideal essence. And this is also true for humans: We have an ideal conception of what the essence of a human […] The post Thomas Aquinas — The world is divine! appeared first on Ralph Ammer.
About 2300 years ago, the great Chinese thinker Xunzi 荀⼦ wrote: “Human nature is bad“. But he wasn’t just having a bad day. The question—Are humans fundamentally good or bad?—is a major fork in the road. How you answer this question profoundly impacts your morals and how you live your life. Previous to Xunzi, another famous scholar had claimed that human nature was inherently good. Mengzi 孟子: Human nature is good The Ox Hill Mengzi had illustrated his idea with a story about a wooded hill. After the trees get chopped down and the sprouts are grazed by animals, the hill appears barren and unfruitful. He compares this hill to someone who can’t bring forth his good character under bad circumstances. For him, goodness is an integral part of every person’s nature. It merely requires the right circumstances to emerge. Goodness will grow forth naturally from every person if no one interferes. Willows and Bowls Someone suggested to Mengzi that a good character had to be forged from a man’s nature like bowls were made from a tree. Mengzi objected that a tree must be violated in order to be turned into useful bowls. He can’t accept the comparison between […] The post Xunzi vs. Mengzi – Are People (No) Good? appeared first on Ralph Ammer.
Should we just live in the moment? In “Matter and Memory” the French philosopher Henri Bergson claims that this is not even possible. 1. Perception is physical First of all: How do we perceive the “current moment” anyway? Bergson suggests that the whole point of perception is action. For example, when some single-cell organism touches an obstacle, it moves away. That is the whole point of perception: to move in the right direction, to find food, to not be food—to survive. Perception serves future action, not insight. Accordingly, our brain is fully embedded in the material world and responds to the movements around it. Bergson refers to such a purely physical reaction as pure perception. Yet he acknowledges that we are more complicated than single-celled organisms. The movements of our environment have to make their way through our complex sensory system with all its twists and turns. And this leaves us more options on how to act. So we don’t just react like a single-celled organism, we can choose from a range of potential movements. But how? We remember. 2. Memory is temporal Bergson distinguishes two kinds of memories: Some memories have become part of our body, they are a […] The post Bergson — Why we live in the past appeared first on Ralph Ammer.
To “animate” means to breathe life into things. In these 5 exercises we make stones come alive. Preparation To get started I suggest this simple setup for you to try at home: Ready? Let’s go! Thinking in time Stop-motion is simple: Take a picture, move the object, take the next picture, move the object, etc. Once you are done, you can play back all those images as a little movie. Tip: You can do the following exercises exactly as shown here or play around with them. Just make sure to have fun! Exercise 1: Timing Turn a stone into a bouncing ball. Start with a stone above the middle of the page and hit the record button. Then move it down a little, take the next frame, move it again, and so on. Once it has reached the bottom, gradually move it up again until it is back to its starting position. Tip: At first you will notice that our steps are too big. As a result the animation plays way too fast! Just start over and make the steps smaller. Another tip: You can make the movement more natural by varying the distances. And you can make the “ball” […] The post A quick beginner’s guide to animation appeared first on Ralph Ammer.
You are awake. You think and you feel. But what is it that is doing all this thinking and feeling? We call it “consciousness” and over 100 years ago the philosopher Edmund Husserl made a bold attempt to uncover its secrets. Subjective experience is private The thing is: Consciousness is not “out there”, it is “in here“. It is personal and subjective. When I say that I like squirrels or that my foot hurts, then you will have to take my word for it. You can’t know what it is like to be me, and I cannot know what it is like to be you. Consciousness can only be observed from the inside, not from the outside. Since we can’t see the world through other peoples’ eyes, their experience remains deeply mysterious to us. Thus we all see the world differently. And this can lead to bitter conflict. Science is based on objective insight One way to overcome such conflict is to take an objective position. We take a neutral view from outside and focus on the things that we can all agree upon. We have learned to see ourselves “from the outside”. In fact, we can build a whole […] The post Edmund Husserl — Consciousness appeared first on Ralph Ammer.
More in programming
Hey peoples! Tonight, some meta-words. As you know I am fascinated by compilers and language implementations, and I just want to know all the things and implement all the fun stuff: intermediate representations, flow-sensitive source-to-source optimization passes, register allocation, instruction selection, garbage collection, all of that. It started long ago with a combination of curiosity and a hubris to satisfy that curiosity. The usual way to slake such a thirst is structured higher education followed by industry apprenticeship, but for whatever reason my path sent me through a nuclear engineering bachelor’s program instead of computer science, and continuing that path was so distasteful that I noped out all the way to rural Namibia for a couple years. Fast-forward, after 20 years in the programming industry, and having picked up some language implementation experience, a few years ago I returned to garbage collection. I have a good level of language implementation chops but never wrote a memory manager, and Guile’s performance was limited by its use of the Boehm collector. I had been on the lookout for something that could help, and when I learned of it seemed to me that the only thing missing was an appropriate implementation for Guile, and hey I could do that!Immix I started with the idea of an -style interface to a memory manager that was abstract enough to be implemented by a variety of different collection algorithms. This kind of abstraction is important, because in this domain it’s easy to convince oneself that a given algorithm is amazing, just based on vibes; to stay grounded, I find I always need to compare what I am doing to some fixed point of reference. This GC implementation effort grew into , but as it did so a funny thing happened: the as a direct replacement for the Boehm collector maintained mark bits in a side table, which I realized was a suitable substrate for Immix-inspired bump-pointer allocation into holes. I ended up building on that to develop an Immix collector, but without lines: instead each granule of allocation (16 bytes for a 64-bit system) is its own line.MMTkWhippetmark-sweep collector that I prototyped The is funny, because it defines itself as a new class of collector, fundamentally different from the three other fundamental algorithms (mark-sweep, mark-compact, and evacuation). Immix’s are blocks (64kB coarse-grained heap divisions) and lines (128B “fine-grained” divisions); the innovation (for me) is the discipline by which one can potentially defragment a block without a second pass over the heap, while also allowing for bump-pointer allocation. See the papers for the deets!Immix papermark-regionregionsoptimistic evacuation However what, really, are the regions referred to by ? If they are blocks, then the concept is trivial: everyone has a block-structured heap these days. If they are spans of lines, well, how does one choose a line size? As I understand it, Immix’s choice of 128 bytes was to be fine-grained enough to not lose too much space to fragmentation, while also being coarse enough to be eagerly swept during the GC pause.mark-region This constraint was odd, to me; all of the mark-sweep systems I have ever dealt with have had lazy or concurrent sweeping, so the lower bound on the line size to me had little meaning. Indeed, as one reads papers in this domain, it is hard to know the real from the rhetorical; the review process prizes novelty over nuance. Anyway. What if we cranked the precision dial to 16 instead, and had a line per granule? That was the process that led me to Nofl. It is a space in a collector that came from mark-sweep with a side table, but instead uses the side table for bump-pointer allocation. Or you could see it as an Immix whose line size is 16 bytes; it’s certainly easier to explain it that way, and that’s the tack I took in a .recent paper submission to ISMM’25 Wait what! I have a fine job in industry and a blog, why write a paper? Gosh I have meditated on this for a long time and the answers are very silly. Firstly, one of my language communities is Scheme, which was a research hotbed some 20-25 years ago, which means many practitioners—people I would be pleased to call peers—came up through the PhD factories and published many interesting results in academic venues. These are the folks I like to hang out with! This is also what academic conferences are, chances to shoot the shit with far-flung fellows. In Scheme this is fine, my work on Guile is enough to pay the intellectual cover charge, but I need more, and in the field of GC I am not a proven player. So I did an atypical thing, which is to cosplay at being an independent researcher without having first been a dependent researcher, and just solo-submit a paper. Kids: if you see yourself here, just go get a doctorate. It is not easy but I can only think it is a much more direct path to goal. And the result? Well, friends, it is this blog post :) I got the usual assortment of review feedback, from the very sympathetic to the less so, but ultimately people were confused by leading with a comparison to Immix but ending without an evaluation against Immix. This is fair and the paper does not mention that, you know, I don’t have an Immix lying around. To my eyes it was a good paper, an , but, you know, just a try. I’ll try again sometime.80% paper In the meantime, I am driving towards getting Whippet into Guile. I am hoping that sometime next week I will have excised all the uses of the BDW (Boehm GC) API in Guile, which will finally allow for testing Nofl in more than a laboratory environment. Onwards and upwards! whippet regions? paper??!?
Having spent four decades as a programmer in various industries and situations, I know that modern software development processes are far more stressful than when I started. It's not simply that developing software today is more complex than it was back in 1981. In that early decade, none
In previous articles, we saw how to use “real” UART, and looked into the trick used by Arduino to automatically reset boards when uploading firmware. Today, we’ll look into how Espressif does something similar, using even more tricks. “Real” UART on the Saola As usual, let’s first simply connect the UART adapter. Again, we connect … Continue reading Espressif’s Automatic Reset → The post Espressif’s Automatic Reset appeared first on Quentin Santos.
