1. No GPS required: our app can now locate underground trains
Total comment counts : 56
Summary
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Top 1 Comment Summary
The article discusses a discovery by a French company named Snips, which developed an app that could detect when a train entered or left a station by utilizing the pressure sensor in smartphones. The app noticed a distinct change in air pressure when the train moved in or out of tunnels, which are common between subway stations. This pressure change provided a clear signal for tracking the train’s location underground. The original blog post detailing this innovation can be found via a Medium link provided in the text.
Top 2 Comment Summary
The summary of the article feedback is:
The article is praised for its engaging and conversational tone, making it enjoyable to read despite covering detailed topics like frequency charts. The writing quality in the English version is highlighted as particularly well-done.
2. Unusual Raku Features
Total comment counts : 19
Summary
The article discusses the release of version 0.5 of a book, marking the end of its alpha phase, where all intended content is now included, and the focus shifts to editing and formatting. The author also reflects on their experience with the programming language Raku:
Raku Overview: Initially described as bizarre, Raku is now seen by the author as a “laboratory for language features,” testing various programming concepts like concurrency models.
Junctions: These are unique to Raku, allowing operations on multiple values simultaneously, representing boolean logic in a novel way. They can’t be destructured but can be used to represent quantifiers elegantly.
Whatever (*) Symbol: In Raku, the
*symbol has multiple roles, including creating anonymous functions and being used in sequence operations. Its behavior can be complex, especially when multiple*s are used in expressions.Regexes in Raku: Raku introduces a new regex syntax that improves upon existing standards by offering better composability and readability. It allows for embedding regexes within others, enhancing the parsing capabilities and introducing quality-of-life features like value separators and simplified lookaheads.
The article concludes with a note on the new cover for the book, which the author finds just satisfactory for now, and mentions upcoming improvements like professional cover design. The footnotes provide additional context on Raku’s features and the book’s development process.
Top 1 Comment Summary
The article discusses the author’s experience with implementing a feature similar to compositional regular expressions in JavaScript, which they developed independently. This feature allows for creating more manageable and reusable regular expressions, enhancing the functionality akin to having a first-class parser within the language. The author shares an example of using this library for parsing media types with regexes, available on RunKit. They mention that while ideal programming languages should natively support parsers instead of relying on regex, the library “templated-regular-expression” on npm and GitHub offers a useful workaround by allowing regex patterns to be broken into smaller, more maintainable pieces.
Top 2 Comment Summary
The article discusses the performance of Raku, noting that despite its capabilities, Raku is significantly slower than Python 3.13 when parsing log files with regex, taking 6.5 times longer to complete the task, even when excluding startup time.
3. 3600 MHz Raspberry Pi 5 with Liquid Nitrogen
Total comment counts : 7
Summary
The article discusses an attempt to overclock a Raspberry Pi 5 to make it the world’s fastest Pi, detailing various modifications and experiments:
Overclocking: Initial overclocking efforts reached 3 GHz with an improved air cooler, but the Power Management IC (PMIC) was identified as a limiting factor for higher frequencies due to voltage and power consumption issues.
Operating System: The author switched from Ubuntu to the official Raspberry Pi OS and applied the NUMA patch to enhance performance by improving memory controller’s parallelism.
Cooling: Liquid nitrogen (LN2) was used for extreme cooling, but even with this, the Pi could only be pushed to 3.6 GHz before locking up, regardless of lowering temperatures to -40°C or even -90°C.
Power Circuitry: An attempt to enhance the power delivery system with the ElmorLabs AMPLE-X1 was mentioned, although specific results from this modification weren’t detailed in the summary.
Benchmarking and Stability Issues: The Pi experienced stability issues during high-load scenarios, particularly with NEON instructions, leading to shutdowns at peak currents and power levels, suggesting potential over-current or over-temperature protection mechanisms rather than voltage issues.
Challenges: Despite various attempts to bypass hardware limitations, the Pi could not sustain higher clock speeds, pointing towards inherent design limitations in the PMIC or other hardware components.
The author shared insights from weeks of experimentation, highlighting the complexity and limits of pushing the Raspberry Pi 5 beyond its standard operational boundaries.
Top 1 Comment Summary
The article seems to have left the reader unimpressed, appearing more like an advertisement for Elmor Labs with suggestions to simply replace parts with Elmor alternatives. The reader criticizes the focus on cooling as superficial, suggesting instead that development should leverage ARM-based debug tools. Additionally, for those not using Raspberry Pi, alternatives like setting up a bare metal environment to manually test clock bus configurations are mentioned.
Top 2 Comment Summary
The article describes a personal anecdote where the author, as a child, won a science fair by conducting an experiment using a 286 computer. The project was successful, although it resulted in significant condensation.
4. We built a self-healing system to survive a concurrency bug at Netflix
Total comment counts : 39
Summary
The article discusses a significant production incident at Netflix involving a concurrency bug in an internal library used by client scripts. Here are the key points:
Incident Overview: On a Friday afternoon, Netflix engineers noticed a gradual increase in CPU usage due to a concurrency issue within scripts running on their server cluster. This bug caused CPU usage to spike because of infinite loops in
HashMap.get()calls instead of usingConcurrentHashMap.Impact: The bug was causing the loss of one CPU every two minutes, which translated to losing around 30 CPUs per hour. With each instance having 8 CPUs, they were effectively losing 4 instances of capacity every hour, which over 24 hours would lead to a significant capacity loss, especially during peak usage times.
Response Options:
- Fixing the Bug: The team responsible could fix it, but not until Monday.
- Rolling Back: This was not an easy option for unspecified reasons.
- Server Reboot: Detecting and rebooting affected servers was also not straightforward.
Cultural Approach: Netflix’s culture was highlighted as one that dealt with such issues practically, focusing on clear goals and effective problem-solving rather than amplifying the crisis with suboptimal management tactics like forced overtime or constant status meetings.
Resolution Strategy: The article does not detail the immediate fix but emphasizes Netflix’s practical approach to problem-solving, suggesting they would find a solution that aligned with their operational goals without causing undue stress or panic.
The narrative underscores the importance of having robust systems and a culture that can handle unexpected technical issues with calmness and efficiency, even when immediate solutions are not apparent.
Top 1 Comment Summary
The article recounts an anecdote from about 30 years ago where the author worked at a small networking company. Their coworkers, who previously worked at another company (C), were perplexed by the market reputation of their competitor’s (S) AppleTalk routers as being highly reliable despite lab tests showing that company S’s routers crashed much more frequently than their own. The secret behind the competitor’s product reliability was that it could reboot quickly enough to not interrupt the connection timeout of higher-level protocols, making crashes effectively invisible to users. In contrast, company C’s routers took longer to reboot, leading to noticeable disruptions in service. The lesson learned was that a fast restart capability could significantly enhance perceived product reliability.
Top 2 Comment Summary
The article discusses a scenario modeled by a differential equation where the rate of change of “bad instances” over time is described. Here’s a summary:
- The model assumes that every hour, 5% of the bad instances are removed, which reduces the number of bad instances.
- The equation provided models this scenario where:
- bad(t) represents the fraction of bad instances at time t.
- Initially, at time t=0, there are no bad instances, hence bad(0) = 0.
- The rate of change of bad instances, d(bad(t))/dt, is influenced by two factors:
- A decrease due to removal of bad instances at a rate of 5% per hour (-0.05 * bad(t)).
- An increase due to some external factor introducing new bad instances at a rate of 1% of the good instances (0.01 * (1 - bad(t))).
- The solution to this differential equation gives the function for bad(t), which describes how the fraction of bad instances changes over time, resulting in a specific exponential decay and growth pattern.
The resulting formula for bad(t) matches the graphical representation shown in the referenced blog post, confirming the mathematical model’s accuracy in describing the observed phenomenon.
5. 80286 ATX mainboard based on the IBM 5170 AT PC
Total comment counts : 11
Summary
The article discusses a project to design an ATX mainboard based on the IBM 5170 AT PC, utilizing the 80286 processor. Here are the key points:
Purpose: The project is intended for educational and experimental use, aimed at computing enthusiasts and possibly students interested in historical computing technologies.
Components: It includes an ATX mainboard and an ISA memory card.
Usage and Warnings: The design is under GPL3 license with several caveats:
- No guarantees of functionality or suitability for any purpose are provided.
- Builders must have significant expertise in electronics assembly and adhere to safety guidelines.
- The hardware is for personal, experimental use only, with no applications where failure could cause damage or injury.
- Users should expect potential data loss when using this system.
Educational Value: The project could serve educational purposes, particularly in analyzing CPU timing, data translation, and DMA mechanisms.
Acknowledgements: The designer thanks several contributors, notably Johann for help with reverse engineering PAL chips and creating tools for this purpose, and others like Alvaro64 for providing hardware and Sergey for his work on classic PCs.
Support: The designer provides extensive information due to limited capacity for ongoing user support, focusing instead on new project development.
Documentation: Comprehensive documentation is available, with updates as necessary to address user queries or project developments.
Top 1 Comment Summary
The article critiques a project’s licensing terms, pointing out several issues:
Inconsistent Licensing: The license claims to be GPL3 but includes terms that contradict GPL3 principles, especially since GPL3 isn’t typically applicable to hardware.
Overly Restrictive Terms: It seems to blend elements of Creative Commons licenses (CC-BY-SA-NC) with additional vague restrictions like “safety,” which are hard to define and enforce.
Internal Inconsistencies: The license mentions it’s for “hobby/personal/educational use” only, yet education often involves commercial activity, making this clause internally inconsistent.
Recommendation for Clarity: The author suggests simplifying the license to a straightforward CC-BY-SA, adding necessary warnings and disclaimers, and advises against using the non-commercial (-NC) clause unless the creators intend to exclusively sell the product themselves. The argument is that overly restrictive licensing might hinder the project’s potential and community engagement without benefiting the creators or the community.
Top 2 Comment Summary
The article reflects on the nostalgia and simplicity of the older ISA bus technology compared to the more complex PCI bus with its Plug and Play (PnP) features. The author fondly remembers the ease of setting up hardware with ISA, where configuring IRQ jumpers was straightforward and less prone to the issues often encountered with PnP in its early days. They share a personal anecdote about successfully integrating a simple LED display and logic directly onto an ISA wire wrap card, highlighting a preference for the directness of older technology like microcontrollers which offer fewer layers of abstraction. Despite this, the author acknowledges the value of PCI’s backwards compatibility, noting that they still use an old PCI SCSI card in a modern setup, appreciating its longevity and adaptability.
6. Rust’s Sneaky Deadlock With if let Blocks
Total comment counts : 10
Summary
The article discusses the author’s experience with Rust, particularly focusing on issues related to deadlocks when using RwLock (read-write lock) in the language. Here are the key points:
Rust’s Safety Features: The author appreciates Rust’s compiler for catching many issues like memory bugs and multithreaded problems but notes that it does not catch deadlocks.
Deadlock Issue: The article explains how deadlocks can occur in Rust when multiple locks are acquired simultaneously. Specifically, it highlights a scenario where attempting to acquire a write lock while holding a read lock on the same resource leads to a deadlock.
Prevention Techniques:
- The simplest solution is to release (drop) the read lock before attempting to acquire the write lock.
- Alternatively, using explicit block statements to ensure locks are dropped at the end of their scope.
Example and Problem: An example is given where a
RwLockguards an optional value. When using anif letstatement to read and possibly write to this lock, a deadlock can occur if the initial read lock is not released before attempting to write, especially if the value was initiallyNone.Syntax and Misunderstanding: The article clarifies that in an
if letstatement, the variable is held for the entire block, including theelsepart, which can lead to unexpected lock retention and thus deadlocks.Solutions and Advice:
- For complex lock scenarios, writing unit tests to cover different control paths is recommended.
- Wrapping lock operations in explicit blocks to ensure proper dropping of locks.
Real-world Impact: The author mentions encountering this issue in the wasmCloud project, indicating the practical implications of such programming pitfalls.
The article serves as a cautionary tale about the subtleties of lock management in Rust, providing insights and solutions for developers to avoid common deadlock situations.
Top 1 Comment Summary
The article discusses an error message from Rust’s Clippy tool concerning the use of Mutex::lock. It explains that attempting to lock a Mutex inside another Mutex lock can lead to a deadlock:
Error Description: When a
Mutexis locked within the scope of anotherMutexlock, as shown in the code example, it results in a deadlock because the second lock attempt will wait indefinitely for the first lock to be released, which it won’t be since it’s still in use.Code Example: The example shows an
if letstatement where theMutexis locked to check if a value exists. If a value does not exist, another lock is attempted within this block, leading to the deadlock.Clippy’s Suggestion: Clippy suggests moving the lock call outside of the
if letexpression to prevent the deadlock. It also provides a link for further information and notes that this warning is enabled by default.
This error pattern could be extended to cover similar locking behavior with RwLock.
Top 2 Comment Summary
The article mentions that a specific issue in Rust, detailed in GitHub issue #124085, will be addressed in the Rust 2024 release.
7. Show HN: Stretch My Time Off – An Algorithm to Optimize Your Vacation Days
Total comment counts : 83
Summary
The article discusses how someone living in a place with no public holidays can extend their time off. It mentions:
- Location: The person lives in a location with no public holidays.
- Time Off: They have no days off initially, but the article suggests methods to stretch this time, though it doesn’t specify how.
- Creation: The article was made by Zach with the assistance of GPT-4o and encourages viewing the project on GitHub.
Top 1 Comment Summary
The article reflects on the author’s past and current approaches to using Paid Time Off (PTO). Initially, the author and friends would strategize to maximize the benefit of PTO, focusing on getting the most days off per day of PTO used. Now, the author prefers taking PTO more spontaneously, particularly when feeling burnt out, rather than saving it for extended periods like holidays. This change in approach suggests a shift towards using PTO for immediate personal well-being rather than strategic time management.
Top 2 Comment Summary
The article discusses a user’s skepticism regarding a claim that one can extend their time off from 25 days to 61 days by leveraging public holidays and adjacent weekends in 2024. The user feels misled because:
Calculation Discrepancy: The claim counts weekends adjacent to public holidays as part of the extended time off, but the user notes that these weekends should already be included in the initial count, making the extension less impressive than advertised.
Inconsistency: The user points out an inconsistency where one Saturday next to a Sunday public holiday was not counted, while other adjacent days (Fridays or Mondays next to weekends) were included in the extension calculation.
Psychological Impact: The user mentions that such misleading claims trigger a defensive reaction, undermining the credibility of the product, even if it remains useful. This reaction is likened to the counterproductive effect of overpromising in advertisements.
The user references an ongoing discussion on Hacker News for further context or debate on the issue.
8. Argentinian farmer finds family of 20k-year-old armadillos
Total comment counts : 15
Summary
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Top 1 Comment Summary
The article humorously critiques the scale of objects in photographs, suggesting that if the depicted “car-sized” blobs were accurate, it would imply an unrealistic scale where Argentinians would be three meters tall. It reflects on how the internet often leads to such mild disappointments due to misleading or exaggerated content.
Top 2 Comment Summary
The article from 2020 reports the discovery of four glyptodont fossils in the Buenos Aires Province by researchers from the Institute of La Plata (CONICET-UNLP). These findings are significant because they provide new insights into the Pleistocene megafauna of South America. Glyptodonts are large, extinct relatives of the armadillo, known for their distinctive armored shells. The fossils were found in the area of General Belgrano, contributing to the paleontological record of the region. This discovery aids in understanding the biodiversity, distribution, and behavior of these ancient creatures.
9. Thinking about recipe formats more than anyone should
Total comment counts : 36
Summary
The article discusses the author’s exploration into standardizing recipe formats for their website. Initially, the author considered using Cooklang, a recipe markup language, but also looked into other standards due to some limitations in Cooklang. Here are the key points:
Cooklang: Allows for marking ingredients with
@, quantities in brackets{100%g}, timers with~{10%minutes}, and uses#for cookware. Metadata is prefixed with>>. However, it doesn’t support multi-line metadata or easily list ingredients for simple recipes like “mix all ingredients.”Recipe Schema (JSON-LD): Used by large recipe websites for SEO. It provides a structured way to include additional details like calorie counts or dietary suitability, but the author finds it impractical for manually writing recipes due to its complexity.
Decision: The author prefers a hybrid approach where recipes are formatted in Cooklang for simplicity but also includes JSON-LD on the recipe page for SEO benefits. They also mention using microformats for displaying recipes.
Implementation: The author has a working branch on their site that supports
.cookfiles, which they plan to detail in a future post once fully implemented.Personal Note: The author humorously acknowledges overthinking the format choice, referencing a popular XKCD comic about standards.
The article concludes with the author’s plan to integrate these formats into their blog posts tagged as recipes, making the extra information available when needed.
Top 1 Comment Summary
The article discusses a novel way of structuring recipes using a tree-like model. Instead of traditional formats with separate lists for ingredients and step-by-step instructions, the author proposes an “upside-down tree” approach:
- Ingredients are the starting nodes at the bottom of the tree.
- Steps form the branches, where each ingredient (or combination thereof) has a many-to-one relationship with the subsequent steps, leading up to the final node.
- The Dish is the topmost node, representing the completed recipe.
This structure aims to convey the progression from individual ingredients through various cooking steps to the final dish in a more visual and intuitive manner, potentially reducing redundancy and enhancing understanding with less text. An example of this concept applied to a recipe for “Bul Koki” is provided, along with an image illustrating the tree structure.
Top 2 Comment Summary
The article discusses the importance of recipe formatting for clarity and ease of use in cooking. The author points out that higher-level format issues, such as the logical structure of a recipe, can significantly affect the cooking process. They mention a specific example with a Hainanese chicken recipe from The Guardian, which they found difficult to follow due to its format. The author then used a tool called “o1-preview” to restructure the recipe into a more user-friendly format, highlighting how converting well-written recipes into structured data can enhance the cooking workflow.
10. From BSP to ESP – How S3ctor Abused Quake Editors to Redefine the Morrowind Mod
Total comment counts : 5
Summary
Summary:
S3ctor, a developer involved with OpenMW, shares his journey of merging the level design philosophies of Quake’s idTech engine with that of Morrowind’s OpenMW. From a young age, S3ctor was fascinated by game engine technology, particularly after being inspired by id Software’s Doom 3 and John Carmack’s insights into game engine design.
He discusses the differences between modern mesh-based workflows, where level design and asset creation are distinct roles, and the older brush-based workflows from idTech, where level designers can also act as modelers. This flexibility in brush-based design, still used by Valve, allows for quicker iteration and customization in game environments.
S3ctor demonstrates this by comparing the process of creating a simple house structure in OpenMW’s tool, OpenCS, which uses a more rigid prefab approach, with Trenchbroom, a Quake editor utilizing brushes. The latter allows for immediate modifications and variations, showcasing the efficiency and creativity brush-based systems offer to modders and developers.
Top 1 Comment Summary
The article discusses the unique aspects of the Quake .map format, which is a text-based format for editing game maps. Unlike common 3D modeling techniques that build objects from vertices, edges, and faces, Quake’s .map format uses planes as its fundamental graphic primitive. These planes, defined by three points, intersect to form edges. The author expresses a fascination with this format, viewing it as an interesting artifact of game development history, somewhat akin to a steampunk aesthetic in graphics design. The article also speculates that this plane-based representation might extend into the compiled BSP (Binary Space Partitioning) format used internally by the Quake engine, suggesting it’s an optimal choice for the engine’s needs in spatial partitioning and optimization.
Top 2 Comment Summary
The article points out that if the author is also the submitter, the title of the submission partially obscures the top line of text when viewed on a mobile phone.