1. Why do railway tracks have crushed stones alongside them?
Total comment counts : 31
Summary
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Top 1 Comment Summary
The article explains that keeping crushed stones under the tracks clean is important to prevent fouling, which could cause derailment. The stones move slightly as each train passes above them, and this helps keep the track straight and level. Fouling stops this effect, and railway maintenance involves digging out all the stones, washing them, and putting them back every 25 years.
Top 2 Comment Summary
The article discusses how roots of plants are not an issue for train tracks, but rather dried vegetation alongside or on the tracks can cause fires due to sparks caused by the metal wheels. Ballasts are used to control the spread of fire, and workers are responsible for torching any plants growing too close to the tracks. Weed killers are also used to maintain the tracks.
2. GPS (2022)
Total comment counts : 12
Summary
The Global Positioning System (GPS) made it easier for vehicles and hikers to determine their location accurately. GPS consists of satellites surrounding Earth, and in this blog post, the author explains how GPS works. The article describes a simple system for determining a location that uses landmarks and measuring tapes, and it is improved by using drones to replicate measurements and using sound to measure distances. The author explains that the latter solution is effective but may have a fatal flaw when someone else tries to estimate their position.
Top 1 Comment Summary
Gold codes are useful in solving engineering problems where two items need synchronization. These codes provide an effective brightness increase and perfect time sync with no hardware changes. However, be cautious about using the codes once per millisecond, as this can interfere with GPS. Transmitting at a different data rate or generating your gold code set can prevent disruptions to the GPS.
Top 2 Comment Summary
The author upvoted a post thinking it was current before realizing it was actually from 2022, but still found it pleasant to see again.
3. The death of self-driving cars is greatly exaggerated
Total comment counts : 42
Summary
Despite the lack of progress in the autonomous vehicle sector, self-driving technology is continuing to steadily improve over the last few years. Companies such as Waymo and Cruise aim to expand their businesses ten-fold by the summer of 2024. It remains to be seen if the companies will succeed in turning a profit without compromising safety. While safety has been the focus for the sector so far, companies also now need to figure out how to monetize the technology.
Top 1 Comment Summary
The article argues that Tesla’s decision to rely solely on vision for self-driving cars is flawed. The author believes that, if given additional senses, humans would use them for safer driving.
Top 2 Comment Summary
The task of addressing safety-critical output from unconstrained input is a difficult problem and should not be underestimated. Innovators like Elon Musk or Geohot have been impractically optimistic, and while being optimistic can be a good trait for engineering innovation, managing expectations is also important. Ultimately, success is determined by results, not just plans or predictions.
4. Show HN: Rarbg on IPFS
Total comment counts : 26
Summary
The article describes a decentralized application that allows users to query a complete dump of RARBG, which is hosted on IPFS. This application was developed as a fork of Library Genesis IPFS and uses WebAssembly to fetch pages from the database and evaluate user queries in the browser. Users can also download the page for local searches without constant internet access, or copy the RARBG folder to a USB drive or CD for sharing.
Top 1 Comment Summary
The article describes that there is a column for IMDB in the RARBG dump, but it was not included in the search function. The dump contains over 826,000 torrents with IMDB IDs and over 2 million without, including porn, music, and software. The categories are listed but not well-coded.
Top 2 Comment Summary
The article announces the release of a large database dump for RARBG, which the uploader hopes others will find useful. It includes links to the database dump on GitHub as well as a discussion thread on Hacker News.
5. Apple Virtualization Framework
Total comment counts : 22
Summary
The article cannot be summarized as it provides instructions to enable JavaScript in the browser to view its content.
Top 1 Comment Summary
The author uses Virtualization.framework for Orbstack, an alternative to Docker Desktop and WSL. While it is convenient, it has bugs and limitations, including unstable crashes and limited device support. The author spent a day prototyping a custom VMM that was able to allocate dynamic memory and achieve faster file sharing, but this is not an option as Apple does not permit third-party VMMs to set the necessary CPU flags for Rosetta, which many users rely on for fast x86 emulation. Therefore, the author continues to use Virtualization.framework but only out of necessity.
Top 2 Comment Summary
This article describes the author’s experience using vftool to host Docker and setting up Rosetta to run x86 images. However, they have been experiencing some issues with the guest Ubuntu kernel periodically encountering smp errors and the guest clock resetting to almost a month in the past, causing the author to force an sntp correction. The cause of these issues is unknown, and the author questions whether they are related to the Ubuntu kernel, virtualization framework, vftool, or bad configuration.
6. Induction of a torpor-like state in rodents by ultrasound
Total comment counts : 11
Summary
Scientists have developed a way of placing rodents into a torpor-like state using ultrasound. The first-of-its-kind method involves firing ultrasound signals at the area of the brain responsible for controlling metabolism and body temperature, reducing rodents’ average body temperature by up to 6.25 degrees Fahrenheit and slowing down heart rates and reducing oxygen consumption. Researchers believe that the animal study could provide clues as to how hibernation-like states, or torpor, could be induced in humans who have suffered serious injuries (such as strokes or heart attacks) or are on long-haul spaceflights. However, there are several hurdles to overcome before the technology can be tested on humans.
Top 1 Comment Summary
The article discusses the potential applications of a new form of ultra-intense laser technology (UIH), stating that it may unlock new medical treatments and contribute to advancements in long-duration human spaceflight. Despite this, the article criticizes a reporter for speculating excessively on the topic.
Top 2 Comment Summary
The UK NHS has released a statement discouraging the use of “4d” ultrasounds for creating pre-birth videos, as these emit frequencies in the same range as prenatal ultrasounds. Studies have shown that prolonged exposure to ultrasound frequencies can cause damage to endothelial cells. This highlights the importance of adopting a precautionary principle approach.
7. A new line drawing method for the cycle savvy
Total comment counts : 8
Summary
Matthias Kramm’s recent 4k demo “Boo!” introduces a new method of computing lines, which significantly increases the size of realtime filled sprite vector cubes displayed in the demo. The method, called the BRR (“bit reverse rendered”) line method, can now be done in just five cycles per pixel, up from 7+ cycles per pixel. Kramm explains the various approaches to computing lines, including Bresenham, fractional precalculation, and full precalculation, and compares them to the BRR line method. He also provides a detailed explanation of how the BRR line method works, using a comparison operation and a bitreverse pattern to introduce notches in the line, and demonstrates the improved stability of BRR lines compared to traditional line drawing. Kramm concludes that the cheapness of lines has changed the playing field in sprite vectors and can be used in other effects as well.
Top 1 Comment Summary
The article discusses a program that is 4096 bytes long and runs on a machine with a clock frequency of 985.248 kHz. The machine only has a single core and arithmetic operations are limited to 8-bit values without hardware multiplication. The program cleverly uses the CPU of the floppy drive for a speed up, leading to true parallelism on multiple cores.
Top 2 Comment Summary
The article describes a new and simple technique that is more cycle-efficient and produces stable animation lines compared to previous methods. The author expresses surprise that this technique has only been discovered recently, and notes its ongoing improvement.
8. Lung cancer pill cuts risk of death by half
Total comment counts : 16
Summary
Taking the drug osimertinib once a day after surgery can reduce the risk of dying from lung cancer by 51%, according to a global study led by Yale University. The trial involved patients in 26 countries with a mutation of the EGFR gene which is found in a quarter of global lung cancer cases and accounts for as many as 40% of cases in Asia. After five years, 88% of patients who took the daily pill after the removal of their tumour were still alive, compared with 78% of patients treated with a placebo. Treatment after surgery with osimertinib, also known as Tagrisso and made by AstraZeneca, “significantly lowered” the risk of death in lung cancer patients, the trial found.
Top 1 Comment Summary
The article discusses a drug that targets a particular mutated gene in non-small cell lung cancer and has a high efficacy rate for the patients who have that mutation. However, this only helps with about 1.4% of all cancers as cancer is not one disease but rather many thousands of diseases. While this is a success story enabled by genomic sequencing and drug development, there is still a long way to go in finding targeted therapies for rare cancers.
Top 2 Comment Summary
The author’s mother-in-law has stage 4 lung cancer, and Tagrisso treatment has extended her life by shrinking the cancer. However, at some point, the cancer will develop resistance and the patient will have to go on chemotherapy, which may lower the quality of life. The author is thankful for modern medicine and the extra time they have with their mother-in-law.
9. High prices make textbook ‘piracy’ acceptable to most students
Total comment counts : 64
Summary
A new survey by the Danish anti-piracy group, Rights Alliance, reveals that despite several legal proceedings against students, 50% of all students find it acceptable to use pirated books with no apparent crackdown on piracy. Students would consider changing their behaviour if prices dropped significantly, according to the study, which also found that 70% of students admitted to knowing that piracy of textbooks is illegal. Furthermore, students suggested that access to legitimate digital books through official libraries would be another solution to reducing piracy.
Top 1 Comment Summary
The author recalls setting up a P2P sharing system with a DIY book scanner in a university’s Unix room/hackerspace. They encouraged other students to upload books, and the room became a hub for off-curriculum work. When discovered, they were sternly reprimanded but grateful for a networking professor who advocated for them. The author reflects on how hacker culture has changed due to societal pressure and cites Aaron Swartz’s JSTOR scandal as the end of university hacker culture.
Top 2 Comment Summary
The article suggests bundling materials into tuition expenses as a way to incentivize the right people to optimize the market for textbooks. Teachers and departments would have to justify costs from a materials budget to administrators, which could pressure the textbook market downwards. The current system of requiring students to purchase textbooks selected by others with no transparency or choice is fundamentally broken market mechanics and creates a moral hazard. The solution is to have those making the market decisions - the teachers and departments - also paying for the textbooks.
10. Anything can be a message queue if you use it wrongly enough
Total comment counts : 37
Summary
The article discusses the high costs associated with using Managed NAT Gateway in AWS and offers a solution to reduce the cost by up to 700%. The solution involves using Tailscale exit node with a public IPv4/IPv6 address attached to it and attaching it to the same VPC as webhook egress nodes. The article explains the concept of S3, which is essentially like the malloc() function for the cloud, and how it can be used to allocate space for and submit arbitrary bytes to the cloud. The article also explains how Unix’s core philosophy that everything is a file makes it easier for software to control network links, and how this can be used to read packets from the kernel, write them to S3, and then read them back into the kernel to save money on network bills.
Top 1 Comment Summary
Firebase Realtime Database was created as a result of a chat system called Envolve. The chat system was being used in a game which utilized channels, passed game state through chat, and used display-none on channels to focus on its frontend instead of dealing with real-time message passing. Firebase Realtime Database was then developed as a headless version of the chat infrastructure, where the team re-wrote the program in Scala.
Top 2 Comment Summary
The article discusses the author’s experience using a MySQL database as a replacement for a message queue. All servers were already connected to the database so it was the easiest solution to implement. A new row would be written to the table and all servers would remember the last row seen. The table is occasionally cleared. Although there may be race conditions, the system serves the purpose of sending Discord notifications for a video game high score and is still functioning in that way.