1. I designed a cube that balances itself on a corner
Total comment counts : 56
Summary
The article discusses Willem Pennings’ personal project of building a cube that can balance itself on a corner and rotate around its axis. The cube is inspired by the “Cubli” created by researchers at ETH Zürich, but Pennings has made improvements to the design. The cube’s mechanical structure consists of cornerstones and face plates, with three of the face plates supporting a motor and reaction wheel assembly. Pennings used stainless steel for most of the structural parts and aluminum for the face plates to save weight. He manufactured the metal parts with the help of PCBWay. The motor and flywheel assembly were carefully designed to be robust and lightweight. Pennings explains the assembly process in detail, including mounting the reaction wheel and securing the motor shaft with ball bearings. The end result is a strong and lightweight structure. Overall, the project is a learning experience and research endeavor, with potential applications in satellite attitude control.
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The author, who has a background in controls and signal processing, admits to making mistakes in flipping signs of various signals. They initially believed it was due to their lack of experience, but later realized that they had been wrong about that assumption as well.
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The article describes a video that showcases an object that responds to being pushed around in a way that resembles magnetism. The object appears to be alive and actively maintains its balance against changes in its environment. The author expresses excitement for the future availability of smaller, mass-produced versions of the object to play with.
2. Detroit’s abandoned tunnel systems open door to another world
Total comment counts : 15
Summary
The article explores the network of tunnel systems beneath the city of Detroit, shedding light on its historical significance. These tunnels include an underground pedestrian tunnel built in the 1920s to address the high number of pedestrian fatalities caused by automobiles. The article also discusses the Detroit Rock Salt mines, which operated from 1895 to 1984 and played a crucial role in the city’s economic prosperity. Additionally, the Fisher Building in Detroit has an elaborate tunnel system connecting it to other buildings in the area. The Detroit Medical Center is also connected by a tunnel system, providing convenient travel for patients and employees. The article mentions the role of Detroit in Prohibition-era smuggling and speakeasies, as well as the utility tunnels that carry water and steam throughout the city. The Detroit Metropolitan Airport features an illuminated tunnel with a unique design.
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The underground part of Seattle’s city is open for tours, featuring abandoned streets and storefronts that were covered when the current downtown was built on top of the old one.
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The article mentions that tours of the Detroit Salt Mines used to be available, and the Detroit Salt Company is still active. There is a small tunnel underneath the freeway near the “Uniroyal Giant Tire” off of I-94, which is said to be interesting. The article provides a link for more information about the Uniroyal Tire location.
3. Show HN: A platform for remote piano lessons based on the Web MIDI API
Total comment counts : 28
Summary
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During the COVID pandemic, the author needed to set up remote piano lessons. Initially, they tried merging two videos to show both the hands on the keys and the face, but encountered latency issues. They solved this problem by using a top-down camera angle and placing clear perspex at a 45-degree angle in front of the raised laptop. They also directed lamps at the piano player’s face using the Pepper’s Ghost effect. This allowed the teacher to see both the hands on the keyboard and the player’s face through one camera, and made it appear as if the player was looking directly into the camera. The author shared their solution to help others facing similar challenges.
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The article discusses a webMIDI app that recently shipped. The author congratulates the developers on their achievement and mentions that they have been working on a similar app with a multiplayer feature in mind. They inquire about the latency of the app and provide feedback on the landing page and app functionality. The author suggests adding a video example on the landing page, allowing visitors to try the piano before prompting login for remote features, and addressing confusing clickable buttons. They also share their experience with the app, mentioning that connecting the keyboard worked well but pressing keys with a mouse did not produce any sound. They also note that pressing keys on their MIDI keyboard caused the keys to be selected indefinitely, preventing them from being pressed again. The author offers assistance and wishes the developers good luck with further development.
4. Show HN: Multi-monitor KVM using just a USB switch
Total comment counts : 41
Summary
The article emphasizes the importance of feedback and states that they take it seriously. It also mentions the availability of qualifiers in their documentation. Furthermore, the article discusses the ability to use multiple computers with a single monitor, mouse, and keyboard. This is mentioned twice in the article.
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The article suggests an alternative setup for achieving monitor input switching and USB switching. The author recommends using DDC commands for monitor input switching and a USB KVM with a single button for USB switching. They suggest using a cheap AliExpress macropad instead of expensive stream decks or prebuilt macropads, and programming it with GitHub projects. To press the USB KVM button, the author suggests using FingerBot or Switchbot. They also mention using an AHK switch to watch for keyboard shortcuts and trigger both the DDC commands and the USB switch button. The setup allows for remote control but has a few seconds delay.
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The article mentions the use of udev to send a DDC command when a USB switch appears. It provides a specific command using the udev conditionals for vendor and model IDs. The command executes the “ddcutil” program with specific parameters to set a value using the VCP code 60 and the value 0x0f for a serial number “ABCDEFGHI”.
5. Show HN: Emacs minor mode for connecting assembly and assembled code buffers
Total comment counts : 7
Summary
The article discusses a minor mode in Emacs that allows for the connection between hexl and nasm source code buffers. This mode, called hexasm, parses a listing file generated by nasm to establish a mapping between source code lines and hex addresses. This enables a more efficient workflow when working with hex and assembly code in Emacs.
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The article explains that there is a cool feature but it seems to have limitations. It mentions that it only works if the buffer is named “os.asm” and it has a hardcoded path on the hard drive.
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The article discusses a “2D REPL” experience with assembler, similar to what is available in Common Lisp. The author mentions their previous experimentation with SIMD intrinsics with SB-SIMD. They also mention a niche use case for this minor mode, which is learning to program for microcontrollers with very limited RAM.
6. Undisclosed tinkering in Excel behind economics paper
Total comment counts : 14
Summary
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The article discusses Jönköping University and how it is not allowed to call itself a university in Swedish due to certain legal requirements. Instead, it uses its English name, “Jönköping University,” even in the Swedish language. However, formally it is considered a “högskola” or “college.”
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The article suggests that in the field of social sciences, researchers often obtain data that undermines their profession, label it inconclusive to their university, and fail to publish it before their research grants expire. The author claims to have witnessed this themselves, citing Excel-related issues behind the publication of certain papers. Additionally, the article mentions that the industry faces challenges in collecting data due to its high cost and subjectivity. It describes an instance where seven data points were manipulated into a much larger number, and the principal researcher’s calculations were inaccurate.
7. ForceGen: End-to-end de novo protein generation
Total comment counts : 4
Summary
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The article discusses the potential applications of a new research paper in the fields of regenerative medicine, dermatology, and connective tissue development. The author suggests that the findings could be used for cartilage and joint replacement, aging therapies, skin grafts, and possibly even creating more advanced joint and connective tissue structures.
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The article is not provided. Can you please provide the text that you would like me to summarize?
8. A man has been swatted 47 times for making a joke about Norm Macdonald
Total comment counts : 63
Summary
This article discusses the rise of “swatting,” a dangerous prank where individuals call in false bomb threats or mass shootings in order to send heavily armed police teams to the target’s location. The article highlights the case of a teenager in California who allegedly operated a swatting service and targeted hundreds of high schools, churches, and even the US Supreme Court. The teenager charged as little as $40 for his services and would post audio of the 911 calls as proof. The article also mentions a science fiction author in Milwaukee who has been swatted multiple times as part of a targeted harassment campaign. Despite arrests being made in some cases, the article points out that law enforcement is struggling to effectively handle the threat of swatting.
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The article mentions that in April 2023, the person in question was targeted by a “swatting” incident four times in a single day. During the fourth incident, the Metropolitan Police Department (MPD) dispatched six officers armed with assault rifles to the person’s home at 9 PM. The author suggests that the MPD is partially responsible for allowing themselves to be manipulated in this way.
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The article discusses the deployment of the STIR/SHAKEN system and its impact on preventing fake calls to 911. The author questions how someone can still make a call with a fake number without it being identified. Despite the supposed deployment of STIR/SHAKEN in the US telephony network, public safety answering points (PSAPs) are apparently not yet equipped to detect the attestation level of such calls. The article provides a background document for further reference.
9. Keycloak SSO with Docker Compose and Nginx
Total comment counts : 21
Summary
The article discusses the process of setting up Keycloak, an open-source tool for user management and single sign-on (SSO), using Docker. Keycloak is interoperable with major SSO protocols and provides robust security features. The article provides step-by-step instructions for setting up Keycloak using Docker Compose and configuring Nginx as a reverse proxy. It also mentions the option to customize Keycloak using themes and provides a Dockerfile for building a custom Keycloak image. The article concludes with suggestions for further customization and improvement of the instructions.
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The author of the article shares their experience in setting up a home lab and choosing between Authelia and Keycloak for authentication and single sign-on (SSO). They mention that while Keycloak is a comprehensive solution, it requires additional services to work with traefik forward auth. On the other hand, Authelia is described as working well, although it lacks a user interface for editing users and does not have two-way synchronization with an LDAP server. However, they recommend Authelia as a good option for adding authentication and SSO to services, especially if static files and environment variables can be used for configuration.
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The author of the article discusses their experience setting up a single sign-on (SSO) system for their homelab. They wanted to be able to log in with Google or GitHub authentication and tried using JetBrains Hub and Keycloak but found them difficult to set up. They eventually decided to use Dex, which was easy to set up with some basic YAML, a SQLite database, and a domain. They combined Dex with OAuth2 Proxy and a custom Nginx template for a simplified SSO configuration. They also added Cloudflare Access and WAF for security. The author provides links to the tools they used in their setup.
10. What it was like working for Gitlab
Total comment counts : 50
Summary
The author worked at GitLab from 2015 to 2021 and is now reflecting on their time there. They initially joined because they wanted to work on the Rubinius project, but also had a task to improve GitLab’s performance. They had a lot of autonomy and went through many changes, including the company growing from around 30 employees to 2000. However, they eventually experienced burnout. They also mention the transition to remote work, and their small living arrangements at the time. Despite being a remote company, GitLab had social events and meetups.
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The author of the article questions whether it is acceptable to pay employees less based on their location, comparing it to paying someone less because of their race or gender. The author suggests that location is a relevant factor in determining pay, as it involves setting up a subsidiary in the employee’s country, dealing with legal and tax systems, and considering time zones and travel costs. The author argues that comparing location-based pay differentiations with discrimination based on race or gender hinders productive discussion by equating GitLab to a racist and sexist organization.
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The article discusses a common scenario in big companies where employees start with a lower rank and report directly to the CEO, but as more managers are added above them, they are eventually put on a performance improvement plan (PEP) and feel the need to leave. The author suggests that this is a reason why people in big companies often struggle to achieve great things. Additionally, even if an employee starts a successful project within a company, they can be easily surpassed by others who are then able to criticize their performance.