Hell Gate, a treacherous stretch of the East River in New York City, posed a significant navigational hazard for centuries. This document details the extensive efforts undertaken to remove these obstacles, culminating in the large-scale demolition project of 1876. Initial attempts, like removing smaller rocks and improving existing channels, proved insufficient. General John Newton meticulously planned and executed the removal of the largest obstructions, Flood Rock and Hallet's Point, using innovative techniques like extensive tunneling and strategically placed explosives. The successful demolition of Flood Rock in 1885 dramatically improved navigation, marking a triumph of engineering and a significant milestone in the development of New York City's harbor.
GPS is increasingly vulnerable to interference, both intentional and unintentional, posing a significant risk to critical infrastructure reliant on precise positioning, navigation, and timing (PNT). While GPS is ubiquitous and highly beneficial, its inherent weaknesses, including low signal power and lack of authentication, make it susceptible to jamming and spoofing. The article argues for bolstering GPS resilience through various methods such as signal authentication, interference detection and mitigation technologies, and promoting alternative PNT systems and backup capabilities like eLoran. Without these improvements, GPS risks being degraded or even rendered unusable in critical situations, potentially impacting aviation, maritime navigation, financial transactions, and other vital sectors.
HN commenters largely agree that GPS is vulnerable to interference, both intentional and unintentional. Some highlight the importance of alternative positioning systems like Galileo, Beidou, and GLONASS, as well as inertial navigation for resilience. Others point out the practicality issues of backup systems like Loran-C due to cost and infrastructure requirements. Several comments emphasize the need for robust electronic warfare protection and redundancy in critical systems relying on GPS. A few discuss the potential for improved signal authentication and anti-spoofing measures. The real-world impacts of GPS disruption, such as on financial transactions and emergency services, are also noted as compelling reasons to address these vulnerabilities.
Britain's naval dominance during the Age of Sail wasn't solely due to superior shipbuilding or fighting prowess, but a combination of factors creating a positive feedback loop. Consistent funding, driven by effective financial institutions and a willingness to prioritize naval spending, allowed for a larger, continuously maintained fleet. This larger fleet, in turn, enabled Britain to secure crucial trade routes and resources, further bolstering its economy and funding. This self-reinforcing cycle, combined with a professional, well-trained officer corps and a strategic focus on maintaining naval supremacy, cemented British dominance at sea.
HN commenters largely agree with the LessWrong post's premise that British naval dominance stemmed from superior financing, enabled by a more stable and trustworthy government that could borrow at lower rates. Some elaborate on this, pointing to Britain's sophisticated financial instruments like the Bank of England and its ability to fund long wars. Others highlight additional contributing factors, such as the strategic geographic location of Britain, the professionalization and meritocratic structure of the Royal Navy, and Britain's investment in research and development of naval technology. A few commenters express skepticism about oversimplifying a complex historical issue, emphasizing the influence of factors like superior timber resources, experience gained through near-constant warfare, and social factors influencing naval manpower.
A new bicycle-mounted sensor called Proxicycle aims to improve the mapping of safe cycling routes. It uses ultrasonic sensors to detect passing vehicles and their proximity, collecting data on near-miss incidents and overall road safety for cyclists. This data can then be aggregated and shared with city planners and cycling advocacy groups to inform infrastructure improvements, advocate for safer road design, and ultimately create more cyclist-friendly environments. Proxicycle's goal is to provide a more comprehensive and data-driven approach to identifying dangerous areas and promoting evidence-based solutions for cycling safety.
Hacker News users discussed the practicality and potential impact of the Proxicycle sensor. Several commenters were skeptical of its ability to accurately assess safety, pointing out that near misses wouldn't be registered and that subjective perceptions of safety vary widely. Some suggested existing apps like Strava already provide similar crowd-sourced data, while others questioned the sensor's robustness and the potential for misuse or manipulation of the data. The idea of using the data to advocate for cycling infrastructure improvements was generally well-received, though some doubted its effectiveness. A few commenters expressed interest in the open-source nature of the project and the possibility of using the data for other purposes like route planning. Overall, the comments leaned towards cautious optimism tempered by practical concerns.
Organic Maps, an offline open-source map app, has been forked into a community-driven project called Community Maps. This fork was initiated due to concerns over development direction, specifically the original developer's resistance to community contributions and desire to transition towards a sponsored/freemium model. Community Maps aims to prioritize community involvement, maintain the open-source and offline nature of the app, and ensure its future is guided by its users. The project is seeking contributors and donations to support ongoing development and server costs.
Hacker News users discussed the community fork of Organic Maps, largely focusing on the motivations behind the fork and its potential for success. Several commenters expressed skepticism about the fork's long-term viability, citing the difficulty of maintaining a complex project like Organic Maps without the original developers. Others were more optimistic, highlighting the community's enthusiasm and the potential for improved privacy and freedom from corporate influence. The discussion also touched on the specific improvements the fork aimed to achieve, such as adding missing features and enhancing existing functionality. Some users questioned the necessity of the fork given Organic Maps' existing open-source nature, while others argued that a community-driven approach would be more responsive to user needs. Several commenters also inquired about the licensing of the forked project and the relationship between the forked project and the original Organic Maps developers.
The blog post explores the complexities and challenges of modern air traffic control (ATC), highlighting the delicate balance between automation and human oversight. It details the layered system, from strategic planning to real-time adjustments made by controllers, emphasizing the crucial role human expertise plays in managing unexpected events and ensuring safety. The post also touches on the increasing demands on the system due to growing air traffic, the limitations of current radar technology, and the potential benefits and risks of further automation, ultimately arguing for a cautious approach that prioritizes safety and leverages the strengths of both humans and technology.
HN commenters largely discuss the plausibility and implications of the linked blog post's scenario, where a rogue actor exploits vulnerabilities in air traffic control systems. Some express skepticism about the technical details, questioning the feasibility of the described attack vectors and the level of access an attacker could realistically obtain. Others highlight the existing security measures in place and the difficulty of carrying out such a complex attack. Several comments delve into the potential consequences, ranging from localized disruptions to widespread chaos, and discuss the broader implications for cybersecurity in critical infrastructure. A few users share personal anecdotes and experiences related to air traffic control systems, offering additional context to the discussion. Several commenters mention the blog post's narrative style, with some praising its engaging presentation while others criticize it as overly dramatic or unrealistic.
"Dead Reckoning" explores the fascinating history and evolution of navigation, focusing on the crucial role of "deduced reckoning." This method, originating in ancient times, involves calculating one's current position by using a previously determined position, combined with estimates of speed, direction, and elapsed time. The article traces its development from early Polynesian voyages using celestial cues and wave patterns, through the advancements of tools like the chip log and magnetic compass, to modern inertial navigation systems. It highlights the inherent inaccuracies and accumulated errors of dead reckoning, emphasizing the constant need for corrections using external references like celestial observations or landmarks – a process humorously illustrated by the evolution of the phrase "dead reckoning" itself. Ultimately, the article underscores the ingenuity and enduring importance of this fundamental navigation technique despite its limitations, showcasing its lasting impact on exploration, trade, and warfare across the ages.
Hacker News users discussed the fascinating history and limitations of dead reckoning navigation. Several pointed out the crucial role of accurate timekeeping in longitude calculations, with one user highlighting the story of John Harrison and his invention of the marine chronometer. Others emphasized the compounding nature of errors in dead reckoning, making it unreliable over long distances or durations. Some commenters shared personal anecdotes of using dead reckoning in various contexts, like hiking and sailing. The inherent difficulties of accurately estimating speed and direction without external reference points were also noted, as was the susceptibility to environmental factors like currents and wind. One commenter amusingly pointed out how even small errors can have large consequences, referencing being "hopelessly lost in a shopping mall." Finally, the resilience and ingenuity of early navigators who relied on this method were acknowledged.
US Routing is a Python library designed for fast route calculations within the United States. It utilizes a pre-built graph of US roads, stored efficiently in memory, allowing for rapid queries without external dependencies or API calls. This offline capability makes it suitable for applications needing quick routing solutions, such as logistics or mapping tools, where network latency or cost is a concern. The project is open-source and available on GitHub.
HN users generally praised the project for its speed, simplicity, and use of OpenStreetMap data. Several commenters appreciated the clear documentation and the straightforward Python interface. Some questioned the licensing implications of using Valhalla's routing engine, specifically whether the non-commercial clause of the Valhalla license affects the US Routing library. Others suggested alternative approaches like GraphHopper or OSRM, and discussed the tradeoffs between local routing engines and cloud-based solutions. A few users mentioned potential use cases like delivery route optimization and logistics planning. The performance comparison with other routing libraries generated considerable interest, with some expressing skepticism and asking for more detailed benchmarks.
This paper presents a real-time algorithm for powered descent guidance, focusing on scenarios with non-convex constraints like obstacles or keep-out zones. It utilizes a novel Sequential Convex Programming (SCP) approach that reformulates the non-convex problem into a sequence of convex subproblems. These subproblems are solved efficiently using a custom interior-point method, enabling rapid trajectory generation suitable for online implementation. The algorithm's performance is validated through simulations of lunar landing scenarios demonstrating its ability to generate feasible and fuel-efficient trajectories while respecting complex constraints, even in the presence of disturbances. Furthermore, its computational speed is shown to be significantly faster than existing methods, making it a promising candidate for real-world powered descent applications.
HN users discuss the practical applications and limitations of the proposed powered descent guidance algorithm. Some express skepticism about its real-time performance on resource-constrained flight computers, particularly given the computational complexity introduced by the non-convex optimization. Others question the novelty of the approach, comparing it to existing methods and highlighting the challenges of verifying its robustness in unpredictable real-world scenarios like sudden wind gusts. The discussion also touches on the importance of accurate terrain data and the potential benefits for pinpoint landing accuracy, particularly in challenging environments like the lunar south pole. Several commenters ask for clarification on specific aspects of the algorithm and its implementation.
New research reveals that hunter-gatherers, not early farmers as previously thought, colonized the remotest Mediterranean islands, including Crete, Cyprus, and the Balearic Islands, thousands of years earlier than previously believed. Analysis of obsidian artifacts across these islands points to seafaring capabilities and extensive trade networks originating from mainland sources like Anatolia, Sardinia, and the Lipari Islands during the Epipaleolithic and early Mesolithic periods. This suggests sophisticated maritime navigation skills and a wider spread of these groups across the Mediterranean much earlier in prehistory than the established narrative allows, pushing back the timeline for island colonization by several millennia.
HN commenters discuss the logistical challenges of early seafaring, questioning the assumed simplicity of raft technology and navigation. Some highlight the difficulty of crossing open water without modern navigational tools, emphasizing the need for advanced knowledge of currents, winds, and stars. Others point out the physical demands of such journeys, suggesting the necessity of significant provisions and robust vessels, perhaps beyond simple rafts. The discussion also touches on the surprising distances covered and the implications for understanding early human migration and interaction. One commenter mentions the discovery of obsidian tools on the islands, further supporting the idea of intentional travel and trade networks. Finally, several users express fascination with the ingenuity and resilience of these early seafarers.
Jeff Geerling's blog post highlights Beidou Position System (BPS), China's independently developed global navigation satellite system, as a lesser-known alternative to GPS. He details its development, global coverage, and increasing accuracy, emphasizing its potential as a backup or even primary navigation system, particularly for those needing to operate independently of US-controlled infrastructure. Geerling shares his experience testing BPS receivers, noting its comparable performance to GPS in his basic experiments and the growing availability of BPS-compatible devices. He concludes by advocating for greater awareness of BPS as a viable option in the GNSS landscape.
HN commenters discuss the viability and practicality of BPS, noting it's largely theoretical and faces significant hurdles. Several point out the immense infrastructure investment required for terrestrial positioning systems like BPS, especially compared to the established satellite-based GPS. Some question the accuracy claims and highlight potential interference issues in dense urban environments. Others express skepticism about BPS's resistance to jamming and spoofing, crucial for critical infrastructure. A few comments mention Loran-C as a more mature terrestrial alternative, although it has its limitations. Overall, there's a consensus that while intriguing, BPS lacks the development and backing to become a serious competitor to GPS in the foreseeable future.
The article "Overengineered Anchor Links" explores excessively complex methods for implementing smooth scrolling anchor links, ultimately advocating for a simple, standards-compliant approach. It dissects common overengineered solutions, highlighting their drawbacks like unnecessary JavaScript dependencies, performance issues, and accessibility concerns. The author demonstrates how a concise snippet of JavaScript leveraging native browser behavior can achieve smooth scrolling with minimal code and maximum compatibility, emphasizing the importance of prioritizing simplicity and web standards over convoluted solutions. This approach relies on Element.scrollIntoView() with the behavior: 'smooth' option, providing a performant and accessible experience without the bloat of external libraries or complex calculations.
Hacker News users generally agreed that the author of the article overengineered the anchor link solution. Many commenters suggested simpler, more standard approaches using just HTML and CSS, pointing out that JavaScript adds unnecessary complexity for such a basic feature. Some appreciated the author's exploration of the problem, but ultimately felt the final solution was impractical for real-world use. A few users debated the merits of using the <details> element for navigation, and whether it offered sufficient accessibility. Several comments also highlighted the performance implications of excessive JavaScript and the importance of considering Core Web Vitals. One commenter even linked to a much simpler CodePen example achieving a similar effect. Overall, the consensus was that while the author's technical skills were evident, a simpler, more conventional approach would have been preferable.
GPS jamming and spoofing are increasing threats to aircraft navigation, with potentially dangerous consequences. A new type of atomic clock, much smaller and cheaper than existing ones, could provide a highly accurate backup navigation system, independent of vulnerable satellite signals. These chip-scale atomic clocks (CSACs), while not yet widespread, could be integrated into aircraft systems to maintain precise positioning and timing even when GPS signals are lost or compromised, significantly improving safety and resilience.
HN commenters discuss the plausibility and implications of GPS spoofing for aircraft. Several express skepticism that widespread, malicious spoofing is occurring, suggesting alternative explanations for reported incidents like multipath interference or pilot error. Some point out that reliance on GPS varies among aircraft and that existing systems can mitigate spoofing risks. The potential vulnerabilities of GPS are acknowledged, and the proposed atomic clock solution is discussed, with some questioning its cost-effectiveness and complexity compared to other mitigation strategies. Others suggest that focusing on improving the resilience of GPS itself might be a better approach. The possibility of state-sponsored spoofing is also raised, particularly in conflict zones.
Polish researchers suspect that GPS jamming in the Baltic Sea, affecting maritime and air navigation, is being deliberately caused by ships, possibly linked to the ongoing war in Ukraine. The Centre for Eastern Studies (OSW) report highlights numerous incidents of interference, particularly near Russian naval exercises and around strategic areas like the Bornholm Basin, suggesting a potential Russian military strategy to disrupt navigation and create uncertainty. While technical malfunctions are possible, the patterns of interference strongly point toward intentional jamming, impacting both civilian and military operations in the region.
Several Hacker News commenters discuss the plausibility and implications of GPS jamming in the Baltic Sea. Some express skepticism, suggesting the observed disruptions could be caused by unintentional interference or even solar flares. Others point out the increasing availability and use of GPS jammers, highlighting their potential use in smuggling or other illicit activities. The prevalence of spoofing is also raised, with one commenter mentioning the known use of GPS spoofing by Russia around airports and other strategic locations. Another commenter questions the motivation behind such jamming, speculating that it could be related to the ongoing war in Ukraine, possibly to mask ship movements or disrupt navigation. A few comments also touch on the broader implications for maritime safety and the potential for escalating tensions in the region.
NASA has successfully demonstrated the ability to receive GPS signals at the Moon, a first for navigating beyond Earth’s orbit. The Navigation Doppler Lidar for Space (NDLS) experiment aboard the Lunar Reconnaissance Orbiter (LRO) locked onto GPS signals and determined LRO’s position, paving the way for more reliable and autonomous navigation for future lunar missions. This achievement reduces reliance on Earth-based tracking and allows spacecraft to more accurately pinpoint their location, enabling more efficient and flexible operations in lunar orbit and beyond.
Several commenters on Hacker News expressed skepticism about the value of this achievement, questioning the practical applications and cost-effectiveness of using GPS around the Moon. Some suggested alternative navigation methods, such as star trackers or inertial systems, might be more suitable. Others pointed out the limitations of GPS accuracy at such distances, especially given the moon's unique gravitational environment. A few commenters highlighted the potential benefits, including simplified navigation for lunar missions and improved understanding of GPS signal behavior in extreme environments. Some debated the reasons behind NASA's pursuit of this technology, speculating about potential future applications like lunar infrastructure development or deep space navigation. There was also discussion about the technical challenges involved in acquiring and processing weak GPS signals at such a distance.
Shunpo is a minimalist Bash tool designed to streamline directory navigation. It learns frequently visited directories and allows users to quickly jump to them using short, custom aliases. By storing these aliases and their corresponding paths in a simple text file, Shunpo avoids complex databases and remains lightweight and portable. It offers basic commands for adding, removing, listing, and navigating to saved locations, simplifying the process of moving between commonly accessed folders within the terminal.
Hacker News users discussed Shunpo's utility and potential drawbacks. Some found its core functionality—quickly jumping to frequently used directories—appealing, especially combined with tools like fzf. Others questioned its value proposition over existing solutions like autojump, z, or fasd, particularly given its reliance on find. Concerns were raised about performance in large directory trees and the security implications of executing arbitrary commands generated from find results. Some suggested improvements, including leveraging shell builtins for better performance and integrating more advanced selection mechanisms. The project's minimalism was both praised and criticized, with some appreciating its simplicity and others desiring more features like directory tracking or the ability to ignore certain paths.
SimpleSearch is a website that aggregates a large directory of specialized search engines, presented as a straightforward, uncluttered list. It aims to provide a quick access point for users to find information across various domains, from academic resources and code repositories to specific file types and social media platforms. Rather than relying on a single, general-purpose search engine, SimpleSearch offers a curated collection of tools tailored to different search needs.
HN users generally praised SimpleSearch for its clean design and utility, particularly for its quick access to various specialized search engines. Several commenters suggested additions, including academic search engines like BASE and PubMed, code-specific search like Sourcegraph, and visual search tools like Google Images. Some discussed the benefits of curated lists versus relying on browser search engines, with a few noting the project's similarity to existing search aggregators. The creator responded to several suggestions and expressed interest in incorporating user feedback. A minor point of contention arose regarding the inclusion of Google, but overall the reception was positive, with many appreciating the simplicity and convenience offered by the site.
The blog post argues that file systems, particularly hierarchical ones, are a form of hypermedia that predates the web. It highlights how directories act like web pages, containing links (files and subdirectories) that can lead to other content or executable programs. This linking structure, combined with metadata like file types and modification dates, allows for navigation and information retrieval similar to browsing the web. The post further suggests that the web's hypermedia capabilities essentially replicate and expand upon the fundamental principles already present in file systems, emphasizing a deeper connection between these two technologies than commonly recognized.
Hacker News users largely praised the article for its clear explanation of file systems as a foundational hypermedia system. Several commenters highlighted the elegance and simplicity of this concept, often overlooked in the modern web's complexity. Some discussed the potential of leveraging file system principles for improved web experiences, like decentralized systems or simpler content management. A few pointed out limitations, such as the lack of inherent versioning in basic file systems and the challenges of metadata handling. The discussion also touched on related concepts like Plan 9 and the semantic web, contrasting their approaches to linking and information organization with the basic file system model. Several users reminisced about early computing experiences and the directness of navigating files and folders, suggesting a potential return to such simplicity.
Researchers have demonstrated a method for using smartphones' GPS receivers to map disturbances in the Earth's ionosphere. By analyzing data from a dense network of GPS-equipped phones during a solar storm, they successfully imaged ionospheric variations and travelling ionospheric disturbances (TIDs), particularly over San Francisco. This crowdsourced approach, leveraging the ubiquitous nature of smartphones, offers a cost-effective and globally distributed sensor network for monitoring space weather events and improving the accuracy of ionospheric models, which are crucial for technologies like navigation and communication.
HN users discuss the potential impact and feasibility of using smartphones to map the ionosphere. Some express skepticism about the accuracy and coverage achievable with consumer-grade hardware, particularly regarding the ability to measure electron density effectively. Others are more optimistic, highlighting the potential for a vast, distributed sensor network, particularly for studying transient ionospheric phenomena and improving GPS accuracy. Concerns about battery drain and data usage are raised, along with questions about the calibration and validation of the smartphone measurements. The discussion also touches on the technical challenges of separating ionospheric effects from other signal variations and the need for robust signal processing techniques. Several commenters express interest in participating in such a project, while others point to existing research in this area, including the use of software-defined radios.
Summary of Comments ( 8 )
https://news.ycombinator.com/item?id=44020574
HN commenters discuss the immense and dangerous project of clearing Hell Gate, a treacherous strait in New York's East River. Several express awe at the engineering feat, particularly the complex calculations and controlled explosions involved. Some highlight the historical significance of improving navigation and commerce in the area, while others focus on the ecological impact, mentioning the displacement of wildlife and changes to the river's flow. A few commenters note the article's dry technical style, with one suggesting a more narrative-driven account would be engaging. The discussion also touches upon the human element, with comments about the workers involved and the broader impact on the city's development. A compelling comment thread explores the different methods considered, including a ship canal across Astoria, highlighting the eventual choice of underwater blasting as the most effective (and dramatic) solution.
The Hacker News post titled "The Conquest of Hell Gate [pdf]" linking to a US Army Corps of Engineers history of the Hell Gate clearing project has generated several comments discussing various aspects of the project.
One commenter highlights the sheer scale of the project, expressing awe at the 1.8 million pounds of explosives used and the resulting displacement of water, mentioning that "the whole of New York harbor felt it." They also note the meticulous planning and execution that prevented any damage to surrounding structures.
Another comment focuses on the human element, drawing attention to the dangerous working conditions faced by the individuals involved, particularly those working underwater in caissons. They point out the risks of "the bends" (decompression sickness) and other hazards.
The ingenuity and engineering prowess displayed in the project also receives attention. One commenter praises the innovative techniques used, like the grid system of tunnels and shafts drilled to place the explosives, considering it a marvel of engineering for its time.
There's discussion about the historical context, with some comments mentioning the impact of the improved navigation on New York's development as a major port. One commenter notes that Hell Gate posed a significant challenge to shipping and that its clearing was crucial for the city's economic growth. Another relates how this project, along with the Erie Canal, cemented NYC's dominance as a port.
A few comments touch on the environmental impact, with one commenter speculating about the ecological consequences of such a massive explosion, though no definitive information is offered within the comment thread.
Finally, a commenter points out a technical detail regarding the specific type of explosive used – Rackarock – and provides some information about its composition and properties, highlighting its relative safety for transport and storage compared to other explosives of the time. This commenter also mentions the subsequent use of Rackarock in the Panama Canal project.
Overall, the comments on Hacker News reflect a general appreciation for the engineering feat, acknowledging the challenges faced and the ingenuity applied in the conquest of Hell Gate. They also highlight the human cost and the significant impact the project had on the development of New York.