Lightcell Energy presents a groundbreaking approach to electricity generation with its innovative photovoltaic technology, moving beyond the limitations of traditional silicon-based solar panels. Their core innovation, the Lightcell, distinguishes itself through a unique process that utilizes concentrated sunlight to stimulate a specialized photovoltaic material. Unlike conventional solar cells that directly convert photons to electricity, the Lightcell leverages an intermediary step. Incoming concentrated sunlight heats this material, causing it to emit photons at a specific wavelength optimized for efficient energy conversion by a secondary photovoltaic cell. This two-step process, termed thermophotovoltaic (TPV) conversion, offers several key advantages.
Firstly, the Lightcell boasts significantly higher potential efficiencies compared to traditional solar technologies. By leveraging the intermediate photon emission stage, the system can bypass certain energy loss mechanisms inherent in conventional photovoltaic processes, theoretically enabling a much greater percentage of the incident solar energy to be transformed into usable electricity. This increased efficiency translates to a greater power output from a given area, making Lightcell technology particularly attractive for applications where space is a premium.
Secondly, the Lightcell's design intrinsically incorporates energy storage capabilities. The specific material used within the system can retain the absorbed heat energy for an extended period. This allows for on-demand electricity generation, even when direct sunlight is unavailable, effectively decoupling electricity production from immediate solar irradiance. This feature represents a significant departure from traditional solar panels, which require external battery systems for energy storage and cannot generate power during nighttime or periods of cloud cover. The integrated energy storage within the Lightcell system simplifies the overall system architecture and potentially reduces the overall cost and complexity of deploying this technology.
Thirdly, the high energy density of the Lightcell technology makes it suitable for a wide range of applications, from powering individual homes and businesses to providing electricity for larger-scale infrastructure projects. Its modular design allows for scalability and flexible deployment, adapting to diverse energy needs. The potential applications range from supplementing existing grid infrastructure to providing off-grid power solutions for remote locations. The company emphasizes the potential of this technology to contribute to a more sustainable and resilient energy future, by providing a cleaner and more reliable alternative to conventional fossil fuel-based power generation.
While Lightcell Energy acknowledges the technology is still under development, they highlight ongoing efforts to optimize the materials, refine the manufacturing processes, and ultimately bring this innovative approach to commercial viability. The promise of higher efficiency, integrated energy storage, and flexible deployment positions Lightcell technology as a potentially disruptive force within the renewable energy landscape, offering a compelling vision for the future of electricity generation.
The website "FFmpeg by Example" provides a practical, example-driven guide to utilizing the FFmpeg command-line tool for various multimedia manipulation tasks. It eschews extensive theoretical explanations in favor of presenting concrete, real-world use cases and the corresponding FFmpeg commands to achieve them. The site is structured around a collection of specific examples, each demonstrating a particular FFmpeg operation. These examples cover a broad range of functionalities, including but not limited to:
Basic manipulations: These cover fundamental operations like converting between different multimedia formats (e.g., MP4 to WebM), changing the resolution of a video, extracting audio from a video file, and creating animated GIFs from video segments. The examples demonstrate the precise command-line syntax required for each task, often highlighting specific FFmpeg options and their effects.
Audio processing: The examples delve into audio-specific manipulations, such as normalizing audio levels, converting between audio formats (e.g., WAV to MP3), mixing multiple audio tracks, and applying audio filters like fade-in and fade-out effects. The provided commands clearly illustrate how to control audio parameters and apply various audio processing techniques using FFmpeg.
Video editing: The site explores more advanced video editing techniques using FFmpeg. This encompasses tasks such as concatenating video clips, adding watermarks or overlays to videos, creating slideshows from images, and applying complex video filters for effects like blurring or sharpening. The examples showcase the flexibility of FFmpeg for performing non-linear video editing operations directly from the command line.
Streaming and broadcasting: Examples related to streaming and broadcasting demonstrate how to utilize FFmpeg for encoding video and audio streams in real-time, suitable for platforms like YouTube Live or Twitch. These examples cover aspects like setting bitrates, choosing appropriate codecs, and configuring streaming protocols.
Subtitle manipulation: The guide includes examples demonstrating how to add, remove, or manipulate subtitles in video files. This encompasses burning subtitles directly into the video stream, as well as working with external subtitle files in various formats.
For each example, the site provides not only the FFmpeg command itself but also a clear description of the task being performed, the purpose of the various command-line options used, and the expected output. This approach allows users to learn by directly applying the examples and modifying them to suit their specific needs. The site focuses on practicality and immediate application, making it a valuable resource for both beginners seeking a quick introduction to FFmpeg and experienced users looking for specific command examples for common tasks. It emphasizes learning through practical application and avoids overwhelming the reader with unnecessary theoretical details.
The Hacker News post for "FFmpeg by Example" has several comments discussing the utility of the resource, alternative learning approaches, and specific FFmpeg commands.
Many commenters praise the resource. One user calls it a "great starting point" and highlights the practicality of learning through examples. Another appreciates the clear explanations and the well-chosen examples which address common use cases. A third commenter emphasizes the value of the site for its concise and focused approach, contrasting it favorably with the official documentation, which they find overwhelming. The sentiment is echoed by another who found the official documentation difficult to navigate and appreciates the example-driven learning offered by the site.
Several comments discuss alternative or supplementary resources. One commenter recommends the book "FFmpeg Basics" by Frantisek Korbel, suggesting it pairs well with the website. Another points to a different online resource, "Modern FFmpeg Wiki," which they find to be more comprehensive. A third user mentions their preference for learning through man pages and flags, reflecting a more command-line centric approach.
Some commenters delve into specific FFmpeg functionalities and commands. One user discusses the complexities of hardware acceleration and how it interacts with different FFmpeg builds. They suggest static builds are generally more reliable in this regard. Another commenter provides a specific command for extracting frames from a video, demonstrating the practical application of FFmpeg. A different user shares a command for losslessly cutting videos, a common task for video editing. This sparks a small discussion about the nuances of lossless cutting and alternative approaches using keyframes. Someone also recommends using -avoid_negative_ts make_zero for generating output suitable for concatenation, highlighting a lesser-known but useful flag combination.
Finally, there's a comment advising caution against blindly copying and pasting commands from the internet, emphasizing the importance of understanding the implications of each command and flag used.
The blog post by Jonathan Corbet details the intriguing availability of personalized voice recordings from Elwood Edwards, the voice famously associated with the iconic "You've got mail!" notification from America Online (AOL) in the 1990s. Mr. Edwards, leveraging the contemporary gig economy facilitated by platforms like Cameo, is now offering bespoke voice recordings for a modest fee. This presents a unique opportunity for individuals to acquire custom messages delivered in the instantly recognizable timbre that once heralded the arrival of electronic mail for millions. The blog post highlights this nostalgic service, emphasizing the affordability and accessibility of obtaining a personalized greeting, announcement, or other short recording spoken by the very voice that defined a generation's online experience. Corbet notes the potential applications, ranging from whimsical novelty recordings to incorporating the iconic voice into professional projects, underscoring the versatility of this offering. Essentially, anyone now has the power to commandeer the voice that once signified digital connection for a personalized message, a testament to the democratizing influence of platforms like Cameo in connecting individuals with recognizable personalities and talents. This blog post serves as both an announcement of this service and a brief commentary on the changing landscape of media and celebrity accessibility in the digital age. It evokes a sense of nostalgia while simultaneously highlighting the entrepreneurial spirit of Mr. Edwards in adapting to the modern gig economy and engaging directly with his audience in a new and innovative way.
The Hacker News post titled "Personalized voice recordings by Elwood 'You've got mail!' Edwards" has generated a moderate number of comments, mostly focusing on the nostalgia and novelty of the service offered.
Several commenters express their fondness for the iconic "You've got mail" phrase and its association with the early internet era. They share personal anecdotes about AOL and the excitement surrounding email notifications at the time. This nostalgic sentiment translates into an appreciation for Edwards's offering, with some expressing interest in purchasing personalized recordings.
Some users discuss the potential uses for such recordings, ranging from voicemail greetings to novelty gifts and even integration into smart home systems. One commenter suggests using the service for a wake-up alarm, while others brainstorm humorous and creative applications.
A few comments touch upon the technical aspects of voice cloning and AI-generated speech, contrasting Edwards's genuine recordings with the potential for future technology to replicate his voice. There's a sense of valuing the authenticity of a recording from the original voice actor.
One commenter questions the pricing strategy, suggesting a tiered model based on usage might be more appealing. This sparks a small discussion about the value proposition and target audience for the service.
A couple of comments also mention other famous voice actors and the potential for similar personalized recording services. This suggests a broader interest in nostalgic audio experiences and personalized messages from recognizable voices.
While the overall number of comments is not extensive, the discussion highlights the positive reception of Edwards's service, driven largely by nostalgia, the unique value proposition, and the creative potential for personalized voice recordings.
The blog post by Paulo Syibelo introduces "DoubleClickjacking," a novel web-based attack vector that exploits the trust users place in double-clicking actions. The core vulnerability lies in the way websites handle these double-clicks, often assigning them different functions than single clicks. Syibelo argues that attackers can manipulate this behavior to trick users into performing unintended actions with potentially severe consequences.
The attack typically involves overlaying a seemingly innocuous element, such as a button or link, over a legitimate website element. This overlay is transparent or visually disguised to blend seamlessly with the underlying content. When the user believes they are interacting with the visible element through a double-click, they are actually triggering an action on the hidden, underlying element controlled by the attacker. This deception allows attackers to bypass security measures that rely on single-click confirmations, such as transaction authorizations or sensitive data modifications.
Syibelo provides a hypothetical scenario involving a banking application. An attacker could overlay a fake "View Transaction Details" button over a legitimate "Transfer Funds" button. An unsuspecting user, accustomed to double-clicking to view details, would inadvertently initiate a fund transfer without their explicit consent. This highlights the potential for financial loss and data breaches through DoubleClickjacking.
The blog post further emphasizes the insidious nature of this attack. Traditional clickjacking protection mechanisms, which focus on preventing single-click hijacking, are ineffective against DoubleClickjacking. Syibelo suggests that the inherent trust users have in double-clicking contributes to the vulnerability, as they are less likely to scrutinize the action compared to a single click, especially if the visual cues appear legitimate.
While the blog post doesn't offer concrete solutions to mitigate DoubleClickjacking, it serves as a crucial awareness piece, highlighting a potential security gap in web applications and urging developers to consider the implications of double-click functionality. The post concludes by emphasizing the need for further research and the development of robust countermeasures to protect against this emerging threat. Syibelo stresses that as web interactions become more complex, understanding and addressing vulnerabilities like DoubleClickjacking are vital for maintaining online security.
The Hacker News post titled "DoubleClickjacking: A New type of web hacking technique" linking to an article on paulosyibelo.com has generated several comments discussing the validity and novelty of the described attack.
Several commenters point out that this is not a new technique, and is in fact a variant of clickjacking which has been known for a long time. They argue that the article's framing of "DoubleClickjacking" is misleading, as it's simply clickjacking with a double-click trigger, rather than a single click. Some commenters provide links to older resources and discussions about clickjacking, demonstrating the established nature of this type of attack.
One commenter questions the practical exploitability of this particular double-click variant. They argue that legitimate uses of double-click on the web are relatively rare, and therefore the opportunities for malicious exploitation are limited. They suggest that tricking a user into double-clicking something unintentionally is significantly more difficult than a single click.
Another commenter discusses the mitigations against clickjacking, such as the X-Frame-Options header, and emphasizes the importance of developers using these protections. They highlight that the vulnerability lies in the vulnerable website's lack of proper defenses, rather than a novel attack vector.
The discussion also touches upon the user's role in preventing such attacks. One comment suggests being cautious about interacting with embedded content, especially from untrusted sources, regardless of the specific clickjacking technique employed.
Overall, the comments express skepticism about the "newness" of DoubleClickjacking, clarifying that it's a variation of a well-known attack. They highlight the importance of existing security measures and developer awareness in mitigating these kinds of threats. The practicality of exploiting a double-click scenario is also debated, with some suggesting its limited applicability compared to traditional clickjacking.
Ryan Isenberg has embarked upon an ambitious project, christened the "Cosmos Keyboard," which aims to revolutionize personalized typing experiences. The core concept revolves around leveraging 3D scanning technology to meticulously capture the unique contours of an individual's hands. This detailed scan then serves as the foundational blueprint for generating a custom-designed keyboard, ergonomically optimized for the specific user. The envisioned process involves employing readily available 3D scanning applications, readily accessible on contemporary smartphones, to acquire a high-fidelity three-dimensional model of the user's hands in a relaxed, typing posture.
This digital representation is then processed by specialized software, developed by Isenberg, which algorithmically analyzes the hand shape, finger lengths, and overall hand proportions. This analysis informs the generation of a personalized keyboard layout, determining the optimal positioning and spacing of individual keys. The ultimate goal is to create a keyboard that perfectly complements the user's hand geometry, thereby promoting comfort, minimizing strain, and potentially enhancing typing speed and accuracy. The project is currently in its developmental stages, with Isenberg showcasing preliminary results and outlining his vision for the future of personalized keyboard design. He details the technical challenges involved, including ensuring scan accuracy, developing robust algorithms for key placement, and exploring various manufacturing techniques for the custom keyboards. While the final implementation details are still being refined, the Cosmos Keyboard project presents a compelling exploration of the intersection of 3D scanning, ergonomic design, and personalized computing peripherals. It promises a potential paradigm shift in how we interact with our digital devices, moving beyond the one-size-fits-all approach of traditional keyboards.
The Hacker News post "Cosmos Keyboard: Scan your hand, build a keyboard" linking to ryanis.cool/cosmos/ generated a moderate amount of discussion with a range of perspectives on the project.
Several commenters expressed skepticism about the practicality and ergonomics of the keyboard. One commenter questioned the claimed typing speed improvements, suggesting that the learning curve and potential for hand strain might negate any benefits. Another raised concerns about the lack of tactile feedback, a feature considered crucial by many keyboard enthusiasts. The reliance on visual confirmation of keystrokes was also seen as a potential drawback, potentially slowing down typing and increasing eye strain.
The customizability aspect of the keyboard, while intriguing to some, was also met with skepticism. One commenter pointed out that achieving a truly optimal layout requires extensive experimentation and data analysis, a task that might be too daunting for most users. The potential for creating suboptimal layouts, leading to decreased typing speed and increased error rates, was also mentioned.
Some commenters questioned the necessity of the hand-scanning process. They argued that existing keyboard customization software already allows users to adjust layouts and key sizes without the need for 3D scanning.
Despite the skepticism, some commenters expressed interest in the project. The potential for creating a truly personalized keyboard that accommodates individual hand shapes and typing styles was seen as a compelling idea. One commenter suggested that the keyboard might be particularly beneficial for individuals with hand injuries or disabilities.
A few commenters focused on the technical aspects of the project. They inquired about the technology used for hand scanning and the algorithms used for generating the keyboard layout. There was also some discussion about the choice of materials and the manufacturing process.
Overall, the comments reflect a cautious but curious attitude towards the Cosmos keyboard. While the concept of a personalized, hand-scanned keyboard generated some excitement, many commenters expressed valid concerns about its practicality, ergonomics, and potential drawbacks.
Summary of Comments ( 118 )
https://news.ycombinator.com/item?id=42697001
Hacker News users express significant skepticism regarding Lightcell's claims of a revolutionary light-based engine. Several commenters point to the lack of verifiable data and independent testing, highlighting the absence of peer-reviewed publications and the reliance on marketing materials. The seemingly outlandish efficiency claims and vague explanations of the underlying physics fuel suspicion, with comparisons drawn to past "too-good-to-be-true" energy technologies. Some users call for more transparency and rigorous scientific scrutiny before accepting the company's assertions. The overall sentiment leans heavily towards disbelief, pending further evidence.
The Hacker News post titled "Lightcell: An engine that uses light to make electricity" (https://news.ycombinator.com/item?id=42697001) generated a moderate discussion with a degree of skepticism and calls for further clarification.
Several commenters questioned the fundamental physics behind Lightcell's claims. One user pointed out the seeming violation of the second law of thermodynamics, arguing that converting ambient heat to usable energy at the claimed efficiency would be revolutionary, and if true, should have attracted far more attention and scrutiny. This sentiment was echoed by others who expressed doubt about achieving the stated energy conversion efficiency without violating established physical laws.
The lack of detailed technical information was a recurring theme. Commenters lamented the website's reliance on marketing jargon and the absence of peer-reviewed publications or detailed experimental data. They called for more transparency, suggesting that providing specifics about the technology, including the materials used and the precise mechanism of energy conversion, would lend credibility to Lightcell's claims.
The discussion also touched upon the potential applications of the technology if it were to prove viable. Some commenters speculated about the implications for energy production and storage, while others questioned the economic feasibility and scalability of the proposed solution.
One commenter mentioned a prior discussion on Hacker News about a similar technology, highlighting the recurring nature of such claims and the importance of rigorous scientific validation. They also linked to a Wikipedia article about "Blackbody radiation," suggesting it as a relevant concept for understanding the thermodynamic challenges involved in Lightcell's proposed technology.
A few commenters offered more cautious perspectives, suggesting the possibility that Lightcell might have stumbled upon a genuine breakthrough, albeit one that requires further investigation and verification. However, the overall tone of the discussion remained predominantly skeptical, emphasizing the need for concrete evidence to support the company's ambitious claims.