Jürgen Schmidhuber's "Matters Computational" provides a comprehensive overview of computer science, spanning its theoretical foundations and practical applications. It delves into topics like algorithmic information theory, computability, complexity theory, and the history of computation, including discussions of Turing machines and the Church-Turing thesis. The book also explores the nature of intelligence and the possibilities of artificial intelligence, covering areas such as machine learning, neural networks, and evolutionary computation. It emphasizes the importance of self-referential systems and universal problem solvers, reflecting Schmidhuber's own research interests in artificial general intelligence. Ultimately, the book aims to provide a unifying perspective on computation, bridging the gap between theoretical computer science and the practical pursuit of artificial intelligence.
Sublinear time algorithms provide a way to glean meaningful information from massive datasets too large to examine fully. They achieve this by cleverly sampling or querying only small portions of the input, allowing for approximate solutions or property verification in significantly less time than traditional algorithms. These techniques are crucial for handling today's ever-growing data, enabling applications like quickly estimating the average value of elements in a database or checking if a graph is connected without examining every edge. Sublinear algorithms often rely on randomization and probabilistic guarantees, accepting a small chance of error in exchange for drastically improved efficiency. They are a vital tool in areas like graph algorithms, statistics, and database management.
Hacker News users discuss the linked resource on sublinear time algorithms, primarily focusing on its practical applications. Several commenters express surprise and interest in the concept of algorithms that don't require reading all input data, with examples like property testing and finding the median element cited. Some question the real-world usefulness, while others point to applications in big data analysis, databases, and machine learning where processing the entire dataset is infeasible. There's also discussion about the trade-offs between accuracy and speed, with some suggesting these algorithms provide "good enough" solutions for certain problems. Finally, a few comments highlight specific sublinear algorithms and their associated use cases, further emphasizing the practicality of the subject.
Catalytic computing, a new theoretical framework, aims to overcome the limitations of traditional computing by leveraging the entire storage capacity of a device, such as a hard drive, for computation. Instead of relying on limited working memory, catalytic computing treats the entire memory system as a catalyst, allowing data to transform itself through local interactions within the storage itself. This approach, inspired by chemical catalysts, could drastically expand the complexity and scale of computations possible, potentially enabling the efficient processing of massive datasets that are currently intractable for conventional computers. While still theoretical, catalytic computing represents a fundamental shift in thinking about computation, promising to unlock the untapped potential of existing hardware.
Hacker News users discussed the potential and limitations of catalytic computing. Some expressed skepticism about the practicality and scalability of the approach, questioning the overhead and energy costs involved in repeatedly reading and writing data. Others highlighted the potential benefits, particularly for applications involving massive datasets that don't fit in RAM, drawing parallels to memory mapping and virtual memory. Several commenters pointed out that the concept isn't entirely new, referencing existing techniques like using SSDs as swap space or leveraging database indexing. The discussion also touched upon the specific use cases where catalytic computing might be advantageous, like bioinformatics and large language models, while acknowledging the need for further research and development to overcome current limitations. A few commenters also delved into the theoretical underpinnings of the concept, comparing it to other computational models.
A Brown University undergraduate, Noah Golowich, disproved a long-standing conjecture in data science related to the "Kadison-Singer problem." This problem, with implications for signal processing and quantum mechanics, asked about the possibility of extending certain "frame" functions while preserving their key properties. A 2013 proof showed this was possible in specific high dimensions, leading to the conjecture it was true for all higher dimensions. Golowich, building on recent mathematical tools, demonstrated a counterexample, proving the conjecture false and surprising experts in the field. His work, conducted under the mentorship of Assaf Naor, highlights the potential of exploring seemingly settled mathematical areas.
Hacker News users discussed the implications of the undergraduate's discovery, with some focusing on the surprising nature of such a significant advancement coming from an undergraduate researcher. Others questioned the practicality of the new algorithm given its computational complexity, highlighting the trade-off between statistical accuracy and computational feasibility. Several commenters also delved into the technical details of the conjecture and its proof, expressing interest in the specific mathematical techniques employed. There was also discussion regarding the potential applications of the research within various fields and the broader implications for data science and machine learning. A few users questioned the phrasing and framing in the original Quanta Magazine article, finding it slightly sensationalized.
This paper proposes a new quantum Fourier transform (QFT) algorithm that significantly reduces the circuit depth compared to the standard implementation. By leveraging a recursive structure and exploiting the symmetries inherent in the QFT matrix, the authors achieve a depth of O(log * n + log log n), where n is the number of qubits and log * denotes the iterated logarithm. This improvement represents an exponential speedup in depth compared to the O(log² n) depth of the standard QFT while maintaining the same asymptotic gate complexity. The proposed algorithm promises faster and more efficient quantum computations that rely on the QFT, particularly in near-term quantum computers where circuit depth is a crucial limiting factor.
Hacker News users discussed the potential impact of a faster Quantum Fourier Transform (QFT). Some expressed skepticism about the practicality due to the significant overhead of classical computation still required and questioned if this specific improvement truly addressed the bottleneck in quantum algorithms. Others were more optimistic, highlighting the mathematical elegance of the proposed approach and its potential to unlock new applications if the classical overhead can be mitigated in the future. Several commenters also debated the relevance of asymptotic complexity improvements given the current state of quantum hardware, with some arguing that more practical advancements are needed before these theoretical gains become significant. There was also a brief discussion regarding the paper's notation and clarity.
Summary of Comments ( 11 )
https://news.ycombinator.com/item?id=43288861
HN users discuss the density and breadth of "Matters Computational," praising its unique approach to connecting diverse computational topics. Several commenters highlight the book's treatment of randomness, floating-point arithmetic, and the FFT as particularly insightful. The author's background in physics is noted, contributing to the book's distinct perspective. Some find the book challenging, requiring multiple readings to fully grasp the concepts. The free availability of the PDF is appreciated, and its enduring relevance a decade after publication is also remarked upon. A few commenters express interest in a physical copy, while others suggest potential updates or expansions on certain topics.
The Hacker News post titled "Matters Computational (2010) [pdf]" linking to a PDF of Jörg Fliege's book "Matters Computational" has a moderate number of comments, discussing various aspects of the book and computational mathematics in general.
Several commenters praise the book's comprehensive nature and clarity. One user highlights its value as a reference for "all sorts of basic algorithms and data structures," appreciating the detailed explanations and pseudocode provided. They specifically mention its usefulness for understanding fundamental concepts like numerical stability.
Another commenter focuses on the book's treatment of linear algebra, noting its depth and accessibility, even for those without a strong mathematical background. They contrast it with other resources they found less helpful.
A few comments delve into specific topics covered in the book. One user discusses the exploration of floating-point arithmetic and its associated challenges, acknowledging the importance of understanding these concepts for anyone working with numerical computations. Another highlights the chapter on optimization, mentioning its practical value and the inclusion of various optimization algorithms.
Some commenters offer broader perspectives on computational mathematics and its role in computer science. One reflects on the importance of a strong mathematical foundation for software engineers, advocating for more emphasis on these concepts in education.
The discussion also touches on the book's availability. The author's decision to make it freely available is commended, with some users expressing gratitude for open access to such valuable educational resources. A link to the author's webpage is shared, offering further context.
While a number of commenters express interest in the book based on the description and other comments, there isn't extensive engagement in deep technical discussions. The overall sentiment is positive, with the comments primarily focusing on the book's breadth, clarity, and value as a resource for understanding fundamental computational concepts.