标签：#science

Nobody likes getting a swab shoved up their nose. A startup in Japan has developed a much less intrusive system.

SpaceX is preparing to build a terrestrial mobile network to "acquire quite a few" of the customers now subscribed to T-Mobile, AT&T, and Verizon. The message to compete head-to-head with the US carriers was delivered by SpaceX president Gwynne Shotwell and CEO Elon Musk during the Q&A section of the company's first earnings call. "The […]

Originally published at Programming Tech Lab . Welcome to the Garage: What is Linear Regression? Step away from the kitchen counter and step into a bustling auto garage. Imagine you are an experienced mechanic evaluating used cars brought in for trade-ins. A customer drives in a sedan with 50,000 miles on the odometer and asks: "How much is my car worth?" Without needing a complex computer program, your brain instantly draws a connection: as the mileage on a car goes up, its resale price goes down. If a car has 0 miles (brand new), it commands peak market price. If it has 200,000 miles, it drops significantly toward scrap value. This straight-line relationship between two factors—where changes in one variable cause a predictable increase or decrease in another—is the core concept behind Linear Regression . Deconstructing the Formula (Without the Headache) In high school math, you probably saw the classic line equation: y = mx + b In machine learning, Linear Regression uses this exact same formula to make predictions: Predicted Value (y) = ( Slope m × Input Feature x ) + Starting Point b Let's map this directly to our mechanic's garage evaluation: Target (y): The estimated resale price of the car ($). Input Feature (x): The total miles on the odometer. Starting Point / Intercept (b): The price of the car when mileage is 0 (Brand New MSRP). Slope / Weight (m): The rate of depreciation (e.g., losing $0.10 in value for every 1 mile driven). If a car starts at a baseline price of $30,000 and depreciates by $0.10 per mile, a car with 50,000 miles is predicted to be worth: Predicted Price = $30,000 - ($0.10 × 50,000) = $25,000 How the Algorithm Draws the Perfect Line: Least Squares If you plot 100 used cars on a graph where the horizontal axis (X) is Mileage and the vertical axis (Y) is Price, the dots won't form a perfectly straight laser line. Some owners took great care of their vehicles; others had minor scratches. So how does a Linear Regression algorithm draw the sin

SpaceX's AI revenue grew more than three times to $2.6 billion from the year before, mostly because of deals that the company made to provide compute to other AI companies, according to SpaceX's quarterly earnings. The AI division, which the company said in its documents to go public was the source of most of its […]

Have you ever had this happen? You're chatting with a friend about buying a new pair of shoes. A few hours later... Instagram shows you an ad for those exact shoes. Or maybe you're talking about planning a trip. Suddenly...Your feed is filled with hotel deals, flight offers, and travel videos. The first thought that comes to almost everyone's mind is: "𝐌𝐲 𝐩𝐡𝐨𝐧𝐞 𝐢𝐬 𝐥𝐢𝐬𝐭𝐞𝐧𝐢𝐧𝐠 𝐭𝐨 𝐦𝐞." 👀 Honestly... I've thought the same. And maybe you have too. But what if I told you that the truth is actually more fascinating than the myth? So... is your phone secretly listening? Probably not. Not because it can't. But because it usually doesn't need to. Think about it. Every day you leave behind hundreds of tiny digital clues. 🔍 What you search. ❤️ What you like. ⏱️ How long you watch a video. 🛒 What you browse. 📍 Where you go. 👥 Even who you interact with online. Individually...They don't say much. Together...They tell a story that's surprisingly accurate. A story about your habits. The scary part? AI doesn't need to hear your conversations. Sometimes...It already knows what you're likely to do next. Not because it can read your mind. But because it's incredibly good at recognizing patterns. And when a prediction is accurate enough... It starts to feel like magic. Or surveillance. Here's what fascinates me the most. The real superpower of modern AI isn't listening. It's predicting. And sometimes...Those predictions are so good that they make us question reality itself. The next time you think, "My phone is definitely listening to me." Ask yourself a different question. "How much of my digital behavior have I already shared without realizing it?" Because maybe...The microphone isn't the real story. Your patterns are. 💬 Have you ever had an experience that made you think your phone was listening to you? What happened? Takeaway : Technology doesn't always become powerful by knowing more. Sometimes... It becomes powerful by predicting better. Technology becomes less magical when you und

What the Unabomber, Steve Bannon’s tech guy, and Bernie Sanders taught me about the great data center backlash of 2026.

I started this project because an LLM annoyed me. I gave a very strong model 322 , a small Dota 2 drafting game. The choices looked like the kind of work a computer should enjoy: repeated packs of players and heroes, visible ratings, familiarity scores, chemistry, rerolls and a simulated tournament at the end. I was disappointed by how well the LLM did. I am not a Dota expert, and I had only started watching it occasionally again during the previous six months or year. I still seemed to be doing better. The interesting engineering question was not how to write a longer prompt. It was how to replace the card-by-card language-model judgement with a deterministic policy, then test that policy without confusing improvement with luck. A stochastic benchmark needs shared randomness The browser history gave us a useful irritation and almost no reliable comparison. My earlier manual record contained 50 runs with a 14% title rate. The LLM won once in nine attempts. Putting 14% beside 11% looks temptingly quantitative, but the random offers, rejected packs and opponent fields were not preserved. The samples were small, unpaired and produced under different choices. That is not a model benchmark. It is a reason to build one. The offline solver generated every random choice from indexed tapes. Policy A and policy B received the same player offers, hero samples, field candidates and tournament randomness for a given episode. We could then compare the paired result: did the new policy win this exact episode where the old policy lost it? This is the common-random-numbers idea in a practical form. Sharing the luck removes a large amount of noise that has nothing to do with the policy change. Keep the simulator separate from the policy Before evaluating a strategy, we reproduced the game. The public client and seven data files were frozen with SHA-256 hashes. Draft legality, automatic hero allocation, chemistry, scoring and the tournament were ported into a deterministic Python engi

Key takeaways Three engines, three internets: across the searches where all three answered, Google, Bing, and Brave agreed on the #1 result only 29% of the time, and Google and Bing shared just 3 of the top 10 on average. Each engine has a personality. Bing rewards traditional publishers (Forbes appeared in 9 of 15 top-10s, PCMag in 8). Google leans on its own properties and forums (Reddit and YouTube each showed up in 57% of Google SERPs, Wikipedia in 43%). Brave is a blend of both. The platforms Google loves, Bing ignores: Reddit, YouTube, and Wikipedia appeared in 0% of the Bing top-10s we checked. If you track rankings on one engine, you are blind on the others. Cross-engine divergence is the case for multi-engine SERP monitoring — not a single Google rank check. Everyone talks about "ranking on Google." But Google is not the only place your customers search, and the other engines do not agree with it — or with each other. We ran the same 15 searches through Google, Bing, and Brave using Crawlora's search APIs and compared the top 10 results. The short version: the three engines return strikingly different pages, reward different kinds of sites, and rarely even agree on what belongs at #1. How much do the engines overlap? For each search we took the top 10 result domains from each engine and counted how many they shared. No pair shares even half its results on average, and all three engines agree on fewer than 3 of 10: Engine pair Avg shared (of 10) Overlap Google ∩ Bing 3.0 30% Google ∩ Brave 5.1 51% Bing ∩ Brave 4.0 40% All three 2.7 27% A page ranking #3 on Bing might be nowhere on Google. If your rank tracker only watches one engine, most of this picture is invisible to you. They rarely agree on #1 The single most valuable position — the #1 organic result — matched across all three engines for only 2 of the 7 searches where every engine answered (29%). Here is the real head-to-head: Search Google #1 Bing #1 Brave #1 Agree? best running shoes runrepeat.com wi

Also: Cyborg diving suits for cockroaches, why sleepy sperm whales blow bubbles, Betelgeuse's companion star.

The risk of more debris hitting the moon is on the rise as the space race heats up.

Half the market is arguing about whether RAG or a semantic layer is the right foundation for enterprise AI. They are not competing. They answer different questions, and most teams need both. Two shapes of question Every question an agent receives breaks into one of two forms: "What did we say about X?" — lives in contracts, policies, tickets, docs. Unstructured. RAG was built for this. "What is true about X?" — lives in your warehouse and governed metrics. Structured. A semantic layer was built for this. Treating them as rivals is how teams end up with a system that can quote the pricing policy but cannot tell you this quarter's realised price. Where each one breaks RAG Semantic layer Good at Retrieving relevant prose Resolving definitions and joins Fails on Aggregation, math, current state Anything not modelled as data Permissions Flattened at ingest, rebuilt at query time Compiled per person, per query Answer stability Varies with retrieval ranking Identical by construction Audit story Cites a chunk Reproduces the exact SQL The permissions row is the one that ends pilots. A retrieval index that ingested everything has, by construction, assembled your most sensitive object — and reconstructing entitlement at query time is guesswork. The layer that actually decides Neither a document chunk nor a metric definition is worth much until something compiles it into a governed query and runs it. That is the piece most architectures are missing: intent → context resolution → constrained planning → governed execution . RAG can feed the first step. It cannot perform the last three. Point an agent at raw tables and the best models score in the low teens on real enterprise data. Give the same model compiled, governed context and it clears the high nineties. The retrieval quality was never the bottleneck. The full breakdown — the precise division of labour, why hybrid architectures win, and how compile-time governance closes the gap RAG cannot — is here: 👉 RAG vs. Semantic Layer

Industrializing the disassembly of an undocumented processor from a raw binary is a complex task that can be broken down into four key steps: Verify that the binary does not belong to a known processor. Verify that the binary is not obfuscated, compressed, or encrypted code for a known processor. Build an undocumented processor generator. Create the analysis pipeline and custom disassembler generation process. For the first phase of this project, the goal is to build dedicated, lightweight disassemblers—since, for bare-metal binaries, tools like Ghidra require manual processor target selection before analysis can begin. 1. Why Build a Custom Disassembler? To determine whether a binary was compiled for a specific architecture, the strategy consists of disassembling the binary (both statically and dynamically) against candidate instruction sets until: One or more bytes fail to match any valid instruction for that architecture, allowing us to rule it out. The disassembly succeeds completely. (Note: a successful disassembly does not guarantee that the binary was originally intended for that CPU; control flow validity must also be verified). Static disassembly is the first line of defense. However, if it fails due to obfuscation, compression, or encryption, we must escalate to dynamic execution and analysis. Only after systematically eliminating all known architectures can we confidently conclude that we are dealing with a custom or undocumented processor . 2. How to Build Your Custom Disassembler Before deploying heavy machinery for undocumented processors, the logical first step was to check against known architectures. Approach 1: Ghidra and SLAgh Ghidra relies on the SLAgh specification language and maintains an extensive library of processor definitions. The original plan was to leverage its API to extract a normalized opcode mapping table. However, after several attempts, Ghidra proved unsuitable for this specific pipeline for two reasons: Operand Type Loss: Detail

That's a rebuild I shipped. The system: a RAG assistant for fraud analysts — ask it "how do we handle card testing followed by a successful auth?" and it should answer from the team's own SOPs and case history. The complaint: the answers were wrong, therefore the model must be dumb, therefore procurement should buy a bigger model. The model was fine. It was answering perfectly — from garbage context. Walk the forensic trail with me, because every step is checkable on your own system this week. Exhibit A: the chunking was destroying meaning before anything was embedded The ingestion split SOP documents every N characters, mid-sentence. Which means half the vectors in the index encoded fragments like this: chunk_147 = " ...ing to a freight forwarder. In these cases, do NOT " chunk_148 = " cancel the order immediately. First verify the customer via " The policy — don't cancel, verify first — exists in no single chunk. An embedding can't encode a meaning that isn't in its input. Retrieval was being asked to find semantics the pipeline had already shredded. Fix one: chunk on structure (sections, paragraphs), never on character counts, with enough overlap that no rule straddles a boundary. Exhibit B: dense-only retrieval, bimodal queries Fraud analyst queries split into two populations: pattern questions ("high-value order, new account, rushed shipping") and identifier questions ("what's the SOP for decline code 4863?", "rule VEL-013 rationale"). The system was dense-only — and embeddings treat a rare token like 4863 as noise, so identifier queries retrieved similar-feeling chunks instead of the literal match. Half the query population was structurally doomed regardless of model quality. Fix two: hybrid retrieval — BM25 for the identifiers, embeddings for the patterns, reciprocal rank fusion to merge. Exhibit C: nobody could see any of this, because quality was a rumor No golden dataset. No retrieval metric. The system's accuracy was whatever the loudest anecdote said it

From how galaxies form to the beginnings of the universe, the images from the space telescope are giving cosmologists new data to explore—and theories to build out.

Everything you need to know about the solar eclipse and lunar eclipse that will occur in August 2026.

大模型来了，有个说法是如果一个问题容易验证 那么ai就容易学会解决！说说这个特性与p np问题的关联性 这个说法听起来很直观，但其实 混淆了"验证的复杂性"和"学习/求解的复杂性"这两件不同的事 。我们把它拆开看。 先把"容易验证"在 P/NP 里的精确定位理清 在计算复杂度理论中： NP = 给定候选解（证书），能在多项式时间内验证其正确性的问题 P = 能在多项式时间内直接求解的问题 P ≠ NP ? = 是否所有容易验证的问题，也都容易求解？ 所以"容易验证"在 CS 里的严格含义是： 验证者在多项式时间内工作 ， 不是说 AI 训练成本低 。 "容易验证 ⇒ AI 容易学会"——部分成立，但有重要的限定 这个直觉 在某些场景下确实成立 ，原因是"验证"提供了 稠密的训练信号 ： ✅ 成立的情形：验证器可作奖励/过滤 当一个问题具备"易于验证"的结构时，我们可以用它来： 生成训练数据 ：比如 SAT 问题，随机生成一个赋值，代入公式验证，正确就得到一对 (公式, 赋值) 训练样本—— 数据无限且免费 RL 中的奖励塑形 ：LLM 生成代码 → 编译器/单元测试验证 → immediate reward Self-play / 自我蒸馏 ：AlphaGo 等用模拟器验证落子结果 Verifier-Guided Search ：用"易于验证"的判据引导 beam search / MCTS，如 AlphaCode、AlphaGeometry 💡 这就是为什么像 代码生成、形式化证明、数学解题 这些领域近期进展飞快——它们都有"相对容易的验证器"（单元测试、类型检查器、证明校验器）。 ❌ 但这个推论远非普遍成立 "容易验证"≠"AI 容易学会"，有几个关键原因： 1. 验证器只给二值信号，梯度稀疏 验证器通常只输出 0/1（对/错），而深度学习需要平滑的损失曲面。对于复杂的 NP 问题，绝大多数随机猜测都是错的 → 奖励恒为 0 → 梯度消失，学不到东西 。这就是"稀疏奖励"难题。 2. P ≠ NP 意味着：验证简单 ≠ 求解简单 即使验证是 O(n)，找到那个能通过验证的解可能仍需 O(2ⁿ)。AI 模型本质上是在做启发式搜索，面对组合爆炸， 没有 free lunch 。例如： 数独：验证 O(n²)，但最难的数独对人类和 AI 都极具挑战 TSP：验证一条回路 O(n)，但找最优回路是 NP-Hard 3. 分布偏移与泛化 NP 问题的"容易验证"是** worst-case 复杂度**意义下的。AI 学到的是训练分布的统计规律，遇到分布外的实例会失效。比如 LLM 在数学竞赛题上表现好，但换个数字或换种表述就可能崩。 4. 验证本身也可能不在 NP 里 很多现实问题是 PSPACE 或更难 （如围棋先手胜负），验证一个"策略"需要指数时间——这种问题连"提供证书让 AI 模仿"都很困难。 一张对照表 问题类型 验证复杂度 AI 易学吗？ 例子 P 类 多项式 通常容易 （有高效算法可直接教） 排序、最短路径 NP-Complete，且有稠密验证信号 多项式 中等 （RL + 验证器有效） SAT、数独、TSP 近似 NP-Complete，但验证信号稀疏 多项式 困难 （奖励太稀） 某些密码学难题 超出 NP（PSPACE 等） 超多项式 极难 （验证本身就很贵） 围棋先手胜、QSAT 不可判定 不存在 不可能 （理论上限） 程序等价性 真正的关联在哪里 "容易验证 ⇒ AI 容易学会"更准确的说法应该是： 📌 如果一个问题有"多项式时间的验证器"，并且我们能从中提取稠密的训练信号（如 partial credit、逐步验证），那么 AI 可以通过"生成 + 验证"的循环去逼近求解。 这本质上就是 用 NP 的"验证侧"去攻击"求解侧" ——也是当前 LLM + Verifier 范式（如 RLHF 中的 reward model、AlphaProof 的 formal verifier）的理论基础。 但要注意： 这不是 P=NP 的证明，AI 找到的解在 worst-case 仍可能不是最优的 AI 解决的是 平均情况（average-case） 或 特定分布 ，而非 worst-case 一旦问题规模增大到超出训练分布，性能会急剧下降 一个更深的视角：平均-case 复杂度 理论计算机科学里有个分支叫 Average-Case Complexity ，研究"典型实例"的难度。很多 NP-Complete 问题在 average-case 下其实有不错启发式算法——这也解释了为什么 AI 在某些 NP 问题上表现惊喜，但在 adversarial 构造的 hard instance 上翻车。 所以回到你的说法： "

"We believe that a capture of Swift, an attempted capture of Swift, is very much in the cards."

More EVs reaching the end of their life means more batteries to recycle. But waste management companies have yet to catch up to the new reality.

Tracking smells in turbulent air takes a keen sense of direction and sharp memory.

A discovery in a solar system 73 light-years from Earth is challenging definitions and “blurring the lines between stars, planets, and moons.”