标签：#science

On Saturday, at around 2:06 pm ET, a meteor streaked over the northeastern US and exploded north of Cape Cod Bay. The fireball was caught on camera by several people, shook houses, and can even be seen clearly in satellite imagery, lighting up the sky. Some residents initially thought that the shaking and boom may […]

As temperatures rise, some creatures pick fights while others struggle to learn.

From specialized motors to the use of machine learning algorithms, Turkey’s billion-dollar hair-transplant industry is the result of a constant process of innovation.

A crack in an aircraft window, a fracture starting at a bolt hole, a shaft that snaps at the shoulder where the diameter steps down. These failures share a cause that has nothing to do with the average load the part carries. The metal broke because a change in geometry concentrated stress into a tiny region, and that local peak — not the nominal stress — drove the crack. This article explains the stress concentration factor: what it means, where the classic value of 3.0 comes from, how to apply it, and the mistakes that make engineers underestimate the danger of an innocent-looking hole. Why this calculation matters Real parts are not smooth bars. They have holes for fasteners, fillets where sections change, keyways, grooves, threads, and shoulders. Every one of those features disturbs the flow of stress through the material. Where the lines of force have to bend around an obstacle, they crowd together, and the local stress climbs well above the value you would compute from force divided by area. The stress concentration factor, K_t, is the multiplier that captures this. It matters most for two failure modes. Under static loading of a brittle material, the peak stress can trigger fracture before the bulk of the section yields. Under cyclic loading, the concentrated stress is where fatigue cracks nucleate — and the vast majority of fatigue failures begin at a geometric discontinuity. If you size a part on nominal stress alone and ignore K_t, you have skipped the step where most failures are actually decided. The core formula The stress concentration factor is defined as a simple ratio: K_t = sigma_max / sigma_nom Here sigma_max is the true peak stress at the discontinuity and sigma_nom is the nominal stress computed from elementary mechanics. The subscript t means "theoretical" — K_t depends only on geometry and loading mode, not on the material. It comes from elasticity theory, finite element analysis, or experiment, and it assumes the material is still behaving ela

A new book looks into the long history of people who have opposed vaccines.

A walk in the cemetery led to Cornell researchers discovering an underground colony of bees with an estimated population of 5.5 million—one of the largest ever recorded.

The activewear giant has used chemical recycling to make jersey for 16 teams competing in the tournament. But the technique is unlikely to help solve fashion’s waste issue.

What is nbwipers? nbwipers is a CLI tool that strips outputs and metadata from Jupyter notebooks before git commit. Written in Rust - faster than nbstripout Supports git clean filter Works with .ipynb files Why use it? Jupyter notebooks store cell outputs inside the .ipynb file (JSON). This causes problems: Noisy diffs - output changes pollute every commit Repo size - images and large outputs bloat the repo Security - sensitive data can leak in outputs (API keys, query results) The solution: strip outputs automatically on git add via a clean filter. Why not nbstripout? nbstripout is written in Python. It is slow - git status , git diff , and git add all became noticeably slow on this repo because nbstripout was invoked for every .ipynb file. The main cause is Python startup time. With 100+ notebooks, nbstripout can take 40+ seconds where a Rust-based tool takes ~1 second. Faster alternatives: Tool Language Notes nbstripout-fast Rust Up to 200x faster; no git filter install support nbwipers Rust Inspired by nbstripout-fast; adds git filter + pyproject.toml config nbwipers is essentially nbstripout-fast with better git integration. Switching to nbwipers fixed the slowness. Setup 1. Install felixgwilliams/nbwipers is now in the aqua registry as of v4.517.0 . Using aqua , add to aqua.yaml : packages : - name : felixgwilliams/nbwipers@v0.6.2 Then run: aqua install 2. Configure git filter Run once per repo (writes to .git/config ): git config filter.nbwipers.clean "nbwipers clean -" git config filter.nbwipers.smudge cat git config filter.nbwipers.required true Or edit .git/config directly: [filter "nbwipers"] clean = nbwipers clean - smudge = cat required = true required = true makes the commit fail if nbwipers is not installed. This prevents accidentally committing outputs. 3. Add .gitattributes In the repo root, add .gitattributes : *.ipynb filter=nbwipers **/.ipynb_checkpoints/*.ipynb !filter **/.virtual_documents/*.ipynb !filter The !filter lines exclude checkpoint an

Peer review now optional, political staff would screen grants for forbidden topics.

The Pentagon awarded SpaceX a $4.16 billion contract to build missile-tracking satellites linked with President Donald Trump's planned "Golden Dome" defense system, as reported earlier by Bloomberg. In an announcement on Friday, the US Space Force says the sensor-equipped satellites will allow it to detect and track targets from space. The Elon Musk-owned SpaceX - […]

They seem to reorganize their tissues and then just keep living.

The detonation of the New Glenn rocket resulted in a huge fireball in Florida and may have long-term implications for the company's ambitions.

A new crew launched to China's Tiangong space station, and one of the astronauts will stay for a year.

While Blue Origin investigates the root cause behind last night's spectacular explosion of its New Glenn rocket, it's already clear that this will be a major setback for NASA's Moon base plans and Amazon's fledgling Leo space internet constellation. The incident occurred at about 9pm at Blue Origin's Florida launch site during a hot-fire test, […]

Everyone can build it. Almost no one can afford to run it at scale. And the companies selling the picks and shovels are about to get undercut by the same forces they unleashed. by VEKTOR Memory — 20 min read How This Article Started: 20 Forums, 40 Headlines, and a Growing Sense That Everyone Was Confused I woke up to clear skies and the sun finally shining, and I set out to understand this idea, the truth behind it, and the nagging suspicion that the narrative around AI and software costs had become so loud, so uniform, and so confidently confusing that someone needed to sit down and actually go through it. No tweets, or are they now X's? No LinkedIn thought leader infomercials, no Substack hype, just actual research and deep thoughts. So I spent time reading, collating data. Forums, whitepapers, LinkedIn posts, Hacker News threads, VC essays, Reddit arguments. I went looking for the real signal underneath the noise. What I found instead was the full spectrum of human overconfidence, lots of moat real estate. On one end: the hype machine at full throttle. “Software is going to zero.” “A solo dev can now build what a 50-person team built in 2021.” “The era of the $500/month SaaS subscription is over.” “Vibe coding will replace your entire engineering org.” These headlines were everywhere. Breathless. Confident. Shared tens of thousands of times, this angle gets views, of course, the algorithm loves being fed claps, shares, comments, and reposts. Most were written by people who had a very good Tuesday with Codex, Windsurf, Claude and Cursor and decided that instant dev, open source to Github and getting oodles of stars, maybe even roping in a celebrity, was now the permanent condition of software development. “We are now famous on GitHub!" Very hipster, very vibes, see you on the playa.. On the other end: the backlash. Experienced engineer, people with 15 to 25 years in production systems are pushing back hard. “Show me the vibe-coded app that survived its first real

Most scraping projects start by finding a website to scrape. This one started from the opposite direction: I knew the data existed as official government downloads, and my job was to make it accessible via a clean API. The data source Ofsted (the UK school inspections body) publishes monthly management information as CSV files on GOV.UK. The file covers all 22,000+ state-funded schools in England with their latest inspection grades, local authority, postcode, phase, and size data. It's 16 MB, published under the Open Government Licence v3.0 — explicitly permitting commercial use. No scraping needed. No authentication. Just a CSV download and some parsing logic. The architecture The actor is deliberately simple: Fetch the GOV.UK stats page to find the current month's CSV URL (the URL hash changes with each release) Download the CSV (~16 MB from assets.publishing.service.gov.uk ) Parse it with csv-parse Apply the user's filters (name, local authority, region, postcode prefix) Push matching records to the Apify dataset No Crawlee. No browser. No proxy. Just fetch() and a CSV parser. const match = html . match ( /href=" ( https: \/\/ assets \. publishing \. service \. gov \. uk \/[^ " ] +latest_inspections_as_at [^ " ] + \. csv ) "/ ); That one regex does the URL discovery. The GOV.UK page lists files in reverse chronological order, so the first match is always the latest release. The interesting part: Ofsted changed their grading system mid-build I built this in May 2026. In November 2025, Ofsted scrapped their 20-year-old four-word judgement system (Outstanding / Good / Requires Improvement / Inadequate) and replaced it with a report card format — six separate grade areas, each on a five-point scale: Exceptional Strong Expected standard Needs attention Urgent improvement Plus a standalone Safeguarding verdict (Met / Not met). The April 2026 CSV reflects this change entirely. There's no "Overall effectiveness" column. Schools inspected before November 2025 have null gr

If it scales up, it can help us diversify our sources of a key element.

Amazon is turning a corner with its launch providers, but ULA's Vulcan remains grounded.

Iron-rich immune cells in the liver may act as sensors for magnetic fields, serving as an internal compass.

The Centers for Research in Emerging Infectious Diseases were launched during the Covid-19 pandemic. The group lost its funding under Trump in part due to conspiracy theories.