Jonathan, the roughly 190-year-old tortoise shown on St Helena’s 5 pence coin, prompted commenters to marvel at tortoise life: one recounted how a vet rescued Fredrik after a fight left him overturned, and mentioned another mishap during mating. Some wondered why evolution had not made tortoises better at righting themselves. Replies argued that a large shell may make flipping less likely even as it makes recovery harder, and that natural selection involves trade-offs. One commenter suggested a belly sensor to alert staff if a tortoise flips; another joked that attaching a device could itself be uncomfortable.
The website-access complaints widened into a debate about online security. One commenter blamed Cloudflare and surveillance-driven consolidation for making ordinary browsing frustrating; another said this particular challenge was not Cloudflare’s and defended its checks as better than alternatives. Visitors also traded memories and travel advice about St Helena and Tristan da Cunha: St Helena’s airport has made it easier to reach, while Tristan remains a weather-dependent sea journey. One commenter recalled visiting while their father worked as the island’s dentist, and another shared a long-standing wish to visit both islands.
Summary generated by AI from the linked article. hn.today is not affiliated with Hacker News or Y Combinator.
![A simplified proof of ETH is False [pdf]](https://hntoday.pixelshot.io/screenshots/20261027/4cf93cef081f42a3_tn.jpeg)
The Exponential Time Hypothesis (ETH) conjectures that certain problems cannot be solved in subexponential time. A paper shows that a simplified argument claiming to prove ETH is false. (shivakintali.github.io)
Imagining movements activates many of the same brain systems as performing them, though signals to the muscles are inhibited. Studies show mental practice can improve motor learning and performance, complementing physical training. (nautil.us)
![The Exponential Time Hypothesis Is False [pdf]](https://hntoday.pixelshot.io/screenshots/20261026/eac4664270214aef_tn.jpeg)
The Exponential Time Hypothesis says that 3-SAT cannot be solved in subexponential time. The paper argues that this hypothesis is false, challenging a common assumption in computational complexity. (github.com)
OpenAI worked with academic researchers on a result challenging the Exponential Time Hypothesis, a major conjecture about how quickly certain computational problems can be solved. The work presents evidence that the hypothesis is false. (openai.com)
Early NASA spacesuits used custom-fitted diapers, requiring male astronauts to provide measurements so the garments would fit securely. The sizing process became an awkward but practical part of preparing for spaceflight. (chron.com)
Neanderthals and other human relatives had sophisticated abilities, and ancient DNA shows some were absorbed into modern humans through interbreeding. Their disappearance raises unresolved questions about why Homo sapiens became the only surviving human species and how much that outcome owed to ability or chance. (nytimes.com)
Today's best Hacker News stories, summarized and screenshotted, one email a day.