Hacker News

New stories

Live mirror
30 storiesupdated just nowView source snapshot
  1. Show HN: Font Generator(ufontgenerator.com ↗)
    discuss
  2. The Long Doomsday of A.I.(newyorker.com ↗)
    discuss
  3. Claude Cowork and chat are now one Claude(claude.com ↗)
    discuss
  4. We Must Create the Shit Machine(mcsweeneys.net ↗)
    discuss
  5. WAP – World Action Protocol(github.com/world-action-protocol ↗)
    discuss
  6. Show HN: C. Build with AI. Keep the Experience(cleanroom-qvq1xbb8o-ag3497120s-projects.... ↗)
    discuss
  7. Show HN: The Bill You Don't See Coming: AWS Extended Support Surcharges(greenops.cloud ↗)
    discuss
  8. I sent Google proof of a bot farm. They called it "normal user behavior."(dayzlegame.com ↗)
    discuss
  9. Tin: A Text INdex for Postgres(planetscale.com ↗)
    discuss
  10. Nano Empire – Open-source MCP gateway with x402 micropayments and A2A routing(run.app ↗)
    discuss
  11. NHTSA Orders Tesla to Provide Answers on Cybercab Certification(driveteslacanada.ca ↗)
    1comments
  12. Show HN: A free search console for grant making(charitysense.com ↗)
    discuss
  13. The Temple of (online) Techno — MMO Rave World(hallucinate.site ↗)
    discuss
  14. Mice with human brain cells offer a tool to study disease(npr.org ↗)
    1comments
  15. Show HN: YOLO FPS-per-dollar numbers for edge AI boards ($75-$215)(github.com/chorylee ↗)
    discuss
  16. GPT-6 Astra Controlling Blender for VFX(twitter.com/ryanvogel ↗)
    discuss
  17. Venus may have swallowed its own moon(sciencedaily.com ↗)
    discuss
  18. AI must not outrun safety controls, DeepMind co-founder warns(ft.com ↗)
    discuss
  19. Backflip: Apple now wants to train AI models with user data after all(heise.de ↗)
    discuss
  20. Nvidia's AI Climate hoax – report(ketanjoshi.co ↗)
    discuss
  21. Introducing the DeepMind Institute(deepmind.com ↗)
    discuss
  22. Setting Up Pi with DeepSeek v4.1 Flash on OpenRouter(vincentschmalbach.com ↗)
    discuss
  23. Brainrotposts: The Fruit Fly Judges Your Shit Posts(brainrotposts.com ↗)
    discuss
  24. The Volatile Finances of Airline Pilots, America's Unpredictable Millionaires(wsj.com ↗)
    discuss
  25. Debris Found in Yemen Suggests Saudi Arabia Fired Its First Chinese Missile(wsj.com ↗)
    discuss
  26. Code Is Crap(googleblog.com ↗)
    6comments
  27. Neuroprosthesis for paralysis enables simultaneous speech and body language(nih.gov ↗)
    discuss
  28. In the Age of AI, Some in China Wonder If Learning English Is Worth the Trouble(nytimes.com ↗)
    discuss
  29. Show HN: Rockbox and Doom on iPod nano 3rd gen(twitter.com/freemyipod ↗)
    discuss
  30. Show HN: KiwiDesk – Tiling that feels like it shipped with macOS(github.com/kiwicanopy ↗)
    discuss

Show HN: Why is a fly so hard to swat?

1 pointsby 45m agoflyswat.win
1 comments
45m agoHN ↗

I was at my desk when a large and very loud fly started circling my head and tapping the screen. I swatted it but missed every time, so I casually asked my AI assistant why. That kicked off an interesting thread.

I was surprised to learn that a fly does not curve. It flies a straight run, turns 90 degrees in 0.05s, then flies straight again (Wagner 1986 for houseflies; Tammero and Dickinson 2002 for fruit flies).

I also learned that each straight section has random duration (obstacles excepted). The pattern is exponential, which makes it very hard to predict. Watching it for longer really doesn't help.

Human reaction time is 0.15s at the fast end, so even if you guess correctly, it may still be gone. However, you still have a chance, which is why we keep coming back, in the game and in real life.

The resting fly research is Card and Dickinson (2008). It shifts position to jump away from the swatter and is off the wall in 0.2s, before your arm has moved. So standard advice is to aim a little ahead of where it faces.

The parameters are printed on the page. Depth is not modeled and the page says so.

20 swats, then you see your percentage score. I'm getting better, but still top out at about 25%.

It's plain JavaScript with no framework and no dependencies. Tests are node --test with nothing to install. No cookies... because they attract flies :)