Ask HN: The government of my country blocked VPN access. What should I use?

959 points by rickybule 15h ago 535 comments

Ask HN: What to learn for math for modeling?

32 points by shivajikobardan 2d ago 14 comments

Apple App Store Review Mess

2 points by markatkinson 1h ago 0 comments

Ask HN: What to do when you suspect your interview is with a state operative?

15 points by puppycodes 7h ago 1 comments

Ask HN: Why hasn't x86 caught up with Apple M series?

433 points by stephenheron 3d ago 616 comments

Best up-to-date guides on Vibe Coding

2 points by grigy 4h ago 0 comments

Staying up to date on the best AI dev workflow?

4 points by peapod91 6h ago 0 comments

Ask HN: How much better can the LLMs become assuming no AGI

2 points by yalogin 9h ago 3 comments

Ask HN: How can I recover and run my old mobile game from the 2010s?

56 points by diasks2 4d ago 46 comments

Ask HN: Anyone working on bringing software back from US clouds?

8 points by sam_lowry_ 18h ago 6 comments

Ask HN: Services for Shutting Down a Startup?

2 points by Felicia_Juhn 11h ago 4 comments

Ask HN: Where can I see a live octopus in Maine?

7 points by Octopus88 13h ago 1 comments

Ask HN: How to teach a 4 year old to code?

5 points by kamphey 8h ago 8 comments

CompactifAI Inference API

3 points by Compactifai 15h ago 0 comments

Ask HN: Did modern AI's coding abilities make you lose interest in programming?

30 points by amichail 1d ago 42 comments

Ask HN: What are the best Google alternatives in 2025?

15 points by eel 1d ago 4 comments

Anthropick.com Redirects to ChatGPT

13 points by nerdcortex 1d ago 2 comments

Ask HN: What to Do with Old iPads?

30 points by owenmakes 2d ago 19 comments

Ask HN: GitHub Copilot down?

58 points by thecopy 1d ago 21 comments

Petition to stop Google from restricting sideloading and FOSS apps

275 points by nativeforks 21h ago 181 comments

Ask HN: Best codebases to study to learn software design?

103 points by pixelworm 5d ago 90 comments

Units of Economics of LLMs. Reply to Ed Zitron's "AI Is a Money Trap"

6 points by tudorizer 2d ago 8 comments

Ask HN: Does sentience put stress on the brain?

7 points by trinsic2 2d ago 7 comments

Ask HN: Is there a temp phone number like temp email?

9 points by piratesAndSons 2d ago 11 comments

Ask HN: How to Learn to Build Agentic AI Systems (Like Claude Code)

8 points by hhimanshu 1d ago 4 comments

Out of curiosity: what kind of people use this "forum" (I mean Hacker News)?

21 points by adinhitlore 2d ago 28 comments

Ask HN: Windows 11 Update Fail – Linux Distro Suggestions?

4 points by giardini 15h ago 7 comments

Ask HN: Why are so many services rejecting Google Voice numbers for signups?

13 points by electric_muse 2d ago 19 comments

Ask HN: What measures are you taking to stop AI crawlers?

6 points by kjok 1d ago 14 comments

Ask HN: Is backlink trading still a problem worth solving?

3 points by sathishn 1d ago 2 comments

Ask HN: What should I use to run React Native tests on a device?

4 points by dboreham 2d ago 0 comments

Stop squashing your commits. You're squashing your AI too

4 points by jannesblobel 2d ago 10 comments

Ask HN: Are AI filters becoming stricter than society itself?

29 points by tsevis 5d ago 16 comments

Ask HN: I just abandoned my PyCharm subscription, what should I use now?

23 points by jmward01 4d ago 23 comments

Ask HN: Any experienced devs who use AI extensively in their work?

3 points by atleastoptimal 2d ago 4 comments

Ask HN: How do you find early stage startups to join

44 points by gavino 6d ago 23 comments

Rupert's Property

54 robinhouston 8 8/28/2025, 10:02:28 PM johncarlosbaez.wordpress.com ↗

Comments (8)

Strilanc · 5h ago

Oh damn, in this year's sigbovik, Tom7 was trying to find out if shapes were Rupert or not: https://sigbovik.org/2025/proceedings.pdf#page=346

robinhouston · 2h ago

I believe that the name ‘Noperthedron’ for this new polyhedron that has been proven not to be Rupert was given in homage to tom7’s coinage ‘Nopert’ in that SIGBOVIK paper.

dwrensha · 6h ago

Last month, before this result came out, the question "Is Every Convex Polyhedron Rupert?" was added as a formal Lean statement to Google's Formal Conjectures repository:

https://github.com/google-deepmind/formal-conjectures/blob/1...

I wonder how feasible it would be to formalize this new proof in Lean.

robinhouston · 1h ago

Interesting. My guess is that it's not prohibitively hard, and that someone will probably do it. (There may be a technical difficulty I don't know about, though.)

David Renshaw recently gave a formal proof in Lean that the triakis tetrahedron does have Rupert's property: https://youtu.be/jDTPBdxmxKw

yorwba · 3h ago

The most annoying bit might be that they use different, though equivalent, definitions of the property, so you would also need to formalize the proof of the equivalence of definitions.

karmakaze · 5h ago

Intuitively not surprising as the property doesn't hold for a sphere which can be approximated. But there's a world of difference between intuition and proof, especially on the edge.

I would hope there are others with more faces that don't have the property and this could have the fewest faces.

pavel_lishin · 10h ago

I could have sworn that Matt Parker did a video on this as well, but I couldn't find one.

jerf · 6h ago

https://youtu.be/gPIRLQZnRNk , 7:20 specifically for cubes.

I knew I'd seen it before too so you nerd-sniped me.