testing MuJoCo 4.0 on a towel-folding scene I built for @watonomous! this is a big advance for rollouts in deformable object manipulation.

I scripted a trajectory that folds the towel in half, then ran the same scene on 3.14, 3.17 and 4.0 to see what changed.

Upgrading also drops the old 50-contact cap (it landed in 3.16), so cloth stops sinking into the table.

I dropped a 1 kg ball onto the towel. On 3.14 it punched through to the table: the towel held 6% of its weight. On 4.0 it held 100%.

With every particle in contact (486 contacts vs 50), the whole towel sits on lf of it sinking in, so the gripper has a real edge to slide under. That should make grasping easier.

Not towel-related, just a 4.0 elasticity/plasticity feature I found interesting: yield lets a sheet keep a crease.

I pinned one edge of two identical stiff sheets, folded both in half the same way and let go. The elastic one sprang back open; the one with yield stayed folded.

calm project simulating humanity's next 10000 years in spatial conquest:
- Seeded Markov sim, zoomable from the whole universe to one person.
- 3-layer decoder-only transformer with handwritten backprop in TypeScript and no ML libraries. Tokens are decades.
- PPO self-play ht frozen earlier versions of themselves and get smarter over the centuries.

-> apparently Dyson spheres aren't meta
-> bars are still a thing in 11876
-> opus 100% grokked while training on the hunger games movies 💀

see if we reach Andromeda: 2soon2026.vercel.app

plz don't roast it was for a hacky i believe in non-determinism

built with goat @shaomng

built an autonomous wet lab @Hack_Harvard with @nkimmer_17, @jerryli_design and nehal 🧪🤖

Devpost: devpost.com/software/autoc…
Github: github.com/shaoming11/hh-…
Youtube: youtube.com/watch?v=eKyWVe…

the hardware: two open-source SO-101 arms, an Arduino Mega, a $10 load cell, hobby servos and 3D-printed parts. ~$300 in parts

ui: a live MuJoCo digital twin that mirrors the real arms' encoders

we built the harness for robotic swarms
@HackTheNorth

built with @theraytan @VedantSheel @_jasondeng

(early prototype)

> our budget:
- 3 robot cars at $50 each
- went dumpster diving to build out the cardboard field

> hardware stack:
- one camera per car, no encoders, no lidar, all run from one laptop

we trained a VLA to make sandwiches.

last week, at the battle of the schools hackathon, hosted by @WATaiTeam and @UTMIST1, we built the Brackey Way, winning 1st in the robotics track 🏆

demo: youtube.com/watch?v=gxXGyd…
devpost: devpost.com/software/the-b…
- recorded on 100 episodes using meta quest
- imitation learning to fine-tune pi0's foundation model
- detected lettuce with HSV segmentation
- used a finite state machine to sequence tasks (bread -> lettuce -> bread)

built with @AydanLing, @notmaxxx__, @kaitlynchuchu

thank you @bracketbot for helping us troubleshoot throughout the event + lending us GPU clusters at 4 in the morning 🥹