When the Simulator Becomes the Curriculum
TL;DR for operators A simulator can generate effectively unlimited trajectories. That does not automatically make those trajectories useful training data for a reasoning model. Sim2Reason turns simulated mechanics into questions with answers that can be checked automatically, then uses those questions for reinforcement-learning post-training. The reported transfer is substantial enough to matter operationally: on Qwen2.5-32B, International Physics Olympiad mechanics accuracy rose from 19.8% to 25.2%. By contrast, supervised fine-tuning on 200,000 teacher-generated trajectories lowered the same score to 15.9%. ...