SearcharxivSearch

arXiv subjects

Travis Smith

Publications and source records attributed to Travis Smith.

3 recordsLinked to original sources

The Little Scientist: LLM Agent-Driven Discovery via the Scientific Method

What happens when you teach an LLM-based agent the scientific method? Motivation: Scientific discovery emerges from cycles of hypothesis, implementation, empirical testing, and feedback. Can this process be automated? We approach automated algorithm design through the lens of the scientific method, where an LLM-based agent goes through each step of the process in an ordered, iterative fashion. Results: We present The Little Scientist, a framework in which a "Scientist agent" works inside an evaluation environment that benchmarks its code and returns structured per-instance diagnostics. When the Scientist plateaus at a local optimum, a "Kuhn agent" injects a paradigm-shifting conjecture paired with a cross-disciplinary inspiration, forcing exploration of a different region of the LLM's latent space. We demonstrate the framework on two problems that require fundamentally different modes of discovery. For protein fitness prediction, the Scientist discovered Delta V, an ensemble calibration strategy that ranks first on the ProteinGym DMS Substitutions Zero-Shot leaderboard across all five official evaluation metrics, exceeding the #2 model (VenusREM) by +0.033 mean Spearman correlation across 217 DMS assays. For DNA motif discovery, the Scientist wrote an algorithm from scratch--DALE (Dual-seed Algorithm for Latent Enumeration)--that outperforms STREME (the default in the MEME Suite) across 132 ENCODE transcription factors (mean AUROC 0.842 vs. 0.803, Wilcoxon p < 10^{-6}) while running 11x faster. This demonstrates that the framework can produce genuinely novel algorithms, not just optimize existing components. Together, these results show that an LLM agent stepping through the scientific method can discover both new algorithms and new ensemble strategies that outperform prior solutions. The entire research program consumed 704M tokens on a single virtual machine with no GPUs

q-bio.QM

The Wide Field Imager (WFI) Instruments for the Polarimeter to Unify the Corona and Helliosphere (PUNCH)

We describe the design, hardware integration, and calibration performance of the Wide-Field Imager (WFI) instruments for the Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission. The WFI instruments are a trio of visible-light heliospheric imagers that, together, view the outer corona and solar wind from under 3.5{\deg} to over 47{\deg} from the Sun, via sunlight that is Thomson-scattered from free electrons. In flight, the WFIs are arranged so that their collective fields of view form an approximately symmetric trefoil on the sky, comprising three circular-truncated square fields spaced 120{\deg} apart in position angle. The WFIs work with the NFI instrument, described elsewhere, to implement the full PUNCH field spanning all solar position angles, at elongations from 1.5{\deg} to 47{\deg} from disk center. WFI is implemented using dioptric (lens) optics and deep multi-stage baffles that attenuate solar, planetary, and lunar stray light sufficiently for ground processing to reveal the faint signal for the primary science. WFI measures both total brightness (tB) and polarized brightness (pB), via an on-board polarizing filter wheel (PFW) and charge-coupled device (CCD) camera that share a common design with those of the NFI instrument.

astro-ph.IM

Fracture mechanical behavior of polymers: 1. Amorphous glassy state

Theoretical analyses and experiments have been carried out to investigate fracture behavior of glassy polymers. Our birefringence measurements quantify the local stress buildup at cut tip during different stages of drawing. Based on polymethyl methacrylate (PMMA), bisphenol A polycarbonate (PC) and polyethylene terephthalate (PET), we find several key results beyond the existing knowledge base. (1) The inherent fracture and yield strengths sigma_F(inh) and sigma_Y(inh) differ little in magnitude from the breaking and yield stress (sigma_b and sigma_y). (2) Stress intensification (SI) near a pre-through-cut builds up deviates from the theoretical description of linear elastic fracture mechanics (LEFM) upon approaching the cut tip. (3) SI meets a natural cutoff below which stress ceases to increase. (4) The stress stip at cut tip shows a trend of approximate linear increase with the far-field load s0 for all three polymers and different cut size a. (5) A characteristic length scale P emerges from the linear relation between stip and KI. For these glassy polymers, P is on the order of 0.1 mm. (6) Fracture toughness of brittle polymers is characterized by critical stress intensity factor K_Ic = sigma_F(inh)(2*pi*P)1/2, revealing relevance of the two crucial quantities. (7) The critical energy release rate GIc for brittle glass polymers such as PMMA is determined by the product of its work of fracture wF (of uncut specimen) and P. (8) The elusive fractocohesive length Lfc defined in the literature as G_Ic/w_F naturally arises from the new expression for G_Ic as stated in (7), i.e., it is essentially P. These results suggest that a great deal of future work is required to acquire additional understanding with regards to fracture and failure behaviors of plastics.

cond-mat.soft