We use a bath of chaotic surface waves in water to mechanically and macroscopically mimic the thermal behavior of a short articulated chain with only nearest-neighbor interactions. The chaotic waves provide isotropic and random agitation to which a temperature can be ascribed, allowing the chain to passively explore its degrees of freedom in analogy to thermal motion. We track the chain in real time and infer end-to-end potentials using Boltzmann statistics. We extrapolate our results, by using Monte Carlo simulations of self-avoiding polymers, to lengths not accessible in our system. In the long chain limit we demonstrate universal scaling of the statistical parameters of all chains in agreement with well-known predictions for self-avoiding walks. However, we find that the behavior of chains below a characteristic length scale is fundamentally different. We find that short chains have much greater compressional stiffness than would be expected. However, chains rapidly soften as length increases to meet with expected scalings.Anyone who has ever put the wrong weight motor oil into a car engine can attest to the fact that the length of a chain molecule largely determines its mechanics [1]. A low-weight oil may be too thin and a high-weight oil too viscous for efficient operation. Biopolymers such as DNA also evidence changing mechanical behavior with changing length. Recent work shows that short strands are far more flexible than would be expected from simply scaling down the behavior of long strands [2]. Understanding this scale dependence in polymers is crucial to creating new materials, as is being done with polymer thin films [3, 4] and so-called "DNA origami" [5,6]. Polymer mechanics is well explored in the coarse-grained sense, with many established methods for direct measurement [7][8][9] and simulation [10][11][12][13]. However, there is scant experimental evidence directly relating whole polymer mechanical properties to behavior at the single bond level. These questions have been addressed in macroscopic granular polymer studies [14,15] however such systems lack a thermodynamic temperature, muddying the link to true thermal systems. Statistical physics predicts [16], and empirical studies confirm [17] that the end-to-end potential of a sufficiently long polymer chain is harmonic, regardless of the microscopic interactions. Similarly, universalities are predicted for the scaling of statistical parameters (i.e., variance and mean) of both bond winding angle [18] and linear dimension [19,20] in a polymer chain when considered as a self-avoiding walk (SAW). While this is a powerful and robust result regarding the chain-scale mechanics, it does little to elucidate the behavior towards the monomer scale, as it does not address short chains.In this paper we build a macroscopic analog to polymer physics in a bottom-up fashion which allows us to observe not only chain-scale but also true monomer-scale behavior. We find that short polymer chains exhibit behavior fundamentally different than that predicted for thei...