Forecasting the progression of human civilization on the Kardashev Scale through 2060 with a machine learning approach.

Energy has been propelling the development of human civilization for millennia. Humanity presently stands at Type 0.7276 on the Kardashev Scale, which was proposed to quantify the relationship between energy consumption and the development of civilizations. However, current predictions of human civilization remain underdeveloped and energy consumption models are oversimplified. In order to improve the precision of the prediction, we use machine learning models random forest and autoregressive integrated moving average to simulate and predict energy consumption on a global scale and the position of humanity on the Kardashev Scale through 2060. The result suggests that global energy consumption is expected to reach ~ 887 EJ in 2060, and humanity will become a Type 0.7449 civilization. Additionally, the potential energy segmentation changes before 2060 and the influence of the advent of nuclear fusion are discussed. We conclude that if energy strategies and technologies remain in the present course, it may take human civilization millennia to become a Type 1 civilization. The machine learning tool we develop significantly improves the previous projection of the Kardashev Scale, which is critical in the context of civilization development.

A bimodal distribution of haze in Pluto's atmosphere.

Pluto, Titan, and Triton make up a unique class of solar system bodies, with icy surfaces and chemically reducing atmospheres rich in organic photochemistry and haze formation. Hazes play important roles in these atmospheres, with physical and chemical processes highly dependent on particle sizes, but the haze size distribution in reducing atmospheres is currently poorly understood. Here we report observational evidence that Pluto's haze particles are bimodally distributed, which successfully reproduces the full phase scattering observations from New Horizons. Combined with previous simulations of Titan's haze, this result suggests that haze particles in reducing atmospheres undergo rapid shape change near pressure levels ~0.5 Pa and favors a photochemical rather than a dynamical origin for the formation of Titan's detached haze. It also demonstrates that both oxidizing and reducing atmospheres can produce multi-modal hazes, and encourages reanalysis of observations of hazes on Titan and Triton.

Surface Mapping of Earth-like Exoplanets using Single Point Light Curves.

Spatially resolving exoplanet features from single-point observations is essential for evaluating the potential habitability of exoplanets. The ultimate goal of this protocol is to determine whether these planetary worlds harbor geological features and/or climate systems. We present a method of extracting information from multi-wavelength single-point light curves and retrieving surface maps. It uses singular value decomposition (SVD) to separate sources that contribute to light curve variations and infer the existence of partially cloudy climate systems. Through analysis of the time series obtained from SVD, physical attributions of principal components (PCs) could be inferred without assumptions of any spectral properties. Combining with viewing geometry, it is feasible to reconstruct surface maps if one of the PCs are found to contain surface information. Degeneracy originated from convolution of the pixel geometry and spectrum information determines the quality of reconstructed surface maps, which requires the introduction of regularization. For the purpose of demonstrating the protocol, multi-wavelength light curves of Earth, which serves as a proxy exoplanet, are analyzed. Comparison between the results and the ground truth is presented to show the performance and limitation of the protocol. This work provides a benchmark for future generalization of exoplanet applications.

Xiamenmycin attenuates hypertrophic scars by suppressing local inflammation and the effects of mechanical stress.

Hypertrophic scarring is a common disease affecting millions of people around the world, but there are currently no satisfactory drugs to treat the disease. Exaggerated inflammation and mechanical stress have been shown to be two main mechanisms of excessive fibrotic diseases. Here we found that a benzopyran natural product, xiamenmycin, could significantly attenuate hypertrophic scar formation in a mechanical stretch-induced mouse model. The compound suppressed local inflammation by reducing CD4+ lymphocyte and monocyte/macrophage retention in fibrotic foci and blocked fibroblast adhesion with monocytes. Both in vivo and in vitro studies found that the compound inhibited the mechanical stress-induced profibrotic effects by suppressing proliferation, activation, fibroblast contraction, and inactivating FAK, p38, and Rho guanosine triphosphatase signaling. Taken together, the compound could simultaneously suppress both the inflammatory and mechanical stress responses, which are the two pivotal pathological processes in hypertrophic scar formation, thus suggesting that xiamenmycin can serve as a potential agent for treating hypertrophic scar formation and other excessive fibrotic diseases.