What’s Going On with These Mines?

Expanding mine surface area in red in 2005, 2010, 2015, and 2020 from the Landsat Operational Land Imager 8. Chinaka et al, Remote Sensing 15,18 (2023).

Geoscientists at the University of Delaware have discovered some decisively odd mining activity at the China-Myanmar border. They used machine learning and remote sensing technology from the Landsat 5 and 8 satellite missions to track changes in the surface of two rare earth mines on either side of the border. In contrast to what Chinese policies say, they found that the mining area increased by about 2.5 square kilometres from 2005 to 2020.Press release here, paper here.

Move over LHC: This particle accelerator is just 10 cm long

This episode of Science News covers a new technology for particle accelerators, called plasma wakesurfing. It has the potential to dramatically decrease the size of particle accelerators.

Helix Beams Illuminate Periodic Surfaces

Doughnut beams with orbital angular momentum are used to investigate surfaces with repeating patterns. Source: Wang et al, Optica 10, 9, 1245 (2023).

Physicists at the University of Colorado, Boulder, have created doughnut-shaped beams of light and used them to study periodic surfaces (with repeating patterns). Photographing this kind of repeating surface in detail has been challenging for scientists because it’s hard to disentangle the periodicity of the surface from that of the light waves. The team overcame this difficulty by using beams with orbital angular momentum. Those are created by suitably correlating the phases of the light’s wavefront, so that it twists around the beam axis in a helix. When the beams then interact with the periodic surface, the phases of the waves in the beam diverge, and the interference pattern carries information about the surface. This new method can be used to detect anomalies and defects in periodic grids with over twice the accuracy of previous techniques. Press releases here and here, paper here.

Science, with style.

Nautilus is where you'll find rigorous science, written with impeccable style. Our newsletter will light up your emotions, introduce you to a delightfully weird and surprising mix of big ideas, and do it alongside original award-winning art. It's like your favorite professor, in leather pants.

CO2 Is Higher Now Than Ever In The Past 14 Million Years

Levels of CO2 as measured via proxy indicators for the past 66 million years. Source: The CenCO2PIP Consortium, Science 382, (2023).

Climate scientists have analysed a collection of proxy carbon indicators to reconstruct atmospheric carbon dioxide levels of the past 66 million years. The result is the most complete carbon history to date. It reveals that the last time atmospheric carbon dioxide level reached today’s level was 14 million years ago, much longer ago than scientists previously thought. They found a high Earth System Sensitivity of 5-8 °C – that’s the warming following a doubling of CO2 levels. However, this value cannot directly be compared with the often-quoted Equilibrium Climate Sensitivity for Climate Models, because the reconstruction of this past data only allows the computation averages over long durations. Press release here, paper here.

Science and the law come into conflict more often than you might think. In this episode, I want to tell you about several cases that I have followed which have concerned me greatly. The issue here isn't the actual scientific evidence, but rather the way that scientists pursue and discuss this evidence, usually in a straightforward and frank manner that doesn't sit well with courts. You can take the quiz here. 

Our podcast “Science with Sabine” is available on Spotify, Amazon, Apple, Castbox, Google Podcasts, Pocket Casts, and Radio Public.