The study reveals that three consecutive years of drought contributed to the ‘Barbarian Conspiracy’, a pivotal moment in the history of Roman Britain. Researchers argue that peripheral tribes took advantage of famine and societal breakdown caused by an extreme period of drought to inflict crushing blows on weakened Roman defences in 367 CE.

The researchers used oak tree-ring records to reconstruct temperature and precipitation levels in southern Britain during and after the ‘Barbarian Conspiracy’. They found that southern Britain experienced an exceptional sequence of remarkably dry summers from 364 to 366 CE, with average monthly reconstructed rainfall in the main growing season (April-July) falling to just 29mm in 364 CE.

The drought-driven grain deficits would have reduced the grain supply to Hadrian’s Wall, providing a plausible motive for the rebellion there which allowed the Picts into northern Britain. The study suggests that given the crucial role of grain in the contract between soldiers and the army, grain deficits may have contributed to other desertions in this period.

The researchers argue that military and societal breakdown in Roman Britain provided an ideal opportunity for peripheral tribes, including the Picts, Scotti, and Saxons, to invade the province en masse with the intention of raiding rather than conquest. Their finding that the most severe conditions were restricted to southern Britain undermines the idea that famines in other provinces might have forced these tribes to invade.

Ultimately, the researchers argue that extreme climate conditions lead to hunger, which can lead to societal challenges, and eventually outright conflict. The relationship between climate and conflict is becoming increasingly clear in our own time, making these findings relevant not only for historians but also for policymakers and researchers today.

When two materials come into contact, charged entities on their surfaces get a gentle nudge. This phenomenon is what creates static electricity when you rub a balloon against your skin. Similarly, water flowing over certain surfaces can gain or lose charge. Researchers have now harnessed this effect to generate electricity from rain-like droplets moving through a tube.

The study’s corresponding author, Siowling Soh, explains that the new flow pattern used in their setup – plug flow – generates a substantial amount of electricity. “Water that falls through a vertical tube can produce enough power to light 12 LEDs,” says Soh. This breakthrough could allow rain energy to be harvested for generating clean and renewable electricity.

Unlike traditional hydroelectricity, which is limited to locations with large volumes of water like rivers, this new system uses smaller channels that rainwater can pass through. The researchers designed a simple setup where water flowed out the bottom of a tower through a metallic needle, spurring rain-sized droplets into a 12-inch-tall and 2-millimeter-wide vertical polymer tube.

As the droplets collided at the top of the tube, they created a plug flow – short columns of water interspersed with pockets of air. As the water flowed down the inside of the tube, electrical charges separated, generating electricity. The team collected the water in a cup below the tube and placed wires to harvest the energy.

The plug flow system converted more than 10% of the energy of the water falling through the tubes into electricity, which is five orders of magnitude more than traditional charge separation methods. In another experiment, the researchers found that moving water through two tubes simultaneously generated double the energy. Using this information, they channeled water through four tubes and powered 12 LEDs continuously for 20 seconds.

The researchers believe that plug flow energy could be simpler to set up and maintain than hydroelectric power plants and more convenient for urban spaces like rooftops. They acknowledge funding from various organizations in Singapore and look forward to further developing this innovative technology.

The safety of our drinking water is often taken for granted, but a recent study from Washington University in St. Louis reveals that even seemingly harmless substances can pose significant risks when combined during the treatment process. Inactive ingredients in agricultural products, such as herbicides and fertilizers, have long been considered inert and thus, non-threatening to human health. However, researchers Jean Brownell and Kimberly Parker have discovered that these chemicals can be converted into hazardous byproducts known as nitrosamines during water disinfection.

Brownell’s investigation found that amines, used as stabilizing agents in herbicides to increase solubility and reduce drift, may be more important than active agents in herbicides when it comes to forming DBPs linked to various health risks. The study suggests that these inactive ingredients could enter the environment at rates similar to precursors from pharmaceuticals, which is a significant concern given their potential impact on water treatment processes.

The implications of this research are far-reaching and require immediate attention. As agricultural practices change, it’s essential to reevaluate our assumptions about herbicide use and its effects on drinking water quality. Brownell’s analysis confirms that shifting trends in herbicide formulation and use necessitate a closer look at nitrosamine precursors. These studies need to be done at specific locations and times of year to account for variations across space and time, which can be large and impactful.

The importance of collecting and sharing high-quality data from farmers and agencies across regions cannot be overstated. This information is crucial for developing consistent best practices for water and food safety. As Parker noted, “This paper raises questions that require more work to find answers.” Indeed, it does, but the potential consequences of inaction are too great to ignore.

The time has come to rethink our assumptions about agricultural runoff and its impact on drinking water quality. We need to evolve our studies and question our assumptions to ensure what we’re assuming is either truly generalizable or alternatively, needs to be applied to local areas. The future of our health and safety depends on it.