Electrically charged volcanic ash short-circuited Earth’s atmosphere in 1815, causing global poor weather and Napoleon’s defeat, says new research.
Historians know that rainy and muddy conditions helped the Allied army defeat the French Emperor Napoleon Bonaparte at the Battle of Waterloo. The June 1815 event changed the course of European history.
Two months prior, a volcano named Mount Tambora erupted on the Indonesian island of Sumbawa, killing 100,000 people and plunging Earth into what became know as a ‘year without a summer’ in 1816.
Victor Hugo in the novel Les Miserables said of the Battle of Waterloo: “an unseasonably clouded sky sufficed to bring about the collapse of a World.” Now we are a step closer to understanding Tambora’s part in the Battle from half a world away.
Now, Dr. Matthew Genge from Imperial College London has discovered that electrified volcanic ash from eruptions can “short-circuit” the electrical current of the ionosphere—the upper level of the atmosphere that is responsible for cloud formation.
The findings, published in 2018 in Geology, could confirm the suggested link between the eruption and Napoleon’s defeat.
Dr. Genge, from Imperial’s Department of Earth Science & Engineering, suggests that the Tambora eruption short-circuited the ionosphere, ultimately leading to a pulse of cloud formation. This brought heavy rain across Europe that contributed to Napoleon Bonaparte’s defeat.
The paper shows that eruptions can hurl ash much higher than previously thought into the atmosphere—up to 100 kilometers above ground.
Dr. Genge said: “Previously, geologists thought that volcanic ash gets trapped in the lower atmosphere, because volcanic plumes rise buoyantly. My research, however, shows that ash can be shot into the upper atmosphere by electrical forces.”
Levitating Volcanic Ash
A series of experiments showed that that electrostatic forces could lift ash far higher than by buoyancy alone. Dr. Genge created a model to calculate how far charged volcanic ash could levitate and found that particles smaller than 0.2 millionths of a meter in diameter could reach the ionosphere during large eruptions.
He said: “Volcanic plumes and ash both can have negative electrical charges and thus the plume repels the ash, propelling it high in the atmosphere. The effect works very much like the way two magnets are pushed away from each other if their poles match.”
The experimental results are consistent with historical records from other eruptions.
Weather records are sparse for 1815, so to test his theory, Dr. Genge examined weather records following the 1883 eruption of another Indonesian volcano, Krakatoa.
The data showed lower average temperatures and reduced rainfall almost immediately after the eruption began, and global rainfall was lower during the eruption than either period before or after.
Ionosphere Disturbances and Rare Clouds
He also found reports of ionosphere disturbance after the 1991 eruption of Mount Pinatubo, Philippines, which could have been caused by charged ash in the ionosphere from the volcano plume.
In addition, a special cloud type appeared more frequently than usual following the Krakatoa eruption. Noctilucent clouds are rare and luminous and form in the ionosphere. Dr. Genge suggests these clouds therefore provide evidence for the electrostatic levitation of ash from large volcanic eruptions.
The paper, entitled, “Electrostatic levitation of volcanic ash into the ionosphere and its abrupt effect on climate,” by Matthew J. Genge, is published in Geology. This study was funded by the Science and Technology Facilities Council.
By Caroline Brogan
Could Nanoparticles from Tea Leaves Destroy Cancer Cells?
Nanoparticles derived from tealeaves inhibit the growth of lung cancer cells, destroying up to 80% of them; new research by a joint team from Swansea University in Wales of the United Kingdom and India has shown.
The team made the discovery while they were testing out a new method of producing a type of nanoparticle called quantum dots. These are tiny particles, which measure less than 10 nanometers. A human hair is 40,000 nanometers thick.
Although nanoparticles are already used in healthcare, quantum dots have only recently attracted researchers’ attention. Already they are showing promise for use in different applications, from computers and solar cells to tumor imaging and treating cancer.
Quantum dots can be made chemically, but this is complicated and expensive and has toxic side effects. The Swansea-led research team was therefore exploring a nontoxic, plant-based alternative method of producing the dots, using tea leaf extract.
Tealeaves contain a wide variety of compounds, including polyphenols, amino acids, vitamins, and antioxidants. The researchers mixed tealeaf extract with cadmium sulphate (CdSO4) and sodium sulphide (Na2S) and allowed the solution to incubate, a process which causes quantum dots to form. They then applied the dots to lung cancer cells.
The researchers found:
- Tealeaves are a simpler, cheaper, and less toxic method of producing quantum dots, compared with using chemicals, confirming the results of other research in the field.
- Quantum dots produced from tea leaves inhibit the growth of lung cancer cells. They penetrated into the nanopores of the cancer cells and destroyed up to 80% of them. This was a brand new finding and came as a surprise to the team.
The research, published in Applied Nano Materials in 2018, is a collaborative venture between Swansea University experts and colleagues from two Indian universities.
Dr Sudhagar Pitchaimuthu of Swansea University, lead researcher on the project, and a Ser Cymru-II Rising Star Fellow, said: “Our research confirmed previous evidence that tea leaf extract can be a nontoxic alternative to making quantum dots using chemicals. The real surprise, however, was that the dots actively inhibited the growth of the lung cancer cells. We hadn’t been expecting this. The CdS quantum dots derived from tealeaf extract showed exceptional fluorescence emission in cancer cell bioimaging compared to conventional CdS nanoparticles. Quantum dots are therefore a very promising avenue to explore for developing new cancer treatments. They also have other possible applications, for example in anti-microbial paint used in operating theaters, or in sun creams.”
Dr. Pitchaimuthu outlined the next steps for research: “Building on this exciting discovery, the next step is to scale up our operation, hopefully with the help of other collaborators. We want to investigate the role of tealeaf extract in cancer cell imaging, and the interface between quantum dots and the cancer cell. We would like to set up a “quantum dot factory” which will allow us to explore more fully the ways in which they can be used.”
Sound Waves Levitate Multiple Objects—Technology for Touchless Medical Procedures
In the perhaps not so distant future, surgeons could perform a range of medical procedures all without touching the patient.
Surgeons won’t be shrunk and sent into the body like in the 1960s Sci-Fi, Fantastic Voyage, but could program a specialized array of mini-speakers to create an intricate sound field that ‘traps’ and manipulates selected objects in ‘acoustic tweezers’ for manipulation within tissue.
Advancements in acoustic tweezers from Professor Bruce Drinkwater in the Department of Mechanical Engineering, University of Bristol, UK and his colleague Dr. Asier Marzo, from Universidad Publica De Navarra in Spain, are driving the technology towards this futuristic-sounding reality. The team’s recent developments, published in December in the Proceedings of the National Academy of Sciences (PNAS), demonstrate for the first time the acoustic levitation and manipulation of multiple objects simultaneously.
Professor Drinkwater envisions an iteration of this system eventually being used to acoustically stitch up internal injuries or deliver drugs to target organs. He said: “Now we have more versatility—multiple pairs of hands to move things and perform complex procedures; it opens up possibilities that just weren’t there before.”
Sound exerts a small acoustic force and by turning up the volume of ultrasonic waves, too high pitched for humans to hear, scientists create a sound field strong enough to move small objects. Now Professor Drinkwater and Dr. Marzo have enabled the efficient generation of sound fields complex enough to trap multiple objects at the target locations.
Dr. Marzo explained: “We applied a novel algorithm that controls an array of 256 small loudspeakers—and that is what allows us to create the intricate, tweezer-like, acoustic fields.”
Acoustic tweezers have similar capabilities to optical tweezers, the 2018 Nobel Prize winner, which uses lasers to trap and transport micro-particles. However, acoustic tweezers have the edge over optical systems when it comes to operating within human tissue.
Lasers only travel through transparent media, making them tricky to use for applications within biological tissue. On the other hand, ultrasound is routinely used in pregnancy scans and kidney stone treatment as it can safely and noninvasively penetrate biological tissue.
Another advantage is that acoustic devices are 100,000 times more power efficient than optical systems. Professor Drinkwater explained: “Optical tweezers are a fantastic technology but always dangerously close to killing the cells being moved; with acoustics we’re applying the same sort of forces but with way less energy associated. There’s lots of applications that require cellular manipulation and acoustic systems are perfect for them.”
To demonstrate the accuracy of their system, the scientists attached two millimetric polystyrene spheres to a piece of thread and used the acoustic tweezers to “sew” the thread into a piece of fabric. The system can also simultaneously control the 3D movement of up to 25 of these spheres in air.
The team is confident that the same methodology could be adapted to in-water particle manipulation in approximately one year. They hope that soon after, it could be adapted for use in biological tissue.
Dr. Marzo explained: “The flexibility of ultrasonic sound waves will allow us to operate at micrometer scales to position cells within 3D printed assemblies or living tissue. Or on a larger scale, to levitate tangible pixels that form a physical hologram in mid-air.” The paper’s name is: “Holographic Acoustic Tweezers” by A. Marzo, and B.W. Drinkwater. The project has been funded by the UK Engineering and Physical Science Research Council (EPSRC).
CAPTION: Researcher tests acoustic traps generated by the ‘Holographic Acoustic Tweezers.’ (Sergio Larripa, Asier Marzo, Bruce Drinkwater)