Diving into three-dimensional fluids

My research group has been working for some years on methods that allow straightforward comparison of large datasets [see ‘Recognizing strain’ on October 28th 2015].  Our original motivation was to compare maps of predicted strain over the surface of engineering structures with maps of measurements.  We have used these comparison methods to validate predictions produced by computational models [see ‘Million to one’ on November 21st 2018] and to identify and track changes in the condition of engineering structures [see ‘Out of the valley of death into a hype cycle’ on February 24th 2021].  Recently, we have extended this second application to tracking changes in the environment including the occurance of El Niño events [see ‘From strain measurements to assessing El Niño events’ on March 17th, 2021].  Now, we are hoping to extend this research into fluid mechanics by using our techniques to compare flow patterns.  We have had some success in exploring the use of methods to optimise the design of the mesh of elements used in computational fluid dynamics to model some simple flow regimes.  We are looking for a PhD student to work on extending our model validation techniques into fluid mechanics using volumes of data from measurement and predictions rather than fields, i.e., moving from two-dimensional to three-dimensional datasets.  If you are interested or know someone who might be interested then please get in touch.

There is more information on the PhD project here.

You can only go there in your head

“Inner space and outer space are similar, aren’t they really?  You’re never going to get to the edge of the universe in a spaceship.  You might as well try going on a bus.  You can only go there in your head.”  This is a quote from David Hockney in ‘Spring Cannot Be Cancelled‘  by David Hockney and Martin Gayford.  It’s a beautiful book.  Full of thought-provoking insights and recent artwork by Hockney painted in Normandy mainly during the pandemic.  I read it last month while in the Yorkshire Dales [see ‘Walking the hills‘ on April 13th 2022].  Hockney writes about his need to paint.  He finds it utterly absorbing and endlessly sustaining.  Gayford compares this need and experience to the work of American psychologist, Mihaly Csiksczentmihalyi [see ‘Slow-motion multi-tasking leads to productive research‘ on September 19, 2018] who wrote about concentration so intense that there is no spare capacity to think about anything else, your self-consciousness disappears and you lose your sense of time leading to a deep sense of happiness and well-being.  I cannot paint but I can achieve something approaching a similiar state when I am writing.

Source:

Martin Gayford and David Hockney, Spring cannot be cancelled – David Hockney in Normandy, London: Thames & Hudson, 2021.

Existential connection between capitalism and entropy

global average temperature with timeAccording to Raj Patel and Jason W Moore, in his treatise ‘Das Kapital’ Karl Marx defined capitalism as combining labour power, machines and raw materials to produce commodities that are sold for profit which is re-invested in yet more labour power, machines and raw materials.  In other words, capitalism involves processes that produce profit from an economic perspective, and from a thermodynamic perspective produce entropy because the second law of thermodynamics demands that all real processes produce entropy.  Thermodynamically, entropy usually takes the form of heat dissipated into the environment which raises the temperature of the environment; however, it can also be interpreted as an increase in the disorder of a system [see ‘Will it all be over soon?’ on November 2nd, 2016].  The ever-expanding cycle of profit being turned into capital implies that the processes of producing commodities must also become ever larger.  The ever-expanding processes of production implies that the rate of generation of entropy also increases with time.  If no profit were reinvested in economic processes then the processes would still increase the entropy in the universe but when profit is re-invested and expands the economic processes then the rate of entropy production increases and the entropy in the universe increases exponentially – that’s why the graphs of atmospheric temperature curve upwards at an increasing rate since the industrial revolution.  As if that is not bad enough, the French social economist, Thomas Piketty has proposed that the rate of return on capital, “r” is always greater than the rate of growth of the economy, “g” in his famous formula “r>g”.  Hence, even with zero economic growth, the rate of return will be above zero and the level of entropy will rise exponentially.  Piketty identified inequality as a principal effect of his formula and suggested that only cataclysmic events, such as world wars or revolutions, can reduce inequality.  The pessimistic thermodynamicist in me would conclude that an existential cataclysmic event might be the only way that this story ends.

Sources

Raj Patel & Jason W. Moore, A history of the world in seven cheap things, London: Verso, 2018.

Thomas Piketty, A brief history of equality, translated by Steven Rendall, Harvard: Belknap, 2022.

Diane Coyle, Piketty the positive, FT Weekend, 16 April/17 April 2022.

Image: Global average near surface temperature since the pre-industrial period from www.eea.europa.eu/data-and-maps/figures/global-average-near-surface-temperature

Fancy a pint of science?

In September I am planning to initiate a new research project on the interaction of bacteria with cellular and hard surfaces.  It is in collaboration with Jude Curran and is co-funded by Unilever and the Biotechnology and Biological Sciences Research Council.  We have already used the optical method of caustics in a microscope to track and characterise the movement of synthetic nanoparticles as small as 3 nm in an array of biologically-relevant solutions [see ‘Nano biomechanical engineering of agent delivery to cells’ on December 15th, 2021].  We have also used the same technique to characterise and quantify the motion and growth of bacteria in solutions.  Now, we plan to use caustic signatures as a label-free tracking technology for pre-clinical testing of antimicrobial solutions and coatings.  We plan to start by considering binding and removal of viral particles and bacterial spores from hard and soft laundry surfaces using various bacterial species, including Staph aureus which is responsible for laundry malodour; before progressing to the interaction of bacteria with human oral and skin cell cultures.  We are in the process of recruiting a suitable PhD student so if you are interested or know someone who might be suitable then get in touch.  If you want to learn more about our tracking technology and fancy a pint of science, then join us in Liverpool in May for part of the world’s largest festival of public science.  I will be talking about ‘Revealing the invisible: real-time motion of virus particles’  on May 10th at 7.30pm on Leaf of Bold Street.

Liverpool Pint of Science programme

UK Pint of Science programme