Author Archives: Eann Patterson

Walking the hills

daffodils at moel famauA regular reader of this blog commented last week on the enjoyment she gained during the pandemic from their daily walk around a local lake which reminded me about a recent experience on one of our regular weekend hikes around Moel Famau, which have been real rather than virtual for some months now [see ‘Virtual ascent of Moel Famau‘ on April 8th, 2020].  It was an unseasonally warm day and there was a strong scent from the daffodils in the broad verge next to the farm track that we were walking down.  The impact of the scent on my sense of well-being was almost like a form of synaesthesia [see ‘Engineering synaesthesia‘ on September 21st, 2016].  I am on vacation this week, hoping to slow down [see ‘Slow down, breathe your own air‘ on December 23rd 2015], climb some hills and feed my consciousness some different sensory experiences [see ‘Feed your consciousness with sensory experiences‘ on May 22nd 2019].

Dwelling in the present

Photograph of St Michael's Church, Stoke Gifford

St Michael’s Church, Stoke Gifford

I have been visiting the Airbus site at Filton near Bristol since the mid-1990s. It is where the wings for new designs of aircraft are developed and tested. My involvement has been in the developing of techniques for measuring strain in aircraft structures during static and fatigue tests. At the moment, we are working on methods to integrate fields of measurements with computational predictions of stress and strain [see ‘Jigsaw puzzling without a picture‘ on October 27th, 2021]. I frequently travel by train to Bristol Parkway Station and walk past the church in the photograph without even noticing it despite it being next to the station. To be fair, the view of it from the station entrance is obscured by a billboard. However, last week as I walked back to the station with a half-hour to spare, I noticed a gate leading into a churchyard. I slipped through the gate thinking that perhaps there might be an interesting old church to explore but it was locked and I had to be satisfied with a stroll around the churchyard. I was slightly shocked to realise the church, and the village green beyond it, had been hidden in full view for more than thirty years of walking within a few tens of metres of it perhaps once a month. I had always been too focussed on the research that I was heading to Airbus to discuss, or too tired at the end of a day, to notice the things around me. Our senses flood our brains with information most of which is ignored by our conscious minds that are busy time traveling through past memories or looking into the future [see ‘Time travel and writing history‘ on March 23rd, 2022].  However, there is pleasure to be gained by dwelling in the present and exploring the sensory experience flooding into our brains.  As Amy Liptrot commented in her book ‘The Outrun‘, “the more I take the time to look at things, the more rewards and complexity I find”.

Sources:

Enuma Okoro, The Pleasure Principle, FT Weekend, 19 February/20 February 2022.

Mia Levitan, Descent into digital distraction, FT Weekend, 5 March/6 March 2022.

 

From nozzles and diffusers to stars and stripes

Schematic diagram of explanation in textAt the end of a lecture on energy flows in my first year undergraduate course on thermodynamics, I talk about nozzles and diffusers as examples of practical applications of the rest of the material in the lecture.  It is hazardous to sit in the front row of the lecture theatre because I take in a water bottle with a trigger spray to demonstrate how the nozzle increases the velocity of the fluid at the expense of pressure while gently sprinkling water on the front row.  I am always intrigued by the symmetry of nozzles and diffusers.  Diffusers increase pressure of a fluid at the expense of its velocity, i.e., a mirror image of the action of a nozzle.  The cross-sections are also mirror images because a nozzle has a cross-section that decreases in the flow direction while a diffuser has a cross-section that increases in the flow direction.  At least for sub-sonic flows, because the shapes are reversed for super-sonic flow; so a sub-sonic nozzle looks like a super-sonic diffuser and a sub-sonic diffuser looks like a super-sonic nozzle.  If that all sounds like fluid mechanics then the thermodynamic message is that, in nozzles and diffusers, the rates of heat and work transfer are approximately zero while the change in the kinetic energy of the fluid is very large.  I finish the lecture with a video clip of a school quartet of trombones playing ‘Stars and Stripes Forever’ which wakes up the students who have slept through the lecture and allows me to point out the diffusers (bell of the trombone) transmitting acoustic pressure.

You can watch the video clip on YouTube at https://www.youtube.com/watch?v=mHw8P8NnUvI

Time travel and rewriting history

decorative paintingI have written in the past about consciousness being an accumulation of sensory experiences [see ‘Is there are real ‘you’ or ‘I’? on March 6th, 2019].  Our memory consists of fragments of images, sounds, smells and feelings from the past that we can re-assemble into a complete experience often triggered by something in the present that resembles a fragment of a past experience.  We can time travel in our minds by thinking about the past.  It is so ubiquitous that we barely stop to think about it. Yet, we are fascinated by the possibility of time travel into the future.  However, our subconscious minds are constantly time traveling into the future [see ‘Predicting the future through holistic awareness’ on January 6th, 2021].  They are constantly making predictions about what will happen next, whether anticipating the path taken by a ball so that your hand can be positioned to catch it or picking up an umbrella as you leave the house so that you do not get soaked when it rains later in the day.  The further we attempt travel into the future the less dependable our predictions become and I suspect the same is true for travel backwards in time.  The reliability of our recollection of past experiences become less as time and entropy erode the connections between the fragments in our mind so that we struggle to reassemble all of the fragments in the correct order and our personal history is unintentional rewritten.

Source:

Stefan Klein, We are all stardust, Melbourne: Scribe, 2015  (a conversation with Hannah Monyer on memory entitled ‘Do You Remember?’).