Category Archives: Soapbox

Thinking in straight lines is unproductive

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I suspect that none of us think in straight lines.  We have random ideas that we progressively arrange into some sort of order, or forget them.  The Nobel Laureate, Herbert Simon thought that three characteristics defined creative thinking: first, the willingness to accept vaguely defined problems and gradually structure them; second, a preoccupation with problems over a considerable period of time; and, third, extensive background knowledge. The first two characteristics seem strongly connected because you need to think about an ill-defined problem over a significant period of time in order to gradually provide a structure that will allow you to create possible solutions.    We need to have random thoughts in order to generate new structures and possible solutions that might work better than those we have already tried out; so, thinking in straight lines is unlikely to be productive and instead we need intentional mind-wandering [see ‘Ideas from a balanced mind‘ on August 24th, 2016].   More complex problems will require the assembling of more components in the structure and, hence are likely to require a larger number of neurons to assemble and to take longer, i.e. to require longer and deeper thought with many random excursions [see ‘Slow deep thoughts from planet-sized brain‘ on March 25th, 2020] .

In a university curriculum it is relatively easy to deliver extensive background knowledge and perhaps we can demonstrate techniques to students, such as sketching simple diagrams [see ‘Meta-knowledge: knowledge about knowledge‘ on June 19th, 2019], so that they can gradually define vaguely posed problems; however, it is difficult to persuade students to become preoccupied with a problem since many of them are impatient for answers.  I have always found it challenging to teach creative problem-solving to undergraduate students; and, the prospect of continuing limitations on face-to-face teaching has converted this challenge into a problem requiring a creative solution in its own right.

Source:

Simon HA, Discovery, invention, and development: human creative thinking, Proc. National Academy of Sciences, USA (Physical Sciences), 80:4569-71, 1983.

New horizons

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Along with many people, I have been working from home since mid-March and it seems likely that I will be doing so for the foreseeable future.  Even if a vaccine is discovered for COVID-19, it will take many months to vaccinate the population.  For the first few months of lockdown, I worked on an old workbench in the basement of our house; however, now I have an office set up in the attic and the picture above is the view from my desk.  It certainly has eye-stretching potential but it is also frustrating because I can see the roof of the building in which my university office is located.  However, the lockdown in the UK has been relaxed and so we are going on holiday to Cornwall where we will be walking sections of the South West Coastal Path and reading a pile of books.  If you want experience the walking with us then I recommend reading ‘The Salt Path‘ by Raynor Winn [see ‘The Salt Path‘ on August 14th, 2019]. Although I will be indulging in a digital detox [see ‘Digital detox with a deep vacation‘ on August 10th, 2016] combined with some horizon therapy [see ‘Horizon therapy‘ on May 4th, 2016], the flow of posts to this blog will be uninterrupted because lock-down has allowed me write sufficient pieces in advance to maintain the publishing schedule.

I noticed that both of the posts cited above about the importance of relaxing were published in 2016, along with Steadiness and Placidity on July 171th, 2016.  2016 must have been a stressful year!

Balancing conscious and unconscious life

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Recently, I visited a local artist to choose a painting for a birthday present.  He showed me a pair of small oil paintings in which I had expressed an interest via photographs he had sent me by email.  I agreed to buy both of them and then we drifted into his studio where he showed me the pieces he was working on.  There were many unfinished paintings and he described how difficult it was to finish some of them.  He measured the time taken on some of them in months and, for a few, in years.  I was struck by the similarity with scientists who indulge in slow-motion multi-tasking and switch between research projects in different fields, often leaving something unfinished to focus on something else and then returning to pursue the original research topic [‘Slow-motion multi-tasking leading to productive research‘ on September 19th, 2018].  I suspect both artists and scientists who indulge this approach are looking to achieve ‘a perfect balance of their conscious and unconscious life’ out of which Barbara Hepworth believed ideas are born and realized [see ‘Ideas from a balanced mind‘ on August 24th, 2016].

The studio in the photograph is Barbara Hepworth’s in St Ives, Cornwall.

Physical actions to inhibit COVID-19 infection

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Figure 4 from Ai & Melikov, 2017

Politicians in many countries are fond of claiming that they are following scientific advice when telling us what we can or cannot do in an effort to prevent the spread of the coronavirus, COVID-19.  However, neither they nor the journalists who report their statements tell us what scientists have actually established.  So, I have been reading some of the literature.

A paper by Leung et al [1] published this month in Nature Medicine reports that surgical face masks could prevent transmission of human coronavirus and influenza viruses from symptomatic individuals.  Their conclusions were based on a study of 246 individuals ranging in age from 11 to more than 65 years old of which 59% were female.  Sande et al [2] in 2008, found that any type of general mask is likely to decrease viral exposure and infection risk on a population level; with surgical masks being more effective than home-made masks and children being less well protected.  The relative ineffectiveness of fabrics used in home-made masks, including sweatshirts, T-shirts, towels and scarfs, was demonstrated in 2010 by Rengasamy et al [3], who found that these fabrics had 40-97% instantaneous penetration for monodisperse aerosol particles in the 20 to 1000 nm range.  While in the same year, Cowling et al [4] conducted a systematic review of the subject and concluded there was some evidence to support the wearing of masks or respirators during illness to protect others, and public health emphasis on mask wearing during illness may help reduce influenza virus transmission.  There were fewer data to support the use of masks or respirators to prevent becoming infected.  So, the rational conclusion appears to be that we should wear face masks to protect society as a whole and remember they do not necessarily protect us as individuals.

The emphasis on social distancing is causing widespread economic distress and also appears to be causing a decrease in mental health.  It perhaps should be called physical distancing because that is what we asked to do – to keep 2 m apart or 1.5 m in some places.  In 2017, a team of engineers from the University of Hong Kong and Aalborg University in Denmark [5], concluded that a threshold distance of 1.5 m distinguished between two basic transmission processes of droplets, i.e. a short-range mode and a long-range airborne route.  They reviewed the literature, conducted experiments and performed computational simulations before concluding the risk of infection arising from person-to-person interactions was significantly reduced when people were more than 1.5 m apart because droplets greater than 60 microns in diameter are not transmitted further than 1.5 m; however, smaller droplets are carried further.  In the same year, Ai & Melikov [6] reviewed the airborne spread of expiratory droplets in indoors environments; they found inconsistent results due to different boundary conditions used in computer models and the available instrumentation being too slow to provide accurate time-dependent measurements.  However, it would appear, based on several investigations, that the risk of cross-infection is decreased sharply at distances of 0.8 to 1.5 m (see graphic).  Indoors, the flow interactions in the human microenvironment dominate airborne transmission over short distances (<0.5 m) while the general ventilation flow is more important over longer distances.  Hence, at short distances, the posture and orientation of individuals is important; while at longer distances, if the rate of change of air in the room is high enough then the risk of cross-infection is low.

These findings would seem to suggest that there is some scope to balance restarting social and economic activity with protecting people from the coronavirus by relaxing ‘social’ distancing from 2 m to 1.5 m unless you are  wearing a mask.  After all, we would simply following the example of Taiwan where there are almost no new cases.

References

[1] Leung NH, Chu DK, Shiu EY, Chan KH, McDevitt JJ, Hau BJ, Yen HL, Li Y, Ip DK, Peiris JM, Seto WH. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nature Medicine. 2020 Apr 3:1-5.

[2] van der Sande M, Teunis P, Sabel R. Professional and home-made face masks reduce exposure to respiratory infections among the general population. PLoS One. 2008;3(7).

[3] Rengasamy S, Eimer B, Shaffer RE. Simple respiratory protection—evaluation of the filtration performance of cloth masks and common fabric materials against 20–1000 nm size particles. Annals of occupational hygiene. 2010 Oct 1;54(7):789-98.

[4] Cowling BJ, Zhou YD, Ip DK, Leung GM, Aiello AE. Face masks to prevent transmission of influenza virus: a systematic review. Epidemiology & Infection. 2010 Apr;138(4):449-56.

[5] Liu L, Li Y, Nielsen PV, Wei J, Jensen RL. Short‐range airborne transmission of expiratory droplets between two people. Indoor Air. 2017 Mar;27(2):452-62.

[6] Ai ZT, Melikov AK. Airborne spread of expiratory droplet nuclei between the occupants of indoor environments: A review. Indoor air. 2018 Jul;28(4):500-24.