Tag Archives: 5Es

Depressed by exams

I am not feeling very creative this week, because I am in middle of marking examination scripts; so, this post is going to be short.  I have 20 days to grade at least 1100 questions and award a maximum of 28,400 marks – that’s a lot of decisions for my neurons to handle without being asked to find new ways to network and generate original thoughts for this blog [see my post on ‘Digital hive mind‘ on November 30th, 2016].

It is a depressing task discovering how little I have managed to teach students about thermodynamics, or maybe I should say, how little they have learned.  However, I suspect these feelings are a consequence of the asymmetry of my brain, which has many more sites capable of attributing blame and only one for assigning praise [see my post entitled ‘Happenstance, not engineering‘ on November 9th, 2016].  So, I tend to focus on the performance of the students at the lower end of the spectrum rather than the stars who spot the elegant solutions to the exam problems.


Ngo L, Kelly M, Coutlee CG, Carter RM , Sinnott-Armstrong W & Huettel SA, Two distinct moral mechanisms for ascribing and denying intentionality, Scientific Reports, 5:17390, 2015.

Bruek H, Human brains are wired to blame rather than to praise, Fortune, December 4th 2015.


Steamy show

The Australian Academy of Technology and Engineering published a report sometime ago called ‘Technology is really a way of thinking‘.  They were right.  Once you become an engineer, then you can’t help looking at everything through the same ‘technology’ lens.  Let me give you an example.

A couple of weekends ago we went to see  ‘Anthony and Cleopatra‘ performed by the Royal Shakespeare Company in Stratford-upon-Avon.  It was a magnificient spectacle and a captivating performance, especially by Josette Simon as Cleopatra.  Before the performance started, we couldn’t help noticing the columns of steam forming in the auditorium from the ceiling downwards.  Initially, we thought that they were a stage effect creating an atmosphere in the theatre; but then I realised, it was ‘steam’ forming as the air-conditioning pushed cold air into the auditorium.  It’s the same effect that sometimes causes alarm on an aircraft, when it appears that smoke is billowing into the cabin prior to take-off.

The air in the theatre was a mixture of air and water vapour that was warm enough that the water was completely gaseous, and hence, invisible.  However, when the air-conditioning pumped cold air into the theatre, then the mixture of air and water was cooled to below the dew point of the water vapour causing it to condense into small droplets that were visible in the auditorium’s downlighters, forming the columns of ‘steam’.  Of course, the large mass of warm air in the auditorium quickly reheated the cold air, causing the droplets to evaporate and the columns of steam to disintegrate.  Most people just enjoyed the play; it’s just the technologists that were preoccupied with what caused the phenomenon!

If you want a more technical explanation, in terms of partial pressures and psychrometry, then there is an Everyday Engineering Example lesson plan available : 5E lesson plan T10 – psychrometric applications.

Picture: https://www.rsc.org.uk/shop/item/30200-anthony-and-cleopatra-poster-2017/