I mentioned a couple of weeks ago that I am teaching thermodynamics at the moment [see ‘Conversations about engineering over dinner and a haircut‘ on February 16th, 2022]. I am using a blended approach [see ‘ Blended learning environments‘ on November 14th, 2018] to deliver the module to more than 300 first year undergraduate students with one hour in the lecture theatre each week while the students follow the components of the MOOC I developed some years ago [see ‘Free: Energy! Thermodynamics in Everyday Life‘ on November 11th, 2015, and ‘Engaging learners online‘ on May 25th, 2016]. I have found that first year undergraduates are reluctant to participate in the online discussions that are part of the MOOC and so last year I asked them to discuss each topic in small groups with their academic tutor. I got some very positive feedback from tutors who had interesting and stimulating discussions with their students. We are repeating the process again this year. The first discussion is about energy transformations: noting that energy is always conserved but constantly transformed into different forms, each student is asked to start from an energy state of their choice and to trace the transformations backwards until they can go no further. In the lecture preceding the discussion with their tutor I provide some examples for starting states, including breakfast cereal, a pole vaulter in mid-jump and a bullet train. I also describe the series of transformations from the Big Bang to tectonic plate movement: after the initial expansion caused by the Big Bang, the universe cooled sufficiently to allow the formation of sub-atomic particles followed by atoms of hydrogen and some helium and lithium that gravity caused to coalesce into clouds which became the early stars, or solar nebula. A crust formed on the solar nebula which broke away to form planets. Our planet has a molten core with temperatures varying from 4,400 to 6000 degrees Celsius, compared to around 5,500 degrees on the surface of the sun. The temperature variation in the Earth’s core cause thermal currents which drive the movement of tectonic plates and so on [see ‘The hills are shadows, and they flow from form to form, and nothing stands‘, on February 9th, 2022]. Most chains of energy transformation lead backwards to the sun and forwards to dissipation of energy into some unusable form which we might call ‘entropy’ [see ‘Life-time battle‘ on January 30th, 2013].
Distance of the Moon
I mentioned a few weeks ago about tectonic plate movement [see ‘The hills are shadows, and they flow from form to form and nothing stands‘ on February 9th, 2022]. The plate on which my house sits is moving eastwards at about the same speed as my fingernails are growing, i.e., a couple of centimetres each year, and that is about the same rate at which the Moon is receding from the Earth. When the Moon was formed about 4.5 billion years ago from debris floating around the Earth, its orbit had a time-averaged distance from the Earth of about 38,500 kilometres so a tenth of its current distance from the Earth. Of course, there was no one around to see it this close to Earth but in my imagination it reminds me of Italo Calvino’s story, the Distance of the Moon, in which it is possible to sail a boat out to sea and use a ladder to climb from the boat to the Moon.
The Distance of the Moon was published as part of the Cosmicomics about which I have written before. See: ‘Man, the Rubbish Maker‘ on October 26th, 2016; ‘Will it all be over soon?‘ on November 2nd, 2016; and ‘Only the name of the airport changes‘ on June 12th, 2019.
References:
Italo Calvino, The Complete Cosmicomics, London: Penguin Books, 2002.
https://www.lpi.usra.edu/education/explore/marvelMoon/background/moon-influence/
Image: Museum of the Moon in Liverpool Anglican Cathedral in 2018.
Conversations about engineering over dinner and a haircut
Recently, over dinner, someone I had just met asked me what type of engineering I do. I always find this a difficult question to answer because I am sure that they are just being polite and do not want to hear any technical details but I find it hard to give an interesting answer without diving into details. Earlier the same day I had given a lecture on thermodynamics to about 300 undergraduate students so I told my inquisitor about this experience and explained that thermodynamics was the science of energy and its transformation into different forms. Then, I muttered something about being interested in making and using measurements to ensure that computational models of aircraft and nuclear power stations are reliable and the conversation quickly moved on. A week or so earlier, I was having my hair cut when the barber asked me a similar question about what I did and I told him that I was a professor of engineering which led to a conversation about robots. We speculated about whether we would ever lose our jobs to robots and decided that we were both fairly secure against that threat. There is a high degree of creativity in both of our roles – while I always ask for the same haircut, my hair is in a different state every time I visit the barbers’ and I leave looking slightly different every time. I don’t think that I would like the uniformity that a row of robots in the barbers’ shop might produce. And, then there is the conversation during the haircut. A robot would need to pass the Turing test, i.e., to exhibit intelligent behaviour indistinguishable from a human, which no computer has yet achieved or is likely to do so in our lifetime, at least not a cost that would allow them to replace barbers. The same holds for professors – the shift to delivering lectures online during the pandemic might have made some professors worry that their jobs were at risk as recorded lectures replaced live performances; however, student feedback tells us that students have a strong preference for on-campus teaching and the high turnout for my thermodynamics lectures supports that conclusion.
Footnotes:
For a new website I was asked to describe my research interests in about 25 words and used the following: ‘the acquisition of information-rich measurement data and its use to develop digital representations of complex systems in the aerospace, biological and energy sectors’. Fine for a website but not dinner conversation!
There have been some attempts to build a robot that cut your hair, for example see this video.
Image shows a colour contour map describing the shape of a facemask produced using fringe projection which could be used as part of the vision system for a robotic barber. For more information on fringe projection see: Ortiz, M. H., & Patterson, E. A. (2005). Location and shape measurement using a portable fringe projection system. Experimental mechanics, 45(3), 197-204 or watch this video from the INDUCE project that was active from 1998 to 2001.
The hills are shadows, and they flow from form to form, and nothing stands
The title of this post comes from two lines in ‘In Memoriam A.H.H.‘ by Alfred, Lord Tennyson. The theory of plate tectonics evolved about fifty years ago so it is very unlikely that Tennyson was thinking about the hills as waves of rock flowing across the landscape. However, we now understand that Earth’s crust is divided into plates that are moving as a result of currents in the liquid magna beneath them. For example, the African plate is moving northwards crashing into the Eurasian plate causing the edges of the plate to buckle and flow forming the Alps and Pyrenees along the edge of the Eurasian plate. At the same time, the Eurasian plate is moving eastwards very slowly at a speed of about 2.5 cm per year, or about 2 metres in an average human lifetime. So, nothing stands still. Everything is a process. It’s just that some processes are quicker than others [see ‘Everything is in flux but it’s not always been recognised‘ on April 28th, 2021].
Reference:
Helen Gordon, Notes from deep time, London: Profile Books, 2021.