The Liverpool Gas Light Company was formed in 1816, just as the amount of carbon dioxide in the atmosphere started to rise above the pre-industrial revolution level of 278 ppm. A rival Oil Gas Company was formed in 1823 and became the Liverpool New Gas and Coke Company in 1834. The two rival companies merged in 1848. Last year a piece of cast iron gas main from around this period was salvaged while replacing a gas main on the Dock Road in Liverpool. It was date-stamped 1853. For the last month, works have been underway to replace the original gas main in our street which appears to be of a similar age. The concept of gas-fired central heating using pressurised hot water was developed in the 1830s by Angier March Perkins [1838 US patent], amongst others; but did not become fashionable until the 1850s which coincides approximately with laying of the original gas main in the road outside our house. There is a cavernous coal hole under the pavement (sidewalk) in front of our house which would have been used to store coal that was burned in fireplaces in every room. So, we can deduce that the house, which was built in the early 1830s, did not initially have gas-fired central heating but that it could have been installed sometime in the second half of the 19th century, just as the level of carbon dioxide in the atmosphere started its exponential increase towards today’s level of 412 ppm [monthly average at Mauna Loa Global Monitoring Laboratory for August 2020]. Carbon dioxide represents about 80% of greenhouse gas emissions, according to the US EPA, and heating of commercial and residential properties accounts for 12% of these emissions in the US and for 32% in the UK. Hence, before our house is two hundred years old, it is likely that we will have converted it to electrical heating in order to reduce its carbon footprint. We have made a start on the process but it is pointless until our power supply is carbon neutral and progress towards carbon neutrality for electricity generation is painfully slow in the UK and elsewhere [see ‘Inconvenient facts‘ on December 18th, 2019].
You can check live carbon dioxide emissions from electricity generation and consumption using the ElectricityMap.
Is a coconut an isolated thermodynamic system? This is a question that I have been thinking about this week. A coconut appears to be impermeable to matter since its milk does not leak out and it might be insulated against heat transfer because its husk is used for insulation in some building products. If you are wondering why I am pondering such matters, then it is because, once again, I am teaching thermodynamics to our first year students (see ‘Pluralistic Ignorance‘ on May 1st, 2019). It is a class of more than 200 students and I am using a blended learning environment (post on 14th November 2018) that combines lectures with the units of the massive open online course (MOOC) that I developed some years ago (see ‘Engaging learners on-line‘ on May 25th, 2016). However, before devotees of MOOCs get excited, I should add that the online course is neither massive nor open because we have restricted it to our university students. In my first lecture, I talked about the concept of defining the system of interest for thermodynamic analysis by drawing boundaries (see ‘Drawing boundaries‘ on December 19th, 2012). The choice of the system boundary has a strong influence on the answers we will obtain and the simplicity of the analysis we will need to perform. For instance, drawing the system boundary around an electric car makes it appear carbon neutral and very efficient but including the fossil fuel power station that provides the electricity reveals substantial carbon emissions and significant reductions in efficiency. I also talked about different types of system, for example: open systems across whose boundaries both matter and energy can move; closed systems that do not allow matter to flow across their boundaries but allow energy transfers; and, isolated systems that do not permit energy or matter to transfer across their boundaries. It is difficult to identify closed systems in nature (see ‘Revisiting closed systems in nature‘ on October 5th, 2016); and so, once again I asked the students to suggest candidates but then I started to think about examples of isolated systems. I suspect that completely isolated systems do not exist; however, some systems can be approximated to the concept and considering them to be so, simplifies their analysis. However, I am happy to be corrected if anyone can think of one!