Highest mountain, deepest lake, smallest church and biggest liar

Last month we took a short vacation in the Lake District and stayed in Wasdale whose tag-line is highest mountain, deepest lake.  The mountain is Scafell Pike, the highest mountain in England at 978 m, which we never saw because the clouds never lifted high enough to reveal it.  The lake is Wast Water, the deepest lake in England at 74 m, which rose slowly during our week due to the almost continuous rain falling on the surrounding hills.  But that’s typical Lake District weather because the area protrudes to the west of England so it is the first landfall for rainstorms moving east after they have replenished with water over the Irish Sea.  We spent our time reading in our cottage and venturing out to walk in lowlands when the lake was a calm presence, occasionally reflecting the surrounding mountains but more often dark reflecting the low clouds.  We were not tempted to test its temperature but I would expect it to have been around 4 °C because this is the temperature of the water in the depths of all deep lakes all year around.  Hence, in winter the surface layers of water will usually be colder than 4 °C and in summer warmer than 4 °C reflecting the air temperature, so in spring when we visited it would probably have been around 4 °C.  Water expands when it freezes which is possible on the surface of bodies of water where it can expand into the air; however, at depths in deep lakes the pressure prevents the expansion required for the freezing process and equilibrium between opposing processes occurs at about 4 °C.  Thus, the water at the bottom of all deep lakes remains at 4 °C all year with a gradient of increasing temperatures towards the surface in summer and of decreasing temperatures in winter.

Wasdale also claims the smallest church, St Olaf’s and the biggest liar, Will Ritson (1808-1890) who was a landlord of the Wastwater Hotel.  He won the annual world’s biggest liar competition by saying, when it was his turn, that he was withdrawing from the competition because having heard the other competitors he could not tell a bigger lie.

Image: Wast Water with clouds sitting on Great Gable at the east end of the lake.

Immeasurable productivity?

This is the second in a series of ‘reprints’ from my archive of posts.  I will be back with new posts in a few weeks refreshed after my vacation.  This post was first published in November 2013 under the title ‘Productive cheating‘.

I cut out a Dilbert cartoon from the New York Times a few weeks ago that I found amusing and shared it with my new Head of School.  Dilbert informs his boss that he will be taking advantage of the new unlimited vacation policy by being away for 200 days in the coming year but will still double his productivity.  His boss replies that there is no way to measure productivity for engineers.

Of course, bosses are very interested in measuring productivity and marketing executives like to brag about the productivity or efficiency of whatever it is they are selling.  Engineers know that it is easy to cheat on measures of productivity and efficiency, for instance, by carefully drawing the boundaries of the system to exclude some inputs or some wasteful outputs [see my post on ‘Drawing Boundaries’ on December 19^th, 2012 ].  So claims of productivity or efficiency that sound too good to be true probably aren’t what they seem.

Also in the New York Times [on October 15^th, 2013] Mark Bittman discussed the productivity of the two food production systems found in the world, i.e. industrial agriculture and one based on small landholders, what the ETC group refers to as peasant food webs.  He reports that the industrial food chain uses 70% of agricultural resources to provide 30% of the world’s food while peasant farming produces the remaining 70% with 30% of the resources.  The issue is not that industrial agriculture’s claims for productivity in terms of yields per acre are wrong but that the industry measures the wrong quantity.  Efficiency is defined as desired output divided by required input [see my post entitled ‘National efficiency‘ on May 29^th, 2013].  In this case the required output is people fed not crop yield and a huge percentage of the yield from industrial agriculture never makes to people’s mouths [see my post entitled ‘Food waste’ on January 23^rd, 2013].

Sources:

http://www.nytimes.com/2013/10/15/opinion/how-to-feed-the-world.html?ref=markbittman&_r=0

http://www.etcgroup.org/content/poster-who-will-feed-us-industrial-food-chain-or-peasant-food-webs

Admiral’s comments on fission hold for fusion 70 years later

Last month the US Energy Secretary, Jennifer Granholm announced a successful experiment at the Lawrence Livermore National Laboratory in which 192 lasers were used to pump 2.05 mega Joules of energy into a capsule heating its contents to 100 million degrees Centigrade causing fusion of hydrogen nuclei and the release of 3.15 mega Joules of energy.  An apparent gain of 1.1 mega Joules until you take account of the 300 mega Joules consumed by the 192 lasers.  The reaction in the media to this fusion energy experiment and the difficulties associated with building a practical fusion power plant, such as the Spherical Tokamak Energy Production (STEP) project in the UK (see ‘Celebrating engineering success‘ on November 11th, 2022) reminded me of a well-known memorandum penned by Admiral Rickover in 1953.  Rickover was first tasked, as a Captain, to look at atomic power in May 1946 not long after first human-made self-sustaining nuclear chain reaction was initiated in Chicago Pile #1 during an experiment led by Enrico Fermi in 1942.  He went on to become Admiral Rickover who directed the US Navy’s nuclear propulsion programme and the Nautilus, the first nuclear-powered submarine was launched in 1954.  With thanks to a regular reader of this blog who sent me a copy of the memo and apologies to Admiral Rickover, here is his memorandum edited to apply to fusion energy:

Important decisions about the future of fusion energy must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of fusion.  These people are, nonetheless, interested in what a fusion power plant will do, how much it will cost, how long it will take to build and how long and how well it will operate.  When they attempt to learn these things, they become aware the confusion existing in the field of fusion energy.  There appears to be unresolved conflict on almost every issue that arises.

I believe that the confusion stems from a failure to distinguish between the academic and the practical.  These apparent conflicts can usually be explained only when the various aspects of the issue are resolved into their academic and practical components. To aid in this resolution, it is possible to define in a general way those characteristics which distinguish one from the other.

An academic fusion reactor almost always has the following basic characteristics: (1) It is simple. (2) It is small.  (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose . (7) The reactor is in the study phase.  It is not being built now.  On the other hand, a practical fusion reactor can be distinguished by the following characteristics: (1) It is being built now.  (2) It is behind schedule. (3) It is requiring an immense amount of development on apparently trivial items. (4) It is very expensive. (5) It takes a long time to build because of the engineering development problems. (6) It is large. (7) It is complicated.

The tools of the academic-reactor designer are a piece of paper and a pencil with an eraser. If a mistake is made, it can always be erased and changed.  If a mistake is made, it can always be erased and changed.  If the practical-reactor designer errs, they wear the mistake around their neck; it cannot be erased.  Everyone can see it. 

The academic-reactor designer is a dilettante.  They have not had to assume any real responsibility in connection with their projects.  They are free to luxuriate in elegant ideas, the practical shortcomings of which can be relegated to the category of ‘mere technical details’.  The practical-reactor designer must live with these same technical details.  Although recalcitrant and awkward, they must be solved and cannot be put off until tomorrow.  Their solutions require people, time and money.

Unfortunately for those who must make far-reaching decisions without the benefit of an intimate knowledge of fusion technology and unfortunately for the interested public, it is much easier to get the academic side of an issue than the practical side. For the large part those involved with academic fusion reactors have more inclination and time to present their ideas in reports and orally to those who will listen.  Since they are innocently unaware of the real and hidden difficulties of their plans, they speak with great facility and confidence.  Those involved with practical fusion reactors, humbled by their experiences, speak less and worry more.

Yet it is incumbent on those in high places to make wise decisions, and it is reasonable and important that the public be correctly informed.  It is consequently incumbent on all of us to state the facts as forth-rightly as possible.  Although it is probably impossible to have fusion technology ideas labelled as ‘practical’ or ‘academic’ by the authors, it is worthwhile both authors and the audience to bear in mind this distinction and to be guided thereby.

Image: The target chamber of LLNL’s National Ignition Facility, where 192 laser beams delivered more than 2 million joules of ultraviolet energy to a tiny fuel pellet to create fusion ignition on Dec. 5, 2022 from https://www.llnl.gov/news/national-ignition-facility-achieves-fusion-ignition

Storm in a computer

As part of my undergraduate course on thermodynamics [see ‘Change in focus’ on October 5^th, 2022) and in my MOOC on Thermodynamics in Everyday Life [See ‘Engaging learners on-line‘ on May 25th, 2016], I used to ask students to read Chapter 1 ‘The Storm in the Computer’ from Philosophy and Simulation: The Emergence of Synthetic Reason by Manuel Delanda.  It is a mind-stretching read and I recommended that students read it at least twice in order to appreciate its messages.  To support their learning, I provided them with a précis of the chapter that is reproduced below in a slightly modified form.

At the start of the chapter, the simplest emergent properties, such as the temperature and pressure of a body of water in a container, are discussed [see ‘Emergent properties’ on September 16^th, 2015].  These properties are described as emergent because they are not the property of a single component of the system, that is individual water molecules but are features of the system as a whole.  They arise from an objective averaging process for the billions of molecules of water in the container.  The discussion is extended to two bodies of water, one hot and one cold brought into contact within one another.  An average temperature will emerge with a redistribution of molecules to create a less ordered state.  The spontaneous flow of energy, as temperature differences cancel themselves, is identified as an important driver or capability, especially when the hot body is continually refreshed by a fire, for instance.  Engineers harness energy gradients or differences and the resultant energy flow to do useful work, for instance in turbines.

However, Delanda does not deviate to discuss how engineers exploit energy gradients.  Instead he identifies the spontaneous flow of molecules, as they self-organise across an energy gradient, as the driver of circulatory flows in the oceans and atmosphere, known as convection cells.  Five to eight convections cells can merge in the atmosphere to form a thunderstorm.  In thunderstorms, when the rising water vapour becomes rain, the phase transition from vapour to liquid releases latent heat or energy that helps sustain the storm system.  At the same time, gradients in electrical charge between the upper and lower sections of the storm generate lightening.

Delanda highlights that emergent properties can be established by elucidating the mechanisms that produce them at one scale and these emergent properties can become the components of a phenomenon at a much larger scale.  This allows scientists and engineers to construct models that take for granted the existence of emergent properties at one scale to explain behaviour at another, which is called ‘mechanism-independence’.  For example, it is unnecessary to model molecular movement to predict heat transfer.  These ideas allow simulations to replicate behaviour at the system level without the need for high-fidelity representations at all scales.  The art of modelling is the ability to decide what changes do, and what changes do not, make a difference, i.e., what to include and exclude.

Source:

Manuel Delanda Philosophy and Simulation: The Emergence of Synthetic Reason, Continuum, London, 2011.

Image: Painting by Sarah Evans owned by the author.