Physics

IoP Energy: Notes Towards A Diagrammatic Teaching Approach?

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After a fascinating discussion led by the excellent Alex Weatherall (click here to participate in his Google doc Physics-fest — and follow @A_Weatherall on Twitter for more), I was thinking on possible teaching approaches for energy.

Although I think the IoP‘s (the UK’s Institute of Physics) approach is conceptually sound (see previous post here) and addresses many of the shortcomings in the traditional and time-hallowed “forms of energy” approach, many Physics teachers (myself included) are struggling to find direct and simple ways of communicating the highly nuanced content to students.

For example, to describe a filament bulb:

A (filament) light bulb is a device that takes energy in (input) through an electrical pathway (the current) to the thermal energy store of the filament (the metal is getting hotter) which transfers the energy through the radiation pathways of light (visible and IR). There is an increase in the thermal store of the room due to transfer via the heating pathway. The less energy transferred by heating compared to visible light the more efficient the light bulb.

I think this is in accordance with the letter and spirit of the “IoP Energy Newspeak” approach; but sadly, I can picture many students struggling to understand this, even though it was written by many hands (including mine) with the best of intentions.

But then I began to think of adopting a diagrammatic “enoji” approach. (See here for suggested energy icons, or energy + emoji = enoji)

 

Diagrams for Stores and Pathways

An energy store is represented by a “watertight” container. For example, the gravity store of a ball at the top of a slope could be represented thus:

gravity-store

Because it is an energy store, the amount of energy (represented by the level of orange liquid) in the store remains constant. Energy will not spontaneously leave the store. Energy stores don’t have holes. The unit we use with energy stores is the joule.

However, energy pathways do have holes. In contrast to an energy store, the energy level in a pathway will spontaneously decrease as the energy is shifted to another store.

pathway

To keep the energy level constant in a pathway, it needs to be constantly “topped up” by the energy from an energy store.

Since a pathway represents a “flow” of energy, the unit we use with an energy pathway is the watt (one joule per second). The “orange liquid level” in the pathway icon could therefore represent the amount of energy flowing through in one second (although I concede that this idea, though promising, needs more thought).

 

“Enoji Energy Shift” Diagrams

Adopting this convention, the “enoji energy shift” diagram for a ball rolling down a slope might look like this:

pathway2

An energy store does not have any holes — unless it is linked to a pathway, like the gravity store above. Energy will move in the direction indicated by the energy pathway icon.

Simplified in a student exercise book, it could be represented like this:

simplepathway1

The small upward and downward arrows are an attempt to indicate what happens to the energy level over time.

 

The Filament Lightbulb “Enoji Energy Shift” Diagram

This could be represented in a student exercise book like this:

pathway-bulb

Since there are no small up and down arrows on the pathway or thermal store enojis, this indicates that the energy levels are relatively stable (provided we have a constant input of energy from the power station). However, the energy level of the thermal store of the surroundings just keeps on going up…

 

And finally…

Please note this is a work in progress.

I fully expect many teachers will think that the suggested set of conventions may well prove more confusing for students.

However, what I am attempting to do is to give students a set of simple, coherent yet serviceable analogies. In other words, this might provide a conceptual “tool kit” of physical representations of very abstract processes involving energy.

I hope readers will agree that it offers some scope for further development. Comments, criticisms and suggestions would be most welcome.

Look at the pretty pictures…

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Uniformity of practice seldom continues long without good reason.

So opined the estimable Dr Johnson in 1775. In other words, if a thing is done in a certain way, and continues to be done in that same way for a number of years by many different people, then it is a pretty safe bet that there is a good reason for doing the thing that way. And this is true even when that reason is not immediately apparent.

For the choice of this situation there must have been some general reason, which the change of manners has left in obscurity.

— Samuel Johnson, A Journey To The Western Islands of Scotland (1775).

Consider the following examples of “uniformity of practice”:

wp-1487108711715.png

wp-1487109018433.pngexam1

They are fairly bog-standard GCSE examination questions from the last two years from three different exam boards. But compare and contrast with an O-level Physics paper from 1966:

exam2.jpg

exam3.jpg

 

The “uniformity of practice” that leaps out at me is that the more modern papers, as a rule, have many more illustrations than the older paper. Partly, of course, this is to do with technology. It would have been (presumably) vastly more expensive to include illustrations in the 1966 paper.

Even if we assume that the difficulty level of the questions in the modern and older papers are equivalent (and therein lies a really complex argument which I’m not going to get into), there is a vast difference in the norms of presentation. For example, the modern papers seems to eschew large blocks of dense, descriptive text; this extends to presenting the contextual information in the ultrasound question as a labelled diagram.

Now I’m not saying that this is automatically a good or a bad thing, but there does seem to be a notable “uniformity of practice” in the modern papers.

Now what could the “general reason” for this choice?

Rather than leave the “change of manners” responsible for the choice “in obscurity”, I will hazard a guess: the examiners know or suspect that many of their candidates will struggle with reading technical prose at GCSE level, and wish to provide visual cues in order for students to play “guess the context” games.

Now I’m not assigning blame or opprobrium on to the examiners here. If I was asked to design an exam paper for a wide range of abilities I might very well come up with a similar format myself.

But does it matter? Are we testing Physics or reading comprehension here?

My point would be that there can be an elegance and beauty in even the most arid scientific prose. At its best, scientific prose communicates complex ideas simply, accurately and concisely. It may seem sparse and dry at first glance, but that is only because it is designed to be efficient — irrelevancies have been ruthlessly excised. Specialised technical terms are used liberally, of course, but this is only because they serve to simplify rather than complicate the means of expression. 

Sometimes, “everyday language” serves to make communication less direct by reason of vagueness, ambivalence or circumlocution. You might care to read (say) one of Ernest Rutherford’s papers to see what I mean by good scientific prose.

The O-level paper provides, I think, a “beginner’s guide” to the world of scientific, technical prose. Whereas a modern question on falling objects might tack on the sentence “You may ignore the effects of air resistance” as an afterthought or caveat, the O-level paper uses the more concise phrase “a body falling freely” which includes that very concept.

To sum up, my concern is that in seeking to make things easier, we have actually ended up making things harder, and robbing students of an opportunity to experience clear, concise scientific communication.

IoP Energy: “Store” of Wisdom or Little Shop of Horrors?

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“Something with a lot of energy will kill you.”

This has stayed with me from my PGCE course at Swansea University, many years ago. It was said by Frank Banks, the course tutor, in response to the question “What’s the simplest way to describe energy?”

And as pithy descriptions of energy go, it’s not half-bad. A small stone, dropped from the top of a skyscraper: lots of energy before it hits the ground — it could kill you. A grand piano, dropped from six feet above your head: lots of energy — it could kill you. Licking your fingers and touching the bare live and neutral wires in a socket: the conduction electrons in your body suddenly acquire a lot of energy — and yes, they could kill you. (With alternating current, of course, the electrons that will kill you are already inside your body — freaky!)

This attention-grabbing definition of energy seems to lead naturally to a more formal definition of “Energy is the capacity to do work“. This still leaves the problem of defining work, of course, but as R. A. Lafferty once said, that’s another and much more unpleasant story.

As I mentioned in an earlier post, I have been writing the Energy scheme of work for GCSE Science. As part of that brief, I wrote a short summary for my science colleagues of the IoP’s new approach to energy. I present it below without much amendment (or even a proper spellcheck) in the hope that someone, somewhere, at some time — may find it useful  🙂

The problem with teaching energy

One reason for the difficulty in deciding what to say about energy at school level is that the scientific idea of energy is very abstract.  It is, for example, impossible to say in simple language what energy is, or means.  Another problem is that the word ‘energy’ has entered everyday discourse, with a meaning that is related to, but very different from, the scientific one. [ . . .]

This ‘forms of energy’ approach has, however, been the subject of much debate. One criticism is that pupils just learn a set of labels, which adds little to their understanding. For example, one current textbook uses the example of a battery powered golf buggy. It asks pupils to think of this in the following terms:

Chemical energy in the battery is transformed into electrical energy which is carried by the wires to the motor. The motor then transforms this into kinetic energy as the buggy moves.

This, however, adds nothing to the following explanation, which does not use energy ideas:

The battery supplies an electric current which makes the motor turn. This then makes the buggy move.

A good general rule when explaining anything is that you should use the smallest number of ideas needed to provide an explanation, and not introduce any that are unnecessary

Robin Millar [2012] http://www.lancsngfl.ac.uk/nationalstrategy/ks3/science/files/TeachingAboutEnergy(RobinMillar).pdf

Energy – a new hope (!)

The new approach to the teaching of energy developed by the Institute of Physics (IoP) suggests that we limit our consideration of energy to situations where we might want to do calculations (at KS4, KS5 or beyond).

We should talk of energy being stored and shifted. The emphasis should be on the start and end of the process with minimal attention being given to any intermediate stages.

Consider the following examples:

  • lifting an object. Chemical potential energy store is emptied, and gravitational potential energy store is filled (note that we are not interested in intermediate motion as it doesn’t affect the final energy store).
  • rolling an object down a slope to the bottom. Gravitational potential energy store is emptied and thermal energy stores (of slope, of pen) increased.
  • Boiling water in kettle. Chemical store (from coal/gas power station) is emptied. Thermal store of water increased, thermal store of air increased, thermal store of kettle increased.

[Examples taken from http://scientistshavesaid.blogspot.co.uk/2013/02/teaching-energy.html]

The new approach has been adopted by all UK exam boards for their new specs and is used in the AQA approved textbooks.

The following energy stores are considered: kinetic energy store, gravitational potential energy store, elastic potential energy store, thermal energy store, chemical potential energy store, nuclear energy store, vibrational energy store, electromagnetic energy store (note: the last is limited to situations involving static electric charges and static magnetic poles in magnetic fields).[NB Items in bold are those required for GCSE Combined Science.]

One major difference is that electric current and light are no longer considered as forms of energy. Rather, these are now regarded as means of transferring energy.

Rise of the Enojis

enojis

[Image from http://www.supportingphysicsteaching.net/En02PN.html]

I suggest these energy icons should be called enojis (by analogy with emojis).

Probably the biggest adjustment for most teachers will be to avoid referring to light and sound as forms of energy and to treat them as pathways for transferring energy instead.

“Energy is the new orange” and summary

More (much more!) on the IoP’s “energy as an orange liquid” model can be found at http://www.supportingphysicsteaching.net/En02TL.html and http://www.supportingphysicsteaching.net/En02PN.html.

Image credit

enoji2

Songs In The Key Of Energy

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​The fact narrated must correspond to something in me to be credible or intelligible. We as we read must become Greeks, Romans, Turks, priest and king, martyr and executioner, must fasten these images to some reality in our secret experience, or we shall learn nothing rightly.

–Ralph Waldo Emerson, “History”

The autumn term is always the longest term: that long drag from the wan sunlight of September to the bleak darkness of December. This is the term that tests both the mettle and the soul of a teacher. At the end of it, many of us have cause to echo the gloom of Francisco’s lines from Hamlet — “’tis bitter cold, and I am sick at heart.”

But even when it seems like it’s all over, it’s still not over. 

The heavy hand of collective-responsibility roulette has tapped me on the shoulder. It’s my turn to write the scheme of work and resources for the next term. I am to write the energy module for the new GCSE Science course. And it must be done, dusted and finished over the Christmas break. The Christmas break.

And the surprising and unexpected truth is . . . I actually think I’m going to like doing it! Yes, really.

Strange to say, I have always enjoyed writing schemes of work. To my mind, it’s a bit like fantasy teaching instead of fantasy football. I move lesson objectives and resources hither and thither where others shift premier league strikers and goalkeepers.

Some aspects of the Science curriculum are abtruse and hard to communicate. Undoubtedly, some of the things we narrate do not always correspond closely enough to something which is already in students to be either credible or intelligible to them. The images and concepts must be fastened to some reality in their “secret experience” for them to learn rightly.

And what can we do to help them? Simply this: make sure that students get as much hands-on practical work as possible. Of course, it goes without saying (I hope!) that it should go hand-in-glove with coherent and thorough explanations of the theoretical underpinnings of scientific understanding.

One without the other is not enough.

Physics: it’s remarkably similar to Maths. But there’s a point to Physics

Let us hope that our students (in the words of R. A. Lafferty) never see a bird fly by without hearing the stuff gurgling in its stomach.

The Care And Feeding Of Ripple Tanks (Part One)

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And so they’re back — ripple tanks, that is. And a Required Practical to boot!

They were a staple of Physics teaching when I started my career, but somehow they fell into an undeserved desuetude. I know many fine teachers and excellent technicians who have never used one in anger, which is a real pity, since they are a great teaching tool.

So I present here my eclectic mix of ripple tanks: what you really need to know.

The Basics: “Look at the shadows, honey, look at the shadows!”

A ripple tank is simply a container with a transparent base. The idea is to put water in the container and make waves or ripples in the water. A light source is positioned above the water so that a screen underneath the transparent tank is illuminated. The crests and troughs act as converging and diverging lenses and produce a pattern of light and dark lines on the screen which enables us to observe wave behaviour more easily.

Remember: look at the pattern of shadows on the floor or bench top, not the ripple tank itself.

If doing this as a demo, sight lines will usually be a bitch for your class. If you have an old fashioned OHP, just put the tank on top of it and project the shadow pattern on to a wall or screen. Alternatively, experiment with positioning the light source underneath the tank and projecting the pattern on to the ceiling.

“Water, Electricity, Children and Darkness: What Could Possibly Go Wrong?”

The ripple tank works best in subdued lighting conditions. Make sure that walkways are free of bags and other trip hazards. If you want students to complete other work during this time, giving them desk lamps (e.g. the ones used by biologists for microscopes) can be useful, and can actually create a nice atmosphere.

Have some towels ready to mop up any water spills.

Most ripple tanks use a low voltage (12V) bulb and vibration generator (0-3 V) to minimise any electrical hazards involved. Be vigilant when plugging in the low voltage supply to the mains and ensure that the mains cable stays dry.

Fill ‘Er Up!

Have a large plastic beaker handy to fill and drain the ripple tank in situ. Don’t try to fill a ripple tank direct from the tap and carry a filled ripple tank through a “live” classroom — unless you want to risk a Mr Bean-type episode. (But you may need to add more water if demonstrating refraction — just enough to cover the plastic or glass sheet used to change the depth.)

In general, less is more. The ripple tank will be more effective with a very shallow 2-3 mm of water rather than a “deep pan” 2-3 cm.

Use the depth of water as a “spirit level” to get the ripple tank horizontal. Adjust the tank so that the depth of water is uniform. (If this seems low tech, remember that it is likely that ancient Egyptians used a similar technique to ensure a level platform for pyramid building!)

It’s also helpful to try and eliminate surface tension by adding a tiny amount of washing up liquid. I dip the end of a thin wire in a small beaker of detergent and mix thoroughly.

And so it begins…

Before switching on the vibration generator etc., I find it helpful to show what a few simple manually-created waves look like using the tank. Using a dropping pipette to create a few random splashes can be eye catching, and then showing how to create circular and straight wavefronts by tapping rhythmically using  the corner of a ruler and then a straight edge.

It’s Not All Relative: Five Things That Einstein Never Said

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We have all done it, haven’t we? Each and every one of us has, at some point, appropriated (or misappropriated) a quotation from a great thinker or writer to lend a spurious profundity to our own footling little thoughts.

While it may be well-nigh irresistible to wrap ourselves in the borrowed robes of literary or scientific genius, the temptation is fraught with dangers. To spare both our own blushes and those of our unsuspecting audience, it’s a good idea to check whether the Great Person actually said what they are reputed to have said.

For one reason and another, the life, career and reputation of Albert Einstein makes him an especially tempting target for spurious attributions.

This is my eclectic list of five things that Einstein did NOT say, and yet seem to be quoted and requoted again and again, especially in an educational context.

It is a melancholy truth that these particular memes will most likely be circulating on the internet until the last router rusts away to nothingness. However, on the principle that it better to light a candle than complain about the dark, I present this list (although, given their preternatural persistence, a flamethrower might be more appropriate).

Watch out, any one of them may well be coming to a CPD near you sometime soon…

Nein-stein No. 1

Everyone is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.

This, according to Quote Investigator [QI 1], was first attributed to Einstein as recently as 2004. The original allegory about animals attending a school and being judged against inflexible criteria, can be traced back to physicist Amos E. Dolbear who published it under a pseudonym in 1898.


Nein-stein No. 2

Everything is energy and that’s all there is to it. Match the frequency of the reality you want and you cannot help but get that reality. It can be no other way. This is not philosophy. This is physics.

Philosophy this gem certainly isn’t. Sadly, it bears no relation to any recognisable form of Physics either. (“Pass the bag labeled ‘New Age Quantum Claptrap’ please, Alice.”)

The original form of this quotation was penned by special effects artist Darryl Anka in 1998 — forty years after Einstein had shuffled off this mortal coil (or, at least, had become significantly less ordered).

Incidentally, Anka never attempted to attribute this thought to Einstein. In fact, he claimed that it had been obtained via “trans-dimensional channelling” from an extraterrestrial entity named “Bashar”. [QI 2]


Nein-stein No. 3

Two things inspire me to awe: the starry heavens and the moral universe within.

A beautiful quote, but Einstein? Naaaah. From Immanuel Kant’s Critique of Practical Reason (1788), actually. Highbrow enough for ya? [Ref 1]


Nein-stein No. 4

The definition of insanity is doing the same thing over and over and expecting different results.

Not Einstein. Not Benjamin Franklin. Not Rita Mae Brown either. The earliest instance tracked down by Wikiquote was from a Narcotics Anonymous publication from 1981.


Nein-stein No. 5

Two things are infinite: the universe and human stupidity. Actually, I’m not sure about the universe.

Einstein may or may not have said this, but the only evidence we have is from the works of therapist Frederick S. Perls, who credited the quote to a “great astronomer” in a book published in 1947. In later works, Perls specifically named Einstein as the originator of the quote which was said during a personal meeting with Perls. However, Perls did present different versions of the statement over the years. [QI 3]

The F.B.I. and Gang Signs for Physicists

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Those notions which are to be collected by reason . . . will seldom stand forward in the mind, but lie treasured in the remoter repositories of memory, to be found only when they are sought.

— Samuel Johnson, The Rambler, 7 April 1759

Sir John Ambrose Fleming (1849-1945) was the inventor of the thermionic valve, devices that formed the glowing (literally!) and pulsing heart of most electronic circuits until the invention of the transistor in the 1960s and the dawn of the Age of Semiconductors.

His part in most GCSE and A-level courses is small in extent but of significant and perhaps under acknowledged importance: he is the original framer of Fleming’s Left Hand Rule and Fleming’s Right Hand Rule. These respectively predict the direction of the force produced on a current-carrying conductor in a magnetic field (left hand) and the direction of induced current flow when a conductor cuts magnetic field lines (right hand). In short, they summarise the physics of everything from the humble electric motor to the Large Hadron Collider via the rail gun; not to mention the giant spinning generators that produce the humming electrical essence that powers our civilisation.

To use the rules, hold your thumb and first two fingers at right angles to each other. I tell my students that the left hand rule and right hand rule are physicists’ gang sign — it’s not too great a stretch of the imagination, at that. If you have ever invigilated a Physics exam, you can tell the point when the students have reached the Fleming’s Left/Right Hand Rule question . . . just look at their hands!
image

But I digress. I began this post because I was taught the following mnemonic for FLHR:

image
From: http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/keeping_things_moving/the_motor_effect/revision/3/

And to be honest, I have passed it on without thinking too hard about it. However, a student recently introduced me to the F.B.I. Mnemonic. Start with your thumb and say “F for force”, first finger and say “B for B-field” and then second finger and say “I for current”.

image
From: https://en.m.wikipedia.org/wiki/Fleming%27s_left-hand_rule_for_motors

The great advantage of this is that F, B and I are the standard physical symbols for the quantities they represent, unlike the multistage hoop-jumping demanded by the traditional mnemonic.

I don’t know about you, but I think I will be using the FBI mnemonic from now on (which, incidentally, was developed by Robert Van De Graaff (1901-1967), of Van De Graaff generator fame).

The Renaming of Parts; or, Energy is the New Orange

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image

A PC approach to energy?

Neil Atkin recently wrote a fascinating post about the “New” approach for teaching the concept of energy to secondary school students, and provides some interesting commentary and some very useful links: go read!

I first came across the work of Ogborn and Boohan, on which much of the “New Approach” is based, in the 1990s. I remember embracing it enthusiastically. However, I subsequently returned to the more “traditional” kinetic-chemical-heat-potential-light-sound “naming of parts” model, mostly because many of the resources favoured by our students followed the older convention.

And so it has remained for a number of years, so I was all set to give the “New Approach” a proper rubbishing (as might be gleaned from my selection of the Gary Larson cartoon above) as a specious form of PC — physical correctness as opposed to political correctness, perhaps.

But as I read more about the “New Approach”, I gradually came to the conclusion that it is conceptually sound. More importantly, I think it follows one of the basic principles suggested by Engelmann and Carnine:

[I]f we are to understand how to communicate a particular bit of knowledge . . . we must understand the essential features of the particular concept that we are attempting to convey. Only if we understand what it is and how it differs from related concepts can we design a communication that effectively conveys the concept to the learner.
— The Theory Of Instruction, location 296

In other words, I think the “New Approach” is a more accurate representation of the physics of energy, and less likely to lead to misconceptions and false inferences.

Energy Is The New Orange

image

Read Dr Dav’s excellent blog post from 2013 for a clear summary of the arguments in favour of the New Approach, as well as Robin Millar’s excellent paper on the topic.

Rise of the Enoji

One of the suggestions made in the IOP’s Energy 11-14 is to use ideograms or icons to represent different energy stores.

image

By analogy with the ubiquitous ’emojis’ I suggest that we should call these energy icons Enojis. Who knows, it could just catch on…

In Defence Of ‘Inadequate Philosophy’

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[B]ecause all my moral and intellectual being is penetrated by an invincible conviction that whatever falls under the dominion of our senses must be in nature and, however exceptional, cannot differ in its essence from all the other effects of the visible and tangible world of which we are a self-conscious part.
— Joseph Conrad, Author’s Note to The Shadow-Line

Anthony Radice writes a provocative blog as The Traditional Teacher: whilst I often agree with much of what he says, sadly our foundational philosophies could not be further apart.

[P]revalent theories are having a disastrous impact on the world of education. Influenced by these theories, there are many nowadays who think that materialism can be justified by statements such as ‘Evidence suggests that ‘conscience’ and ‘consciousness’ and other mental processes are products of human brain activity’.
[22/6/15]

I wrote the quoted words in the comments of the Traditional Teacher’s previous blog post [21/6/15], and I stand by them still. I would describe myself as a methodological naturalist rather than as a materialist. The label “materialist” calls to mind the seventeenth century view that there is only “atoms and the void”. This is indeed a mechanistic philosophy perhaps best described as ontological naturalism: in other words, all that exists is atoms and the void. If we know the initial states of all the particles then it would seem that we then can predict the future state of the universe at any time. This does indeed suggest that the past, present and future are pre-determined.

However, it soon became clear that such a view could not be justified. Perhaps a two-body Newtonian system can be deterministic in the sense that its past, present and future can be calculated provided enough information about its state at one instant is known. However, the lack of an exact solution to the famous Three Body Problem shows that even mechanistic ontological naturalism does not automatically entail determinism.

Since methodological naturalism does not involve a commitment to an ontology but rather to a methodology (perhaps best exemplified by the empirical sciences, but not limited to them), it does not entail a commitment to any form of determinism either.

I believe the foregoing shows that both “flavours” of naturalism do not automatically lead to determinism. Mr Radice, however, is not impressed:

Indeed, we have reached the stage where many do not hold others responsible for their actions, at least in theory. Their materialistic determinism leads them to ‘explain’ actions in psychological or social or (insert favourite flavour of determinism) terms. But this doesn’t explain anything, because it leaves out the person. It removes humanity because it removes conscience and freedom. All humanity is excused because humanity, it turns out, does not exist.

Sadly, I do not follow his reasoning. If materialism does not entail determinism (as I think I have shown above), then it does not rule out conscience or freedom or humanity. In fact, methodological naturalism leads me to conclude that there is substantial evidential warrant for supposing that they do exist. And this in spite of the fact, as Mr Radice points out, that they “are not material objects subject to laboratory experimentation”. True, but irrelevant — so are many of the entities and concepts dealt with by modern science: virtual photons for example. I believe philosopher Robert T. Pennock puts it well:

Many people continue to think of the scientific world view as being exclusively materialist and deterministic, but if science discovers forces and fields and indeterministic causal processes, then these too are to be accepted as part of the naturalistic worldview . . . An important feature of science is that its conclusions are defeasible on the basis of new evidence, so whatever tentative substantive claims the methodological naturalist makes are always open to revision or abandonment on the basis of new, countervailing evidence.
Tower of Babel, pp.90-91

Mr Radice seems to believe that since an individual neuron cannot be conscious, this means that a collection of neurons (a brain, for example) cannot be conscious simply because of the action of neurons:

But this sort of statement doesn’t explain what something is, only how it is manifested in the material realm. It mistakes symptoms for the cause. Understanding is always about finding the cause. What causes the brain activity? A human person with freedom and a conscience.
[22/6/15]

In his philosophy, neural activity is a product of consciousness rather than vice versa. This is a classic case of the Fallacy of Composition: since A is part of B, and A has property X, therefore B has property X. For example, since a single water molecule is not wet, this means that a collection of water molecules cannot be wet, therefore water is not wet. We only experience the property of wetness when water molecules combine on a large scale. Wetness is an emergent property.

Likewise, consciousness is also an emergent property. As Bo Bennett puts it:

[I]t is difficult to imagine a collection of molecules resulting in something like consciousness, because we are focusing on the properties of the parts (molecules) and not the whole system, which incorporates emergence, motion, the use of energy, temperature (vibration), order, and other relational properties.
Logically Fallacious, p.112

Essentially, Mr Radice argues that consciousness is a form of magic with no connection with the empirical universe. Such a viewpoint cannot explain why chemicals such as alcohol and other drugs affect human consciousness, or why brain injuries are demonstrated to cause permanent changes in people’s character.

And one final point:

The Nazis may have been defeated, but their idea that human beings are no more than ‘blood and dirt’ is alive and well, and very fashionable indeed. 
[21/6/15]

Nazi philosophy is not famous for its internal coherence, but the idea that empirical materialism was a major part of their worldview is not borne out by the evidence.

The party as such represents the point of view of a positive Christianity without binding itself to any one particular confession. It fights against the Jewish materialist spirit within and without . . . The leaders of the party undertake to promote the execution of the foregoing points at all costs, if necessary at the sacrifice of their own lives.
The Nazi Party Programme 1920, Article 24

More Physics Clangers

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image

Teachingscienceinallweathers highlights some disappointing Physics errors on the DfE’s National Curriculum documents for Science which have remained uncorrected for over a year (see here, here and here).

This would be bad form on, say, a school website. For an organisation that is in charge of a national education system whose elected leaders do not hesitate to label schools as “coasting” and “lacking rigour”, it is unbelievably shabby and smacks of arrogant, lazy hypocrisy. And these documents are no longer drafts: the DfE website says that “these programmes of study are issued by law; you must follow them unless there’s a good reason not to. All local-authority-maintained schools in England must teach . . . key stage 4 from September 2016.”

Some of the persistent errors highlighted by Teachingscienceinallweathers (and others, including @DrDav, @HRogerson and @miss_m_w) are:

1. The formula for kinetic energy is given as “0.5 x mass x (acceleration)^2” instead of “0.5 x mass x (velocity)^2” [p.37]

2. The formula for weight is given as “gravity force = mass x gravity constant” instead of using the correct scientific terminology of “weight = mass x gravitational field strength”. As Teachingscienceinallweathers points out, the magnitude of gravitational field strength is anything but a “gravity constant”, even near to the Earth’s surface. Similarly, stating that “potential energy = mass x height x gravity constant (g)” [p.37] invites confusion between the constant “big G” the Universal Gravitational Constant (which is genuinely a constant) and “little g” which, as noted above, is not.

3. “Charge flow = current x time” [p.37]: the phrase “charge flow” is confusing in this context. Very often, the phrase “flow of charge” is used as a synonym for “current”. I would argue that “Charge transferred = current x time” would be preferable in this case.

4. “Interpret enclosed areas in distance-time and velocity-time graphs” [p.32]: the area enclosed by a velocity-time graph represents the change in displacement; the area enclosed by a distance-time graph represents . . . erm, nothing with any physical significance, as far as I know.

I would argue that the writers of science examination questions and science specifications have tended towards the prolix over the last two decades, and I, for one, would welcome the return to the more concise but rigorous style of writing of yesteryear when an exam question could begin “A monochromatic ray of light is incident on a plane mirror at an angle of 30 degrees to the normal…” and students were expected to draw an appropriate diagram because the language was clear, formal and unambiguous.

That may indeed have been the intention of the National Curriculum writers, but they are some way from achieving it. In fact, this document is nowhere close.

My own personal bête noire is:

explain with examples that motion in a circular orbit involves constant speed but changing velocity (qualitative only) [p.31]

There is no indication that the writers intend to restrict the meaning of orbit to the celestial sense, and so it seems that it refers to motion on a circular path in general. And therein lies the problem: it might be true in cases where the radius and angular velocity are constant, but the writers do not specify this. Are they considering the motion of an object whirled on a string? Motion in a vertical circle? Motion in a horizontal circle? They don’t say. It is a fair generalisation to say that it is hard to set up motion in a vertical circle that features uniform speed without variable torque to compensate for the transfer of k.e. to g.p.e. and vice versa.

“Explanations of circular motion restricted to examples involving constant speed to introduce the concept of centripetal acceleration as a result of changing direction of velocity” is far from perfect but is, I think, more useful than the original.

In short, those who call for rigour should display rigour.