Friday, 24 April 2015

#13



SEAT
BELT

REMEMBER..
NO, NO, NO,
U-turns over
double yellow lines

10 2
Keep Hands
on wheel
10-2

           C

LeFT   B
Signal
           A

Driver’s Education

It is a promising start that the first thing on this blackboard is SEAT BELT as putting one on is the first thing one should do when getting into a car. Seatbelts have been a major contribution to road safety – they reduce the risk of fatal or serious injury in a collision by as much as 50%. Risk compensation theory, where drivers who feel safer in one way instead take risks in other ways, does muddy the statistics somewhat, but there is no doubt that it is better to wear one. Volvo’s decision to make the patent for their three-point system open and let other car manufacturers copy it for free should be applauded. (Drug companies, please take note.)

Anecdotes about car users who died terrible deaths because they were trapped by their seatbelts, or who miraculously survived a collision specifically by not wearing one abound, but whilst it is true that seatbelts may cause serious injury or death (or their non-use save lives) in particular accidents, these incidents are much rarer than those in which the use of seatbelts saves lives. The occurrence of these rare incidents is also usually much overstated, like referring to a 100-year-old who smokes 20 a day, but not mentioning the thousands who die young of lung cancer.

Cries of civil liberties regarding the mandatory use of seat belts should also be ignored – not wearing a seatbelt is not a victimless crime when an unrestrained body becomes a lethal missile for other car occupants. Even for accidents involving just a single driver the cost to society of more serious injury or death cannot be discounted. Clunk click every trip.

As a side note, another safety issue to note before even getting into a car is that bare or stockinged feet are not recommended behind the wheel. They are also unacceptable in a classroom situation and the teacher should enforce this for both theory and practical driving lessons.

It is also good that the dangers of U-turns over double yellow lines (the road marking indicating the division between oncoming lanes in this jurisdiction) are being highlighted. The chalk marks around ‘U-turn’ indicate a thorough demonstration of what a U-turn is with several such manoeuvres clearly shown. This kind of diagram, combined with the repetition of the drawing action can particularly help visual learners who might be struggling with the concept of ‘U’. There might indeed be another such demonstration below the words ‘double yellow lines’ to give extra reinforcement to the point, unless those are meant to be double yellow lines, in which case they are a rather poor effort, being neither yellow nor entirely double.

Whilst at one time ‘10 and 2’ was indeed the preferred position for hands on a steering wheel (although this diagram actually shows something closer to 10:30 and 1:30), the advent of power steering means that the extra leverage gained by beginning a turn with a larger downward movement is no longer necessary. Indeed, the advent of airbags means that ‘10 and 2’ is actually dangerous, with the airbag explosion turning the driver’s hands and forearms into face-seeking projectiles. ‘8 and 4’ or ‘9 and 3’ is now the recommended configuration – it is clearly time to update curriculum materials and send this teacher on a refresher course. Indeed the entire concept of using an analogue clock as a reference is rather outdated – perhaps iPod controls would be more relevant to this cohort, so instead of ‘hands at 9 and 3’ they would be taught ‘hands at skip back and skip forward’.

In the overtaking manoeuvre diagram, the curved arrows showing the overtaking vehicle’s path show that it approaches dangerously close to car B before swerving sharply into the oncoming lane, possibly even clipping the rear bumper. Such manoeuvres should be planned further in advance, executed more smoothly and not bring vehicles into dangerous proximity with each other.

The left signal (or ‘LeFT Signal’) also comes far too late to give other road users warning of the driver’s intentions. Remember: mirror, signal, manoeuvre, not manoeuvre, signal, learn how to use lower case letters.

It is also worth noting that 32% of jurisdictions drive on the left (and rising – the last right-to-left switch was in 2009, whilst the most recent left-to-right change was over 30 years before that), so in those parts of the world this last diagram would show an undertaker rather than an overtaker – something that the learner driver might need if she follows those arrows.

5/10 Good work on buckling up, but the rest of the ideas need bucking up.

Thursday, 5 January 2012

#12



45Rh
102.906
Rhodium

9F
18.998
Fluorine

4Be
9.012
Beryllium

57La
138.906
Lanthanum

C2H6O Example 1
  H H
  | |
H-C-C-O-H
  | |
  H H


Chemistry – A-level standard.

Education cutbacks are clearly hitting hard – this establishment can only afford a periodic table with four elements, and a hand-drawn one at that. Though not displayed in the correct order, all the information about the elements is correct, with the exception of lanthanum’s atomic weight. According to IUPAC, to three decimal places this should be 138.905 instead of 138.906 (actually 138.90547, so the rounding error is not great). Analysing the history of IUPAC’s regular redefinitions of elements’ atomic weight (as scientists become more accurate in their measurements) it can be deduced that not only is this teacher using a hand-drawn periodic table containing only four elements, but that it is at least seven years old (lanthanum's atomic weight was first published as its current value in 2005) and possibly dates back as far as 1969 (when 138.9055 replaced the previous figure of 138.91). Highlighting tiny discrepancies in atomic weight may seem like nitpicking, but it is this kind of fourth decimal place analysis that led to the discovery of deuterium.

What kind of chemistry can be taught using just these four elements is unclear - even the ancient Greeks thought there were at least five elements (according to Aristotle, air, fire, earth, water and aether - none of them actually elements). Fluorine will bond with pretty much anything, so that’s a good start, but not much useful can be made with them together. Lanthanum fluoride can be used as an ion-sensitive electrode, and beryllium fluoride is used in liquid-fluoride nuclear reactors, but you’d have a hard time making the rest of one with just rhodium and lanthanum. Indeed it is ironic that these impoverished students will be devoting a quarter of their time to studying rhodium, the most expensive element that it's actually possible to buy.

What is also ironic is that none of these elements are actually used in Example 1, which uses the much more common (though sadly unknown to this institution) elements of hydrogen, carbon and oxygen to make ethanol. It would be more useful to give the molecular formula of C2H5OH rather than the empirical one, to distinguish it from dimethyl ether, but the structure shown is correct. It’s just a shame that it will mean as much to these students as lanthanum would have done to Aristotle.

6/10 A good effort in trying economic times.

(Many thanks to Vytautas for sending this picture in.)

Thursday, 24 November 2011

#11



CREATIONISM
YES!

DARWIN = CRACKPOT

DARWIN BELIEVES ->
FISH->MONKEY->GLEN->[WO]MAN
WRONG

MID-TERM
ASSIGNMENT
ESSAY –
RELIGION AND
CREATION OF THE WORLD
5000 WORDS
DUE FRIDAY

Biology – GCSE level.

The creation-evolution controversy, particularly its place in the classroom, is undoubtedly a hot topic du jour. Contemporary reaction to Darwin’s theory of evolution was in many ways less critical than that of today. A post-First World War surge of opposition to the idea of evolution, culminating in the Scopes monkey trial, has led to creationism (latterly in the guise of intelligent design) being taught for decades in US schools. The level of scientific support for evolution is overwhelming, but still the debate rages.

The idea that humans evolved from monkeys (or monkeys from fish) is a common misconception of Darwin’s theory, which actually proposes that humans and monkeys share a common ancestor that lived about 40 million years ago. It is also wrong to state that Darwin believed that humans evolved from monkeys via Glen (presumably the ‘missing link’ so beloved of creationists). A number of transitional fossils have been found to support the hominid evolutionary record, including Lucy (Australopithecus afarensi) and Ardi (Ardipithecus ramidus), but as yet there is no Glen. Such a discovery would surely only weaken the creationists’ standpoint.

The decision by the Kansas State Board of Education to allow the teaching of intelligent design as an alternative to evolution was challenged by concerned citizen Bobby Henderson, who called for Flying Spaghetti Monsterism, his belief in a supernatural creator that closely resembles spaghetti and meatballs, to also be allotted equal time in science classrooms. The idea of a parody religion is not new – Bertrand Russell’s celestial teapot is the most famous argument that the philosophic burden of proof lies upon those who make unfalsifiable claims, not on those who reject them. Calls have also been made for physics teachers, alongside Newton’s law of universal gravitation, to teach intelligent falling. President Bush endorsed the teaching of intelligent design alongside evolution, stating, "I felt like both sides ought to be properly taught … so people can understand what the debate is about.” This is apt when he is perhaps the closest thing to a missing link yet found.

If creationism is to be taught in schools, then it should not be in the science classroom, but as a separate subject of politics of science and religion. And it should certainly be more balanced than simply calling Darwin a crackpot. Charles Darwin is one of the most influential figures in human history, and has the ultimate accolade of appearing on the back of an English banknote. What next: Elizabeth Fry = wally? Boulton and Watt = bozos? Adam Smith = nincompoop? (His name has been appropriated by the Adam Smith Institute, responsible for recommending the privatisation of British Rail and the introduction of the Poll Tax, so maybe the jury should stay out on that one.)

A ‘WO’ has been inserted in front of ‘MAN’, pointing out that the gender-neutral ‘human’ should perhaps have been used (despite the original use of ‘man’ as being a gender-neutral indefinite pronoun). Whilst this kind of direct linguistic rejection of a patriarchal hegemony might seem a little ‘bra-burning wimmin’ now, it provides a welcome relief to all the other conservative, reactionary nonsense.

A 5000 word essay by what is presumably this Friday is a tall order, but if God made the world in six days then it should be doable.

0/10 See me.

(Many thanks to Wayne for sending this picture in.)

Thursday, 10 November 2011

#10



WORK HARD AND DO YOUR BEST

X| | 
 | |O
 |X|

Lessons in Life – universal
Computer Science – A-level/undergraduate level

There can be few better exhortations to students than this. Working hard and doing one’s best will always produce the finest possible results, either in the classroom or on the playing field. After any exam or sporting challenge there is no failure if one can say afterwards “I did my best”. (England footballers please take note.)

A game of noughts and crosses is underway on the blackboard. If this has been done by a student then it should have been rubbed off immediately (see post #9 re Wilson and Kelling’s broken windows theory). But if this is actually part of the lesson then a gold star should be awarded as noughts and crosses is a great introduction to many mathematical and computer science concepts from combinations and symmetry to artificial intelligence.

A first question to pose to the class would be how many games of noughts and crosses are possible (the game tree size)? A naive answer would be 9! = 362,880 (assuming X always goes first). However, many games will be over before all the squares are filled, and many more are simply rotations and reflections of others (in effect there are not nine, but only three starting places: corner, centre and edge). Taking these into account gives an answer of 26,830.

Devising an algorithm to produce perfect play is also a favourite challenge, exploring ideas such as backwards reasoning and recursion. These can then be applied to other, more complex games such as Connect 4 and draughts, through to unsolved games such as Reversi, chess and Go (with its game tree complexity of 10360).

However, if this is an attempt to teach the strategy of perfect play then one must hope that the teacher has picked a very poorly-played game to illustrate what not to do. Assuming that X’s first move was in the corner (always the best start: of the then 73 possible games, assuming perfect play on X’s part, 71 result in victory and two in a draw), then O has immediately blundered by playing the far edge instead of the centre (where his/her only hope of a draw can come from), resulting in what should be certain victory for X. X could then force a win by playing the centre, but has him/herself blundered by playing middle bottom. O can now snatch a draw from the jaws of defeat by playing centre or top right, leaving X to harp on about how the Wags should have been allowed to stay in the team hotel.

Despites its pedagogical pedigree, noughts and crosses quickly becomes futile when both players can easily force a draw. This was well-illustrated in WarGames, when the military supercomputer, equating the game to global thermonuclear war, evaluated all possible outcomes and remarked, “Strange game. The only winning move is not to play.” Failing that, just work hard and do your best.

8/10 An inspired choice of teaching material.

Monday, 31 October 2011

#9



Dr Lagina’s Math tutorial

√24/√3 = √(24/3) = √8

= √(4.2) = √4√2 = 2√2

√(81/25) = √81/√25 = 9/5

MOZ

Detention
Bramm S
Blake F
Morty
Hailey Y
Jordan A
Kara B

Mathematics – A-level standard.

These are some good examples of operations with surds, using the rules for both multiplication (n√(a.b) = n√a.n√b) and division (n√(a/b) = n√a/n√b). All the working is correct. The sloppy square root sign in the second example extending over the equals sign could be confusing, and handwriting in general isn’t great, but is legible.

Unfortunately, despite this good academic work, Dr Lagina is entirely unsuited to a career in education due to his surname. It would be no use trying to insist on a different pronunciation such as La-GHEE-na as students of any age will still make cruel remarks – it is little wonder that his detention list is so long. It is a shame that no careers officer ever tried to dissuade him from his current employment path, though he is still young enough to change his vocation. It is either that or change his name: even a teacher should be able to afford the £33 fee for a Deed Poll, though perhaps he has already changed it from something even more embarrassing, like Dr Lesticle, Dr Lyphilis or Nick Clegg.

There are a couple of other points to make. Firstly, a different hand has scrawled MOZ on the blackboard. According to Wilson and Kelling’s broken windows theory, a disordered environment signals a place where people do as they please and get away with it without being detected. Like the New York City Transit Authority removing graffiti from their trains leading to a sudden and significant drop in petty and serious crime, this should have been wiped off before the lesson began in a zero-tolerance approach. Not restoring a disordered environment early means that classroom discipline will only deteriorate, a fact surely worsened when one’s surname rhymes with a part of the female genitals. Whether Moz is the Morty who appears on the detention list, or just a deranged Morrissey fan is not clear.

Secondly, the appearance of Bramm S on the detention list raises the questions of how many students with this unusual name there are in this class that they need to be differentiated by their surnames, and whether this is a class consisting entirely of Gothic novelists, though there is no sign of Mary S or Edgar A P, and the works of Jordan A and Kara B must have been sadly lost to the world of literature.

8/10 – Good work, though loses a mark for ‘math’. And remember that sticks and stones may break your bones, but being called Dr Vagina every day of your working life will never hurt you. Though it may cause a career-ending nervous breakdown.

(Many thanks to Wim for sending this picture in.)

Saturday, 15 October 2011

Break Time!

Just to say that there will be a short break from lessons whilst we at Blackboards in Porn Towers stop looking at pornography for long enough to move to bigger premises. In the meantime, please do browse the archives.

Thank you to everyone for your comments and for sending in so many great images of blackboards in porn. We have been deluged with a shedload* of pornography, but hope to get through the backlog and posting reports again soon. It's a tough job, but somebody has to do it.

(* The SI unit of pornography)