Friday, July 31, 2015

Farleigh Castle, Bradford on Avon and some other stuff

Sun and calm tempted us out today, a forty minute drive to Bradford on Avon by way of Farleigh Castle.

Clare at Farleigh Castle

Farleigh Castle

Clare in St. Thomas Moore Catholic Church, Bradford on Avon

The bridge over the Avon in the centre of town

St. Margaret's Stairs featuring the author, distracted

The author at the footbridge over the Avon
You knew that Avon comes from the Welsh Afon, meaning river, didn't you? Those early Anglo-Saxons, so easily befuddled when conquering the local Celts.

What did we do in Bradford on Afon? After parking at the railway station we meandered into town, walked the fifty yards of The Shambles (the old medieval market) and ended up next door in the Dandy Lion (think about it) pub.

The Dandy Lion pub

We then crossed the road and saw the Catholic Church, the former Town Hall, and stepped inside. Next we ambled on down to the river where we crossed at the footbridge and considered what to do next: walk by the riverside or visit the museum? We decided on the latter and strolled the few hundred yards to its probable location where we failed to find it. We popped into the library to ask and were told it was actually upstairs. Sadly, due to a shortage of volunteers it was closed.

Back across the road and we were at the tea house next to the Tourist Information shed (yes, it was no more than a shed). Two Americanos, a relax in the sun and it was back to the car - just under two hours.


Did you run SETI@home on your computer in the old days? Made a very nice screen-saver as well as doing good, back when we believed in aliens beaming out radio signals. Then they moved it onto BOINC, a general purpose platform, and it got really hard to install and manage, so I abandoned. The years went by.

Today I decided: why not? Do some good: not with SETI@home but with some of the other volunteer-computing projects, you know, protein-folding, analyzing CERN-LHC results and that kind of stuff. So I got myself into the process and found that these days it's not just BOINC you download but a virtual machine box as well (I won't bore you with why).

I did all those things - took a while - and finally I was in the BOINC/BAM project management website environment and had opened an account. And again, it's as hard to manage as ever. I have no idea what all those projects actually do (there are quite a few now) and it doesn't seem at all easy to subscribe to them. Let's just say I tried but nothing much seemed to happen.

I'm sure if I invested a day of my time I could get on top of the offerings and figure out how to download and run the projects of my choice, but .. why is the entry bar so very high? Most people will just back off and bin this whole thing in the 'too difficult' bag.

So many potentially useful sites are ruined by completely neglecting user-interface design and the nature of the user experience. It's a kind of design-autism.

Update: (Aug 2nd): Just to add insult to injury, the Oracle VirtualBox download stopped my Epson printer working. It's now been uninstalled, along with BOINC. Shame.


Yesterday I completed lecture 6 of Professor Susskind's General Relativity course. He was talking about photon orbits around a Schwarzschild black hole and the experience of a falling into a black hole past the event horizon: the infaller gives a very different account to that of an observer remote from the event horizon.

This is an advanced undergraduate class at Stanford University so the mathematics Susskind deployed included generalized coordinates, the Lagrangian formulation of classical mechanics, multivariate calculus and he already covered the basics of differential geometry and tensors. Yet every mountain you climb in physics is just a foothill to a higher range of apparently inaccessible peaks. Susskind gave an incredibly hand-wavy account of the maths underpinning the two observers' very differing observations (one infalling, the other stationary but remote) by looking at hyperbolic coordinates and a transform into the curved spacetime of the Schwarzschild metric.

We haven't got anywhere near the field equations yet.

Thursday, July 30, 2015

The Once and Future Kevin

Few things that Kevin did were unplanned. He thought he was the anchor to his flighty wife Suzanne, the person who smoothed the way, anticipated all of life’s little difficulties. But Kevin was aware that one day he would die. What would Suzanne do without his helpful guidance?

He had heard of email systems which would send a missive at a future date of your own choice. Why not send a note from beyond the grave, perhaps every year, on her birthday? Kevin immediately fired up Word and began to draft. But what could he write? Being dead, he would know nothing of the news, or Suzanne’s predicaments. Perhaps he should compose nostalgic text, recalling their life and times together?

Honestly, he couldn’t summon up the energy.

Instead, he downloaded the ‘Eliza’ program, renamed it ‘Kevin’, and began to improve it. After some months, ‘Kevin’, running on a Google server, could: - access Google News; apply Kevin’s unique take on the world (Kevin had coded himself into the rules engine); and could potentially send emails to Suzanne and even somewhat understand any replies (which was roughly Kevin’s own level of personal competence).

To be on the safe side, ‘Kevin’ sent monthly emails to Kevin, and if Kevin were to miss two replies in a row, ‘Kevin’ would presume him dead and immediately switch to sending timely and relevant messages to his grieving widow.

To his great surprise, Kevin died.

Suzanne was initially quite discombobulated by her husband’s demise. Freed from his smothering routines, she now had to think for herself. After a few weeks she pulled herself together and joined the local tennis club. There she met the handsome and charismatic coach with whom she rapidly developed a warm and affectionate relationship. Coincidentally, he was also called Kevin.

Suzanne never did look at her old email account, sharing her new partner’s instead. She had never got on with computers anyway. All is change in the world of the Internet and ‘Kevin’ was soon off-line in one of Google’s periodic efficiency drives, dumped into archival storage.

But Kevin had one consolation: at least Google never truly forgot him.


(c) Nigel Seel, 2015.

Afterword: Eliza (a nondirectional psychotherapist) would be interested in why I keep returning to this theme. For evidence I point you to my earlier story, 'Dave declares'.


Eliza Doolittle
Just loaded the Prolog implementation of the famous 'Eliza' from the Internet (here, heroically coded by Viren Patel back in 1992). Amazingly it runs without problems on my SWI-Prolog system. Here's a test dialogue .. just a moment ago.

Hello. I am ELIZA. How can I help you?
> I am sick.

I am sorry to hear you are sick.
> Ask me why I am sick

Do you think coming here will help you not to be sick?
> I'd like to think so.

I am not sure I understand you fully.
> Are you ever sick?

Why are you interested in whether I am ever sick or not?
> You interest me.

Why do you think I interest you?
> Because you're tantalising.

Is that the real reason?
> Yes, you interest me.

You seem quite positive.
> I am, very positive.

Is it because you are very positive that you came to me?
This is the point where the content-less nature of the dialogue begins to pall. Still, I think Eliza is fixable: insert a knowledge-base and reasoning system between the input and output processing and 'Eliza' suddenly becomes a lot less vacuous.

I feel digital immortality coming upon me by stealth ..

Wednesday, July 29, 2015

Avoiding left recursion

A reminder of why I had (and still have) some qualms about Prolog, elegant though it is. We're told that Prolog programs are to be read declaratively, as specifications - don't think about the execution model! So pretty much my first SWI-Prolog program is this simple statement of likes below. To make it more interesting, I (counterfactually) state that 'likes' is transitive. So this is the program you get.

Program (wrong)

likes(puss-puss, voles).
likes(adrian, football).
likes(adrian, puss-puss).
likes(alex, jokes).
likes(alex, adrian).

likes(X, Z) :- likes(X, Y), likes(Y, Z).   %  transitivity of 'likes'

And this is what you see when you run the program with the query likes(alex,Y) where the intention is to list all the things Alex likes.


?- likes(alex, X).
X = jokes ;
X = adrian ;
ERROR: Out of local stack

What has happened is that the two facts:

likes(alex, jokes).
likes(alex, adrian).

were matched, then the 'transitivity' clause was invoked, which unfortunately matched itself repeatedly in an infinite loop, until the interpreter ran out of stack space. No problem with the program declaratively, but operationally it loops.

Here's the correct program with the results.

Program (correct)

likes1(puss-puss, voles).
likes1(adrian, football).
likes1(adrian, puss-puss).
likes1(alex, jokes).
likes1(alex, adrian).

likes(X,Y) :- likes1(X,Y).
likes(X, Z) :- likes1(X, Y), likes(Y, Z).   % to stop left recursion, likes1 is first.

Result when executed

?- likes(alex,X).
X = jokes ;
X = adrian ;
X = football ;
X = puss-puss ;
X = voles ;

Even this simple program has a small capacity to surprise: how did it figure out that Alex likes voles?


Note: this post is executable by pasting into your favourite interpreter such as here (click on 'create a new program' once you closed the annoying 'Limited Edition!' window).

When copying from here don't forget the top slash-asterisk and the bottom asterisk-slash sign below, plus the full stop after the query likes(alex, X). For extra credit, try likes(Y, voles).  to illustrate Prolog running backwards.

Tuesday, July 28, 2015

A garden in summer

A trip to Wroughton, near Swindon today to visit my mother (with Elaine, pictured below). The hospice is next door to where she's staying and the gardens (and coffee shop) seemed a nice place to visit. A little video follows the picture. The word 'summer' is being used here in a purely calendric way as the mode of dress suggests.

The public garden at the Prospect Hospice, Wroughton

Not much posting here this past week. My excuse? Family visits trash the serenity needed to compose; the Tour was on and we spent hours trying to figure out whether Contador and/or Nibali were suffering post-juice burn-outs; plus not much new was really happening in the world worth commenting on.

Still, all that stuff is behind us now. I was about to install SWI-Prolog and then got diverted with backing up my data (to numerous hard disks and scattered USB drives - you can't have too much security!). Turns out that when your datasets are in the tens of Gigabytes and you need to encrypt (security!) this takes a while - like a day. So that was Monday and I'm finishing off things this afternoon. Prolog tomorrow?


OK, we cracked: I put the central heating back on this evening.

Wednesday, July 22, 2015

Those that, at a distance, resemble flies

This blogroll classification amused me:
  • Those that belong to the emperor 
  • Embalmed ones 
  • Those that are trained 
  • Suckling pigs 
  • Mermaids (or Sirens) 
  • Fabulous ones 
  • Stray dogs 
  • Those that are included in this classification 
  • Those that tremble as if they were mad 
  • Innumerable ones 
  • Those drawn with a very fine camel hair brush
  • Those that have just broken the flower vase 
  • Those that, at a distance, resemble flies
Taken from 'Celestial Emporium of Benevolent Knowledge' (Spanish: Emporio celestial de conocimientos benévolos), a fictitious taxonomy of animals described by the writer Jorge Luis Borges in his 1942 essay "The Analytical Language of John Wilkins" (El idioma analítico de John Wilkins).

Tuesday, July 21, 2015

The story of our new path

Alex has been put to work this week on his 'staycation' with us: project 'pathfinder'.

The laying of the edging

The excavation of the rubble

The caching of the surplus aggregate (as dug up)

The gravel awaiting (one ton!)

The finished product

The mission pathfinder complete!

Those that, at a distance, resemble flies

The worker refuels
We have a path!

Goodbye Marissal Road

We moved into our council house in Henbury, Bristol in 1954 when I was three. The three children grew up in it and one by one we all left. My mother was the last to vacate the property, after more than fifty years, and so today the house was cleared. I was there before 8 am this morning and took this video tour while waiting for the house clearance team from the British Heart Foundation.

The BHF team were efficient and were done by lunchtime. On my return to lock up, I took these final pictures.

The master bedroom

The back bedroom - most of us occupied it one time or another

The 'box' room - mine while at secondary school

The hall and front door

The kitchen leading to back garden

The living room, looking to the back garden

The living room at the front
It all looks rather forlorn. Pathos turned to bathos when I turned up at the Lawrence Weston 'Citizen Service Point' to hand in the keys. The council employee checked the address on the computer and could unearth no evidence that Bristol Council was aware the property had been vacated. Yes, they had lost my 'notice to quit' letter of three weeks ago.

I am wise in the Kafkaesque ways of public bureaucracies. Calm, calm, calm. Under instruction I wrote a lengthy, handwritten letter outlining all the facts of the case with dates and events, and ended by pleading with the anonymous council recipient to please accept the original termination date despite the absence of said 'quit notice' in their filing system.

We shall see whether such grovelling saves some gratuitous rent payments.

A late birthday present

I went to see my mother today (with Elaine) in Wroughton while the BHF team were house-clearing. We visited the park, fed the homicidal seagulls and watched kids trying to fend off dinghy collisions on the lake. At the end there was a late birthday present for Clare.

We were baffled as to what the heavy cylinder was. I speculated variously on pickled onions and manuka honey. The reality was considerably more wonderful.

A scented candle

It's currently brightening up the hall in olfactory mode - it almost feels wrong to light it.

The English summer and its sunbather

Clare sunbathing in the West Country summer

That jet stream has a lot of explaining to do!

Sunday, July 19, 2015

A psychological assessment (1994)

Twenty one years ago, in 1994, I moved from the Bell-Northern Research (BNR) Systems Engineering Division in Harlow to their main offices in Maidenhead, where I would be working in a new telecoms consultancy group under its director, Ken E.

Ken was an interesting person. He had been a founder member of the Maidenhead organisation back when Northern Telecom had set it up. Unlike his colleagues though, he had never been promoted. The reason, I think, was his personality: in Myers-Briggs terms I would guess he was ENFJ and what this meant in practice was that he was driven more by moral imperatives than by utilitarian pragmatism. Unfortunately, it is the latter which works best in business.

Ken was initially pleased with his new recruit, but couldn't figure me out at all. He arranged for me to be evaluated by a psychologist so off I went one morning to a local business centre where I was interviewed at length, and underwent multiple tests. The creativity test was the pretty useless 'how many uses can you think of for a brick?' though to be fair, creativity testing has hardly advanced since then.

I was given a copy of the psychologist's report, which I include below (I already published this ages ago). Before you conclude I'm just blowing my own trumpet, I hasten to add that the psychologist would have known that BNR did not commission expensive psychological evaluations for absolute dummies - he was obviously going to write a pretty positive report.

One conclusion the expert came to was that I was not altogether brilliant at interpersonal relationships. I proved him entirely correct in the most devastating way. Soon after the test I complained to Ken that I was underpaid and under-promoted for the tasks he had asked me to do. Ken agreed, and behind the scenes moved heaven and earth to get me a sizeable pay award and increase in status.

Soon I was called into his office where he was pleased to tell me of his success. I took the news with considerable equanimity. Ken was highly affronted, mentioning that the least I could have done was to thank him. I seem to recall replying that I believed I was finally being paid at the correct level and that it was surely his job to arrange things like that - I didn't believe that he had done me a favour as such. Given Ken's personality type, I suppose it was inevitable that he never forgave me, and in fact pretty much refused to speak with me after that.

Luckily, around that time I moved (or was moved) out of his group, initially to the 'Multimedia Carrier Switch' new product development and then to the Cable & Wireless account team as technical architect for the Network 2000 project. I still cringe at the memory, however. It was very far from my finest hour.


Psychological Assessment

Name Nigel Richard SEEL
Date of Birth 1951
Age 43


1962-68 Bristol Grammar School
A(S) level passes in: Pure Maths A(1) Applied Maths B(1) Physics A

1969-71 University of Warwick
Completed 1st year (Maths/Physics/Engineering) and 2nd year (Philosophy/Politics)

1972-74 University of London Teaching Certificate

1978-84 Open University BA Hons (1st) Maths & Computing

1985-89 University of Surrey PhD


1971-72 ILEA Clerical work
1974-77 Various schools Maths teacher in London & Liverpool
1977-82 Software Houses, Programming etc
1982-91 STL Researcher, project manager, department manager
1991-94 BNR Manager, Network Planning, Europe Systems Engineering Division


Dr Seel, as his later academic record might suggest, has exceptional intellectual ability. Compared to senior managers as a group, he is outstanding on numerical, logical thinking, verbal and imaginative thinking abilities. Not only does he possess great power of intellect, he can apply it effectively at considerable speed.

Numerical Ability

His score on the test of his ability to make correct decisions and inferences from numerical and statistical data was outstanding and places him in the top 5% of senior managers. He worked with great speed and a high level of accuracy.

Verbal Ability

He attained an outstanding score, in the top 10%, on the test of vocabulary and verbal reasoning. In conversation, he chooses his words quite carefully, and communicates his ideas clearly and succinctly.

Logical Thinking

His performance on the test of critical thinking, covering the dispassionate analysis of information, arguments, inferences and deductions, was outstanding and puts him in the top 15% of senior managers. He has exceptional analytical ability and can apply it rapidly to problems.

Imaginative Thinking

The test of the quantity and quality of his ideas showed him to be above average on the former and outstanding on the latter. He can see aspects of problems or situations that few other people would think of; he has considerable imagination and a capacity for lateral thinking. Indeed, his responses on this test hardly overlapped at all with the kind of answers given by most managers.


General Approach

Dr Seel has a balanced and effective approach to his work, combining ample energy with a sensible amount of planning. He is very logical and systematic, and will apply himself with great diligence to the task in hand. He is meticulous and probably expects others to be likewise. He has the ability to deal with several different projects simultaneously and to respond to changing circumstances in a flexible manner.


He has an average level of drive and will pursue his objectives in a single-minded fashion. He will apply himself in an economical and well-organised manner, and should achieve good productivity.

Quality of Work

He is quite thoughtful and will take the wider strategic picture into account when making plans. His excellent intellectual ability will be evident in most of what he does, though there may be times when his more imaginative and wide-ranging perspective could make him appear to be slightly out of step with those around him.

Mastery of Detail

He has a good eye for detail and will give it the attention it deserves, without letting the broader view get obscured. He is able to trust subordinates enough to delegate to them.

Decision Making

He will err on the side of caution, though not to an extreme degree. In most instances, he will evaluate the evidence quickly and dispassionately before coming to a decision. His excellent analytical powers should help him to arrive at sound and reliable judgment

Tolerance of Pressure

Dr Seel is emotionally stable and usually well-controlled, though on those rare occasions when he does lose his temper there will be no mistaking it. He does worry about his work and may lose sleep over difficult problems, but this is unlikely to affect him. He has the resources of drive and - especially - of intellect to cope with pressure.


Whilst he will make plans and try to stick to them, not least where they relate to hitting deadlines, he is sufficiently flexible to be able to adapt to new circumstances, and to do so with unusual speed and clarity of thought. His capacity for imaginative thinking will help him to respond innovatively to new challenges.


After what might be seen as a rather slow start to his career, he is ambitious and clearly aspires to reach the top levels. He has the intellectual confidence to believe that he can make a contribution at a strategic level, and the motivation to do so; he has a strong need to achieve. At present, he feels frustrated by the position he is in compared to what he feels is his potential.


General Impact

Dr Seel has a slightly unorthodox style that might initially be slightly off-putting for some people. He has a reasonably friendly manner, but he is not inclined to let what he would see as loose assertions or superficial thinking go unchallenged. He is quite careful in choosing his words, and perhaps wants others to be similarly precise. He does not like to be neatly pigeon- holed by those he meets, and indeed they may find it hard to classify him. His slight shyness may also detract from the first impression he makes.

Relationships with Superiors

Superiors will find that he is his own man; he is independent minded and very confident of his own intellectual ability. For some bosses, he could be a rather threatening subordinate. Whilst he is supportive and keen to try to achieve the goals set, he is not someone who will just keep his views to himself. He will want to say what he thinks, and he will put over his ideas with both logical argument and conviction. However, he is sufficiently open-minded to take on board alternative ideas if they are good, and he will try to see the viewpoint of those above him.

Bosses will find that he expects to be given his objectives but little more - he does not welcome hands-on management. He has plenty of initiative and is keen to take on more responsibilities. He will be reasonably honest in the way he communicates with his superiors, and will want them to be straight with him. He is not inclined to give respect to individuals simply on the grounds of rank; he wants to see evidence of commitment and ability.

Relationships with Peers

He is a trifle introverted and not all that socially outgoing by nature. However, peers will find that he is strongly team- oriented and keen to facilitate their efforts to achieve the objectives set. He is reasonably patient and tolerant, though he will tend to come down fairly quickly on what he sees as sloppy thinking. Peers will appreciate the quality of his intellect and his capacity for ideas. He will influence them through his expertise and competence rather than dominating by force of personality. At times, he may not be all that good at reading the motivations and reactions of those around him, but he will try to respond positively to his colleagues' needs.

Peers will find that he does not identify in an emotional way with his own ideas, and that he is objective in assessing them against differing viewpoints; however, he is likely to be right more often than are most people. Peers will find that he is quite serious-minded and very conscientious in his attitude to his work.

Relationships with Subordinates

Subordinates will find that he starts off with them on the basis of trust, and that he will give them a good deal of autonomy until or unless they prove that they are not capable of handling it. He will delegate sensibly and organise the work of those under him in a thoughtful manner, giving due consideration to their own development and need to learn. He will be a fair and usually patient boss, though his intellectual ability and confidence may sometimes have a more over-powering effect on those under him than he imagines.

Although he will try to operate a consultative style most of the time, he is capable of taking a tougher and more directive approach where necessary. He will set high standards and expect his subordinates to show the same commitment as he himself does. Staff will find that whilst he allows freedom and scope for initiative, he will monitor progress quite carefully.


Dr Seel is a little unusual in various ways, which has some positive and negative consequences. He is exceptionally intelligent and shows outstanding intellectual abilities across the board. He possesses the capacity to see beyond the more obvious aspects of a situation and to think in a more lateral way. Despite these attributes, and to some extent because of them, he has not followed an altogether normal education and career path. After a slow start, he is making up for lost time, and is clearly ambitious. He has a need to achieve and to work to the limit of his considerable potential.

His approach to his work is a serious-minded and committed one, and he expects much the same from others. He has a reasonable level of energy and drive, but his style rests more upon his intellectual powers and his ability to analyse logically and quickly. His decisions on technical matters will be well-judged and he will show a good grasp of detail. He is meticulous and careful, and will strive to be precise. Although emotionally stable and usually well- controlled, he can lose his temper and his restraint on rare occasions.

Dr Seel does not like to be put into a category or "typed" in any way, and it is probably quite difficult for people to feel they have an understanding of him on first meeting. He has a tendency to question and to probe in a moderately sceptical style, and whilst this is not done in an aggressive way, it is possible that he could be perceived in a more threatening manner than he realises. This is not helped by his intellectual confidence which, while well-founded, may be seen as challenging by some superiors. He could be viewed as intellectually arrogant, but this would be somewhat unfair to him; he is quite objective and open-minded, and strongly team-oriented.

His own ambitions are not pursued at the expense of others, and he will try hard to facilitate the success of his colleagues. He is quite a friendly and patient man, but he will be quick to identify what he sees as sloppy thinking and lack of precision. Subordinates will find that he is willing to delegate and to trust them enough to give them scope for initiative, though he will monitor their progress quite carefully. They will find that he is demanding but fair. He will want to be given as much freedom as possible by his own boss; he does not like hands-on management. He is not inclined to respect superiors simply on the grounds of their position; they have to be highly competent and committed as well.


Main Assets

- Exceptional intellectual ability on all domains tested
- Likely to achieve work of high technical quality; meticulous
- Plans ahead sensibly and is able to see the strategic picture
- Emotionally stable and can cope with normal pressures
- Confident in his ability and well motivated; has a strong need to achieve
- Likely to be imaginative and innovative in approach, without taking undue risks
- Generally positive in his attitude to others; quite friendly
- Strongly team-oriented; cooperative and constructive in trying to work with peers and subordinates
- Quite objective and fair-minded
- Willing to trust those under him and to delegate accordingly Main Limitations
- A trifle shy and may not make the best impression on first meeting
- Could be perceived as too challenging and threatening by colleagues who lack his intellectual confidence
- Not especially good at anticipating the reactions and motives of those around him


Dr Seel has considerable potential, though precisely which direction it should be developed in is not completely clear. The problem is that he is capable of making at least a reasonable job of almost anything; he has a balanced and quite flexible style, and a conscientious attitude to his work, along with his outstanding intellectual powers. If he has limitations, they are probably in the interpersonal realm, and they relate more to the impression some colleagues may form of him than to any fundamental problems. His intellectual level and his ability to take an independent and possibly even unorthodox perspective on an issue may make him seem out of step and perhaps awkward to deal with at times.

He is not sufficiently outgoing and socially confident to be very adept at dealing with people; his approach is rather honest and straightforward, which could work against him on occasion. It may be that he does not "sell" himself all that well. Longer exposure to him should convince colleagues of his basically very positive attitude to them, however.

He clearly feels considerable frustration at his present level of work, and believes - with justification - that he can contribute at a higher and more strategic level of the business. His powers of analysis and his capacity for lateral thinking suggest that he has a lot to offer in the areas of planning and strategy. For the future, however, he should perhaps seek to get some more feedback on the impression he makes on people and on his style of communicating with them; formal training inputs may be useful here. It may be that he will not be able to exert the influence he deserves until he has developed further in this respect.


So how did the psychologist's predictions work out over the next twenty years? Check my CV.

Clare at 64

Clare's birthday. And here she opens her present and I check out her cards.

We celebrated Clare's birthday with lunch at the Queen Vic, Priddy. Adrian drove us there and Alex got the drinks and paid the bill. At last a return on our investment.

During the meal, which we ate outside in the sunshine and which was very pleasant, one of the table umbrellas was caught by a gust of wind and ended up on the roof. A little later, there was a sound of breaking glass as a barmaid tripped on the step and dropped the pints she was carrying. She was not badly hurt.

Pretty exciting, Priddy.

Saturday, July 18, 2015

Interesting puzzle

I'm still working through Prolog, mainly using Sterling and Shapiro's book and also 'AI Algorithms, Data Structures, and Idioms in Prolog, Lisp and Java'.

And then I came across this puzzle:
A certain question has the following possible answers.
  1. All of the below
  2. None of the below
  3. All of the above
  4. One of the above
  5. None of the above
  6. None of the above
Which answer is correct?

The answer is (e) - see the comments for why - and there is even a Prolog derivation with query x(A,B,C,D,E,F) which proves it.

Friday, July 17, 2015

Litter in the park

Deborah Ross wrote in yesterday's Times:
Litter is a class issue, but why? 

I live an equal distance from two London parks. One is in a well-to-do, middle-class area and one is not. (To give you some idea of how different these parks are, when it last snowed, in the well-to-do park someone built not a snowman, but a snow-flautist, complete with twig for flute, while in the other it was a huge snow-penis, complete with huge snow balls.).

Since I'm often in both parks, what with the dog and all, one thing I have noticed is this: whereas the well-to-do middle-class park (OK, Highgate Wood) does not have a litter problem, the other (OK, Finsbury Park) seriously does.

That is, say I go in the morning: while Finsbury Park is covered in yesterday’s picnic debris, Highgate Wood is not. Different staffing levels? Highgate Wood employs more people to clear up? I don’t think so. Even while I'm walking, I see people chucking drink cans, burger wrappers, crisp packets and chicken bones all over the place in Finsbury Park in a way I never see in the wood.

So, is litter a class issue? If so, why? Particularly when it seems counterintuitive. Wouldn't the middle classes, with their cleaners and gardeners and pond hooverers — I know someone who has a man come in to hoover her pond — be more likely to think that others will step in to do their dirty work?

I have asked around and the following explanations have been offered: paying higher taxes means a higher sense of ownership of public spaces; the less well-off are more disaffected and have less interest in maintaining society’s infrastructure; middle-class culture simply pays more respect to the environment; the middle classes are restrained by social shaming (but shouldn't everyone be ashamed of dropping litter, and if not, why not?). I don’t know. You tell me . .

Once one has recovered from amazement that a Times columnist would be puzzled over so obvious a question, one feels inclined to frame an answer.

The simplest possible response is something like this:
Tidy parks are the result of tidy people, people with prosocial personality traits such as agreeableness, intelligence and empathy. Such people tend to get on in our imperfect meritocracy and thrive in the middle class. The lower classes include many who haven't got on, people who tend disproportionately to the 'dark triad' - lack of empathy, disregard for others, selfishness. For good or ill, these qualities are rather heritable which accounts for their persistence across the social classes. Hence your differential litter phenomenon.
The distinction between the prosocial and antisocial personality type is not well captured in the five-factor model. The newer HEXACO model apparently shows a greater ability to discriminate with its six dimensions of personality:
  • Honesty-Humility (H): sincere, honest, faithful, loyal, modest/unassuming versus sly, deceitful, greedy, pretentious, hypocritical, boastful, pompous.
  • Emotionality (E): emotional, oversensitive, sentimental, fearful, anxious, vulnerable versus brave, tough, independent, self-assured, stable.
  • Extraversion (X): outgoing, lively, extraverted, sociable, talkative, cheerful, active versus shy, passive, withdrawn, introverted, quiet, reserved.
  • Agreeableness (A): patient, tolerant, peaceful, mild, agreeable, lenient, gentle versus ill-tempered, quarrelsome, stubborn, choleric.
  • Conscientiousness (C): organized, disciplined, diligent, careful, thorough, precise versus sloppy, negligent, reckless, lazy, irresponsible, absent-minded.
  • Openness to Experience (O): intellectual, creative, unconventional, innovative, ironic versus shallow, unimaginative, conventional.
You can see how pro- and antisocial personality types are going to map onto this - you can seek confirmation here.

Thursday, July 16, 2015

An honest epitaph

I'm not sure that human beings are intrinsically selfish except in the 'selfish gene' concept, where genes (alleles) inhabit multiple related individuals (and this). But the rest seems spot on. Click on the image to make it larger.

Some variant might work on  my headstone, I'm thinking.

Wednesday, July 15, 2015

Unsettled days

Our pleasantly humdrum routine has been profoundly destabilized by Alex staycationing with us: many long-deferred, if not completely-ignored tasks are being addressed with Alex's characteristic whirlwind of energy.

Item: there was a curious ammonia-like smell in the kitchen, eventually tracked down to the tumble dryer. In an instant, Alex had disassembled it, exposing innards lined with five years accumulated dross which included a small colony of maggots. No doubt a small and lethally-injured vole had recently ventured that way. My mind sheers away from the unpleasant process by which the machine was eventually cleared out - fingers were used, and not mine - and the reconstituted machine sits currently in the naughty corner of the kitchen on probation.

Cleaned up, but is it truly sterile?

Item: Clare wants a path round the back of the house - the current stepping-stone-like flags no longer cut it. After much cogitation and deprecation of boardwalk possibilities (slippery when wet) she settled on gravel. An orgy of computation on Alex's part has followed with refinements including planks cut to length and endless discussions with tradespeople.
Alex's plan for the garden path

The planks for edging - to be cut tomorrow
The gravel was meant to arrive today (it didn't).

Alex has also managed to fit into today two tennis coaching sessions at the local club and has ordered a new racquet on the coach's suggestion.

We still don't really know what's hit us.

I have not managed to find a sanctuary in our house to resume my engagement with Professor Susskind (lecture 6 beckons) but Clare has fled the house,and now wanders lonely as a cloud in the garden.

Clare in the roses
In other news: Pluto has been imaged in unimaginable detail, the pentaquark has been discovered and the Eurozone is splintering as German dominance becomes impossible to cloak ...

Saturday, July 11, 2015

General Relativity

My first thought was that Professor Susskind lacked empathy. He'd be asked a question, plainly a little off the plot. It was clear to me and to half the audience what mistaken assumption the student was making but Susskind never seemed to put himself in the student's mind. He just filtered the question through his own, correct, understanding and seemed not to understand the questioner's context. It reminded me of the many stories of Paul Dirac - how autistic!
Prof. Leonard Susskind
But as I've worked through the lectures I understand the man more. His style is immensely attractive. Very casual in sweatshirt and and cords, he ambles around behind the bench snacking on shortbreads and taking swigs of coffee from a cardboard cup. He makes 'mistakes' all the time, 'forgetting' constants and exponents. Students often pick him up on these.

I get him now. He never looks stressed during questions because he knows everything. He makes the 'mistakes' because it keeps the audience awake and involved: those little cognitive dissonances. He stresses the big picture because that's the narrative which conveys the underlying concepts.

He is the perfect complement to the textbook.

His genius is even deeper. In early lectures he covers enough differential geometry for General Relativity. Differential geometry is hard: as I absorbed his lecture I kept thinking Riemann was a genius. And yet he conveyed the key concepts of generalised coordinates, the metric tensor, connections, curvature and geodesics perfectly. Ditto for tensor algebra and calculus. Truly the theoretical minimum!

Here are the ten lectures I'm referring to (YouTube playlist).

Yesterday Susskind told me about falling into a black hole using the Schwarzschild metric and coordinates. We started from the metric, integrated over a trajectory to get a distance, looked at the conditions under which this trajectory would be a geodesic (it's stationary) and then did some algebra to get velocity at various distances from the black hole from the viewpoint of a distant observer. We derived the well-known weird results that the object appears to stop at the event horizon and takes an infinite amount of time to get there. This is not the view of the freely-falling observer: the formal resolution of this puzzle is to come.

Karl Schwarzschild
At the end of lecture 5, a student asks how Karl Schwarzschild was able to derive his eponymous solution to Einstein's field equations for a non-rotating black hole while serving in the hell of the first world war (he later tragically died). Susskind shakes his head in reverential awe and says only that sometimes, when things get tough, he himself finds peace just thinking through the equations.

Wednesday, July 08, 2015

A rant about Garmin + face recognition everywhere?

I paid £75 for lifetime update of my Garmin SatNav's maps. Has there every been a more unfriendly website than Garmin's? Like other people's nightmares, no-one cares about the chapter and verse of bad website experiences, so in short:
  • You can't update the maps with Chrome, and Internet Explorer just hung - it only works with Firefox.
  • You can't get started without downloading 'Garmin Communicator' - which is different to 'Garmin Express' (which I ended up downloading about seven times).
  • Nothing is explained: the process is totally opaque.
  • The process hangs at many points: it's not clear if it's working or whether it's stopped working (bet on the latter).
  • Technical support, after 15 minutes hanging on, was minimally helpful.
I keep reading about how computer AI systems, are going to replace vast swathes of white collar workers. Yet I keep meeting websites with IQs south of 40. Keep the human help or commerce will grind to a halt.

I was struck by this article (via Marginal Revolution) which both explains the current state-of-the-art in automated facial recognition (scarily good) and describes negotiations in the States between developers and privacy advocates. The talks have broken down.

Initially my sympathies were with the developers, then I began to reflect on daily cold-calling on my phone, chuggers in the town and junk mail. So I want to be accosted by name every fifty yards on the high street by AI mannequins who know my name, interests and way too much about my personal history? I would become a recluse.

Trust me, there's an issue brewing here.

Monday, July 06, 2015

'The Martian' - interview with the author

If you have a few moments, an interview with Andy Weir, author of 'The Martian'.

My sister found this sufficiently gripping that she abandoned both Andy Murray and the Tour de France to watch it. It's good stuff.

Free-riding in Greece

OK, I admit it, I was wrong. I really thought that the Greeks would vote yes and we could resume the long habit of kicking the can down the road. But here we are instead, in a strange but very familiar place.

The Greek situation is a special case of the welfare dilemma, a form of moral blackmail. What do you do when the feckless shirker refuses to act responsibly and demands you continue supporting him and his family? If you don't, he says, my partner and kids will starve and it will be your fault.

My 'partner', Clare, wondered how ISIS would respond to this dilemma. Briskly, I would have thought.

Anyway, the leaders of the EU now have to decide:
  1. Tough it out and turn off the taps. The Greek economy will implode and those tender of heart (there are many) will blame the rich EU in general and the Germans in particular.

  2. Carry on transferring cash to the corrupt and incompetent Greek state, in which case other 'Club Med' dysfunctional states may well give up on paying their way .. and the Germans get to continue to transfer their gold to feckless others in perpetuity.

  3. Kick the can down the road somehow.
How the EU hopes that the general theorem - if something cannot continue for ever then it will stop - does not apply in this case!

There is another option. One which would naturally happen within the borders of a functional state. The authorities would turf out the incompetents and crooks and put in place an efficient administration to sort things out. But somehow, no-one seems to want the Germans to do that.

We were down at Bristol Harbour this morning, a propos of nothing much. It was too rainy for the mini-cruise we had been contemplating.

The SS Great Britain at Bristol Harbour

Sunday, July 05, 2015

'The Diet Myth' - Tim Spector

'The Diet Myth' is full of good, solid advice. The author, Tim Spector, is Professor of Genetic Epidemiology at King’s College, London and a geneticist. If anyone can do solid science without the 'blank slate' agenda, surely it is he.

Here's what The Daily Mail had to say (apologies for the breathless gushing):
"Calorie-controlled diets don’t work. Many of us may have suspected as much for years — but now there’s compelling evidence in a new book by Professor Tim Spector, a leading genetics expert at King’s College London. What’s more, he’s offering a tantalising new theory about what really makes us fat — which could revolutionise our approach to weight loss.

As one of the scientists leading worldwide research into the trillions of bacteria living in our stomachs, Professor Spector believes they hold an amazing power over our health and moods — and that our modern diet may be having a negative effect on them. His specialist area is twins. For more than two decades, he has been scientifically following 11,000 identical twins, examining information on their health, lifestyles and diet habits to discover the role of environmental and genetic factors in disease. And one of his key findings will come as a shock to anyone who puts their faith in calorie-controlled dieting and the idea that the current obesity epidemic is simply down to people taking in more calories, and burning fewer through exercise, than previous generations did.

In fact, suggests Professor Spector, if you put identical twins on high-calorie diets, where they eat an extra 1,000 calories every day, after six weeks they’ll have completely different changes in weight. Some will have gained as much as 13 kg, others as little as 4 kg — all on identical diets. Clearly, calories aren't the only factor. So what’s going on? Professor Spector believes it’s down to the bacteria in our gut. He has found that the type and variety of our gut bugs have an astonishing influence on many aspects of our health.

‘Microbes are not only essential to how we digest food,’ he says.  ‘They also control the calories we absorb and provide vital enzymes and vitamins, as well as keeping our immune system healthy.’

Our gut microbes are also linked to cardiovascular health, risk of diabetes and mental wellbeing. In a book published this week, The Diet Myth: The Real Science Behind What We Eat, Professor Spector argues that, with the right regimen of diet and exercise, we can change our personal mix of gut bacteria to become one that keeps us happy, healthy — and lean. For he also believes bacteria are likely to be responsible for much of our obesity epidemic. The root of the problem, he says, may be our modern diet and its effect on our gut bugs.

Compared with our ancestors, we have only a fraction of the diversity of microbial species living in our guts. Fifteen thousand years ago, man regularly ate around 150 ingredients in a week. Nowadays, most people consume fewer than 20 separate food items, and many — if not most — of these are artificially refined, says Professor Spector.

To test what a modern-day junk food diet does to our gut bacteria, he enlisted the help of his 22-year-old son, Tom. For ten days, Tom, a student, went on a diet exclusively of Chicken McNuggets and Big Macs, washed down with McFlurry ice cream desserts and regular Cokes.  By the sixth day, he reported feeling bloated and sluggish. On the eighth, he’d started to sweat after the meals.

‘Tom found that his [university] assignments took even longer than usual,’ says Professor Spector. ‘Friends remarked that his skin seemed to have a yellow tinge and he looked unwell.’

Hardly surprisingly, by the end of the experiment, Tom had put on 4 lb. But what was telling were the results of the tests on his gut bacteria, which found that just three days in, 40 per cent of the bugs had died. The bacteria that remained in Tom’s gut showed a worrying profile. Levels of health-promoting bugs had plummeted, while dangerous bacteria had thrived. Tom’s levels of firmicutes, for example — which create chemicals that fuel our cells with sugars, fatty acids, proteins and vitamins, enabling the body’s myriad systems to communicate with one other properly — had halved. Meanwhile, he had higher levels of bacteria associated with inflammation, which is linked to cancer and heart disease, and with damage to the immune system.

Professor Spector found that several rare bacteria species flourished on the diet, including one called Lautropia. This, he explains, is ‘usually only noticed in immune-deficient patients’. Tom’s mix of gut bugs was still unhealthy a week later but, thankfully, slowly began to return to normal after he began eating properly again. But what about the weight he’d gained?

Nowadays, we naturally associate junk food diets with weight gain. But is it the food itself that causes the pounds to pile on — or could it be a result of the damage it causes to our diversity of gut bacteria? To find out, Professor Spector, who is head of the Department of Twin Research and Genetic Epidemiology at St Thomas’ Hospital, London, turned to his area of expertise. Professor Spector’s work has revealed a number of significant findings in relation to bacteria. A study of four pairs of twins where one was obese and the other was not found notable differences between their gut microbes — with the leaner twin in each pair ‘having a richer and healthier set, and the fatter twin having a less diverse, inflammatory-looking profile’. Stool samples were then taken from the twins and transplanted into the guts of mice.

‘The results were surprisingly clear-cut,’ says Professor Spector. ‘The mice receiving the fat twins’ stool samples quickly became 16 per cent fatter. ‘This was clear proof that fat-associated microbes are really toxic and can be transmitted like an infection. The toxic microbes are more likely to grow rapidly in our guts and be a problem if other microbes are suppressed or if there is a lack of diversity.’


"When researchers fed rats artificial sweeteners at the recommended human doses for three months, they found that their levels of bacteria and diversity dropped significantly. And this particularly harmed the health-enhancing microbes, according to a 2008 study in the Journal of Toxicology and Environmental Health. Tests on mice by Israeli researchers suggested that artificial sweeteners can alter the balance of gut bacteria, so that the bugs, in turn, release chemicals that, ironically, raise blood sugar levels, increasing the risk of weight gain and diabetes.

But chocolate’s fine... as long as it’s dark

When participants in a study at the University of Reading were given cocoa extracts for four weeks, their levels of beneficial stomach bacteria rose significantly. Meanwhile, levels of potentially harmful bugs and bodily inflammation fell, The American Journal of Clinical Nutrition reported in 2011. It seems microbes enjoy chocolate as much as we do. In the gut, they play a major role turning chemicals from cocoa into substances that lower the level of potentially harmful fat and ‘bad’ LDL cholesterol in our bloodstream. To get the benefits without piling on the pounds, the darker the chocolate, the better. Milk chocolate contains only one-fifth of the cocoa of dark chocolate, so you would have to eat five times as much to get the same bacterial benefits — which would mean a lot more sugar and fat, too."
So a well-written, interesting and insightful book, full of good advice. I have two problems with it. Firstly, Professor Spector has a particular kind of hammer (the gut biome) and therefore everything looks rather like a nail (thus the gut biome is implicated in every kind of food type). This makes the book rather one-sided - I'm not saying he's not right, he has plenty of evidence - but it can't be the whole story.

Secondly, the book isn't really paradigm-busting, it's a long collection of gut-biome-related facts made a little more palatable by telling anecdotes. This just about retains interest, but makes the book hard to summarise. Eat the Mediterranean diet is my best attempt.

In the interests of science I was semi-tempted to enroll in Professor Spector's British Gut Project which would sequence my gut population. But at a cost of around £75 for a relatively opaque report I couldn't summon up the enthusiasm; an anaemic version of 23andMe.

Read the book if someone lends it to you.

Saturday, July 04, 2015

Price is no object

We were talking about inheritance tax and our finances as we get older. My mother, I said, lives parsimoniously on a fixed income and still manages to save some money. Clare looked askance at this life of prudence.

"If I see something of great value," she said, "money is no object."

My stomach dropped: behind a neutral smile my thoughts turned to this picture.

Pink Diamonds
"Care to give an example?" I asked nervously.

"Well, yesterday in the Co-Op I saw this delicious croissant for 70p. I could have just bought a packet for £1.36 but no, this freshly-baked croissant was just about perfect. So I got it."

I commended her free-wheeling approach to life.

Thursday, July 02, 2015

Beryl Seel meets Daisy

You may remember Daisy, the animatronic cat who demonstrated her repertoire a few days ago (here). Well today, she finally got to meet my mother - they seemed to get on.

If these animals could only talk - I'd buy ... .

Dyrham Park

We visited Dyrham Park today. The entire building is covered in scaffolding, which the National Trust has turned into a feature. You can get up to roof level (75 feet) where you get an overview of the extensive restoration work plus a novel look at the grounds. Pictures below.

Clare on the roof - a vision in Hi-Vis

Your author overlooking the Park

Part of the formal gardens at NT Dyrham Park, nr. Bath

We ambled down from the entrance car park, amazed at the semi-tameness of the deer while keeping a wary eye on the cows before arriving at the house and our favourite attraction, the tea rooms.

As we subsequently completed our walk around the gardens about sixty school kids ran onto the grass, shouting, jumping .. delirious with freedom. Five minutes later the heavens opened and we at least escaped the deluge in the bus.

Wednesday, July 01, 2015

Ham Woods/East Mendip Way

Clare wanted a walk in the woods this morning (the heat, you understand) so we drove to the adjacent village of Croscombe through the speed limits which walk you down from 40 to 30 to 20 mph and then deliver you to the mandatory police van with its speed cameras. We are wise - Clare has been caught here before - and so we passed at a crawl, safely.

The intrepid pair in the woods

Clare does that commune with nature thing

Once off the road our walk was nothing like as idyllic as you might imagine. We advanced along a thin, overgrown cutting tormented by nettles and flies - especially flies. After a hundred yards we met a lone colt semi-blocking our way. Its poor little head was covered with flies. Why, I mused to Clare, did evolution not equip the horse with two little arms so it could swat the wretched creatures off? We left the long-suffering animal and continued our climb through the woods.

Eventually we took a side path out of a deep cutting and sought the East Mendip Way. At last my Nexus 6 with its improved GPS and integrated Google Maps did its magic - after only two misleading detours we managed to find the road. How the SAS manage navigation is beyond comprehension.

Elaine en rose
Here's a bonus picture which the phone somehow dredged up from its filing system. Amazing, arguably, how chic close-cropping with poor lighting and poor image resolution can be.