Bicycling and the permanent headwind

July 30, 2019


Discussion on Facebook

Interesting that the permanent headwind which blows in your face whatever direction you cycle still operates in the hot weather. Clearly its intelligence does not yet equal its malice and agility.

I find that crosswinds are treacherous because: a) they have a similar drag effect to a headwind and b) they have a vastly greater angular range than just head on. Unfortunately that pretty much encapsulates any wind direction. Get out early if you can, before the thermals kick in.

Have you seen the study that shows the wind is always against you? It’s summarized in New Scientist here and the original paper is here.

Further analysis

OK so now we’ve got onto the purely hypothetical case where you cycle from A to B and then back from B to A and the wind continues to blow from B to A as though nothing had happened.  Even so, the analysis in the references above looks rather complicated.

Let’s ignore rolling resistance and consider a cyclist who wants to cycle on the flat from A to B and back again.  He cycles with a power P which gives a limiting velocity V relative to the air. (In the absence of rolling resistance we ignore interactions with the ground.)

So let’s say as an example B is 10 km from A and V is 20 km/h.  In the absence of any wind it takes 0.5 hours to go from A to B, another 0.5 hours to go from B to A, for a total of 1 hour or 60*60 =3600 seconds.  Then with P measured in joules/second, the energy expended will be 3600*P J.

Now a wind of 10 km/h blows from B to A.  The cyclist’s speed relative to the ground is then 10 km/h on the outward leg and 30 km/h on the return leg.  So the time taken is 60+20  = 80 minutes or 4800 seconds and the energy expended is 4800*P J.

The cyclist has spent more time and expended more energy even with a completely unchanging wind.

This analysis clearly applies to any situation where there is a component of the wind along the cyclist’s direction of motion, even if it doesn’t turn round on you…


Boris Johnson and Antisthenes

July 24, 2019


[Antisthenes] said that states are destroyed when they cannot distinguish fools from serious men.

τότ’ ἔφη τὰς πόλεις ἀπόλλυσθαι, ὅταν μὴ δύνωνται τοὺς φαύλους ἀπὸ τῶν σπουδαίων διακρίνειν.

Diogenes Laertius, Lives of the Eminent Philosophers 6.5

We have had some discussion about this on social media.  The question would be how to interpret φαύλους and σπουδαίων, which are basically trivial vs serious, but can represent a number of related contrasts.  The original citation contains a number of discrete opinions on diverse matters and does not really help with interpretation here.

In the course of the discussion, Diarmaid MacCulloch described Johnson as Not a fool, and ultimately not very serious. Ambitious, and utterly untrustworthy.  Which may be the kind of person Antisthenes was thinking of–as far as we can ever tell…

Linear B at the Summer School in Homer, UCL 22-26 July: Day 2

July 23, 2019


1023  We await two new people.  Alexandra comes to shut  off my escape.

1048  I don’t feel too bad…yet…

1052 I want to go home.  The god Νηρεύς exemplifies the classes of consonants omitted in Linear B.

1200  It is a vessel containing honey.  I want to go home.

1245  I go home!

Linear B at the Summer School in Homer, UCL 22-26 July: Day 1

July 22, 2019

Linear B sign inventory

MONDAY JULY 22: 0627  Do I want to wake up now?  No.

0910  The train gets crowded and stops at Denmark Hill for a long time.   The driver announces that a passenger has fainted.

0940  UCL–there are signs to the Slade Summer School and EF. Great! I follow old people to the A V Hill Lecture Theatre.

1002 Antony Makrinos is the Zeus of the Summer School.  There are 98 participants, some male and some female.  UCL has a strict green policy, as well as catastrophically awful admin even by academic standards.

1035 Ester our lecturer goes to find someone who understands the IT.  Everyone is very young, keen and bright.

Tiryns is Ester’s favourite Mycenaean site.


So that’s what a rhyton looks like (from Ayios Vassileios)

You can hear Michael Ventris talking on the BBC about his decipherment here.

1345 Should we have come back now (as in the programme) or at 1430 like she said?  Best to practise our silent staring at blank screen skills for a bit.

1430 When she says she doesn’t expect us to learn the 91 syllabic signs immediately she means the opposite of course.

Exercise in  reproducing the syllabic grid is just like management training where the trainer lets you get so far and then suggests it would be better if you organised yourselves rather than all doing the same thing.  Except that this is interesting and important.

1530 I set off home without pausing for  Disability in Antiquity.  It is hot.


Ester addresses the troops over a completed Linear B exercise (in duplicate)




Linear B at the Summer School in Homer, UCL 22-26 July: Day 0

July 21, 2019


I thought I would keep a diary of doing Linear B at the Summer School in Homer to give people an idea of what it is like.



 What do they mean, registration from nine to ten?  I haven’t got a train up to Town in the morning rush for more than a year now.  Doubtless I will have to stand, and Bloomsbury is in the wrong bloody place anyway.   And what’s this talk about ‘Disability’–the ancients certainly didn’t go in for that kind of polite language.

Three-and-a-half hours less five minutes of classes.  I suppose I will survive.  But I don’t imagine there’s going to be anything interesting on at the Renoir if it does become too much.



But then I have to admit that the Day 1 programme looks very interesting, and I would regret missing it.  The main cause for optimism is surely that all of the participants will be at the same level of not knowing anything about Linears B or A.

Bellingcat, Bertha Dochouse 25 June

June 27, 2019


Bellingcat:  Truth in a Post-Truth World explained how you could work out hidden things from open-source data, and the basis seemed to be that if bad guys were going to flood social media with disinformation they would give away more than they realised.  Eliot Higgins made a charismatic and very English lead figure, and I finally got the point about the MH17 incident–there is not much that can shoot down something flying at the altitude of a civilian airliner.

On the other hand, I did not get much of a feeling for how the members of Bellingcat had assembled themselves into a group in the first place or indeed who it was we heard of extending financial support to Eliot Higgins in the telephone.  The academic talking heads we saw had sensible things to say, but we never found out who exactly they were or what their perspective was.  The film correctly laid emphasis on transparency–or, as I would say, reproducibility–but did not give any examples of Bellingcat’s results being reproduced or verified by other actors.

Eliot Higgins was keen to stress that everything came from open sources, but I am not sure how far the various Russian administrative databases used to identify the Skripal perpetrators would count as open source, more like knowing somebody who had bought a CD of knocked-off data in a Moscow subway.  (The Spectator has an intelligent discussion of the point here.)

Anyway, at the end of the film I felt enthused at the idea that reason and goodwill could triumph, and positively eager to do battle with the forces of darkness.

Genesis 41:56-42:5 in Biblical Hebrew and Modern Hebrew

June 21, 2019

Biblical Hebrew

For people who might be looking for a short parallel passage to compare Biblical Hebrew and Modern Hebrew, we give the examples above and below.


Modern Hebrew

Prospects for a new team in Division 4 of the London Chess League

June 16, 2019


The table above shows results from the 2018/19 season of Division 4 of the London Chess League in terms of the final position of the various teams, the percentage of possible game points they achieved, the mean grade of the sides they fielded and the mean grade of the teams they faced.  We can see that the position followed the strength (mean grade) of the teams very closely and there was no significant difference in the strength of the opposition that different teams faced.


We can also consider the relationship between grading and percentage of possible game points achieved, as below.


On this basis, using the equation of the fitted trend line, we can estimate what average grading would be required to achieve various points percentages:


We do not believe that relegation operates from Division 4, but team members would hardly enjoy losing all the time, so we presume that a new team would wish to average at least 40% of game points, requiring an average grade of 113.  Or an average grade of 125 would be required for 50% performance.

We now consider the possible requirements for the specific boards, using the opposition faced by Team 9 (which scored 46%).


So we see that someone playing on Board 4 would meet opposition with a mean grade around 130 and should be of a strength to have a meaningful game with opposition graded between about 100 and about 150.  (Some figures in red italics are affected by the presence of defaults.)

More about things to read in French

June 12, 2019

Henri-Alban Fournier

So, to continue the story, our client expressed a preference for doomed romance and a decided aversion for the passé simple and suspiciously un-French surnames (so much for Houellebecq!) That led to Modiano and Alain-Fournier.

The latter did not entirely escape censure on Facebook:

I really don’t like Le grand Meaulnes! Hated teaching it! But as ever that says more about me than the book. Should have thought of Le silence de la mer (Vercors) for passé simple if I remember correctly.

I tried re-reading Meaulnes a few years ago and gave up at page 192, oppressed by the thought of another 123 pages of the same…stuff…At least Alain-Fournier is conceptually simpler than Modiano (especially) or Vercors, since he bashes you repeatedly over the head with what he wants to say while they expect you to understand it from what they leave out…

Actually the first 3 paragraphs are not at all bad and helpfully illustrate the use of various tenses in the indicative:

Il arriva chez nous un dimanche de novembre 189…

Je continue à dire “chez nous”, bien que la maison ne nous appartienne plus. Nous avons quitté le pays depuis bientôt quinze ans et nous n’y reviendrons certainement jamais.

Nous habitions les bâtiments du Cour Supérieur de Sainte-Agathe. Mon père, que j’appelais M. Seurel, comme les autres élèves, y dirigeait à la fois le Cours supérieur, où l’on préparait le brevet d’instituteur, et le Cours moyen. Ma mère faisait la petite classe.

You’d almost think it had been written to demonstrate use of tenses!!

Meanwhile, there will be a few Modiano-related events at the Institut français in September…


Patrick Modiano


Recommendations for things to read in French

June 9, 2019

In order of size…that’s the way

Our friend Kseniya is now feeling bored living in Israel.  I suggested that she ought to read some French literature in the original, which would show she was a person of distinction and refinement who had better things to do with her time than look for a job.

So I assembled the items above from my bookshelves, guided by the principles of contemporaneity and concision, with some hope of impossible romance.  (Actually only Le Grand Meaulnes fits that particular bill).

Some discussion on Facebook yielded in addition:

Maupassant, Boule de suif. Or other short stories

But that’s really French literature as she is known in Russia and BdeS relates to a specific juncture of the Franco-Prussian war.  Also Turgenev, Chekhov and Bunin all did the same kind of thing with much greater subtlety and lightness of touch, or better as we simple souls put it.   But on the other hand ‘Misti’ has a cat in it of course and embodies animal cruelty to humans rather than the reverse, which tends to be the case in Maupassant.

I have recently read a few things by Jean-Christophe Rufin with mixed enthusiasm. But the one I’d really recommend, Rouge Brésil, is definitely long!

608 pages, and it looks like the kind of thing that Robert Nye used to turn out by the yard in the 1970s…

How about Beauvoir Le sang des autres?

310 pages!

And from Twitter:

Gaël Faye, Petit Pays (recent winner of the Goncourt des lycéens)

I think our client, as a right-thinking Russian girl, is interested in Metropolitan France, and in particular Paris, and specifically the few particular streets in Paris that all right-thinking Russians dream of.

JMG Le Clézio, L’Africain (Nobel Laureate)

Actually this looks interesting, but it still takes place in Africa (see on Gaël Faye above).

Further suggestions will be more than welcome!


Ordered by date this time