Archive for July, 2019

Bicycling and the permanent headwind

July 30, 2019

cyclinglaw

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

johnson

[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

linbfig21

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
linbsigninv

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.

rhyton1

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.

linbpic11

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

linbpost1

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.

linbpost2

SUNDAY 21 JUNE

 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.

linbpost3

 

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.