Sunday, September 16, 2012

Identity issues


Identity issues

A recent (15th Aug 2012)issue of the Indian Express carries the story of an upcoming leader of a far-right Hungarian party (Jobbik) named Csanad Szegedi who was (in)famous for his loudly proclaimed anti-Semitic views. By an unkind twist of fate the 30-year old discovered in 2010 from a 'convicted felon' – whom he was unable to silence – that his maternal grandparents were Jews, and that his grandmother was an Auschwitz survivor. Jobbik has just disowned him, although Szegedi is not a practising Jew by any means.
The irony of this story is practically Kafkaesque, and it takes the phrase,” He's his own worst enemy” to a whole new level. One wonders what Szegedi will do: take solace in drink, commit suicide, re-invent himself (as what?), - or emigrate to Israel?

However, the story raises other questions that apply almost universally. One could easily change names and consider a Szegedi clone in the RSS (or the Laskar-e-Teuba) who hates Muslims (or Hindus) viscerally, and belatedly finds out that he has Muslim (or Hindu) ancestors. As Szegedi's story makes clear, it is not enough for Szegedi to denounce Jews – he must be free from any ancestral taint.

All identities are constructed. We share 'markers' with our in-group that differentiate us from all out-groups. But the notion that groups can be exclusive and 'pure' is a difficult one to maintain, at least for humans. The evidence indicates that groups are highly overlapping. The identity constructed (and constricted) by absolute exclusivity is fragile – and flies in the face of evidence. For example, the study of caste in India on the basis of genetics was initially expected to show significant divergences between different groups – considering that caste has been entrenched for at least two millenia. Interestingly, the study showed statistically insignificant differences between the so-called 'upper' and 'lower' castes' - evidence of considerable, and ongoing, miscegenation, by a variety of means [1].

Of course, today we believe that, since cultural evolution is faster than genetic evolution, it determines our future to a greater extent than genetic evolution does. Indubitably the culture you grow up in determines to a large extent the kind of occupation that you will end up in: goat-herder, politician or nuclear physicist. Your culture conditions your expectations and defines your opportunities.

With greater access all over the world to education, one may expect a widening of opportunities. However, the access provided by tools such as the internet may turn out to be illusory or non-existent for people on the wrong side of the digital divide. Also, some may be unable to access certain forms of knowledge because of their own cultural preconceptions: imagine a Taliban anthropologist, almost an oxymoron.

To return to Szegedi, he lived and defended a culture that he felt was under siege from inimical forces, much as the Taliban or Boko Haram fear Western 'contamination' and desire 'decontamination'. However, any culture that repudiates the influences of multiple others is inherently weak. The strongest is the culture that opens its arms to worldwide influences, assimilates and transmogrifies them. To a certain extent, the conservative tendency in a culture that insists on purity and exclusivness allows its identity to survive in a recognizable form. At the same time, no culture can remain static and that means that it must be open. Not completely open, perhaps, but at least partially open.

The irony does not end with Szegedi's quandary. The long-term future of Israel as a 'homeland for Jews' is in doubt, despite its overwhelming military and technological superiority. The problem the Jews face is the desire to acquire and retain as much of the 'Promised Land' as possible while denying Palestinians full citizenship, since they can never be bona fide Jews in a 'Jewish homeland'. Demographics mean that Israel will face a problem in remaining a 'Jewish democracy' in the longer term, even if in the short term they continue to out-maneuver the Palestinians and other Arabs.

But the question that Szegedi's story raises has an another implication. What is the difference between the Jews and the Arabs or Europeans? Some recent genetic studies by Harry Ostrer [2] indicate that both Ashkenazi and Sephardic Jews have common genetic markers, but these are traced back to the Levant, and that these are, in fact, shared with the much-reviled Palestinians. The Jews also have 30-60% non-Middle Eastern genetic markers. That is, Jews also have genes in common with Palestinians and non-Jewish Europeans [2,3]. Does it matter? Or is culture the primary determinant? In that case, an Arab or European child brought up by Jews would be Jewish? Why not?

The attempt by sociobiologists such as E.O.Wilson to explain human behaviour in terms of our evolutionary heritage were widely condemned as sexist, racist and elitist. Nevertheless, we desperately need to understand ourselves, our genes, our cultures, and what they mean for our future. Study of aboriginal tribes in Australia suggested that groups avoid inbreeding when intermarriage occurs at a level of about 7-10% [4] and that there is considerable genetic similarity across tribes.

Today, the metaphor of the 'melting pot' in America has been replaced by the 'salad bowl'. Xenophobia in Europe is undergoing a resurgence - like recurrent malaria - which it does whenever times are hard. The issues of identity are not, in an increasingly globalized world, going away any time soon. The idea of 'multiculturalism' is being touted by the British in the days of the Olympics, alongside ever stricter immigration controls: go figure! A country like Japan which is highly insular but rapidly aging will face a demographic crunch as surely as the Europeans, the problem in both cases being a birth rate that has dropped below the replacement rate.Will demographics and economics ultimately trump the distaste for outsiders, Auslanders?
Even if they do, who will convince Szegidi and Breivik?
  1. E.O.Wilson “Sociobiology: the new synthesis” Ch.27, p.11/31.
  2. Legacy: A Genetic History of the Jewish People” (Oxford University Press) by Harry Ostrer
  3. “The Chosen Genes” by Josh Fischmann, http://chronicle.com/article/The-Chosen-Genes/131481/
  4. E.O.Wilson “Sociobiology: the new synthesis” Ch.27 p. 9/31.

Friday, August 10, 2012

Valleys without rainbows


No rainbows in the valley of Shangri-La

When I went trekking in the Himalayas last month, it rained quite a bit on each day – but mostly after noon. Unfortunately, despite all the rain, we were not lucky enough to see a rainbow. I decided that the blame – as usual – lay in the laws of physics (optics and atmospheric science) and on geometry. After all, the Sun has to be behind you, and the falling rain in front, and the clouds should not obscure the Sun's rays, etc.
Our camp was located in a valley – so that is how I imagined a valley in which rainbows are forevere forbidden to its denizens. Rather depressing, truly, but I was already feeling deprived – so the only solace was to concieve of people even more miserable.
According to wikipedia, if the Sun is more than 42 degrees from the horizontal, you cannot see a rainbow. This refers to the primary bow, which lies between 137.6 degrees (red) and 139.4 degrees (blue). The secondary – which is fainter, and reversed in sequence – bow lies in the range of angles 129.6 (red) and 126.5 degrees (blue). That means that the secondary bow would still be visible if the Sun is as high in the sky as 53.5 degrees.
One does not get into the gory details of trigonometry but it is easy to construct many valleys in which no rainbows - either primary or secondary - could be seen. Of course, in some valleys primary bows will not be visible – but secondary bows can still be seen.
For a valley which is a perfect circle, with a radius of 1000 metres, the encircling mountain range would need to be 916 metres high to forbid all primary rainbows, and 1356 metres high to forbid even seconday rainbows. For more realistic shapes, a little trig would be needed.
The secondary rainbow is about 10% of the total intensity of the primary bow – and its angular range is about 75% greater. Sightings of seconday rainbows are rarer than primary bows, because the size distribution of raindrops needs to be more uniform to get good intensity.
What about higher-order rainbows? They are so faint as to be almost invisible against solar glare.
Tertiary and quaternary rainbows have been seen by the most educated and determined rainbow-chasers in 2011:
http://www.sciencedaily.com/releases/2011/10/111005111001.htm
http://www.atoptics.co.uk/rainbows/ord34.htm
Unfortunately, the third- and fourth-order rainbows will not slake the thirst of our encircled denizens either. Firstly, these two bows are in the direction of the Sun – rather than opposite to the Sun, as are the first- and second-order bows. That makes the glare problem more acute than for the second-order bow. Secondly, although the total intensity of the 3ed order bow is 24% of the 1st order bow, it is spread over a larger range of angles – so it is fainter. And, lastly, the angle of the 3rd order is at about 40 degrees – almost the same angle to the horizontal as the 1st order bow (but in the opposite direction). The 4th order bow has 15% of the total intensity of the 1st order bow, and its angle is ~45 degrees to the horizontal. So encircling mountains of a similar height would impose a quarantine on rainbows in the valley.
References:
Photographic evidence for the third-order rainbow, M Grossmann, E Schmidt, & A Haussmann, Applied Optics, Vol. 50, Issue 28, pp. F134-F141 (2011).
Photographic observation of a natural fourth-order rainbow, M Theusner, Applied Optics, Vol. 50, Issue 28, pp. F129-F133 (2011)
All this is somewhat depressing for the dwellers of Shangri-La. Keats in his 1820 poem Lamia lamented Newton's decomposing white light and deconstructing the rainbow, accusing him of (sic) “unweaving the rainbow”.
Richard Dawkins has written a book with exactly that title as a rather belated riposte that “ Science is - or ought to be – the inspiration for great poetry”.
That debate will undoubtedly carry on – but what I think true is that few poets would have the wit or the patience to chase down the tertiary and quaternary rainbows.
Or to do as Jearl Walker did, do an experiment to see a dozen bows in a single drop of water (suspended on a wire and artificially illuminated)!

However, the knowledge of rainbows should be more widely known to the general public – especially poets – because even if the vagaries of weather go against you, you can still see, without too much trouble, rainbows in fountains. Providing the sun direction is right and as long as you do not live in an deprived no-rainbow valley!

Sunday, May 20, 2012



This is a very short post on the papasan chair.
http://en.wikipedia.org/wiki/Papasan_chair
It is striking that there are two design elements in a papasan chair (ignoring the base and the cushion): the circular outer frame and the 'spiral' inner part.
The circle is important because it is the curve which, for a given length, maximizes the enclosed area (known as Queen Dido's problem, which was proved by the calculus of variations by Newton):


galileo.phys.virginia.edu/classes/321.jvn.fall02/var_meth.pdf


http://mathematicalgarden.wordpress.com/2008/12/21/the-problem-of-dido/

The spiral is the most compact curve in the sense - within a given area - it covers the greatest area for a given length, and thus provides maximum support.
However, there is some ambiguity because there are many possible spiral curves:

http://en.wikipedia.org/wiki/Spiral

Logarithmic spiral search patterns are known to be most efficient in 2-D although mathematicians are still arguing about them:
 "On the Optimality of Spiral Search" Elmar Langetepe
SODA 2010: Proc. 21st Annu. ACM-SIAM Symp. Disc. Algor., 2010, pp. 1-12

www.i1.informatik.uni-bonn.de/publications/l-oss-09.pdf

Yes, these arguments also neglect the 6 radial spokes, and the fact that the spiral is really a helix because it's
in 3-D.
Agreed: these two arguments are not watertight, and the spiral part may even be wrong, but anyway:
The papasan chair design optimally uses material by its combination of circular and spiral elements.