Monday, April 20, 2009

Human evolution symposium

Bronya Keats described how population bottlenecks (or founding) associate particular groups and genetic diseases. Also discussed the rate at which alleles for recessive disorders are naturally reduced from a population, and contrasted the normal statistical distribution of genotypes (given allele abundances) with the displaced equilibriums that arise where there is a heterozygote advantage. In the case of sickle-cell anaemia in malaria-affected populations, the gene statistics demonstrate that we are still pressured today by natural selection.

Neil Risch shared data suggesting an over-reaction to racism. Contrary to claims that race is genetically insignificant, machine categorisation of individual genomes does cluster according to race. At the same time, the degree of genetic diversity within each cluster can be used to trace the ancestry (i.e., founder effects from the original dispersal out of Africa). He also discussed the difficulty of race-related genetic effects being confounded by social effects (e.g., a disease risk-factor among African-Americans may have no effect in Africa).

John Hopper argued that it would be more cost-effective for the government to provide genetic testing after early detection (when it may improve cancer treatment) rather than to subsidise using the test to prescreen healthy people (which disproportionately favours the wealthy, and still produces neglegible benefits because the rare individuals that test positive are still not prepared to take significant risk-reduction measures such as prophylactic excision). Looking at his use of flow charts (and my own first aid training), I wonder why we do not have epidemiologists produce a 'curriculum' (a standardised treatment flowchart) for doctors (and instead, we trust the doctors to keep their own expertise up-to-date, knowing that they are being distracted by advertisers)?

Monday, April 13, 2009

Aikido Canberra

(For updates see: Official Aikikai Canberra webpage)

Aikido is fun! It is a form of personal development with the excitement of martial confrontation, the skill of a refined art, and the satisfaction of good exercise.

Aikido involves blending with and redirecting the aggressor's movement (instead of directly opposing with force) to restrain or evade without needing to inflict injury. Aikido is non-competitive (and retains techniques that would not be safe for competitions), the idea is to refine one's self rather than conflict with others. "Aikido" can be translated as "harmonising discipline".

A typical class warms up first with stretching, the time is then punctuated with demonstrations of specific techniques by the instructor, and the bulk is spent practising those techniques in pairs (or small groups). Students take turns to attack or to respond to being attacked, and frequently change partners (so that everyone can train with the more advanced students and with people of different builds). Sometimes training involves weapons (e.g., sword, staff and knife) or multiple attackers.

Aiki-Kai Australia is the local mainstream aikido organisation; we are recognised by the Aikikai Foundation in Japan (headed by the heir of the founder of aikido) and member of the IAF (which organises international events). The technical instruction is overseen through the foundation of Sugano shihan (who introduced aikido to Australia at the direction of the founder of aikido). It has dojos in every state of Australia and organises week-long national training camps every six months (so that students can learn from more senior instructors than their local areas possess).

In Canberra, Australian Capital Territory (ACT), we currently train in two locations and invite you to come and watch a class:

  • Main dojo, learn directly from Hanan Janiv 7th dan shihan. Scout hall, Tooms Pl, Lyons. Wednesday, 7:30-9pm. Possibly also Friday or Monday, contact for details.
  • ANU SRA dojo (The Australian National University). Tuesday 7:30-8:30pm and Sunday 5:00-6:30pm.

Beginners may commence anytime. The simplest option is just to enroll (for a semester) in our ANU dojo beginners' course, at which no special clothing or equipment is expected. Comitted students instead join the national organisation, pay monthly, then (to train in both locations) join ANU Aiki-Kai club and become Sports Union associates (or be ANU students). The total cost per training session works out about the same as taking public transport.



For more specifics, try contacting people via aikido.org.au or the facebook group.

Saturday, April 11, 2009

Physics topics

I'm interested in writing a book to introduce advanced physics to high-school level interested people. Sketch of the topics (hopefully covering all the examples that are important to everyday life and public debate.. should perhaps outline this, and the philosophy, in the first section, perhaps leaving history to brighten the later parts). Maybe the way to pull this off is to only loosely break it into these chapters, but strongly break it into small independent sections: that way mathematical detail can be contained, elsewhere it can be written for a most general possible audience, with loads of pictures (not just technical diagrams). It probably also makes it more fun to write, and useful to a broader crowd.

Physics is the reductionist science. A systematic evidence-based pursuit of knowledge, by the approach of deducing complex system behaviour from the dynamics of simpler individual components, and with emphasis on mathematics of the interactions rather than on cataloguing the complex systems.

Newtonian mechanics. This is always first, getting preliminaries out of the way (levers/gears/pulleys). Important topics: gyroscopes and Coriolis (i.e., unintuitive emergent stuff), waves (the foundations for understanding QM, such as Fourier, and can take examples of sound), impedence matching, fluids/flight. Vector calculus, trig., Lagrangians, conserved quantities. Surface tension (possibly need to break class. mechanics into simple and sophisticated techniques, or sections to showcase different mathematical concepts?).

Thermodynamics. The focus is statistics; gases are just an isolated example. Also cover heater efficiency, Carnot efficiency, stimulated emission, ..

QM. All just classical wave stuff really.

Electromagnetism: from the forces on static-charged pith-balls and magnetised iron-filings or compass needles. Self-consistency argument for Maxwell's equations. Leads to optics, electronics, relativity (Lorentz symmetry), and field theory (gauge symmetry).

Electronics (passives, relays to op amps and computers, meter/motor/generator, radio).

Optics. (This comes after QM.) Why stuff looks how it does.

Special relativity. Heuristic approach? Emc2. Paradox of FTL. Twins with focus on acceleration phase. Rotating disc.

Nuclear. This topic isn't tightly connected to the others, but is important (controversial) and poorly studied. Particle zoo.

General relativity. The idea is to explain basic differential geometry, and just give a fleeting example of an actual space-time. Tensors should have been introduced earlier.

QFT. Show field lagrangian of multiparticle QM. Fibre bundle stuff. Non-scalar stuff.