Monday, 10 November 2014

Teaching training?

In her opinion piece When it comes to education, people who count are kids, Cassandra Wilkinson writes:
Several inquiries, reviews and reports are under way to address the problem of getting kids to learn STEM subjects, but so far there is no clear strategy to address the problem from federal or state education ministers. The national curriculum review has concluded the science curriculum is basically sound. Analysis undertaken by the John Monash Science School in Victoria notes that there are areas for improvement, but says on the whole the science curriculum is “robust, balanced and flexible”. 
Igor Bray from Curtin University’s physics department reports the primary science curriculum is adequate to ensure secondary school children “have an understanding of science and technology through knowledge of specific scientific content, the history and philosophy of science as well as how science and technology is being applied”. 
As a parent of two keen science students, I find these reports grim reading. If the curriculum needed changing that would be pretty straightforward. What seems increasingly clear is that the problem lies with the quality of education that teachers are receiving before they enter a classroom to teach STEM.
There appears to be disconnect between the first two paragraphs, which both indicate that the science curriculum is sound, and the last which talks about "grim reading" and some (implied) problem with the quality of teacher training.

Cassandra goes on to state that
The Australian Academy of Science submission to the national curriculum review makes the critical point: “To be an effective teacher of science you need to understand the science that you teach.”
with which I agree unreservedly. However, I do take issue with the inference drawn in the next two paragraphs:
The submission is made carefully but strongly implies the present system has delivered an oversupply of lower-skilled teachers such as PE instructors and an undersupply of teachers equipped to instruct students of advanced science and maths.
The academy is polite, but the implication seems to be strongly that, like their high school student counterparts, student teachers are not taking the tough courses they need to excel in their professions. “Universities therefore need to prepare pre-service teachers to a level by which they can make a meaningful contribution in a classroom with students,” the academy’s submission says.
My view is that this is nonsense. It is very difficult to "transform" student teachers with weak STEM backgrounds into high quality STEM teachers. The fundamental problem is that the majority of students who study STEM subjects at University, and achieve a high level of understanding, do not view teaching—especially primary teaching—as an attractive or interesting career option. The extra time and effort to get a teaching qualification is "rewarded" by the hard work of coping with disinterested students, all for a lower salary and lesser prestige than a STEM job provides. Simply put, the problem that needs to be addressed is to "make teaching an attractive career for the high achieving STEM students." Over the last few years I have followed developments in Canada, Switzerland, Estonia, Finland, Singapore, Korea and China. In these countries, high quality teachers are well paid and teaching is a prestigious job, with entry into teaching courses restricted to high achievers.

There are, of course, some striking exceptions. My good friend Simon Tyler, who did his PhD in Physics at the University of Western Australia, then undertook a Master of Education and is presently teaching at the John Monash Science School. However, exceptions do not make the rule.

Finally, the vital question of how many STEM graduates Australia requires is not addressed. Is there really an undersupply? The answer is probably no (see here), which is not the answer that advocates for expanding STEM want to hear.

Disclosure: the author is an employee of the University of Western Australia, and the views expressed are those of the author and not those of the University.

Monday, 3 November 2014

Egyptian rock and roll

The latest edition of PhysicsWorld includes an item entitled Egyptian rock and roll:
The pyramids at Giza are one of the seven wonders of the ancient world. But we still do not know for sure how the ancient Egyptians built the giant structures in the first place, or how they moved millions of huge limestone blocks each weighing about 2500 kg. Joseph West from Indiana State University and colleagues have now put their own pet theory to the test. They attached three wooden dowels to each side of a 30 kg concrete block – in effect turning it into a 12-sided polygon that could be rolled instead of dragged. “On the surfaces we tested the block on, we could roll the block with about the same amount of work as would be used in dragging the block over moistened sand,” West reveals. The researchers now plans to scale up their work to test the idea with a 900 kg block and to use fence posts as the rods. But was it likely that the ancient Egyptians used their method? West thinks it “could have been used”, but cautions that “the archeological evidence does not strongly support the idea”. The mystery deepens.
Personally, I think the "mystery" was resolved a long time ago. For example, see Building the pyramids from quarried stone blocks:
Dr R H G Parry[3] has suggested a method for rolling the stones, using a cradle-like machine that had been excavated in various new kingdom temples. Four of those objects could be fitted around a block so it could be rolled easily. Experiments done by the Obayashi Corporation, with concrete blocks 0.8 m square by 1.6 m long and weighing 2.5 tons, showed how 18 men could drag the block over a 1-in-4 incline ramp, at a rate of 18 meters per minute. This idea was previously described by John Bush in 1977 [4], and is mentioned in the "Closing Remarks" section of Parry's book. 
About 20 years ago I attended a seminar by Dick Parry at the University of Western Australia on exactly this topic. His book Engineering the Pyramids includes the material presented in his seminar and describes a simple and elegant solution involving four re-usable cradles. Even earlier, in 1977, the same idea was outlined by John Bush in his delightful one page engineering analysis entitled The Rolling Stones, where he explains how four cradles could used to parbuckle the blocks.