Monday, June 20, 2011

GCSE Physics

Major is taking some of his GCSE exams this year. Seems early, but apparently they've decided to split them up over two years rather than drop them all in at the same time. Makes sense to me rather than trying to cram and revise for all the exams they only need to do so for half of them.

This meant that Major had his revision guides lying around so I picked up the one for Physics. Now this is a cramming guide so I didn't expect much in the way of explanation, but I expected more. One of the things it does illuminate is the type of erroneous knowledge exhibited by those who never went beyond GCSE Science.

I could go into details but in essence there seems to be a greater degree placed on being able to regurgitate facts rather than understanding the principles behind them which is what I remember being the main difference between the GCSEs and A-levels when I took them.

Connections are rarely if ever drawn between areas. The book quite happily discussed heat in the first chapter then in another chapter talks about EM waves and that infra-red radiation allows heat to be seen using special tools. It would describe an equation on one page then two pages later throw a very similar looking one without any reference to the previous.

Energy likewise was disconnected it was made clear the difference between speed and velocity, yet with the equation KE=½mv² constantly referred to the "v" component as "speed" which is correct(ish), but conflicts with the first point.

Similarly assumptions are made but not explained. With (gravitational) Potential Energy it's explained that an object on the floor has no PE; yet raised to a shelf does; following this logic if a hole was dug and the object placed at its base it would have negative PE. How does an object possess negative energy? It's not explained that ground level is used as the baseline.

I also detected a slight possibly political bias as it discussed energy efficiencies; lagging floors and how bad non-renewable sources were etc.Also amused that it stated that the sun was a renewable source as it would "never run out" well not in our lifetime; but then again it's unlikely coal and oil will either.

As an aside I noted that the planet list now excluded Pluto, but there was an expectation to recall the asteroid belt between Mars and Jupiter.

Some extras excluded from my exams (AFAIR) - the two different Beta type radiations which again had me scratching my head at how this was dealt with - A neutron emits an electron (Beta-) and becomes a proton. A proton emits a positron (Beta+) and becomes a neutron. Thinking classically a neutron loses something and becomes a proton so it must be bigger than a proton. Yet a proton loses something and becomes a neutron.... no don't think about it just remember it.

Amusingly it then deals with quarks; definitely not on my syllabus and seems to expect a recollection of which types make up which particles - ouch.

So other than lamenting over some of the simplistic points what am I moaning about. Well that other than a couple of things and some techniques used to simplify  equations the course is little different in style or content from my GCSE 20 plus years ago and that's a problem.

As I said at the beginning with GCSEs knowing rather than understanding seems to be the aim and this is wrong. I recall the large mental leap needed to switch to A-levels that the previous courses simply did not prepare me for. So much time was spent going back over previous work to point out why it worked this way or at times to shove it away and explain that the things we were taught weren't true. I never got the feeling I was learning anything new; just stuck in a rut.

Now I can understand and to an extent sympathise with the 'lies to children' stage. It's difficult to understand the complex things before you can grasp them simply; but the flaw here is both that the dissonance is too great and that it is not a requirement to continue with education to have these 'facts' corrected.

In this instance I'm just covering the 'hard' sciences because I can't recall any other subject having to be taught in this manner. In History you might be taught that the Civil War was the consequence of a single cause (Religion in the case of the UK; and slavery in the case of the USA) later you might be taught that there were a lot of other factors involved, but you won't be taught that your first lesson was wrong. In every other subject I can think of whatever is taught remains true even if extras can be hung from it.

Therein lies the problem as I  see it - science is taught in the same manner and with the same expected results as every other subject, but it can't be done. The simplifying methods used elsewhere don't fit within science. Is there any way around this? Perhaps start each of these types of lessons with "This isn't true - the truth is complex" Not only would it mean those who were interested may study the subject in their own time to discover the truth (and presumably those types would be the ones wanting to progress to higher education) but it stops others leaving education at that point thinking that they know how things work.