I was supposed to be having a voice class this afternoon. According to the timetable, these are classes to help us learn voice projection techniques. Well, we had precisely one lesson with a speech therapist, and she spent the whole time telling us about diseases of the throat, showing unpleasant biological videos of such, with a few minutes about how to avoid them (apparently drink herbal tea and avoid eating sandwiches. Lots of what not to do, and not enough about what to do. Hmmm.
In today's session, we were supposed to have been giving a prepared 5 minute presentation about a topic outside our own science specialism (without using a whiteboard, OHP or paper) and also tell an interesting or amusing scientific anecdote. I fondly assumed that this would be run by a member of staff, who would check our clarity and projection to different parts of the room, and make constructive comments for improvement. No such luck. Instead, we were supposed to present the information we'd found to a group of 3 or 4 other students.
How talking to 3 other people is supposed to help us project to an entire classroom I didn't find out, as no one else turned up. Well, they may have done - but they'd gone by the time I got there. As my morning class finished at 12.30 and my afternoon class wasn't until 3.30pm, I thought I'd go home, have a shower, and pick up the work I left behind this morning when I was too brain-dead to remember what I needed. Of course, it then took me forever to wash my hair, and then the trains were all screwed up, so I didn't get to college until 3.50pm. I went to the room where the class was supposed to be, to find no one there. After wandering around a bit looking in all the likely rooms, I found some people in the common room who'd been timetabled for the earlier class (2pm), and they said hardly anyone had bothered to turn up, and they'd just chatted about random stuff for 20 minutes before giving up. How ... helpful. (You mean I rushed across London for nothing?)
On the basis I thought there was actually going to be a class today, I spent last night trying to prepare a topic. After looking through the list of topics and panicking wildly as they all seemed to be either chemistry or stuff I'd never done (the range of joints in the human body? the structure of proteins or DNA? They weren't in GCSE biology when I was a kid!) I found "What is the difference between force and pressure?", which seemed to be something I should know about.
But I found that although I could find simple definitions in my books for pressure (a force acting over an area), I couldn't find a good definition for force! I looked in four textbooks and did a google search, and the best I could come up with were "examples of forces are pushes, pulls and twists" or "a force is the physical influence which when exerted over a distance causes work to be done" / "a force is the physical influence which causes a body of uniform mass to accelerate". The first definition isn't really a definition at all - it's giving examples of forces without telling me what a force is, and the second two are just statements of well-known equations in words. Not very helpful for my understanding or for my ability to explain this to kids.
Anyway, the people in the common room were physicists, so I tried to ask them for a definition of force. And they kept telling me either that forces are "electrostatic, gravitational, or strong or weak nuclear forces" (i.e. giving examples of forces as a definition) or that a force is "pressure divided by area" (restating an equation in words). I said "I understand what pressure is - it's a force acting over an area, so the same force over a small area gives a big pressure. Now tell me what a force is!". And they just couldn't. They said I'd have to know particle physics to understand it, and I said "How can something so fundamental not have at least one simple definition? - even if that definition has to later be extended?".
We went round and round in circles like that for some time. They kept either giving me examples of forces or restating equations. I said "It's like telling me that some types of furniture are beds, chairs and desks. Which I understand - now tell me what 'furniture' is!". Or "I want to know what a chair is, and you've told me that a chair is a type of furniture, whereas what I actually want to know is that it's something you sit on". I don't know. Are those analogies really that bad? (I thought they were okay for spur-of-the-moment things!). Eventually, after around 25 minutes of arguing, we managed to hash out that a force is "an interaction between matter". I asked if that was always true, and they thought it was (although some of the interactions are on the subatomic level).
Ye gods! The word "force" is all the way through school level science! It's introduced in Key Stage 1 (which they do at ages 5-7!). And yet it's taken a chemist nearly half an hour to prod an acceptable definition out of two physicists! I'd go "Gah, physicists", but I know the problem's not with them personally. How can we teach something that's fundamental and at the heart of the subject without a useful working definition, and expect the kids to actually understand it? "A force is a push or a pull" is fine for Key Stage 1, but by GCSE I'd expect more scientific language - but the language that's used is just restating the formula. If you don't understand where the formula came from, what use is restating it in words?