Expert Insights

I think what I try to get students to see is that we use models and you use a model, while it works. Then when it doesn’t work you develop a more sophisticated model, and what we’re doing now is developing a more sophisticated model of the structure of the atom, of bonding between atoms. So they find that difficult, the fact that you’re putting aside the model you used previously and developing a more sophisticated one. I think that’s something, it just knocks their confidence a bit. I think we’ve got to convince them that, actually, what your teachers told you at school wasn't wrong, it’s just that this is more sophisticated, that science is all about building models to explain reality.

When you think of things in terms of energy you can represent energy … energy can be modelled as a particle, as matter.  It can be modelled using waves and then trying to talk about how we would use each model as it's appropriate for a particular situation.  It's the sort of things we observe might dictate which model we use to explain it, by recognising that in each case there is another model but perhaps just not as useful.  So maybe it goes back to just trying to show that everything that we do is a model, every model has its upside and its downside and that we usually only use a model that’s as detailed as it needs to be for the particular concept that you're trying to get across.  If you want to get across a concept of a car to someone who has never seen a car you don't probably show them a Ferrari or a drag racing car.  Maybe you show them a Lego style block and we do the same thing with our scientific models as well.  I guess trying to get across that idea that this is the model that we're going to use but it can be a lot more complicated.  I don't want you to think it's as simple as this but it's appropriate under the circumstance.  So I guess I spend a lot of time talking about things as models when I'm talking about quantum mechanics.  Our treatment in the first year, which is where I cover it, a little bit of second year but I don't take a mathematical detail treatment of quantum mechanics.  Someone else does that, so I really bow to them. So most of mine is non-mathematical, just simple mathematics and mainly conceptual type of stuff.  I guess some of the things I try and do to illustrate the differences between the models and the way that we use them is to ask questions in class that might be postulated in such a way that you can't answer it if you're thinking about both models at the same time.  So the one I like is where I show say a 2s orbital and the probability distribution of that node in between.  I talk about things that … there's one briefly, this plum pudding model which they all laugh about.  When you look at this 2s model there is a probability and a high probability, relatively so, that the electron can be inside the nucleus, if you think about it in particle terms.  Then talk about the nodes and so on and how they arise in quantum mechanics and so on and then ask questions like if the electron can be here and here but it can never be here how does it get there?  ...  I try and get across maybe the bigger picture, everything we're going to do from this point on (because we do this fairly early in first year)  - everything is going to be a model.  Nothing is going to be right.  Nothing is going to be wrong. Nothing is going to be exactly the way it is.  Everything will be just a model. You'll hear us saying things like ‘this is how it is’ or ‘this is what's happening’.  But really you need to interpret that as ‘this is a model and this is how this model is used to explain this particular phenomenon.

It always seems like we're starting from further behind than a lot of the other sciences are because they seem to know less about chemistry when they get here.  If I say ‘think of a famous physicist’ you probably already have thought of three.  Then you could go outside and ask someone to think of a famous physicist and they'd probably think of at least one of the same ones.  You do the same thing with biologists.  If I say to think of a famous chemist … that's within chemistry circles, we can't do it.  We can name one but you know if you go out there and say, ‘Who is this person?’ they've got no idea.  So for some reason … we've never … chemists have never been able to popularise our topic, our content.  We've never been able to make it exciting enough that someone who is not studying it still wants to know about it.  And so I do think we've got a bigger challenge, for whatever reason.  Maybe there's something about chemistry that makes it less enjoyable, I don’t know.  There's definitely been an ongoing issue for us that it's not … people just don't know anything about it... Most people know Einstein's theory of relativity.  You don't see that really in everyday, go, "There's the theory of relativity at work." Newton's Law, sure, you see those and you … but, yeah, everybody knows Einstein.  And a lot of … I'll call them lay people, I don't like the term, but non-science people, could probably give you a hand wave explanation of what the theory of relativity is about, which is a pretty abstract thing.  I mean, if we think of the equivalent types of things in chemistry that are that abstract, nobody has a clue.  We teach them in third year to the remaining hard core people that are left.