Category Archives: Third level

Introductory physics: heat and temperature

The teaching semester began again at 9.15 this morning. First day back, I’m always struck by how much I enjoy being in the classroom. I think it’s because lecturing is basically a performance, with never a dull moment; anything can go wrong and usually does! I also quite like big classes, it makes for a good atmosphere…

Then there’s the content. This morning 1st Science got to meet Heat and Temperature for the first time. This is my favourite kind of topic – quite simple but of fundamental importance. ‘Heat is a form of energy’, we tell our students, and ‘temperature is a measure of heat’. Actually, the discovery that heat is simply a form of energy was an enormous advance in science, possibly the greatest breakthough of 19th century physics.

And what sort of energy is it? Well, kinetic energy arises due to the motion of molecules (vibration in solids). But there is also potential energy;  since atoms in solids have more-or-less fixed positions in the lattice they have must possess an associated potential energy (so do atoms in liquids for a slightly more subtle reason). So heat is basically a type of internal energy. Except that it’s not always internal; there is also the whole business of heat transfer, a phenomenon that can occur by any or all of three very different mechanisms!

Then there is temperature; a philosopher would have a field day explaining the difference between a quantity that simply is (energy), it’s manifestation (temperature) and human temperature scales. Indeed, the relation between heat and temperature was only quantified with the intoduction of concepts such as specific heat capacity and specific latent heat. Temperature clearly has a fundamental aspect too; for example, what do really mean by absolute zero (or zero Kelvin)? ‘Absolute zero is the temperature at which all molecular motion ceases’, students are told. But what does this mean? Why can’t we reproduce this temperature in the lab? Is -30 Kelvin ( or -303 degrees Celcius) really a nonsense? Fundamental stuff indeed and a nice start to the term…

Achieving the impossible in the lab

Update:

Oops! I thought the dial read zero on the LHS but it doesn’t of course. Also, I’m not sure why it reads degrees Kelvin, there is no such thing.

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Filed under History and philosophy of science, Introductory physics, Teaching, Third level

Those pesky exam corrections

It’s nice and quiet around college this week as the students aren’t back yet. However, this is also correction week since the semester exams took place before the Christmas break (one of the by-products of semesterisation is that we now get to correct twice a year). Most academics detest exam correction but actually I don’t really mind that much – it always takes less time than expected (unlike research) and I like a job that has a definite beginning, middle and end with room for targets and treats along the way. I’ve also learnt a few tricks over the years…

Oh joy

First, I like to correct in series i.e. student by student. Some lecturers claim it’s easier to mark objectively if you correct in parallel i.e. correct all the first questions, then all the second questions etc. However, it’s definitely trickier to tot up the marks at the end this way. It seems to me that there is less chance of marks being overlooked (the real worry) if a script is corrected question by question because you get a feel for how a particular student is getting on as you plough through the script…and it’s also more entertaining. Another trick is to sort the scripts alphabetically before you start – it’s fun working your way through the alphabet, planning for lunch between the Gs and the Hs (bonus marks for students with unusual initials!).

In our college, exam scripts are corrected by name and the students often campaign for anonymous marking. Little do they know that from a teacher’s perspective, it’s much harder to fail a person than a number, particularly if you know that student made a decent effort during the semester. Indeed a great deal of correction time goes on trying to squeeze in a few extra marks for the borderliners; if anything, I would expect pass marks to drop if anonymous marking was introduced.

A decent effort?

Right now, there is quite a row going on in the Institute of Technology sector concerning payment for exam correction. It may come as a surprise that IoT lecturers are paid extra for correcting exams (not very much). I suspect the situation originally arose because secondary teachers are paid to mark the Leaving Certificate and  IoT lecturers are represented by the same union.

Anyway, that payment is now under threat and I’m not sure what to make of the debate. What is certainly unfair is that some lecturers have hundreds of exams to correct due to large class sizes, while others get off lightly. Perhaps a sensible solution would be for the Institutes to intoduce payment that starts after the first hundred scripts. However, I suspect that as 3rd level cutbacks bite deeper, payment for exam correction will become a thing of the past..

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Exam stress

This week is by far the most stressful week of the teaching semester for lecturing staff, as Friday marks the deadline for submission of exam papers. If you teach four courses, which is fairly typical for Institute of Technology lecturers, that’s eight papers of questions and model answers to be handed in if you include the repeats.

I’m not saying it’s a bad idea in principle to have exams submitted half way through the semester, far from it (besides, the timetable is set by the fact that the papers have to be posted to the external examiners). However, it’s a lot of prep and the stress is twofold. First there’s all those neat questions you thought of as you were teaching the course, but now can’t find. Second, it’s the realisation that, in every course, you are far behind where you should be. If only the students knew!

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Enthralled class

Worst of all are the shared papers. This involves inumerable meetings, changes and compromises, until all participants are happy.I often feel it would be easier to write the whole damn paper myself, even if I only teach part of that course!

Still, shouldn’t complain. Next week is midterm and we have a whole week off. I intend to make the most of it, with a weekend in the Comeragh mountains with the Glenwalk Hillwalking Club, followed by some surfing and music in Doolin during the week. I deserve it.

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With Glenwalk in the mountains of Mourne

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Tunes in Doolin last summer

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Institute of the Year 2009/10

This week is Clubs and Societies week at WIT and there is a great atmosphere around the college. As in any third level college, there are many interesting clubs, from Gaelic games to swimming, from canoeing to rock climbing etc. This is an important part of college life as the clubs offer a wonderful opportunity for students to try a sport they may never otherwise encounter. For example, the sailing club gives students an opportunity to learn to sail without the hassle of buying a boat or joining an expensive sailing club. My own favourite is the surf club – this is a big hit as the college is only a few miles from Tramore surf beach and students from distant parts of the country (and abroad) are keen to sign up.

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There is also a good mood around the college because WIT has just been nominated Institute of Technology of the Year in the Sunday Times league table of Irish third level colleges. The Sunday Times ranking is the only league table for the IoT sector and it is the second time WIT has won the award in the last few years.

It’s always good to come first, but it’s hard to know how accurate such rankings really are. Different colleges come top each year, which might indicate that the variation in a given college from year to year is larger than the variation between different colleges. That said, only a small number of colleges vie for top position every year so I guess it’s an honour to be in that number.

The main categories used in the Sunday Times rankings are: median CAO entry points, staff/student ratio, graduate employment, student grades, research income,  % non-standard entry rate and % dropout rate. This year, WIT scored an impressived 9/10 overall,  with the following breakdown:

average CAO entry points : 357

average staff/student ratio: 12:1

graduate employment: 99.2%

student grades of 2.1 and above: 56%

annual research funding: 18.2 million €

non-standard entry: 35%

student dropout rate: 15%

You can see more details here. It’s a good result, but one must admit that the poll is not a scientific study. For example, some academics question the ‘student grades’ category: a high percentage of 2.1s or above is awarded a high score, but it’s always possible that such a score reflects exam standards rather than better teaching (colleges set their own exams). This is an argument for another day, but let me note that even if this were true, I’m not mad about the other extreme: a recent study confirmed that throughout the 1980s, UCC and UCD graded their students far harder than Trinity, a habit that advantaged nobody and disadvantaged their students.

As regards the university rankings in the Sunday Times study, NUI Maynooth is the 2009 University of the Year up from 7th place last year. This is only one of two categories for the universities (I’m not that clear on the difference) but it’s pretty impressive for one of Ireland’s smallest universities. It does however raise a question: how could any college change this much in one year? I suspect it indicates that there are only small differences in scoring between the universities. Indeed, a positive result that can be drawn from the Sunday Times annual rankings is that Irish university students are offered pretty much the same level of education irrespective of which university they attend, in marked contrast with the American system. I like the Irish system better and I think we should stick with it, and forget the recent suggestion of a two-tier university system with an eye to world rankings.

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University College Maynooth

How do the Institutes of Technology compare with the Irish universities? It’s hard to tell as there are separate lists for the two types of college. I think it would be interesting to see a direct comparison between the two: in particular, I think the results in research funding for WIT and CIT might come as a surprise to some university colleagues.

Finally, I can’t resist pointing out the sad irony of WIT coming top in such studies. Waterford is one of the most disadvantaged of Irish cities and one reason for this may be that is the only Irish city without a university, causing an inevitable braindrain of our best schoolleavers to Dublin and making it difficult to attract multinationals to the region. In other words, the city desperately needs the cachet that a university would bring and clearly has a college that could form the basis of such a university, but nobody in government is much interested.

Some might argue that if Ireland were governed by logic rather than history and religion, there would be no university in the town of Maynooth and there would be one in the city of Waterford where it’s needed…I couldn’t possibly comment!

Update: this post has been reproduced on the 9th level Ireland website, you can see the comments there

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