## A Question of Balance

Posted in Cute Problems, The Universe and Stuff with tags , , on November 3, 2021 by telescoper

Here’s an interesting physics problem for you, based on the idea that the mass of a set of bodies changes if the energy of their mutual interactions changes according to Einstein’s famous formula “E=mc2“.

Four identical masses are placed at rest in pairs either side of an extremely sensitive balance in a symmetrical way such that the distance between the members of a pair is identical for each pair and the centre of mass of each pair is equally spaced from the fulcrum of the balance. In this configuration the system is in equilibrium and the balance is level.

As illustrated schematically in the graphic, one pair of weights is adjusted by displacing each weight slightly away from the centre of mass of the pair by an equal and opposite distance, thus keeping the position of the centre of mass of the pair constant. The other pair of weights is not adjusted.

Assuming that the balance is sufficiently sensitive to detect the slight change in mass associated with the gravitational interactions between the masses in each pair, does the balance move?

If it does move which pair moves up: the displaced pair or the undisturbed pair?

## I don’t know how to teach…

Posted in Education, Maynooth with tags , , , , , on October 25, 2021 by telescoper

Making use of this Bank Holiday Monday morning to tidy up some things on my computer I realized I had bookmarked this short clip of Richard Feynman answering a question about teaching. I clearly intended to blog about it at some point but forgot to do so, so I’m correcting that now.

Feynman was of course a renowned lecturer both for university students and for public audiences. I think one of the things that made him so successful is that he liked talking about his subject and liked being the centre of attention; people who like neither of those things are unlikely to make good lecturers!

But the thing that really struck me about what he says in this clip is near the beginning where he says he thinks the way to approach teaching is “be chaotic” to “use every possible way of doing it”. Now some of us are occasionally chaotic by accident, but I think there is a great deal of truth in what he says. I also agree with him when he says “I really don’t know how to do it..” I don’t either

If you start from the premise that every student is different, and will consequently learn in a different way, then you have to accept that there is no one unique style of teaching that will suit everyone. It makes sense therefore to try different kinds of things: worked examples, derivations, historical asides, question-and-answer sessions, and so on. And we shouldn’t rely exclusively on lectures: there must be a range of activities: problems classes, tutorials, supplementary reading, etc. With a bit of luck the majority of your class will find something that stimulates and/or enlightens them.

The point about using every possible method at your disposal has become especially relevant now that we have had about 18 months’ experience of online teaching. I feel very strongly that we should make recordings of lectures routinely available to all students, not as a replacement for the “live” experience but to add to the set of resources a student can draw on. The same goes for other things which came into regular use doing our online period, such as printed lecture notes (again, not as a replacement for a student’s own notes but as a supplement).

I think it also helps to acknowledge that what you can actually achieve in a lecture is very limited: you shouldn’t be simply trying to “deliver” material for later regurgitation. You should be pointing out the particularly interesting aspects, explaining why they are particularly interesting, and what things students should follow up in private study where in textbooks and on the net they will find yet more different ways of approaching the subject.

After over thirty years of teaching have come to the conclusion that the main purpose of university education is to convince students that their brain is more than simply a memory device, i.e. that it can also be used for figuring things out. I’m not saying that a good memory is worthless. It can be extremely useful and memory skills are important. I’m just saying that the brain can do other things too. Likewise, examinations should not be simple memory tests. Sadly school education systems seem to be focussed on coaching students passing exams by rote learning.

We see particular evidence of this in physics, with many students afraid to even attempt to solve problems they haven’t seen before. One infers that they passed exams by simply memorizing answers to questions very similar to those on the paper. Our job is to remove that fear, not by pretending that physics is easy, but by giving students the confidence to start believing that they can do things that they previously thought were too difficult. In other words, university education is often about undoing some of the limitations imposed on students by their school education.

Back to lecturing, there are some obvious basics which lecturers need to do in order to teach competently, including being prepared, talking sufficiently loudly, writing clearly (if relevant), and so on. And of course turning up at the right theatre at the right time. But there are also those things that turn mere competence into excellence. Of course there are many ways to lecture, and you have to put your own personality into what you do, but the main tips I’d pass on to make your lectures really popular can be boiled down into the Three Es. I add that these are things that struck me while watching others lecture, rather than me claiming to be brilliant myself (which I know I’m not). Anyway, here we go:

Enthusiasm. The single most obvious response on student questionnaires about lecturing refers to enthusiasm. My take on this is that we’re all professional physicists, earning our keep by doing physics. If we can’t be enthusiastic about it then it’s clearly unreasonable to expect the students to get fired up. So convey the excitement of the subject! I don’t mean by descending into vacuous gee-whizz stuff, but by explaining how interesting things are when you look at them properly as a physicist, mathematics and all.

Engagement. This one cuts both ways. First it is essential to look at your audience, ask questions, and make them feel that they are part of a shared experience not just listening to a monologue. The latter might be fine for a public lecture, but if a teaching session is to be successful as a pedagogical exercise it can’t be passive. And if you ask a question of the audience, make your body language tell them that it’s not just rhetorical: if you don’t look like you want an answer, you won’t get one. More importantly, try to cultivate an atmosphere wherein the students feel they can contribute. You know you’ve succeeded in this when students point out mistakes you have made. On the other hand, you can’t take this too far. The lecturer is the person who is supposed to know the stuff so fundamentally there’s no symmetry between you and the audience. You have to be authoritative, though that doesn’t mean you have to behave like a pompous schoolmaster. Know your subject, explain it well and you’ll earn respect without needing to bluster.

Entertainment. As I said above, lecturing is very limited as a way of teaching physics. That is not to say that lectures don’t have a role, which I think is to highlight key concepts and demonstrate their applicability;  the rest, the details, the nuts and bolts are best done by problem-based learning. I therefore think it does no harm at all if you make your lectures fairly light on detail and (with reason) enjoyable as pieces of entertainment. By all means introduce the odd joke, refer to surprising examples, amusing analogies, and so on.  As long as you don’t overdo it, you’ll find that a bit of light relief will keep the attention levels up. A key element of this is spontaneity. A lecture should appear as if it develops naturally, in an almost improvised fashion. Of course your spontaneity will probably have to  be very carefully rehearsed, but the sense of a live performance always adds value. A lecture should be a happening, not just a presentation. Lecture demonstrations also play this role, although they seem to be deployed less frequently  nowadays than in the past. Being a showman doesn’t come naturally to everyone, and the audience will know if you’re forcing it so don’t act unnaturally, but at the very least try to move about. Believe me, watching a lecturer drone on for an hour while rooted to the spot is a very tedious experience (especially on a video recording). You’d be surprised how much difference it makes if you can convey at least the impression of being alive.

On this last point, I’ll offer a few quotes from a physicist who definitely knew a thing or two about lecturing, Michael Faraday. First, his opinion was that the lecturer should not be

…glued to the table or screwed to the floor. He must by all means appear as a body distinct and separate from the things around, and must have some motion apart from that which they possess.

Conventional wisdom nowadays suggests that one should take breaks in lectures to stop students losing concentration. I’m not sure I agree with this, actually. It’s certainly the case that attention will flag if you persist with a dreary monotone for an hour, but  I think a lecture can have a natural dynamic to it which keeps the students interested by variation rather than interruption. Faraday also thought this.

A flame should be lighted at the commencement and kept alive with unremitting splendour to the end…I very much disapprove of breaks in the lecture.

Finally, here is one of my all-time  favourite physics quotes, Faraday’s take on the need for lectures to be entertaining:

..for though to all true philosophers science and nature will have charms innumerable in every dress, yet I am sorry to say that the generality of mankind cannot accompany us one short hour unless the path is strewn with flowers.

## Writing Vectors

Posted in mathematics, The Universe and Stuff with tags , , , on October 11, 2021 by telescoper

Once again it’s time to introduce first-year Mathematical Physics students to the joy of vectors, or specifically Euclidean vectors. Some of my students have seen them before, but probably aren’t aware of how much we use them theoretical physics. Obviously we introduce the idea of a vector in the simplest way possible, as a directed line segment. It’s only later on, in the second year, that we explain how there’s much more to vectors than that and explain their relationship to matrices and tensors.

Although I enjoy teaching this subject I always have to grit my teeth when I write them in the form that seems obligatory these days.

You see, when I was a lad, I was taught to write a geometric vector in the following fashion:

$\vec{r} =\left(\begin{array}{c} x \\ y \\ z \end{array} \right).$

This is a simple column vector, where $x,y,z$ are the components in a three-dimensional cartesian coordinate system. Other kinds of vector, such as those representing states in quantum mechanics, or anywhere else where linear algebra is used, can easily be represented in a similar fashion.

This notation is great because it’s very easy to calculate the scalar (dot) and vector (cross) products of two such objects by writing them in column form next to each other and performing a simple bit of manipulation. For example, the scalar product of the two vectors

$\vec{u}=\left(\begin{array}{c} 1 \\ 1 \\ 1 \end{array} \right)$ and $\vec{v}=\left(\begin{array}{c} 1 \\ 1 \\ -2 \end{array} \right)$

can easily be found by multiplying the corresponding elements of each together and totting them up:

$\vec{u} \cdot \vec{v} = (1 \times 1) + (1 \times 1) + (1\times -2) =0,$

showing immediately that these two vectors are orthogonal. In normalised form, these two particular vectors appear in other contexts in physics, where they have a more abstract interpretation than simple geometry, such as in the representation of the gluon in particle physics.

Moreover, writing vectors like this makes it a lot easier to transform them via the action of a matrix, by multipying rows in the usual fashion, e.g.
$\left(\begin{array}{ccc} \cos \theta & \sin\theta & 0 \\ -\sin\theta & \cos \theta & 0 \\ 0 & 0 & 1\end{array} \right) \left(\begin{array}{c} x \\ y \\ z \end{array} \right) = \left(\begin{array}{c} x\cos \theta + y\sin\theta \\ -x \sin \theta + y\cos \theta \\ z \end{array} \right)$
which corresponds to a rotation of the vector in the $x-y$ plane. Transposing a column vector into a row vector is easy too.

Well, that’s how I was taught to do it.

However, somebody, sometime, decided that, in Britain at least, this concise and computationally helpful notation had to be jettisoned and students instead must be forced to write a vector laboriously in terms of base vectors:

$\vec{r} = x\hat{\imath} + y \hat{\jmath} + z \hat{k}$

Some of you may even be used to doing it that way yourself. Why is this awful? For a start, it’s incredibly clumsy. It is less intuitive, doesn’t lend itself to easy operations on the vectors like I described above, doesn’t translate easily into the more general case of a matrix, and is generally just …well… awful. The only amusing thing about this is that you get to tell students not to put a dot on the “i” or the “j” – it always gets a laugh when you point out that these little dots are called “tittles“.

Worse still, for the purpose of teaching inexperienced students physics, it offers the possibility of horrible notational confusion. In particular, the unit vector $\hat{\imath}$ is too easily confused with $i$, the square root of minus one. Introduce a plane wave with a wavevector $\vec{k}$ and it gets even worse, especially when you want to write $\exp(i\vec{k}\cdot \vec{x})$, and if you want the answer to be the current density $\vec{j}$ then you’re in big trouble!

Call me old-fashioned, but I’ll take the row and column notation any day!

(Actually it’s better still just to use the index notation, $a_i$ which generalises easily to $a_{ij}$ and, for that matter, $a^{i}$.)

Or perhaps being here in Ireland we should, in honour of Hamilton, do everything in quaternions.

## Messers, Dreamers and Misfits

Posted in Art, Education, Music with tags , , , on September 5, 2021 by telescoper

After the death of Charlie Watts last week, Fintan O’Toole wrote a piece in the Irish Times (here, unfortunately behind a paywall) pointing out that, along with a large fraction of the English rock musicians that began their careers in the 1960s, Charlie Watts went to Art School; Harrow Art School in his case. O’Toole goes on to argue that society needs to find ways to nurture its creative talents and that modern education is far too utilitarian to allow space for “Messers, Dreamers and Misfits”.

I agree with the broad thrust of Fintan O’Toole’s argument. I think the School and University systems are far too focussed on examination and assessment at the expense of genuine education. What I disagree with is the idea that creativity is only to be found in the Arts. When I saw the phrase “Messers, Dreamers and Misfits” it struck me that this could very well describe many of my colleagues in physics, and in science generally – and I don’t mean that in any way as an insult!

There is an explicit assumption in much of the world that creativity is only to be found in the Arts. That’s just not true. Who can say that Einstein didn’t have a creative mind? It is true that if you want to be, say, a theoretical physicist you do have to do formal training in the methods used, especially mathematics. But that is no different from an art school really. To be a painter you have to learn the techniques needed to manage the media you are using. To be a musician you have to learn the basics of harmony and solve the technical problems involved with playing an instrument. Artists have to pay their dues just like scientists. I wrote about this here, in the context of the great Jazz pianist Bill Evans, where I said:

All subjects require technical skill, but there is more to being a great jazz musician than mastery of the instrument just as there’s more to being a research scientist than doing textbook problems. So here’s to creativity wherever it is found, and let’s have a bit more appreciation for the creative aspects of science and engineering!

Anyway, here in Ireland, the Leaving Certificate results came out on Friday and next week we’ll begin the process that determines how many students we’ll have doing Mathematical and Theoretical Physics at Maynooth. It always surprises me how many students choose study subjects other than Physics, but then I remember that I went from School to Cambridge in 1982 to read Natural Sciences, fully expecting to specialize in Chemistry but just found Physics more interesting and, yes, more fun.

I don’t know whether I count as a creative person at all, but I’m definitely a misfit, prone to dreaming and – especially at the moment in the middle of unpacking my belongings – my house is a mess!

Anyway, here is a message for students just about the start their Third Level education here in Ireland or elsewhere. The most important advice I can give is to choose the subject that you will enjoy most, but pursue your other interests too. Charlie Watts was interested in music while at art school. There’s no reason why a theoretical physicist can’t pursue an interest in music too. I can think of at least one prominent example of a person who managed to become a pop musician and a physicist.

Given my own background I read Fintan O’Toole’s article as clear encouragement to students to pick theoretical physics.

## An Olympic Story

Posted in Sport with tags , , , , on July 26, 2021 by telescoper

Just a quick post to mention a wonderful Olympic story. Louise Shanahan (pictured above) from Cork is competing in the Olympic Games in Tokyo in the 800m for Ireland. She is also in the second year of a PhD in Physics in the University of Cambridge, working in the Atomic, Mesoscopic and Optical Physics (AMOP) group in the Cavendish Laboratory. I wish her all the best in the heats on Friday 30th July and hopefully beyond!

UPDATE: Louise came seventh in Heat 3 so is now eliminated. She kept pace with the leaders before falling away on the final 150m stretch, finishing in a time of 2:03.57.

## R. I. P. Steven Weinberg (1933-2021)

Posted in Biographical, The Universe and Stuff with tags , , , on July 24, 2021 by telescoper

I just heard this morning via Twitter of the death at the age of 88 of the physicist Steven Weinberg. The news media don’t seem to have caught on yet but I’ll add links to appropriate tributes when they do.

UPDATE: You will find an appreciation from UT Austin here and an Associated Press article here.

Steven Weinberg is probably most famous in physics circles for his work on electroweak unification, together with Seldon Glashow and Abdus Salam, for which he jointly won the Nobel Prize for Physics in 1979. He did many other things besides, of course, and his influence is felt across huge swathes of particle physics, quantum field theory and cosmology. As well as a researcher he was a prolific writer, both of technical books – his Gravitational and Cosmology is a classic text on the principles and applications of the general theory of relativity – but also of works for the general public. He was an author of rare elegance and lucidity with some wonderful turns of phrase and a beautifully articulated secular view of the human condition. For example

If there is no point in the universe that we discover by the methods of science, there is a point that we can give the universe by the way we live, by loving each other, by discovering things about nature, by creating works of art. And that—in a way, although we are not the stars in a cosmic drama, if the only drama we’re starring in is one that we are making up as we go along, it is not entirely ignoble that faced with this unloving, impersonal universe we make a little island of warmth and love and science and art for ourselves. That’s not an entirely despicable role for us to play.

I bought Weinberg’s popular book The First Three Minutes about 40 years ago, and I still have a copy today. It’s no exaggeration to say that this book played a major part in my decision to continue a career in theoretical physics. I know I’m not the only physicist of my generation (or others) for whom this is the case. Although I never met Steven Weinberg in person, he was definitely an inspiration and he will be greatly missed.

Rest in peace, Steven Weinberg (1933-2021).

## What should universities keep after Covid?

Posted in Education, Maynooth with tags , , , on May 7, 2021 by telescoper

On the last day of teaching for this academic year, with reasonably encouraging signs of some form of reopening of campus education being possible in September, it will shortly be time to think about how we proceed next academic year.

It seems obvious to me that although university staff have worked very hard over the last year the Covid-19 restrictions have meant that we have not been able to provide the level of education we would have liked and most of us are longing to get back to some form of face-to-face teaching. On the other hand, the restrictions imposed upon us have generated some new approaches and it would be silly just to abandon what we have learnt and go straight back to the way things were before the pandemic.

I have two main things in mind, one on teaching and one on assessment, both of them relating to my own discipline – theoretical physics – but hopefully of some wider interest.

Implementing the Lane-Emden equation as two coupled first-order ODEs.

First, on teaching. Over the past year we have mainly been delivering lectures and tutorials remotely, using a mixture of platforms (Zoom, Panopto, Microsoft Teams, etc). Most lecturers have done lectures as live webcasts as well as recording the sessions to be viewed later. I have used Panopto for most of mine, actually. I am actually looking forward to being able to dismantle the setup I have in my study for this, to reclaim a bit of space, but probably won’t do so until we know for sure what we’ll be doing next Semester!

(By the way does anyone know where I should send the bill to my employers for their use of my study over the last year?)

For the record, I have found about 50% of the registered students have watched the lectures as live broadcasts from my home; the rest watch the recordings offline.

Maynooth didn’t have any facilities for lecture capture on campus until September 2020, in contrast to my two previous employers – the University of Sussex and Cardiff University – who both had systems in place long before the pandemic. I blogged about this 8 years ago, in fact. In Cardiff they actually use Panopto; all lectures were recorded as standard. In my view the benefits of lecture capture far outweigh the disadvantages, and we should incorporate recordings of lectures as part of our standard teaching provision, as a supplement to learning rather than to replace face-to-face sessions.

It seems to me that much of the argument against providing lecture recordings is from older staff who thing the younger generations should learn exactly the same way they themselves did despite the reality that classroom teaching in schools is now utterly different from what my generation experienced.

My view is that every student learns in a different way and we should therefore be doing as much as we possibly can to provide a diverse range of teaching resources so that each can find the combination that suits them best. Technology allows us to do this far better now than in the past.

Some really enjoy live lecture sessions, but others don’t. Others have reasons (such as disability) for not being able to attend in-person lectures, so providing recordings can help them. But why not in that case provide recordings for everyone? That seems to me to be a more inclusive approach.

The problem with continuing lecture capture beyond September 2021 in Maynooth is that we will need to improve the cameras and recording equipment in the large lecture rooms to make this possible for lectures with a significant mathematical content, as the existing setups in teaching rooms do not easily allow the lecturer to record material on a whiteboard or blackboard. In Cardiff the larger rooms have more than one camera, usually one on the lectern and one on the screen or whiteboard (which has to be placed further away and therefore needs to be of higher resolution). In Maynooth we only have small podium cameras in the teaching rooms.

The next topic is assessment. Since we were forced to switch to online timed assessments last May we have been doing most of our assessments that way. The student is given an exam paper at the appointed time, which they do on their own, then scan and upload their answers online (in our case via Moodle).

This mode of assessment has its problem. One is the possibility that students can collude (as there are no invigilators). Another is that not all students have a home environment conducive to taking an examination, nor a decent internet connection.

We decided to implement these as truly “open book” exams in which students are free to consult their notes, textbooks and internet resources. That format means it is pointless to ask the students to regurgitate definitions or learn derivations by rote so we concentrate on problem-solving, testing the understanding and application of concepts. Although it makes it a little harder to construct the examination papers, I think this a good way of assessing ability and knowledge of physics. If we can go do exams back on campus I think we should retain this approach at least for advanced topics, providing supervised spaces on campus to prevent collusion.

There are doubtless many other innovations we have brought in over the last year that people feel strongly about (one way or the other). Feel free to share them through the comments!

## Hawking and the Mind of God

Posted in The Universe and Stuff, Books, Talks and Reviews, Science Politics with tags , , , , , on March 3, 2021 by telescoper

There’s a new book out about Stephen Hawking which has triggered a certain amount of reaction (see, e.g., here) so I thought I’d mention a book I wrote, largely in response to the pseudo-religious nature of some of Hawking’s later writings.

I have in the past gone on record, both on television and in print, as being not entirely positive about the “cult” that surrounds Stephen Hawking. I think a number of my colleagues have found some of my comments disrespectful and/or churlish. I do nevertheless stand by everything I’ve said. I have enormous respect for Hawking the physicist, as well as deep admiration for his tenacity and fortitude, and have never said otherwise. I don’t, however, agree that Hawking is in the same category of revolutionary thinkers as Newton or Einstein, which is how he is often portrayed.

In fact a poll of 100 theoretical physicists in 1999 came to exactly the same conclusion. The top ten in that list were:

1. Albert Einstein
2. Isaac Newton
3. James Clerk Maxwell
4. Niels Bohr
5. Werner Heisenberg
6. Galileo Galilei
7. Richard Feynman
8. Paul Dirac
9. Erwin Schrödinger
10. Ernest Rutherford

The idea of a league table like this is of course a bit silly, but it does at least give some insight into the way physicists regard prominent figures in their subject. Hawking came way down the list, in fact, in 300th (equal) place. I don’t think it is disrespectful to Hawking to point this out. I’m not saying he isn’t a brilliant physicist. I’m just saying that there are a great many other brilliant physicists that no one outside physics has ever heard of.

It is interesting to speculate what would have happened if the list had been restricted to living physicists. I’d guess Hawking would be in the top ten, but I’m not at all sure where…

And before I get accused of jealousy about Stephen Hawking’s fame, let me make it absolutely clear that if Hawking was like a top Premiership footballer (which I think is an appropriate analogy), then I am definitely like someone kicking a ball around for a pub team on a Sunday morning (with a hangover). This gulf does not make me envious; it just makes me admire his ability all the more, just as trying to play football makes one realise exactly how good the top players really are.

I am not myself religious but I do think that there are many things that science does not – and probably will never – explain, such as why there is something rather than nothing. I also believe that science and religious belief are not in principle incompatible – although whether there is a conflict in practice does depend of course on the form of religious belief and how it is observed. God and physics are in my view pretty much orthogonal. To put it another way, if I were religious, there’s nothing in theoretical physics that would change make me want to change my mind. However, I’ll leave it to those many physicists who are learned in matters of theology to take up the (metaphorical) cudgels with Professor Hawking.

Anyway, this is the book I wrote:.

And here is the jacket blurb:

Stephen Hawking has achieved a unique position in contemporary culture, combining eminence in the rarefied world of theoretical physics with the popular fame usually reserved for film stars and rock musicians. Yet Hawking’s technical work is so challenging, both in its conceptual scope and in its mathematical detail, that proper understanding of its significance lies beyond the grasp of all but a few specialists. How, then, did Hawking-the-scientist become Hawking-the-icon? Hawking’s theories often take him into the intellectual territory that has traditionally been the province of religion rather than science. He acknowledges this explicitly in the closing sentence of his bestseller, A Brief History of Time , where he says that his ultimate aim is to know the Mind of God . Hawking and the Mind of God examines the pseudo-religious connotations of some of the key themes in Hawking’s work, and how these shed light not only on the Hawking cult itself, but also on the wider issue of how scientists represent themselves in the media.

I’m sure you’ll understand that there isn’t a hint of opportunism in the way I’m drawing this to your attention because my book is long out of print so you can’t buy it unless you get a copy second-hand…

## The Start of Spring Semester

Posted in Biographical, Education, Maynooth with tags , , , , , , , on February 1, 2021 by telescoper

It’s February 1st 2021, which means that today is Imbolc, a Gaelic festival marking the point halfway between the winter solstice and vernal equinox, i.e. it’s a Cross-Quarter Day. To be pedantic, Imbolc is actually the period between this evening and tomorrow evening as in the Celtic calendar days were counted from sunset to sunset.

The first Day of February is also the Feast day of St Brigid of Kildare (c. 451-525), one of Ireland’s patron saints along with Saints Patrick and Colm Cille. One of her miraculous powers was the ability to change water into ale, which perhaps explains her enduring popularity among the Irish.

In Ireland this day is sometimes regarded as the first day of spring, as it is roughly the time when the first spring lambs are born. It corresponds to the Welsh Gŵyl Fair y Canhwyllau and is also known as the Cross Quarter Day’ or (my favourite) The Quickening of the Year’. According to legend it is also the day on which jackdaws mate. Given how many of them there are around Maynooth there should be a lot of action today.

Today is, appropriately enough in the light of all this, the start of the Spring Semester of teaching at Maynooth University, the fourth Spring Semester I will have experienced here although this is obviously not like the others in that we’ll be teaching online at least for the first half and probably for the entirety. I was planning to stay at home today but I realised I’d left some things I need in the office on campus so will have to go to collect them. That’s why I’m up early. That and the need to shake myself out of the lockdown torpor that has afflicted me since New Year. It’s time to get my act together, pull my finger out, put my best foot forward, etc.

This Semester I am teaching Engineering Mathematics II, Computational Physics I and Advanced Electromagnetism. The former, what you would probably call a `service course’, covers a mixture of things, mainly Linear Algebra but with some other bits thrown in for fun, such as Laplace transforms. Interestingly I find the Mathematical Physics students do not encounter Laplace Transforms in the first year, but perhaps engineers use them more often than physicists do? I think I’ve written only one paper that made use of a Laplace transform. Anyway, I have to start with this topic as the students need some knowledge of it for some other module they’re taking this semester. I reckon six lectures will be enough to give them what they need. That’s two weeks of lectures, there being three lectures a week for this module.

Once again my teaching timetable for this module is quite nice. I have lectures on Monday, Tuesday and Wednesday and then the students have a choice of tutorial (on either Thursday or Friday). That means I can get through a decent amount of material each week before each tutorial. I don’t do the tutorials, by the way: that’s left to one of our PhD students, who gets paid for doing that and correcting the weekly coursework. There are about 50 students on this module, divided into two courses: Electronic Engineering and Robotics and Intelligent Devices. We don’t have Civil or Mechanical or Chemical Engineering, etc, at Maynooth, in case you were wondering. Lectures will be done as webcasts using Panopto but also recorded for later viewing.

My first Computational Physics lecture, which I will do from home, is on Thursday, after which there is a lab session which we will do via Microsoft Teams. That’s the way we did it after lockdown last year and it worked OK. Students attend one two-hour lab session in addition to the lecture, on either Thursday or Tuesday. The first lecture being on Thursday the first lab session will be Thursday afternoon, with the same material being covered the following Tuesday. Fortunately, Python is free to download and easy to install so it’s quite straightforward to run the labs remotely. Teams has a screen sharing facility so it’s quite easy for myself or my demonstrator to see what is wrong in the same way we would do in a laboratory class.

The Advanced Electromagnetism module is a new one for me but I’m quite looking forward to it. Being a final-year module its content is less prescriptive than others and I’ll be adding a few things that I find interesting. Both lectures for that one are on Wednesdays and again will be given as webcasts with recordings available later.

Today is a particularly busy day because in addition to my first lecture (at 2pm) I have a meeting of Academic Council (3pm via Teams), a Euclid telecon (via Zoom) and a meeting with my PhD student via Teams. I have also been trying to sort out tutors and tutorials for the forthcoming Semester: these don’t start until next week so there’s time, but it has been quite a challenge to get everyone sorted. Fortunately I think that’s now done.

Oh, and another thing. I signed up for Irish language lessons (Beginners Level) and will be having classes once a week from now on.

It’s going to be a very busy term but I reckon being busy is probably going to be a good way to get through the next few months.

## Physics versus Astrophysics

Posted in The Universe and Stuff with tags , on January 21, 2021 by telescoper

I don’t often post memes on here, but I couldn’t resist this one. Credit here.