Archive for September 3, 2020

Littlewood on `the real point’ of lectures

Posted in Education, mathematics, The Universe and Stuff with tags , , , on September 3, 2020 by telescoper

We’re often challenged these days to defend the educational value of the lecture as opposed to other forms of delivery, especially with the restrictions on large lectures imposed by Covid-19. But this is not a new debate. The mathematician J.E. Littlewood felt necessary to defend the lecture as a medium of instruction (in the context of advanced mathematics) way back in 1926 in the Introduction to his book The Elements of the Theory of Real Functions.

(as quoted by G. Temple in his Inaugural Lecture as Sedleian Professor of Natural Philosophy at the University of Oxford in 1954 “The Classic and Romantic in Natural Philosophy”.)

Temple concluded his lecture with:

Classic perfection should be reserved for the monograph: the successful lecture is almost inevitably a romantic adventure. It is at once the grandeur and misery of a scientific classic that it says the last word: it is the charm of a scientific romance that it utters the first word, and thus opens the windows on a new world.

Modern textbooks do try to be more user-friendly than perhaps they were in Littlewood’s day, and they aren’t always “complete and accurate” either, but I think Littlewood is right in pointing out that they do often hide `the real point’ so students sometimes can’t see the wood for the trees. The value of lectures is not in trying to deliver masses of detail but to point out the important bits.

It seems apt to mention that the things I remember best from my undergraduate lectures at Cambridge are not what’s in my lecture notes – most of which I still have, incidentally – but some of the asides made by the lectures. In particular I remember Peter Scheuer who taught Electrodynamics & Relativity talking about his first experience of radio astronomy. He didn’t like electronics at all and wasn’t sure radio astronomy was for him, but someone – possibly Martin Ryle – reassured him by saying “All you need to know in order to do this is Ohm’s Law. But you need to know it bloody well.”

Watch “Why the Universe is quite disappointing really – Episode 7” on YouTube

Posted in The Universe and Stuff, YouTube with tags , , , , on September 3, 2020 by telescoper

Back for Episode 7 of this series in which I explain how we can measure the strength of acoustic waves in early Universe using measurements of the cosmic microwave background, and how that leads to the conclusion that the Big Bang wasn’t as loud as you probably thought. You can read more about this here.

The Virtue of Signalling

Posted in Covid-19, Education, Maynooth, Politics with tags , , on September 3, 2020 by telescoper
I was in a supermarket in Maynooth yesterday morning when a bloke was refused entry for not wearing a mask. That’s the first time I’ve seen that happen, though I’ve heard various people mentioning similar stories elsewhere. There is a big sign near the entrance to the store saying that face masks are mandatory, which they have been for some time in Ireland, so he could not make the excuse that he didn’t know. I rather think he was trying to make a point.
The person concerned didn’t get violent, but was extremely loud and abusive to the staff, who shouldn’t have to put up with that sort of behaviour. He stood there for a while shouting expletive in between which his message was that he didn’t care whether he got Covid-19 as it was “just the flu”. I did wonder whether someone might call that Gardaí but after a few minutes, afer which he either felt he had done what he wanted to do or that he was wasting his time, he left.
I have to admit I completely fail to see why certain people find wearing a face mask such an ordeal. It’s really nothing. I understand that some people, with e.g. asthma, might have good reasons for finding it difficult but I’m talking here about people without such reasons who seem to think they’re being asked to bear some intolerable burden, rather than just wearing a piece of light material over their nose and mouth. I’ve got quite used to it and think nothing of it. As winter comes on I even think wearing a mask might help keep my face warm and, more importantly, protect my beard from inclement weather.
The only thing that bothers me slightly is that I have very boring face masks when others seem to have invested in colourful stylish affairs. It makes me feel a bit drab. Perhaps I should invest in some more glamorous masks.
But back to our friend in the supermarket. He of course may not care whether or not he gets Covid-19, but that’s not the main point of wearing a mask. Face masks are far more effective at protecting other people from your germs than protect you from other people’s germs. I suspect, however, that trying to explain this to the person concerned would simply make matters worse. To be happy wearing a face mask you have to be the sort of person who cares about what happens to other people and there are some – regrettably many these days – who just don’t. I’m sure that extreme selfishness translates into their political attitudes too.
When we return to on-campus teaching at the end of this month, students will be asked to wear face coverings in lectures. I’m not sure how that will work out. In particular I don’t know who is supposed to police it. Supermarkets have people on the door to turn away the unmasked. Are we to have that at the entrance to lecture theatres?
Lecturing with a face mask on will be difficult, but in a big theatre the lecturer is sufficiently far from the front of the audience that won’t be necessary.
I’m not sure how effective face masks will be at slowing the spread of Covid-19 – we’ll have to wait and see – but my attitude is that they are just a part of a bundle of measures, including frequent washing of hands, wiping surfaces regularly, maintaining social distancing, etc that all contribute. The great value of a face mask in all this is that it is visible. Wearing a mask is a signal to others that they should remember the danger of the situation and act accordingly. It’s a way of showing leadership.
It has become fashionable (at least among those who possess no virtues) to use the phrase virtue signalling as pejorative term for doing or saying something good in a way that is conspicuous. To the person ejected from the supermarket, the wearing of a face mask is probably an example of virtue signalling. I think it is too, literally, and I’m all in favour of it.