We have been having some work done at home, to have our loft changed into a bedroom and an office for home working. We have had a bookshelf built in to one of the rooms, and it has just been populated by books, so finally I can take a photo and have proper background to my Zoom calls, which I understand is supposed to be a full bookcase
It's the middle of the semester, and it's my busiest semester, in which I teach two full 15-credit final year modules – i.e. I am teaching half of a student's full time effort, and with the extra preparation of online lectures, online tutorials, videos of answers to problems, more time on online discussion, as well as all the non-teaching parts of my job, I am finding myself working after the family has gone to bed most days. Not a position I ever try to get myself in, but I'm more or less resigned to it for the rest of semester.
For most of my lectures and problem solution walk-throughs I'm using a video of me writing on a tablet device, accompanied by my voice. It works tolerably well, though not without glitches. I'm getting increasing adept at re-opening the whiteboard app when part of my writing hand accidently touches a part of the screen and closes it. At the same time, my usage of mild swear words has never been higher, and no doubt the students will also be saying crivvens whenever they need to express some slight horror.
Some of the problem solutions I've been working through involve sticking in actual real-life numbers into calcualtions. These are calculations a bit too complicated to do mentally, and I rarely find myself in need of doing such calcualtions so that I don't have an old-fashioned calculator to hand. I have, of course, a computer, and also a smart phone, and usually I end up using the calcualtor function on my smart phone. As I wrote an equation on my tablet a couple of weeks ago, I did find myself musing that it would be nice if there were an app to recognise the equation and do the sums for you. Lo and behold, of course there is. One of the courses I am teaching right now involves the use of the programming language Maple and there is a app written by the Maple people called Maple Calculator. It has exactly this function; you can take a picture of some mathematics with a camera, it will recognise it (hopefully) and then evaluate it for you.
Here is an example of it working out a calculation for a kinematics problem in special relativity:
I tried to make sure that I wrote the equation very neatly, and indeed it seemed to recognise it okay. The answer, though, is not what I was expecting. The actual answer is around 1.73. It took me a little while to understand why...
While we wait for all academic publishing to be properly open access, Royal Society Publishing have kindly opened up their pretty extensive archive for free for the next week. See here.
They do not have an extensive amount of nuclear physics stuff, but they are currently my publishing BFF because they published my student's article on Terrell rotations earlier this year, whcih I may have metioned here before. More than once. In fact, more than twice. Well, modesty prohibits me from linking to the paper again, but that's okay because there are lots of other articles of interest, dating back, of course, many centuties.
If anyone has any favourite articles from Proceedings of the Royal Society, or the Philosophical Transactions, please do share in the comments.
Here's a snapshot of some sketches by William Herschel, from Philosophical Transactions, vol 74, p233 (1784)
That leaves just one more paper to appear, and also means that I should get on with writing the editorial in time to make a free e-book of the Special Topic.
Roger Penrose was announced this morning as the winner of half of the 2020 Nobel Prize in Physics, with the other half being shared equally between Andrea Ghez and Reinhard Genzel. I will leave others to explain about the physics behind the prize award, since it is not really my area of expertise, but I wanted to post to mention the ways Penrose and his work has cropped up in my life
As a physics-interested schoolboy, I used to read through popular science books. Probably the first one I read, to the best of my memory, was Stephen Hawking's A Brief History of Time, which I got for Christmas the year it came out and was something of a must-read book for more or less anyone, though there was a kind of joke that few people finished it. I did finish it, and though I probably didn't understand it all, I found it at least readable and understood the words and got a sense always of the ideas being communicated, even if perhaps I didn't always gain a deep understanding.
Another one I read, while I was in the lower sixth (what we used to call Year 12) and applying to University, was Penrose's The Emperor's New Mind. I lent my copy to a girl I fancied and never got it back. I later learned that the rule of lending books to anyone was that you just go out and buy yourself another copy straight away. Anyway, I had finished the book, though I'm not sure I can remember too much of it in great detail now. It did make quite an impression on me at the time, though I think it was "harder" than Stephen Hawking's book and no doubt there was lots I didn't understand. I liked it for its broad sweep, combining ideas from physics to advanced mathematics, Turing machines, and on to somewhat more speculative stuff (which I didn't distinguish at the time, I suppose) to do with consciousness.
In December of 1991, when I was in the lower sixth and up in Oxford for an interview to read Physics and Philosophy I noticed that Penrose was giving a lecture for prospective students in Mathematics. In my interview for my place in college when asked if I had any questions I said I'd seen the advert for the talk and I asked if it would be okay if I went along to it. I'm not sure what they thought of my question - I guess I had no idea at the time that it would be perfectly fine for anyone to turn up and they wouldn't exactly be checking to see if I was really a prospective mathematics student. Anyway, I went along, and enjoyed the talk very much. Penrose talked about the famous Penrose tiles. I remember particularly a demonstration of how for certain near-symmetries you could make the symmetry almost perfect - as near to perfect as you liked, except not quite actual perfection - and he showed this by having two identical overhead projector slides with a 5-fold Penrose tiling, which he overlaid, and you could see the bands made in the thin regions where the pattern didn't quite repeat.
I don't think I have seen Penrose in person since then, 29 years ago, but I did get a copy of his huge "The Road To Reality" book as a 30th birthday present a bit later (in 2004). That's been sitting on my office shelves unread, I have to admit. I'm sure, as a practicing theoretical physicist, that I ought to be able to read and understand it, but even to me, opening it up it does look intimidating.
The other Penrose anecdote I have is that I found out at some point (perhaps the advent of wikipedia) that I share a birthday with several famous physicists, two of whom won Nobel prizes long ago). Now I can fill in another cell in this table:
| Physicist | Date of Birth | Year of Nobel Prize |
| E.O. Lawrence | 08/08/1901 | 1939 |
| P.A.M. Dirac | 08/08/1902 | 1933 |
| R. Penrose | 08/08/1931 | 2020 |
| P. D. Stevenson (me!) | 08/08/1974 | - |
The final Penrose-related thing links with my research: Earlier this year I co-published a paper with a bachelor's student based on his Final Year Project on the visual appearance of objects moving very fast (at an appreciable fraction of the speed of light). This is a new look at something which are either called Terrell Rotations, after the author who first got his name attached to it, or as the Penrose-Terrell effect, since Penrose independently submitted a paper on the same topic, published in the same year as Terrell. Even more properly, it can be called the Lampa-Terrell-Penrose effect, since Lampa published it first, in a paper that wasn't so widely known.
Here's a picture of Penrose, which he sent to the Nobel Committee from his house in Oxford this morning
I saw yesterday that the Royal Society published their shortlist for their science books of the year. There are 6 in the shortlist: The World According to Physics by Jim Al-Khalili, The Body by Bill Bryson, The Great Pretender by Susannah Cahalan, Explaining Humans by Camilla Peng, The Double X Economy by Linda Scott, and Transcendence by Gaia Vince.
Unusually, since I don't read a lot of popular science, I've actually read two of the books: Transcendence and The World According to Physics. They are both excellent, and would be worthy winners. I got Transcendence for Christmas last year, and found its arguments compelling that humans' achievements are part and parcel of the way humans work together; the network of ideas, activities, language and culture evolve together with biological humans and have created a kind of super-organism. Mind-blowing, well-researched and full of interesting anecdotes, I found myself wanting to tell people things I'd read in it as I was going through.
The World According to Physics is right up my own subject area, so though I would expect to enjoy it, I wouldn't necesasrily prioritise adding a popular explanation of something I think I know well to my reading list, but I'm glad I did read it: Sure, I knew most of the stuff already, but it was infused with such a joy for the wonder of the Universe, and our way of explaining it through physics, that I rekindled my own sense of awe at what I sometimes let lapse as part of my day-to-day activities. I did even learn a few things, thanks to the inclusion of lots of very up-to-date and speculative ideas (which were flagged as such). I should add that I read a draft of the book and gave some comments, and the author did hand me a copy once it was published. Jim is my colleague at the Unviersity of Surrey. No payment was received for this review ;-)
The document format pdf is pretty good when you want to make nice-looking output for printing for your scientific paper. It's not always so handy when you want to read something on e.g. your phone screen, though, where you have to do a combination of zooming in and scrolling around to be able to read a paper.
A nicely-formated html version of a scientific paper, on the other hand, should be able to render nicely on a wider range of screens, and these days reading from screen has largely superseded reading from paper for me. I read on Twitter about an arxiv-to-html translator called arxiv-vanity. You give it an arxiv URL and it returns a nice readble web-page version of the paper you are interested in.
I tried it on the recent whitepaper / review I was involved in writing on fission theory and the results are impressive. Perhaps arxiv will fold it into its own offering soon.
