An Update!

Well, hello to you and to 2019!

It has been a little while since I wrote here and not since last month when it was also last year, so let’s break that stretch. It was not a stretch of entire quiet, as those of you who follow on social media know (twitter, instagram, Facebook… see the sidebar for links), but I do know some of you don’t directly on social media, so I apologise for the neglect.

The fact is that I’ve been rather swamped with several things, including various duties that were time consuming. Many of them I can’t talk about, since they are not for public consumption (this ranges from being a science advisor on various things – some of which will be coming at you later in the year, to research projects that I’d rather not talk about yet, to sitting on various committees doing the service work that most academics do that helps the whole enterprise keep afloat). The most time-consuming of the ones I can talk about is probably being on the search committee for an astrophysics job for which we have an opening here at USC. This is exciting since it means that we’ll have a new colleague soon, doing exciting things in one of a variety of exciting areas in astrophysics. Which area still is to be determined, since we’ve to finish the search yet. But it did involve reading through a very large number of applications (CVs, cover letters, statements of research plans, teaching philosophies, letters of recommendation, etc), and meeting several times with colleagues to narrow things down to a (remarkable) short list… then hosting visitors/interviewees, arrangement meetings, and so forth. It is rather draining, while at the same time being very exciting since it marks a new beginning! It has been a while since we hired in this area in the department, and there’s optimism that this marks a beginning of a re-invigoration for certain research areas here.

Physics research projects have been on my mind a lot, of course. I remain very excited abut the results that I reported on in a post back in June, and I’ve been working on new ways of building on them. (Actually, I did already do a followup paper that I did not write about here. For those who are interested, it is a whole new way of defining a new generalisation of something called the Rényi entropy, that may be of interest to people in many fields, from quantum information to string theory. I ought to do a post, since it is a rather nice construction that could be useful in ways I’ve not thought of!) I’ve been doing some new explorations of how to exploit the central results in useful ways: Finding a direct link between the Second Law of Thermodynamics and properties of RG flow in quantum field theory ought to have several consequences beyond the key one I spelled out in the paper with Rosso (that Zamolodchikov’s C-theorem follows). Im particular, I want to sharpen it even further in terms of something following from heat engine constraints, as I’ve been aiming to do for a while. (See the post for links to earlier posts about the ‘holographic heat engines” and their role.)

You might be wondering how the garden is doing, since that’s something I post about here from time to time. Well, right now there is an on-going deluge of rain (third day in a row) that is a pleasure to see. The photo at the top of the page is one I took a few days ago when the sky was threatening the downpours we’re seeing now. The rain and the low temperatures for a while will certainly help to renew and refresh things out there for the (early) Spring planting I’ll do soon. There’ll be fewer bugs and bug eggs that will turn into my Summer nemeses attacking my vegetables (spider mites, etc., I’m looking at you). Right now there are a few valiant tomato plants from the Summer (actually bearing fruit) but not much else in the vegetable department (I did not plant any leafy greens and so forth for this Winter period – not enough time to get it done, I’m afraid). On the other hand, I did lead a family clearing of the front garden last weekend, planting several California native plants, and shrinking many California wild flower seeds, so I hope to have another blooming haven for butterflies, hummingbirds, and other creatures come late Spring, through into the Fall! Like last year.

It’s such a tiresome cliche, but I can’t believe it’s 2019 already. Just yesterday I was reminded of this in our group meeting. We were discussing the details of a construction called “boundary counterterms” (motivated by constructing a means of computing the energy of a spacetime in general relativity that involves adding a series of terms to a boundary effective action that ), and the discussion ended with a summary of the countqerterms that had been found. Some of them were found by myself and collaborators in a lovely paper from way back, and it was nice to be reminded of those times and that collaboration. The date? 1999!

The other thing that’s been on my mind a lot has been teaching. This semester I’m taking over the teaching of the first part of graduate electromagnetism, and although it means a lot of time spent developing new material, I’m rather excited, for two reasons. As you may recall from other posts, I’ve done the second part of that course a number of times, and it is fun to teach. It’s where electromagnetism comes to full life, with phenomena like light and light’s interaction with materials of various properties taking center stage. Many everyday phenomena get explained in terms of properties of Maxwell’s equations, and it is great to see the students appreciate all that. The first part is usually a bit more dry, being mostly concerned with static phenomena, where much of Maxwell’s equations are turned off. That course develops a lot of useful techniques that don’t really come into full force until the second part. So part of what I want to do is rebalance things a bit so that the first part is not quite so dry. A great ally in all of this will be the excellent book by Andrew Zangwill (which I’ve talked about on here before – I think it is marvellous!). I’ve always felt bad about trying to use it as the primary text for the second part of the course since my colleagues prefer to use Jackson (an excellent, but much older text) for the first part, following the common tradition of using Jackson for graduate electromagnetism in many departments. It is expensive for students to buy two such books (they are expensive). I’ve been using Zangwill more and more over the years, even if still accommodating students who want to stick with Jackson as their primary purchase. But now that I’m doing the first part of the course as well I can now make Jackson a secondary text and use as primary the excellent modern (refreshing) treatment of Zangwill for both parts as I proceed to rebalance the course quite a bit overall. It should be fun!

Oh, The Book! You’ve been wondering about that, perhaps? (My graphic non-fiction book about science called The Dialogues, for those wondering.) Well, it continues to be well-received by readers, and that’s great. It also made it to a number of lists of books of the year, for the second year in a row! (E.g., Science Friday, Forbes, Physics World… see more on my twitter account.) My dream of breaking the mood and reaching more and new kinds of readers has really been fulfilled, and I’m pleased to see that there are several other graphic book treatments of physics being discussed as serious supplements to the traditional non-fiction books. I’ve been talking a lot about this wherever I can, and will continue to do so, since I think it is a vitally important topic. (Look out for a public talk at Perimeter soon, which will be live cast – see here). I’ve also been happy to see that a number of translations of the book have begun to appear, including in Korean, Spanish, and Italian.

And yes, I’m thinking about two or three other book projects, some fully graphic books, some prose with lots of illustrations. Where and when they’ll appear is something to be determined. Stay tuned.

-cvj