Category Archives: work

An Update!

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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 […] Click to continue reading this post →

Mindscape Interview!

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And then two come along at once… Following on yesterday, another of the longer interviews I’ve done recently has appeared. This one was for Sean Carroll’s excellent Mindscape podcast. This interview/chat is all about string theory, including some of the core ideas, its history, what that “quantum gravity” thing is anyway, and why it isn’t actually a theory of (just) strings. Here’s a direct link to the audio, and here’s a link to the page about it on Sean’s blog.

The whole Mindscape podcast has had some fantastic conversations, by the way, so do check it out on iTunes or your favourite podcast supplier!

I hope you enjoy it!!

-cvj Click to continue reading this post →

Futuristic Podcast Interview

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For your listening pleasure: I’ve been asked to do a number of longer interviews recently. One of these was for the “Futuristic Podcast of Mark Gerlach”, who interviews all sorts of people from the arts (normally) over to the sciences (well, he hopes to do more of that starting with me). Go and check out his show on iTunes. The particular episode with me can be found as episode 31. We talk about a lot of things, from how people get into science (including my take on the nature vs nurture discussion), through the changes in how people get information about science to the development of string theory, to black holes and quantum entanglement – and a host of things in between. We even talked about The Dialogues, you’ll be happy to hear. I hope you enjoy listening!

(The picture? Not immediately relevant, except for the fact that I did cycle to the place the recording took place. I mostly put it there because I was fixing my bike not long ago and it is good to have a photo in a post. That is all.)

-cvj Click to continue reading this post →

Diverse Futures

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I was asked by editors of the magazine Physics World’s 30th anniversary edition to do a drawing that somehow captures changes in physics over the last 30 years, and looks forward to 30 years from now. This was an interesting challenge. There was not anything like the freedom to use space that I had in other works I’ve done, like my graphic book about science “The Dialogues”, or my glimpse of the near future in my SF story “Resolution” in the Twelve Tomorrows anthology. I had over 230 pages for the former, and 20 pages for the latter. Here, I had one page. Well, actually a little over 2/3 of a page (once you take into account the introductory text, etc).

So I thought about it a lot. The editors wanted to show an active working environment, and so I thought about the interiors of labs for some time, looked up lots of physics breakthroughs over the years, and reflected on what might come. I eventually realized that the most important single change in the science that can be visually depicted (and arguably the single most important change of any kind) is the change that’s happened to the scientists. Most importantly, we’ve become more diverse in various ways (not uniformly across all fields though), much more collaborative, and the means by which we communicate in order to do science have expanded greatly. All of this has benefited the science greatly, and I think that if you were to get a time machine and visit a lab 30 years ago, or 30 years from now, it will be the changes in the people that will most strike you, if you’re paying attention. So I decided to focus on the break/discussion area of the lab, and imagined that someone stood in the same spot each year and took a snapshot. What we’re seeing is those photos tacked to a noticeboard somewhere, and that’s our time machine. Have a look, and keep an eye out for various details I put in to reflect the different periods. Enjoy! (Direct link here, and below I’ve embedded the image itself that’s from the magazine. I recommend reading the whole issue, as it is a great survey of the last 30 years.)

Physics World Illustration showing snapshots in time by Clifford V. Johnson

-cvj Click to continue reading this post →

Science Friday Book Club Wrap!

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Don’t forget, today live on Science Friday we (that’s SciFri presenter Ira Flatow, producer Christie Taylor, Astrophysicist Priyamvada Natarajan, and myself) will be talking about Hawking’s “A Brief History of Time” once more, and also discussing some of the physics discoveries that have happened since he wrote that book. We’ll be taking (I think) caller’s questions too! Also we’ve made recommendations for further reading to learn more about the topics discussed in Hawking’s book.

Join us!

-cvj

(P.S. The picture above was one I took when we recorded for the launch of the book club, back in July. I used the studios at Aspen Public Radio.) Click to continue reading this post →

And So it Begins…

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It’s that time of year again! The new academic year’s classes begin here at USC today. I’m already snowed under with tasks I must get done, several with hard deadlines, and so am feeling a bit bogged down already, I must admit. Usually I wander around the campus a bit and soak up the buzz of the new year that you can pick up in all the campus activity swarming around. But instead I sit at my desk, prepping my syllabus, planning important dates, adjusting my calendar, exchanging emails, (updating my blog), and so forth. I hope that after class I can do the wander.

What will I be teaching this semester? The second part of graduate electromagnetism, as I often do. Yes, in a couple of hours, I’ll be again (following Maxwell) pointing out a flaw in one of the equations of electromagnetism (Ampere’s), introducing the displacement current term, and then presenting the full completed set of the equations – Maxwell’s equations, one of the most beautiful sets of equations ever to have been written down. (And if you wonder about the use of the word beautiful here, I can happily refer you to look at The Dialogues, starting at page 15, for a conversation about that very issue…!)

Speaking of books, if you’ve been part of the Science Friday Summer reading adventure, reading Hawking’s A Brief History of Time, you should know that I’ll be back on the show on Friday talking with Priyamvada Natarajan, producer Christie Taylor, and presenter Ira flatow about the book one more time. There may also be an opportunity to phone in with questions! And do look at their website for some of the extra material they’ve bene posting about the book, including extracts from last week’s live tweet Q&A.

Anyway, I’d better get back to prepping my class. I’ll be posting more about the semester (and many other matters) soon, so do come back.

-cvj Click to continue reading this post →

DC Moments…

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I’m in Washington DC for a very short time. 16 hours or so. I’d have come for longer, but I’ve got some parenting to get back to. It feels a bit rude to come to the American Association of Physics Teachers annual meeting for such a short time, especially because the whole mission of teaching physics in all the myriad ways is very dear to my heart, and here is a massive group of people devoted to gathering about it.

It also feels a bit rude because I’m here to pick up an award. (Here’s the announcement that I forgot to post some months back.)

I meant what I said in the press release: It certainly is an honour to be recognised with the Klopsteg Memorial Lecture Award (for my work in science outreach/engagemnet), and it’ll be a delight to speak to the assembled audience tomorrow and accept the award.

Speaking in an unvarnished way for a moment, I and many others who do a lot of work to engage the public with science have, over the years, had to deal with not being taken seriously by many of our colleagues. Indeed, suffering being dismissed as not being “serious enough” about our other […] Click to continue reading this post →

Radio Radio Summer Reading!

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Friday will see me busy in the Radio world! Two things: (1) On the WNPR Connecticut morning show “Where We Live” they’ll be doing Summer reading recommendations. I’ll be on there live talking about my graphic non-fiction book The Dialogues: Conversations about the Nature of the Universe. Tune in either … Click to continue reading this post →

Retreated

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Sorry I’ve been quiet on the blog for a few weeks. An unusually long gap, I think (although those of you following on instagram, twitter, Facebook and so forth have not noticed a gap). I’ve been hiding out at the Aspen Center for Physics for a while.

You’ve probably read things I’ve written about it here many times in past years, but if not, here’s a movie that I produced/directed/designed/etc about it some time back. (You can use the search bar upper right to find earlier posts mentioning Aspen, or click here.)

Anyway, I arrived and pretty much immediately got stuck into an interesting project, as I had an idea that I just had to pursue. I filled up a whole notebook with computations and mumblings about ideas, and eventually a narrative (and a nice set of results) has emerged. So I’ve been putting those into some shape. I hope to tell you about it all soon. You’ll be happy to know it involves black holes, entropy, thermodynamics, and quantum information […] Click to continue reading this post →

Google Talk!

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I think that I forgot to post this link when it came out some time ago. I gave a talk at Google when I passed though London last Spring. There was a great Q & A session too – the Google employees were really interested and asked great questions. I talked in some detail about the book (The Dialogues), why I made it, how I made it, and what I was trying to do with the whole project. For a field that is supposed to be quite innovative (and usually is), I think that, although there are many really great non-fiction science books by Theoretical Physicists, we offer a rather narrow range of books to the general public, and I’m trying to broaden the spectrum with The Dialogues. In the months since the book has come out, people have been responding really positively to the book, so that’s very encouraging (and thank you!). It’s notable that it is a wide range of people, from habitual science book readers to people who say they’ve never picked up a science book before… That’s a really great sign!

Here’s the talk on YouTube:

Direct link here. Embed below: […] Click to continue reading this post →

News from the Front, XV: Nicely Entangled

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This is one of my more technical posts about research activity. It is not written with wide readability in mind, but you may still get a lot out of it since the first part especially talks about about research life.

Some years ago (you’ll perhaps recall), I came up with an interesting construction that I called a “Holographic Heat Engine”. Basically, it arises as a natural concept when you work in what I call “extended” gravitational thermodynamics where you allow the spacetime heat_enginecosmological constant to be dynamical. It is natural to associate the cosmological constant with a dynamical pressure (in the usual way it appears as a pressure in Einstein’s equations) and if you work it though it turns out that there’s a natural conjugate quantity playing the role of volume, etc. Black hole thermodynamics (that you get when you turn on quantum effects, giving entropy and temperature) then get enhanced to include pressure and volume, something that was not present for most of the history of the subject. It was all worked out nicely in a paper by Kastor et. al. in 2009. So…anyway, once you have black holes in that setup it seemed to me (when I encountered this extended framework in 2014) that it would be wilful neglect to not define heat engines: closed cycles in the p-V plane that take in heat, output heat, and do mechanical work. So I defined them. See three old posts of mine, here, here, and here, and there are others if you search.

Well, one of the things that has been a major quest of mine since 2014 is to see if I can make sense of the extended thermodynamics for quantum field theory, and then go further and translate the heat engines and their properties into field theory terms. This seemed possible to me all the way back then since for positive pressure, the cosmological constant is negative, and when you have gravity with negative cosmological constant you’ve got duality to strongly coupled field theories. So those heat engines must be some kind of special tour in the field theories. the efficiency of an engine must mean something about the tour. Moreover, since the efficiency of the engine is bounded by the Carnot efficiency, it seems we have a naturally defined dimensionless number that has a fundamental bound… Alarm bells ringing! – Opportunity knocking to learn something new and powerful! Maybe even important!

So I chipped away at this for some time, over years, doing various projects that […] Click to continue reading this post →

Make with Me!

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Bay Area! You’re up next! The Maker Faire is a wonderful event/movement that I’ve heard about for years and which always struck me as very much in line with my own way of being (making, tinkering, building, creating, as time permits…) On Sunday I’ll have the honour of being on one of the centre stages (3:45pm) talking with Kishore Hari (of the podcast Inquiring Minds) about how I made The Dialogues, and why. I might go into some extra detail about my research into making graphic books, and the techniques I used, given the audience. Why yes, I’ll sign books for you afterwards, of course. Thanks for asking.

I recommend getting a day pass and see a ton of interesting events that day! Here’s a link to the Sunday schedule and amor there you can see links to the whole faire and tickets!

-cvj Click to continue reading this post →

Frank Buckley Interviews…

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Turns out that Frank Buckley, the news anchor at KTLA 5, is not just a really great guy (evident from his manner on TV), but also a really excellent interviewer with a sharp curiosity that gives me hope that great journalism is still alive, well, and in good hands. I showed up at the station expecting to just have a pleasant chat around the book and be done with it, but I walked into the room and he’d done all his research and was sitting with extensive notes and so forth about lots of physics ideas he’d read in the book that he wanted to talk about! So we have a blast talking about the physics of our universe and the world around us in some in-depth detail. It was fantastic, and just the kind f conversation I hope that the book celebrates and inspires people to have!

Check out our interview here (embed below), and be sure to tune in to his […] Click to continue reading this post →

Take Your Pick

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I’ll at two festivals this weekend, which I admit seems a bit over-ambitious! Let me tell you a little about both.

One event is the Los Angeles Times Festival of Books, which you’ve read me talking about many times over the years (that’s a photo from 2015 above). It’s the largest such festival in the USA, and is a wonderful celebration of books and related things. It is on Saturday and Sunday.

The other event is the San Diego Comic Fest, which also runs through the weekend (although it starts Friday). Don’t mix this up with ComicCon (although there are connections between the two if you care to dig a little to find out).

As I write this post I’m actually basking in the sun as I ride on the train (the Pacific Surfliner) from Los Angeles to San Diego, as tomorrow I’ll be giving a talk at the comics fest. Here are the details:
[…] Click to continue reading this post →

North Carolina Science Fair!

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Tomorrow I’ll be giving a talk at the North Carolina Science Festival! The talk will be about black holes, time, space, movies, and books, held inside the historic Morehead planetarium. I’ll sign the book for you after if you want.
Here is a link to the event.

(On the plane over, rather than doing my usual sketch-a-face-from-a-magazine exercise you might be familiar with from earlier posts, e.g. here, I made some new sketches for use in the talk. One of those is above.)

-cvj Click to continue reading this post →