No doubt about it: Spring has sprung. Whoever says there are no seasons in LA - and there are many who do - have no idea what they are talking about. The signs are in the air - there’s been a distinct change of the smell; lots of flowers are blooming. A parade of displays has begun. These are some of the poppies that are in various corners of the campus here at USC:

Here’s another shot….
Continue reading ‘Spring Sprung’
I had some unusual guests in my General Relativity lecture yesterday, Eric Salat and Philip Shane, two film makers from Left/Right productions. They’re working on a documentary for the History Channel on the development of various ideas in physics in the early 20th Century, and they wanted to know more about the topics, and to see a full (1 hour and 50 minute) lecture from me.
While it is the History Channel (hence the dramatic subtitle - sorry), it is not part of the series “The Universe”, by the way. It is another separate part of the increased very welcome expansion of that channel’s science programming. Have you noticed the diversification of their programming that they’ve been doing? I’ve mentioned it before, and a number of people have commented on it to me elsewhere. It has been great to see.
It’s always fun to have more people in the classroom, and so we had a lot of fun… (Or at least, I did…I hope everyone else did too.) I happened to be doing a lecture on Continue reading ‘Tales From The Industry XVIII - History Looked On’

Nicholas Payton came to town last Wednesday. For me, this means drop everything and go and hear him play. Two happy coincidences took place as well, contributing to making it a bit more special. The first was that my friend and colleague from UBC, Moshe Rozali (who sometimes comments here on the blog) was visiting to give a seminar that day. As I’ve been discovering (as a result of this blog more than anything else) we are very much in the same place when it comes to music, books and many things, and so it was just fantastic to be able to take him along. The second was that my friend of many years, cosmologist Marc Kamionkowski, got in touch just on the off-chance by email (I’d not seen him in many months) to ask if I knew if there was any good jazz coming to town! Marc and I have shared our love of Jazz for about 16 years now, going back to our days of meeting up in New York together at various Jazz clubs. So the three of us sat there and enjoyed the concert together. It was at the Jazz Bakery (to which you’ve possibly read me refer here before), and since I’ve not been there in a while, I was pleasantly surprised to see that they’ve replaced the plastic picnic chairs with some more comfortable padded ones. Quite an improvement.
Payton was joined by four excellent musicians, who were just great too: Russell Continue reading ‘Energized’
There was a sweet, sweet moment during the afternoon Cosmology, Gravity, and Relativity session on Friday. (See here.) I don’t think I’ll be able to convey its full intensity to you, but I cannot let it go unmarked. The background comes from a personal place. In addition to my being, for many years, somewhat of a relative anomaly in being a black theoretical (high energy) physicist, there’s another component to that rare situation. My parentage is West Indian (or “Caribbean”, I might say, since in my experience the other term often does not register with many people from the USA), and until recently, I’ve not really known (m)any other such people in theoretical physics*. What struck me on Friday was a single syllable.
Chanda Prescod-Weinstein (left), a graduate student at Waterloo/Perimeter, who has commented on this blog from time to time, and who I met for the first time on Thursday, was giving an excellent overview of her project to begin research on Doubly Special Relativity. Some of the motivating remarks involved simultaneously taking Newton’s constant,
and Planck’s constant
to zero (the idea is that quantum gravity’s Planck length might remain finite in this limit, and thus remain in the physics as a new scale that breaks Lorentz invariance at Continue reading ‘Haitch’
I find myself in Washington DC for two and a half days, attending an interesting conference. It’s the annual meeting of the National Society of Black Physicists* (NSBP), and I’ve been invited to give a talk (which I gave a few hours ago, entitled “The Dynamics of Flavour in Gauge/Gravity duals”, with a focus on what we can learn about experiments and observations of strongly interacting nuclear systems using string theory. Post about that here). I’m here for more just the talk, however. I also want to talk - in the sense of converse. Basically, it is of interest to me to get a feeling for what’s going on with the issues of underrepresented minorities (in this case, people of African descent) in Physics. As you know, the numbers are vanishingly small, and as you also know from reading my writings, I am very interested in this issue, and of course, how to make it not an issue, by helping more people find their way into the field and have as much opportunity to do well as the next person.

(Scene from the opening banquet on Thursday night. The featured speaker (no, not on stage in photo) was 2006 Physics Nobel Laureate, John C. Mather. Click for larger.)
It has been years since I came to one of these, and I must say it is a real pleasure to be here. There seems to be a lot of contrast to how I remember things from the Continue reading ‘DC Crossover’
Fantastic news! There’s going to be a farmer’s market on campus at USC. The first one is on Thursday this week, and rumour has it that it is expected to be monthly! If anyone has more information about this, please let me know in the comments or by email. (Right, enlargeable image of one of the results of my weekly visits to the Hollywood Farmer’s Market. More here.)
Here’s the announcement for Thursday:
Continue reading ‘A Farmer’s Market at USC’
There’s a total eclipse of the moon tonight (Wednesday 20th)! NASA has a nice website on the timings, and some background information. Totality is at about 10:26pm EST, (see the NASA graphic to the right (click for larger)) but you should start watching before that to see the changes, which are always lovely to see. Naked eye is good, but if you have a pair of binoculars to help - even better!
Locally, if you’re interested you can join some of the Astronomy 100 students and TAs Continue reading ‘Total Eclipse of the Moon’
I’m pleased to introduce a guest blogger today. It’s Nick Halmagyi, who you might have seen comment here from time to time. Nick is a postdoctoral researcher in Theoretical Physics, currently at the Enrico Fermi Institute in Chicago. Before that, he was a graduate student in our High Energy Physics group at USC, which is where I met him. Nick wrote his reflections below for Seed, and he reproduces a version of it (with permission - see details below*) here. I hope you enjoy it.
-cvj
___________________________________________________________________________________
Theoretical physics is a tough subject. Just one example of how hard things can get is when you ramp up the energy density of a system, the physics used to describe the system itself starts to change. At first it may be a small tweak in the parameters that appear in the equations (the electric charge for example), but then there can be large, abrupt transitions.
The biggest system we study is the universe, and immediately after the big bang all of its energy occupied a tiny region of space. Back then, the energy density was enormous, and as the universe grew over time it underwent several transitions before it became what we now observe.
I’m a theoretical physicist, in part, because I relish the challenge of studying the entire Continue reading ‘Nick Halmagyi: Why I do Science’
Neil deGrasse Tyson helped Stephen Colbert with his training to be an Astrophysicist recently. Neil’s advice is excellent of course, urging (for example) questioning and open-mindedness. You can learn from the clip below about Colbert’s take on this advice.
Among the many great exchanges:
Continue reading ‘Simple Steps to Becoming an Astrophysicist’
A commenter asked how the aforementioned movie viewing and panel discussion went on Friday (movie: Jumper), and so I thought expand a bit on the answer I gave:
___________________________________________________________________________________
It went very well. We were at the School of Cinematic Arts, at USC. We had a full house in the Norris Theatre, which was great to see. Most of the audience was students from the SCA, I think, with some of the faculty present, and people from the film’s parent studio, and several others. For the panel, present were two of the film’s producers, the visual effects supervisor, costume supervisor, production designer… basically, the perfect people to have a discussion with about the physics! I won’t try to list all names since I did not catch all of them and don’t want to mis-credit people for being there who weren’t.
Teleportation physics aside for a moment, I’m very impressed with how they realized Continue reading ‘Tales From the Industry XVII: Jump Thoughts’

(Camellia blossoms. Click for larger view.)
Continue reading ‘Camellias’
No, not spoiler in that sense. Doug Liman’s new action movie “Jumper” is all about teleportation, you see, and one of the questions that’s going to be on people’s minds is something like “Is teleportation really possible, or is it just some silly science fiction thing?”. I like it when such questions come up, and I like trying to answer them too.
This time I get to do it officially, since Doug Liman’s people are doing a private screening of the film this evening and there’ll be a panel of some of the film’s creators and a scientist for questions and answers afterward. I’ll be the scientist.
The downside is that I’ll be the bad guy of the evening by having to pour a bit of cold water on some of the flights of fancy. The spoiler, you see, as in spoilsport. The upside (besides, you know, free movie) is that I’ll maybe get to explain some really Continue reading ‘Movie Spoiler?’
So the Onion’s gone and mixed some astrophysics with basketball. Headline:
“Shaq Terrified Of Phoenix Suns After Reading About Supernovas”
(Image on right also from the Onion.)
You can tell how it’s going to go from the title, although it’s rather amusing just how much stellar astrophysics they pour into the article (not even trying to disguise it much). Extract:
…new Phoenix Suns center Shaquille O’Neal admitted Monday that, upon reading about the phenomenon of massive stellar explosions popularly known as supernovas, he is now terrified of the entire organization.
(Wow… Shaq isn’t in LA any more? Huh. I’m so out of it. Update: Oh, yeah, I remember now. He went to Miami in 2004. Evidently I don’t follow the NBA.)
…and further:
Continue reading ‘Stellar Basketball Physics’
I’ve mentioned it before a number of times, but it’s always worth remembering the downtown Los Angeles Art Walk every second Thursday of the month. Lots of local people still don’t know about it, so I like to remind from time to time.
For the one today, given the day, you can take your sweetheart along for a Valentine’s day ramble around the neighbourhood. Or, if you’ve either too many or too few to choose from… never mind - just go along yourself! There’s always lots to see.
Some months back I made a huge effort to document photographically (sometimes surreptitiously) some of the work I saw, to show you it. I was planning on doing a long post describing all of it and of course I was so exhausted when I got home that I never did and then I sort of went off the boil on that project. I’ve no idea why I’m mentioning it now - it just came to mind.
Continue reading ‘Art, Walk’

A match made in the heavens? (sorry….couldn’t resist…)
Continue reading ‘While Reading the Physics Personals…’
Well, only four weeks and change behind us in this course, and… the class (see here and here) is ready to understand this wonderful equation:

and all that it implies. What is it? It encodes the shape of spacetime around a spherical blob of mass of total mass M. No, don’t worry too much about the details, since this is not a lecture about General Relativity….. it is just nice (I hope) every now and again to get a look at the sorts of things we use in our day to day work. This “warped” spacetime encodes what we interpret as the gravitational field (in the old Newtonian language) due to a spherical (or, to a good approximation, almost spherical) mass. Like the sun, or the earth, or that tennis ball in the corner there*. It is an exact solution Continue reading ‘Mass Matters’
My first time sitting down to watch this show in a while and, bizarrely enough, there’s a colleague on the telly! Well, I think that perhaps Lisa was trying a little bit too hard in one or two places to get the physics out. On Colbert, I think you just have to go with the flow and the comedy! But she got quite a bit out in the short time she had…
My favourite bit:
Randall: “Like…the fact that Einstein has taught us that spacetime can be curved or warped…”
Colbert: “Don’t patronize me, I know that…”
Continue reading ‘Randall on Colbert’
So Chris and Sheril have announced the next step in the journey to a real debate about science issues of note that intersect with the current political sphere. And they’ve come a long way in a short time! Here’s some of what they said in a recent post:
ScienceDebate2008 is now co-sponsored by the American Association for the Advancement of Science, the National Academies, and the Council on Competitiveness. We were looking at venues, and finally settled on an offer from the Philadelphia-based Franklin Institute–named, of course, after one of this country’s first and greatest scientists. We can’t think of a more appropriate venue.
And guess what?! They’ve actually invited the candidates: Hillary Clinton, Mike Huckabee, John McCain, and Barack Obama.
So the next step is to get the event (they suggest April 18, 2008) taken seriously by Continue reading ‘Science Debate 2008 - Closer to Reality’

A small Romanesque Cauliflower. (Click for larger view.)
Imagine my delight when I spotted this lovely piece of edible mathematics in the Hollywood Farmer’s Market this morning. The stall has several of them of many sizes (this was a very little one) and of several colours. Wonderful. If you don’t know what I mean when I talk about the mathematics, or use the term fractal, look it up. There are several things of note, among which are the wonderful spiral structures that you can Continue reading ‘A Delicious Fractal’
It was one of those Friday nights when I was in the mood to get out of the house, but not entirely sure what to get out to. “Out” was more important than “where”, you see. Wanted to do a bit of thinking and to relax and let the heavy week of too many meetings fall away from my shoulders.
In the end, I did a combination of things. After my mood, followed by my
trajectory, turned away from Pasadena (where I was planning to see Persepolis, as was my original plan - I’ll do it later… really want to see that film) at about 10:30pm I arrived in the Valley and hung out at Charlie O’s which is one of the more happening of the neighbourhoody jazz clubs in LA. (Sadly, in this context, “happening” by LA late night standards means that there’s more than about nine people present.)
There’s always something on each night and you can just walk in and sit at the bar to Continue reading ‘Friday Night Wanderings’

(Meyer lemons in my garden, in the warm sun this morning. Click for larger, warmer view.)
Continue reading ‘Warm Yellow’
Happy Chinese New Year to all! It’s the year of the Rat.
Best wishes to all, and enjoy all of your celebrations if you are observing this event.
-cvj

Well, Tuesday was a big day in class. We reached a landmark - the introduction of one of my very favourite thoughts of the 20th Century: the Equivalence Principle. This is the realization of Einstein’s that there’s something profoundly odd about Newtonian mechanics and Newtonian gravity that hints at something deeper.
Quick reminder from high school (just two formulae, please bear with me): You know Continue reading ‘Equivalence’

(Giant Banyan Tree on the USC campus. Click for larger view.)
This is one of my most favourite features of the landscaping on the campus here at USC. It’s one of the very earliest features that made me feel very much at home on the campus when I first arrived. I remember coming around a corner, seeing it, and Continue reading ‘The Tree, I’
Readers in New York… Uh… Are you ok? Leave a comment to let me know that you and the city are still there, ok?
Just got back from seeing Cloverfield. Quite well done, on balance. They do a great job of mocking up what it would be like to be just an ordinary citizen during your standard city-under-attack scenario. Routine falls apart, people are scared, fighter jets scream by low and fast overhead, there’s only fragments of information about what’s happening, and you find yourself wondering why on earth we build these tall buildings anyway… Yes, the filmmakers did a very Continue reading ‘Just Checking on New York’

Layers in Los Angeles. Click for details.
Lovely layers in the distance on a hike at Runyon Canyon this morning, looking North East. There’s breadth and depth here. You have the Hollywood sign on the left, all the Continue reading ‘Layers’
Today is the 50th anniversary of the day the USA replied to the world-changing Sputnik launch by the USSR almost four months earlier (see my post), as well as Sputnik 2 (carrying the dog Laika) a month after. In some sense, the space race began in earnest with this launch of the craft called Explorer.
A great thing about the Explorer 1 craft was that it even did some groundbreaking Continue reading ‘The Reply’
Oliver Sacks must have a new book out or something*. I’ve heard him twice in as many days in radio pieces, and that usually means only one thing. He’s always an interesting interviewee, and this time the focus is on music. The first piece I heard was one of those amusingly produced pieces by Robert Krulwich, on NPR’s Morning Edition. It was all about people who essentially hallucinate music - it spontaneously appears in their ears and there’s often nothing they can do about it. The audio for the piece can be heard here. It was quite a good piece and I recommend it.
The next thing I heard was on the BBC World Service (my usual late night listening) the segment called “The Interview”. This is a much longer piece, talking about the role of Continue reading ‘Oliver Sacks on Music’
Oh, yeah baby. Right up my alley:

Trinity College Library, Dublin. (Photo: Candida Höfer.)
More of the full spreads can be seen over at The Nonist. They come from a collection Continue reading ‘Hot Library Smut’
At the Science Blogging conference earlier this month, there was a very interesting discussion about communication of science, science and the media, and science in politics. It was led by Jennifer Jacquet of Shifting Baselines, and Sheril Kirshenbaum and Chris Mooney (both of The Intersection), who each did a mini-presentation (Sheril and Chris doing a sort of tag-team double act, starting off with discussing Sciencedebate 2008, and moving into discussions of “framing” science, the separation of the cultures, and so forth - and of course, opportunities for bloggers). Happily there was a video made, and I’ve embedded it below (the quality is mixed, but overall Continue reading ‘Science Communication’
It’s not going to be naked-eye visible, but give a thought tonight to the 250 metre asteroid (2007 tu24) that is going to swing by close to earth tonight! Or, if you have a “modest” telescope, go and look at it. It’s going to scrape by at 1.4 times the distance of the moon. That’s pretty close, by astronomical standards, and gives scientists a chance to see a near earth object rather more closely than usual. From the Continue reading ‘Near Enough’
Well, I’m standing here at 11:45pm slowly stirring some tasty custard I’m making to pour onto a slice of steamed homemade date pudding. A while ago the wonderful Margaret Atwood was on the radio (talking about an influential editor who died recently - can’t recall the name), which is bliss for me since I love hearing her talk about anything. Absolutely anything. I just love her voice, tone, and turns of phrase. There’s a cold wind blowing outside…
Why am I doing all this? Well, it’s really cold outside for a start (yeah, I know) so I need some warm comfort food, but mostly I’m treating myself after a long night of writing php scripts and css code, remembering stuff I learned two years ago, with the aim of rebuilding the old look for the blog. I’m really tired of the clunky default style I’ve had Continue reading ‘Almost Back’
So while you have a look at the following enthusiastic and amusing discussion about how far the Balrog and Gandalf must have fallen (in the film version of the Two Towers), involving discussions of terminal velocities and Balrog profile approximations for air resistance estimates (and so forth)…
(links here, here and here*)
…ask yourself why on earth nobody in the discussion (as far as I can tell from a quick Continue reading ‘Gandalf, Balrog, Physics…’
While the wonderful downpour carries on outside (the whole of Southern California is in the grips of a powerful storm), I’ll continue with the discussion of the re-invigoration of the study that I started a short while ago…

(One of my all-time favourite wood-working tools. The good old-fashioned plane. Planing a bit of wood is jolly good therapy too.)
One of the main things I envisioned, and put into my sketches, was lots of space for books. Lots. I wanted big bookcases that fit the room, and so I planned a simple but robust design that stretched them eight feet from the floor to the ceiling. Of course, I wanted to make them myself - Building them myself would be more fun and much Continue reading ‘Bookcases’
So yesterday at Pinewood Studios they announced the name of the upcoming second James Bond film in the new series that (excellently, in my opinion) re-envisions the Bond movie universe. Last year’s first one was “Casino Royale”, you may recall. Did you hear what the next one will be called?
Continue reading ‘Planck Meets Fleming’
Taking a break from scribbling equations, I confirmed the he-must-be-crazy suspicions of people around me in a cafe the other day by bursting out laughing out loud at this Onion article: Bill Clinton: `Screw It, I’m Running For President’:
After spending two months accompanying his wife, Hillary, on the campaign trail, former president Bill Clinton announced Monday that he is joining the 2008 presidential race, saying he “could no longer resist the urge.”
You’ve probably heard about it already (it was even mentioned on today’s Morning Edition on NPR), but in case you have not, it’s a timely read. My favourite bit:
“No longer will I have to endure watching candidates like Hillary Clinton engaging in single-pump handshakes with voters, as I use every last Continue reading ‘Clinton Fun’
The next Categorically Not! is on Sunday January 27th (upcoming). The Categorically Not! series of events that are held at the Santa Monica Art Studios, (with occasional exceptions). It’s a series - started and run by science writer K. C. Cole
- of fun and informative conversations deliberately ignoring the traditional boundaries between art, science, humanities, and other subjects. I strongly encourage you to come to them if you’re in the area. Here is the website that describes past ones, and upcoming ones. See also the links at the end of the post for some announcements and descriptions (and even video) of previous events. (Above right and left: Reza Aslan speaking on the origin of various ideas in Religion at the event entitled “Beginnings” on 16th December, 2007. Click right one for larger view.)
The theme this month is Science Goes Hollywood. Here’s the description from K C Cole:
Despite our prejudices to the contrary, Hollywood and Science have a lot to say to each other. Take special effects: Nothing Disney dreams up can Continue reading ‘Categorically Not! - Science Goes Hollywood’
Well, actually it sounds like a really lovely book, and the louse to the right (among other creatures) features quite a bit. (Photo by Louis de Vos.) I read about it in a splendid little article in LA Weekly today on the bus home on a wonderfully rainy afternoon here in LA. The book’s all about the common creatures in our homes - “bugs” of various sorts, and the LA Weekly article by Gendy Alimurung is mostly an interview with the authors, Joshua Abarbanel and Jeff Swimmer. The book is called “A Continue reading ‘Lousy Book’
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