Category Archives: science

On “Do-Overs”

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I love “do-overs”. Not because I want to change anything in particular about my life, but because they are so rare, and so interesting. On my way to Vancouver on Monday, I got to do one.

We (myself and the other passengers) boarded our flight at Denver. I usually get on the plane early, and so have the change to watch people go through their routines of boarding and all that entails. After that was all, the plane full of passengers waited for the plane to get ready, doors to close, and so forth. It did not happen. After a while, the pilot came on and explained that they were trying to fix the radio, and it would be another half an hour. So we waited. After another long while, the pilot came on and said that they did not expect that the radio would get fixed in a timely manner after all, and so they were going to try something else. We would “de-plane” (a word I hate by the way – what is wrong with the perfectly good word “disembark”?) and all make our way to another gate where eventually another plane would arrive, and we’d take that one. It would be exactly the same type of plane. We would keep our ticket stubs and just re-board an hour and a half later.

I wandered for a bit, found something not too repulsive to nibble on (seems to get harder and harder in some airports), was disappointed by the meagre bookstore once again, and otherwise killed some time. Then the boarding started again. A “do-over”. Everybody would be going back to the same seats, it would be exactly the […] Click to continue reading this post →

A Hop Over To Canada

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Well, as I said in the previous post, I’m leaving my hideaway/retreat mode and popping over to Vancouver for a short spell to help out at a Summer School. It’s the PIMS (Pacific Institute for Mathematical Sciences) Summer School on Particles, Fields, and Strings. I’m giving four lectures on some of the techniques in string theory that it helps to know in order to do some of the fun things we do to get at interesting physics (such as the topic of the post before). My title is something like “Perturbative and non-perturbative string theory”, and I’ve no clue what the level of the students really is, so goodness knows how far I will get in four one hour lectures. But it does not hurt to try. I’ll be laying the groundwork for several of the lecturers who will be talking about the more advanced stuff closer to their research work, and so I hope to at least help the students gain confidence with ideas and language that will show up all over the place in the two weeks following my presentations.

So what will I cover? Well, I’m going to tailor things to the responses of the students as […] Click to continue reading this post →

Atoms and Strings in the Laboratory?

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depiction of lithium trap from the Kastler Brossel lab in france

A depiction of a lithium trap from the Kastler Brossel laboratory, in France. Details here.

[Despite appearances, I did not choose the music in what is to follow. I just put on iTunes set to random, and started typing, reporting on what was playing as I went along. Nevertheless, there were some nice resonances.]

Now playing: Mr Day, John Coltrane.

So. I must put the Aspen time on hold for a short while, as I promised to give four lectures in Vancouver starting tomorrow. While I sit here in a lounge in Denver at 8:00am, wondering why I booked a 7:00am flight out of Aspen, and also wondering exactly what is in this muffin that I picked up to have with the (rather good) tea they have here this morning, I thought I’d tell you about a little bit of really nice physics that’s going on in the neighbourhoood of my world. Since I’m too cheap and too disinterested to pay for a connection to the web, this’ll only get uploaded quite a bit later when I get a free hookup. (This is a bit more technical in places than usual. Please don’t give up too easily. Oh, and you might have to read some things I point to from earlier to get everything I’m saying – I’m not one for endless repeating myself I’m afraid.)

You can think of this as another story in the line of development I’ve been pushing (and telling people about here and elsewhere) for many years now. Applications of string theory to a broader range of physics areas than the popular discussions of the topic seem to touch upon. I told you last year about the exciting work going on in understanding properties of new phases of nuclear matter being unlocked at the Brookhaven experiment RHIC (colliding heavy nuclei together to create a sort of hot quark-gluon soup). That work continues. This new work pertains to experiments as well, and this time, these are closer to the human scale bench top experiments we all get misty-eyed over (ok, I do, maybe no-one else). It is super-cute stuff. I should […] Click to continue reading this post →

Chiropteral Mirror Symmetry?

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Spurred by the previous post showing M-theory’s possible relation to matters Chiropteral , Joe Polchinski (who I think, in 1995 or 1996, first drew the diagram that I messed with in that post) emailed me* to say that there is a quite striking appearance of batman-ology in the string theory literature. It’s from one of the classic Mirror Symmetry papers of 1990 by Candelas, De La Ossa, Green, and Parkes, “An Exactly soluble superconformal theory from a mirror pair of Calabi-Yau manifolds.” (you can find it via here). Here it is:

batman ish mirror symmetry diagram

What is this? It has to do with spaces in string theory called “Calabi-Yau manifolds”, which are important (in some approaches) as starting points for constructing models […] Click to continue reading this post →

Black Hole Battles

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lenny susskind, kc coleSomehow, I only learned about this today, and it is already standby tickets only, but you never know. If you’re in LA and interested in a different kind of conversation, consider taking in the event (part of the Aloud series) at the downtown Los Angeles Central Library tomorrow night at 7:00pm. It’s between two friends and colleagues of mine, the science writer K C Cole and the scientist Lenny Susskind! The event is entitled, “The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics”, and presumably will be about Lenny’s reflections on some of the exciting squabbles over various important issues in black hole physics that took place (and still take place) in our field of physics. The above turns out to be (I just learned from a Google search) the title of a book he’s written, so you might be interested in it for your Summer (or other) reading.

Some of you may recall her really great conversation with Alan Alda that took place at USC earlier this year. I reported on it here. K C tends to run these sorts of […] Click to continue reading this post →

On Good Ideas

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A commenter, slim potato, implicitly asked a really good question earlier. It was a comment on a post I did yesterday about my struggles with a computation I was working in a notebook working on. I gave an answer, but since I know that a lot of readers don’t read the comments, and because one of the missions of this blog is to give a window on what scientists such as myself do and (importantly) how we do it, I thought I’d elevate the comment and my response into a post. Feel free to add your own thoughts to it in the comments, either as a non-scientist, a scientist, a specialist from another field, or other.

slim wrote:

I would have assumed that most of your time when working on a paper was involved on catching good ideas, not getting muddled with conventions and calculations.

cvj wrote:

Hi,

Thanks. That’s a common misunderstanding of what we do. What makes a field of physical science like physics work is computations – all of that business with calculations (including checking that your computations conventions are internally consistent) is vital to the field.

Frankly, “Good Ideas” are a dime a dozen. Anyone in my field ought to be able to think of at least six of them before breakfast. What makes a good idea go […] Click to continue reading this post →

Once More Unto The Breach…

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Ugh. A night of computing (while making and eating dinner and recuperating from a strange day-long headache – dehydration? side effects from the big hike the day before?) and muttering to myself at various points left me in a state of confusion last night. I went to bed tired and confused after getting into a muddle and realizing that I’d been probably mixing conventions in parts of my computations over the last few days, leaving me with a flipping minus sign in a result. No, I really mean “flipping”, since sometimes a 1/16 was -1/16, and sometimes that represents a physical truth and other times it represents a computational mistake – and I got confused as to which was which. Ugh.

All of this was coupled with occasionally wandering outside into the late night air filled with hungry insects in order to seek the fragment of wireless signal (I accidentally discovered it nearby on the weekend) in order to download the odd reference to check an idea or a fact. I’d have a few minutes before the bugs would find me and start to chew (I suffer from being particularly tasty to insect life – always the first person to be multiply bitten at any outdoor evening gathering), at which point I’d have snagged the download of the paper and can then run back in to the safety of indoors, flapping my arms around my head like a madman. It is an amusing dance, since I can find the […] Click to continue reading this post →

UK Physics Education and the Olympiad

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You might be interested in this for all sorts of reasons, whether you’ve interest in science education in the UK or not. It relates to similar issues elsewhere, such as the USA. It’s a rather good (if a bit depressing) report on physics education in the UK, and how the UK does in the international Physics Olympiad compared to other countries. There’s a visit to the “training camp” for the Olympiad, and interviews with students and teachers. Have a listen – it is only nine minutes long.

The UK does not do very well, to cut to the chase. Not very well at all. China is the powerhouse, with the US and Iran also being very good. Notably, all three countries invest heavily in serious training and educational programs for the Olympiad, and it is also notable that Iran has very strong female representation.

More worrying, perhaps, is the decline of students’ knowledge of physics overall, since […] Click to continue reading this post →

Altered Saturday Plans

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river in aspenWell, I was supposed to go for an early morning hike to start off the day, but it has not happened. It was just meant to be a short one, since I’m staying in a little cabin out of town not too far from the start of a lovely trail. Then I was to go to the farmer’s market (more on that later) and then after lunch go to pick up my ticket for the chamber music concert I’m to go to this afternoon. (I say “pick up” and not “buy” since I was the lucky winner (well, one of them) of a little ticket lottery at the Aspen Center for Physics for tickets to concerts in the neighbouring Aspen Music Festival. Hurrah!)

Well, the hike did not happen. Why? Well, at about 6:30pm yesterday while scribbling fragments of equations and furrowing my brow while sitting in a cafe in town (a change of venue after a day at the Center(re) sitting in the office, you see), I began to realize that a computation I was stuck on might actually be becoming unstuck! Various parts […] Click to continue reading this post →

Fourth Thoughts

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Have a Fantastic Fourth of July, to everyone who is celebrating it!

fantastic four promotional skywriting over LA on the July 2005

It’s been several days since my last confession. Sorry about the silence. I’m honestly not sure exactly what I’ve been doing, since it has been a mostly fragmented set of things, coupled with a generally down mood of introspection over matters personal. Hmm… So nothing new there.

Physics-wise I’m a bit stuck. Not on a particular project this time, but stuck on […] Click to continue reading this post →

Launch of an Idea

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150 years ago today, Charles Darwin presented his theory of evolution to a group of his peers for the first time. It was read at the Linnean Society, and the reading didn’t really rock the world. That came later when Darwin published the Origin of Species. Either way, it is quite an anniversary today, since evolution is without question one of the single most important scientific discoveries ever made about how our world works. (Have a look at my earlier post on the Darwin Online Project, by the way. Lots to see there.)

Actually, Wallace had the idea some 20 years before Darwin, it is said, but few remember him. A recent NPR piece quotes the author David Quammen (”The Reluctant Mr Darwin”): […] Click to continue reading this post →

Goodbye to Correlations and WIRED Science

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Over on Correlations, we’re in the process of saying goodbye. The PBS experiment with a genuinely new (for them) and fun science format, WIRED Science, along with its really fantastic online component (with resources for schools, the general public, the blog Correlations, and so forth), is officially over.

I don’t know exactly what went on behind the scenes at the PBS mother ship, but frankly, it seems that they just did not have the guts to try something new at this time, and are returning to their standard stuff. I thought that the show had a lot of good work in it, including several shining portions, and deserved a bit more time to find its feet. It may well have got there, building followers that would have tuned in regularly for years, becoming a sort of US (and science-oriented) version of the UK’s Tomorrow’s World (a BBC show that ran for 38 years and -despite its flaws- is fondly remembered by many generations). Oh well.

The mood at KCET (the local Los Angeles PBS affiliate that was making the show) was […] Click to continue reading this post →

Thesis Thoughts

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Recently I was reading the PhD thesis of my student, Veselin. He was going to have his examination and so I was looking through a draft. He recently received a fellowship to go to do a postdoc abroad and so has decided that it’s best to write up and get everything done before it gets too late into the Summer. His new job requires him to have a PhD, of course. (He was, I’m happy to report, successfully doctored (as it were), after an excellent performance in his exam.)

I recall being in the same situation myself, 16 years ago. (Wow, so long…) Happy memories. I got a fellowship to go to my first postdoc in the mythical land across the sea, where so much of the wonderful physics I’d been studying was done by the giants of the field. I was going to get to go there and join them. But I had to write up and graduate first.

I loved writing (and, as you may have noticed, still do) and so relished the prospect. I procrastinated an awful lot (as I do…) for a while before getting down to it, even managing to catch chicken pox for a while (which helped keep me at home for a bit, usefully), and then eventually settled down to it. I essentially locked myself away at home for three or four solid weeks, with a little computer, in my room at the top of the […] Click to continue reading this post →