Draw

game of naughts and crosses, spotted in the bar/lobby of an Aspen hotel.I’ve been quiet here recently, I know. Was mostly working, thinking and reading on the weekend. Did not even go on a huge hike (although I did do a nice walk or two). Sometimes, on an evening, I go and read a novel in a bar. (I’m weird that way, I know.) I’ve not been going to the noisy bars full of yelling and the party crowd, but instead like to find a nice sofa in one of the bar/lobby areas of the nicer hotels. Great for reading, and the drink prices are merely extortionate, as opposed to just plain offensive in the more popular places. (Photo: a naughts and crosses game I spotted on a table in one such lobby.)

Well, it’s a draw so far in the battle with my equations and ideas, but I think I’m developing a stronger position. (From this you can deduce that I decided to stick with the same project and hold my ground and struggle on some more.) Perhaps the next […] Click to continue reading this post

Quantum Black Holes – Why Worry?

susskind_by_matthew_black for LA TimesWell, you may not have gone to the chat between K C Cole and Leonard Susskind that I mentioned a while ago at the LA Central Library downtown. I couldn’t make it either, being away at the Aspen Center for Physics. I expect it was good. Anyway, I found a little bit of a report on the conversation, done by reporter John Johnson for the LA Times. It is here. (Clickable image of Susskind to the right is by Matthew Black, for the LA Times.)

It gives you some of the simply-stated reasons as to why there was a big argument between Stephen Hawking and Leonard Susskind in the first place (and between several other physicists too… there are hosts of people working on these things, and it took hosts of people to sort it out to where we are now, not just those two, giants though they are). I recommend having a look, as it is especially for the lay-person, and will give you a good idea of what the fuss is about.

You can also see a little bit about his new book on the subject and a link to a video interview with Brian Cox (the physicist, not the actor) at the LA Times blogs here. There are also links to his Stanford continuing education course on quantum mechanics, including the online lectures you can view at your convenience. What a resource!

You might wonder why we care about all this, since currently the only way we know for sure to make black holes in the universe (astrophysical processes making stellar black […] Click to continue reading this post

Humps

Now playing: I’m Confessin’ (That I love You), Thelonious Monk [Solo Monk]

Well, I’m now beyond the halfway mark of my retreat and I’ve been on the one project all this time. I’ve made progress here and there, had some setbacks, and have got very stuck at times. It’s just one of those things with this sort of work. Par for the course.

humps in road warning sign, UKThere are times when you think that if you do just a bit more on the project, it’ll get over the hump, as it were, and then coast along. So far I worry that there may be simply an infinite set of equally spaced humps of similar height all the way down the road**, in that every now and again I discover a rather pretty little gem of a result that’s quite encouraging, but these gems don’t seem to have anything to do with each other. So it’s a little scattered gravel pit of gems as opposed to a lovely… Ok, cvj, enough with the gem metaphor.

Now playing: Totem Pole (Alt. take), Lee Morgan [The Sidewinder]

The issue here is whether I should jump ship and use the last of my quality time here […] Click to continue reading this post

A Hop Over To Canada

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?

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

On Good Ideas

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

Fourth Thoughts

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

News From The Front, III

[Note: Originally posted on CV on 4th November 2005. 25 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ [Warning! This is an unusually technical post.] Ok, so last time, I told you a bit about the motivations for what I’ve been up to. Now I want … Click to continue reading this post

News From The Front, II

[Note: Originally posted on CV on 31st October 2005. 31 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ Well, I suddenly have 45 extra minutes on my hands as I was supposed to be at a very interesting two hour lunch meeting which I’ve now missed. … Click to continue reading this post

News From The Front, I

[Note: Originally posted on CV on 3rd October 2005. 65 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ Below is a snapshot of a computation I was working on earlier this Summer. Will explain later. Spoke about it at the Southern California Strings Seminar. I’m curious … Click to continue reading this post

Old News

The next three posts are repeats of posts I did on CV in 2005. They were the first three in the series entitled “News From The Front”, and their subject matter partly lay the groundwork for a post on some new results that I hope to write soon. Enjoy! -cvj

Southern California Strings Seminar

Takuya Okuda  talking at the SCSS at UCLA, Dec. 2007

Takuya Okuda talking about Wilson Loops at the most recent SCSS, UCLA, Dec. 2007. Click to enlarge.

The next regional string meeting is a two-day one at Caltech, this Friday and Saturday, organized by Joseph Marsano. It’s going to be full of interesting talks and conversations, as usual. Please encourage your graduate students to come, especially, since special effort is made to make sure that each talk begins with a pedagogical portion to help non-experts in that subfield navigate and see the motivation.

The speakers are: […] Click to continue reading this post

Southern California Strings Seminar

michael gutperle talking at the first SCSS at USC, Sept. 2005The next regional string meeting is a one-day one at UCLA, organized by Michael Gutperle and Per Kraus. It’s going to be full of interesting talks and conversations, as usual. Please encourage your graduate students to come, especially, since special effort is made to make sure that each talk begins with a pedagogical portion to help non-experts in that subfield navigate and see the motivation. (Photo: Michael Gutperle talking at the first SCSS at USC, Sept. 2005; click for larger view.)

The speakers are: […] Click to continue reading this post

Talk Talk

[Post reconstructed after 25.10.07 hack]:

dbranesTwo Thursdays ago I went up to Santa Barbara to give a seminar. I had a great time, and it reminded me why it can be so much fun to go somewhere and visit for even a short time and do that. I got to catch up with several old friends, including Santa Barbara itself, where I lived for a number of years in the 90’s when I was a postdoc. I spent time chatting with the various people there before (at lunch) and after (individually) the seminar, learning about some of the research they’re doing, and also talking about other matters physics-wise and gossip-wise. I wish I’d had more time to talk since I did not get to talk to everyone I wanted to talk to, and not at as much length as I would have liked. (This was partly due to the fact that I spent the morning in my hotel room writing some of the slides for my talk. – I had a presentation the day before to focus on, along with a departmental visitor to host, and the day before I was also occupied. Don’t ask about any earlier than that – I never prepare new material that much in advance. Not because I don’t want to, but it just never happens… if I have more than a day or two, I will find that there’s other stuff I have to do.)

Anyway, a good time was had by all (I think). I can even post a picture of some of us at dinner in the evening after the talk. (Will update later with that, since it was downloaded to computer that’s not here.) We went to an old haunt of mine in downtown Santa Barbara – Roy’s. I’m pleased and surprised that it is still there and going strong, since it is the sort of highly individual restaurant that – since it is also reasonably priced – you’d expect to vanish from such a high value spot in town.

What was I talking about? Well, with three students (Tameem Albash, Veselin Filev, and Arnab Kundu), I’ve been involved in some fun work on some of the physics concerning […] Click to continue reading this post

Whither String Theory? – Too Soon To Tell

stringscape image from physics worldGosh, a thoughtfully-written general level (more or less) article on some of the general outcomes of string theory research! It’s written by Matthew Chalmers, and is in the Sept. ’07 edition of Physics World*. The article can be read online here, and downloadable pdf is here. The graphic on the right came with the article. I don’t fully understand what it is, but the title, like that of the article, is “stringscape”… Look, let’s not over-think this cvj – it’s a pretty decoration.

I’ve done a quick read of it (should re-read more carefully later on – it will no doubt have some emphases with which I disagree somewhat**) and I’d say it is very much worth reading. While not a perfect summary (what is?), compared to a lot that’s been out there, you’ll find it rather more informed, less sensational, (refreshingly unpoisoned by various prejudices, such as the presentations of Smolin and Woit – see numerous earlier discussions in the “More Scenes from the Storm in a Teacup” series of posts, and others), and unafraid to go to some length to unpack the issues somewhat carefully.

Very importantly, it contains numerous quotes from various respected researchers in […] Click to continue reading this post