Ok, so not really life — just my physics. But this title flowed better.
So far today (it’s noon), I have made some real progress on a tricky problem we’ve been working on, that looks like it might soon give some very interesting results, possibly publication-worthy. This is very good. Also today, another paper appeared online with similar results to some of our work, from a different approach. This is potentially very bad. It’s 62 pages of heavy maths, so I’m not sure how bad at this stage. Preliminarily, though, it looks like at least some of our work is not in their paper.
So yes, things might start moving quickly now.
Those of you that have been paying attention might have noticed I’ve been a little quiet recently. Well, here’s a brief summary of past and future plans — and perhaps some reasons for my silence.
My brother was here for three weeks in March/April. We had a great time and did many things. Some highlights were seeing the Cirque du Soleil show KÀ and a whole lot more in Las Vegas, an interesting photo exhibit at Santa Monica, all the usual Hollywood sights (just as there happened to be a huge cheerleading competition on the go) and some interesting parties at Caltech. He also made it down to San Diego with a friend for a few days.
Then I leave on Tuesday for South Africa for three weeks, where I’ll be seeing lots of friends and family, and attending Paul’s wedding! I’m looking forward to it greatly. For the second half of the stay I’ll be joined by Ellen, so we’ll be doing some of the tourist stuff — not least of which will be seeing Little Baby Cheetahs.
I’ll also be working hard on physics, though, as just two weeks after getting back is my oral candidacy exam, a hour talk on the background, progress and future of the research I’m doing, followed by general questions on string theory and high energy physics. I still have lots of background reading to work through, since it’s very easy to get caught up in research details without appreciating the full background of the work. It’s the last exam before the process leading to the final thesis, though, so that’s exciting.
Then a few days after candidacy, I’m off to China, where I’ll be teaching a course on scientific English at the National Institute of Biological sciences, in Beijing; followed by attending the annual Strings conference; and then spending a week actually seeing some of the sights. I’ve spent only 12 hours in eastern Asia, so it should be a very interesting trip.
Then I might decide to sleep.
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A quick information note for Caltech students who may not have read the newsletter: the GSC budget newsletter announces that the GSC request for a minimum stipend level for all students, regardless of support source, has been approved by the Graduate Studies Committee, and will be recommended to all division chairs.
I’m really excited, since the figure they mention will be a BIG increase for me. But it’s worth checking, come next year, that your stipend is up to the minimum — and if not, well, perhaps some complaining might be in order.
It’s nearly the start of the new academic year, and so a season for new beginnings. And there certainly are lots of those!
Firstly, I’ve moved into my new office, on the fourth floor of Lauritsen. Yes, I’ve made it to the top floor! Across the hallway from my office is last year’s Nobel prize winner, and around the corner is Richard Feynman’s old office, and also my advisors’ current office. There’s also the coffee machine and printer, which will save many trips up the stairs!
My new details:
Pasadena, CA 91125
Office telephone: +1 (626) 395 4503 (though my cellphone is still generally a good bet).
Then I’ll be doing a Teaching Assistantship for the first time this year, which will be interesting, and probably annoying sometimes! I’m teaching sections (ie. revising work and going through problems on the blackboard) for Physics 2, the second year undergrad general physics course.
Climbing is also taking off in an increasingly big way — I’m doing short workouts on the bouldering wall at the Caltech gym most days, and I’m going to give the Caltech rock climbing PE course a try — hopefully it’s not aimed at complete beginners, or I might get a little bored! I’m also going climbing for a weekend with two other physics grad students from other parts of the country, at Red Rocks, near Las Vegas, at the end of October. In the style of the Blog Which Must Not Be Named, pics will follow of the crazy routes we do…
All of this, along with the very interesting people I’ve been meeting around orientation, should make for an exciting year!
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It’s now nearly two weeks into TASI 2005, and quite some weeks they’ve been!
For those that don’t know, TASI is a month-long program for graduate students, at the University of Colorado at Boulder. It features four weeks of lectures by experts on various current issues of string theory. It’s an excellent chance to gain familiarity with aspects of string theory that one might not have come across yet as a grad student; but it’s also an excellent chance to get to meet and talk with leading current and future string theorists. Last, but not least, it’s really tiring — five hours of lectures plus an hour and a half of student seminars a day — and it’s all high-intensity stuff.
The networking opportunities are really fantastic. I’ve met a number of people who wrote papers I’ve used recently. For instance, a few months ago we looked for a while at applying some ideas of Samir Mathur on defining black holes in geometries which do not have an obvious simple horizon, to the formulism of Lin, Lunin and Maldacena for describing 1/2BPS (supersymmetric) 10-dimensional geometries with particular isometries (SO(4)xSO(4)). Today at lunch I was discussing some of our ideas with both Mathur and Lin. It’s also a very fun group of people, and we’ve hit the night-life of Boulder more than once.
But talking of connections, there have been some small-world experiences. Amongst the approximately 50 grad students, one is a graduate of the University of Cape Town, and grew up a few kilometres from me in Johannesburg. I’d never met her before — she, like most of the students here, is a few years older than me. But we know tons of people in common, and indeed her boyfriend (who arrived tonight for the weekend) and me are co-authors of a paper dating from a few years ago. I hadn’t seen him since.
The last type of connection, though, is really literal — yes, attaching oneself to rocks. There are about eight people here who are keen on rock climbing, and I’ve been going along. I bought a harness, and have been renting shoes. We went out last weekend, and should be heading out this Friday after lectures, and probably Saturday too. Boulder is excellent for climbing and similar outdoor activities — and judging by the cars parked all along the mountain access roads, that’s what everyone does come the weekend. So I’ll be looking for a climbing partner when I get back to Pasadena!
So yes, the TASI experience certainly keeps one busy — though it is getting a little hard to get out of bed each morning for another long day of lectures!
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Travel can sometimes be annoying. But sometimes it can actually be quite enjoyable.
Yesterday’s travel had the required annoyances, including the need to take two different flights to get from Los Angeles all the (oh so long) way to Denver. Then in Denver, there was the minute by which I missed the hourly bus to Boulder.
But altogether I quite enjoyed it. Salt Lake City is really interesting, particularly flying over the colours of the salt lake itself. I also spent much of the time asleep, on both flights and in the terminal at Salt Lake City.
The best part of the trip, though, was being on a fixed schedule. For quite some time now I’ve been trying to fit too many things into too little time, so I’ve been constantly prioritising things in my mind, and trying to fit as much stuff in to each minute as possible. But once one gets into the car and heads off to the airport (thanks Bert for the lift!), there’s only the fixed schedule of the flights. If there’s a two hour layover in, say, Salt Lake City, that’s two hours during which there’s nothing that has to be done. I could spend as much time as I liked choosing what to have for lunch. Um, breakfast. Whatever.
There’s also the simple instant gratification of succesfully getting through each security check and onto each flight. It’s not much of an achievement, but that’s the point — it’s all one needs to achieve to have had a “perfectly succesful” day of travel.
Anyway, as you can tell, I’m
not now in Boulder, Colorado. The next month will be full of physics, as I’m here for the Theoretical Advanced Summer Institute, a seminar series in string theory. More news on that to follow!
I’ve just finished reading Michelle’s candidacy report, on some of the research she’s been doing into catalysts for certain reactions in organic chemistry. It’s highlighted for me some of the differences between different fields of research — and in particular, between theoretical physics, and the more experimental work that most other people at Caltech do.
Michelle’s report was very easy to read. That’s partially because it’s well written, but I’d say it’s also because the difficulty is in a different place to that of papers that I’m used to reading. “Reading” a longish string theory paper can take literally months — and even then, I can’t claim to understand everything that is being said. Reading Michelle’s report took a few hours, and while I didn’t understand all the jargon, I think I got the gist of the issues and approach that her research took.
On the other hand, having read Michelle’s report has brought me no nearer to actually being able to synthesise anything more interesting than a bowl of pasta and sauce. “Reading” the string theory paper, however, has involved working through the mathematics behind each step, at great length — sometimes hours for a single line. So once I’m finished, I’ve done a substantial portion of the work that was required to write the paper in the first place. The analogy would be me reading Michelle’s paper, and then making some of the reagents too — and that would take months too.
I think this asymmetry in paper content goes a long way towards explaining another huge asymmetry between fields, namely the path of progress toward a PhD. In the case of Michelle, and most other grad students, the work they’re doing is probably what their eventual thesis is going to discuss. String theorists, on the other hand, only work on their actual thesis topic for maybe a little over a year, right at the end. I went to a string theory thesis defense last week, and the speaker had worked on three very different topics over the course of his five years — one in third year, another in fourth, and the thesis topic in fifth year.
How can this be? I’d suggest that reading even unrelated theory papers is not unlike conducting experiments in other fields. One is developing the mathematical tools and approaches that will be needed later. Once a string theorist can read any current paper in the field at least relatively quickly, then it’s a small step to starting with an idea, and then carrying out the same steps of working through the logic — only this time, one is writing a paper.
There’s no real moral to this post; I just find it interesting how superficially similar scientific disciplines can hold their real complexity in so very different areas. I may have a lot more to say about complexity shortly — just as soon as my current workload lets up enough to give me time to write some more blog posts!
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Graduate student life can contain some hidden contradictions. From the outside, it might seem stable, even boring, as one spends pretty much every day doing much the same thing (staring at papers for me, mixing chemicals for some, writing computer code for others).
So one might, if one were so inclined, plot the external appearance of grad student life as a flat line. Now the thing about flat lines, if I may appeal to your mathematics and/or quantum mechanics classes, is that Fourier transformed into momentum space, they look like delta functions — that is, infinitely steep-sided spikes of unit area.
Irrelevant, you say? Nonsense, I say. And anyway, don’t interrrupt me halfway through my post.
Because lurking beneath the surface of any grad student’s apparent calm are dramatic spikes in things such as work satisfaction, fear of advisors (or specifically, running into them and so needing to explain the progress one has / has not made), and perception of progress toward the Valhalla of PhD-dom (Valhalla since progress sometimes seems like a battle to the death, in order to enter paradise. And not because of the plentiful women, the thought hadn’t even crossed my mind).
In somewhat related news, I changed research direction entirely on Tuesday. The old direction was really going nowhere, so it’s something entirely new that we’re looking at now. You might think I’d be disappointed after a good many months’ work on the old area, but I’m actually quite pleased, since I had run out of ideas for the old project. And thank goodness I have no candidacy exams coming up soon!
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It seems that most of the time these days, I being asked to think about things in a different number of spacial dimensions than 3 (up-down, left-right, forwards-backwards). Now, some properties follow through to additional dimensions quite easily, but I was thinking recently about one that doesn’t: knots — it’s a great example of the tricks that dimensions can play on one.
What’s a knot? Take a piece of string (an object extended in one dimension). Form a loop and feed it through the loop. The knot so formed cannot, by continuous deformation of the string, be “undone” without moving an end of the string back through the loop.
But knots only exist in three spacial dimensions.
Try two dimensions (which can be simply drawn on a flat piece of paper). Forming the loop leaves a diagram that is indistinguishable from a straight piece of string plus a seperate loop, which is free to float away. So you no longer have one piece of string.
Now, try four dimensions. The best way to try to visualise this is to treat time as a fourth spacial dimension; that is, any particular piece of string only exists at one instant in time, and it is possible to move the different parts of the string forwards and backwards in time, so long as the string remains continuous.
Ok, form the entire knot at one instant in time. Now move the side of the string that went through the loop, forward a litle in time, so the rest of the knot is not there. Move it spacially a bit such that when you move it back in time to the rest of the knot, the string no longer goes through the loop. You’ve just continuously transformed the knot into a non-knot (as well as given yourself a headache, if my experience is any indication).
So, knots only exist in 3 spacial dimensions.
Exercise for the reader who hasn’t had enough yet: Is there a structure that in 4 spacial dimensions can be tied into the equivalent of a knot?
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So I’m presenting my understanding of a recent paper (hep-th/0411145, by Suryanarayana, for those who care) to my supervisor tomorrow. This, of course, requires a LOT of reading of previous and other papers, to get ANY idea of what is happening.
I’m in the course of going throug the references when all of a sudden I see, “De Mello Koch, R and Gwyn, R., Giant graviton correlators from dual SU(N) super Yang-Mills theory, hep-th/0410236“, etc. etc.
Now Robert De Mello Koch is my undergrad supervisor, and Rhiannon Gwyn (for those who don’t know) is a very good friend currently doing her Masters thesis in Johannesburg.
Nice one, Rhiannon!
(PS. Please note the optimistic attempt to make this post readable to any of the tons of people, around the world, who read this blog).