bergman | August 22, 2007The LHC is coming, and it's time to place your bets. What do you do? (Fun though it may be, shooting the hostage doesn't really help here.) We're committed Bayesians (for the sake of this post, at least), and we want to assign a probability that the LHC will see supersymmetry. More generally, we have a set of possibilities for our observable physics, and we would like to assign probabilities to each. This is called the problem of finding a measure. Since the theory of eternal inflation with its "bubbling universes" is the context where the multiverse often comes up, this is often referred to…
drorzel | August 21, 2007(I think that's right-- we're drifting into phrasebook stuff, here...)
Another day of tourism, another golf shirt with visible salt crystals from dried sweat. Did I mention that it's really frickin' hot?
Today was a split day-- we spent the morning looking at temples near the Kyoto station, and after lunch took a train down to Himeji to see the Tokugawa-era castle there. It was a great day all around-- Too-ji temple was having their monthly flea market/ fair/ whatever, so we picked up some souvenirs, and I ate some weird food-- deep-fried bait (some sort of minnow-like fish), and fried…
bergman | August 21, 2007I'm here at the Simons Workshop at Stony Brook out on Long Island. I'd like to talk a bit about the workshop later, but right now I just want to note that it is 56 degrees out. In New York. In the middle of August.
Thunderstorms I'd understand, but cold, dreary drizzle? It's August, not November. I didn't exactly pack for this.
bergman | August 21, 2007When we left our story, we were stuck in the unfortunate position of living somewhere in a multiverse without any a priori way to figure out where we live. What might we do?
One thing we can do is let the dreaded anthropic principle rears its head. At its most basic essence, the anthropic principle is the statement that we exist. This is data, and we can draw conclusions from this data. The most famous examples of this are Hoyle's prediction of a particular nuclear resonance based on the need for enough carbon in the universe for us to exist and Weinberg's bound on the cosmological constant…
bergman | August 20, 2007Thanx to everyone for all the interesting questions in the previous thread. I apologize for not being able to answer every one of them. I just arrived at a workshop on Long Island, and I'm also feeling a bit under the weather. From what I've seen so far, I think I will do a post on what is perturbative string theory and what does it have to do with spacetime and gravity (maybe it will even lead into a post on what is background independence). Feel free to use this thread for more questions if you like.
drorzel | August 20, 2007My rudimentary Japanese will run out much too fast for me to keep up the conceit of titling all travel updates in Japanese, but we'll run with it while we can... I don't know if there's a Japanese equivalent of "It'sãnot the heat, it's the humidity," so we'll just go with this.
When I told people we were coming to Japan in August, the general reaction was "Good God, why then?" I didn't get to pick the dates for Worldcon, though, and anyway, I thought, "how bad could it be?"
Answer: Pretty freakin' bad. Tromping around eastern Kyoto yesterday was essentially the same as hiking on St. John,…
bergman | August 20, 2007Let's say you have a theory, and, let's say it happens to have a whole lot of solutions. Maybe it's the theory you're thinking about, but it doesn't have to be. Nothing of what I'm going to say depends on any details besides this surfeit of solutions.
I should begin by saying what it means for a theory to have a lot of solutions. In fact, given any set of equations, one will almost always have many solutions. A polynomial of degree n will generically have n roots, for example. In classical physics, instead of a finite number of solutions, you will almost always have an infinite number. If you…
bergman | August 20, 2007When Chad first asked me to guest blog here, my first response was that I didn't have anything to say. After a little thought, however, it occurred to me that this would be an opportunity to do a little exposition. Unfortunately, my research area is quite a bit on the esoteric side, so I had to look elsewhere for possibilities. Thus, the "ask a string theorist" post below. But, the next thing that occurred to me was to talk about multiple universes.
Why do that? Not because I believe that it's central to string theory, and not because I believe that it's even necessarily science. What I do…
drorzel | August 19, 2007I'm sure I'm neither the first nor the last person to note that it probably says something about Japan that the ordinary meet-new-people ritual includes asking them "Please be kind to me." But, you know, sometimes you have to be obvious.
Anyway, I'm in Kyoto, typing on a loaner laptop in the hotel lobby. Don't expect a great deal of blogging via this method, because the keyboard is different, and I keep doing something to put it into hiragana mode, which makes a great big mess. The hotel is very nice, though, abd the staff speak excellent English, so I have not needed my abominable Japanese…
lundblad | August 18, 2007I see below that (in what comes as a total surprise) the string thread has already gotten lively. As an experimentalist doing quantum mechanics at the ultra-low-energy end, I don't have a strong opinion on string theory qua theory, and I really don't have a strong opinion on the sociology-of-theory business, beyond saying that I'm not a cynic, and that I find articles in the popular press about Str1ng Warzz a bit tacky.
I'm also not really qualified to weigh in: my only particle theory background was a year of QFT from a phenomenologist out of Peskin & Schroeder, and while I came…
lundblad | August 18, 2007While I'm sure there will be a lot of chatter around here in the next few weeks about the vacuum (or, God help me, vacua), I feel like I should lay the groundwork by talking about laboratory vacuum. I know I'm here to talk about cold atoms and the hot stuff going in in experimental physics right now, but I've spent a lot of time in the last couple days dealing with vacuum, and I want to tell you about it.
If you want to do most sorts of atomic physics experiment, it's essential that you isolate what you're interested in studying (atoms) from stuff that will either knock those atoms away,…
bergman | August 17, 2007Over at Andrew Sullivan's place, he's been presenting candidates for best movie line ever. Since I seem to have control of a blog of my very own, I'd like to present my nomination:
Holly Gennero McClane: After all your posturing, all your speeches, you're nothing but a common thief.
Hans Gruber: I am an exceptional thief, Mrs. McClane. And since I'm moving up to kidnapping, you should be more polite.
(transcription from IMDB)
Apparently my affection for this line is not widely shared, however, as finding the clip online has proven to be beyond my google skills. On the other hand, I did…
lundblad | August 17, 2007Well, I just flew in from DC, and boy, are my arms tired. But seriously, folks....
It's a fine thing to be asked to guestblog by the eminent Dr. Oilcan, and I'll do my best to entertain you sporadically over the next few weeks. Like he said, I first met Chad back in his Usenet days, which was back in my Usenet days as well. That's obvious, yeah, but it's key that we both refer to time on Usenet as long past. I haven't read or posted to a newsgroup in five years, and even then my interest had been pretty much dead for a couple years.
I first encountered Usenet as a wide-eyed…
bergman | August 17, 2007One of the things Chad didn't mention about me in his introduction is that in addition to being a physics major as an undergraduate, I also majored in mathematics. My research interests these days tend towards the exciting confluence of mathematics and high energy physics. So, in honor of that (but really completely unrelated), I give you:
60499999499 / 490050000000
If you like, consider it an easy puzzle to understand the significance of this number.
bergman | August 17, 2007First of all, I'd like to thank Chad for the keys to his internet-house for the next few weeks. If you're here, you know that one of the things Chad believes in (and is quite good at) is using his weblog for the exposition of science for the general public. While I don't think I can manage any funny dog stories, I'd like to try to follow his example. I have some ideas already planned (such as, god help me, a three part series on the multiverse), but I thought as an initial post here, I'd go straight to the public. What do you want to hear about? Is there some aspect of string theory, quantum…
drorzel | August 16, 2007As mentioned several times hereabouts, Kate and I are headed to Japan on Saturday, where we'll be spending three weeks touring around and attending the World Science Fiction Convention in Yokohama. We will have at least some Internet access, and I may post the occasional travel update from Japan, but I'm not going to try to schedule three full weeks worth of posts to keep the blog going during my absence.
If, for some strange reason, you find that you are wholly dependent on Uncertain Principles for your computer-based entertainment needs, have no fear-- I'm not going to leave you totally…
drorzel | August 16, 2007A couple of days ago, Brad DeLong hoisted a proposal from comments (originally suggested by Bernard Yomtov):
A reporter should not be assigned to cover subject X unless he has as good an understanding of X as a baseball writer is expected to have of baseball.
Kevin Drum isn't sold on the idea:
Man, does this seem backward. If you asked me what was wrong with big-league political reporting in this country, I'd say its biggest problem is that is has too much in common with big league sports writing. Reporters like Adam Nagourney and John Harris don't lack for expertise in politics, after all.…
drorzel | August 16, 2007A little while ago, James Nicoll posted about the shifting subject areas of SF:
In fact, a fairly consistent pattern in SF is to retreat away from areas that have come under the light of scientific examination. When probes began to visit the planets, SF retreated to the stars (There are very few novels these days set in the solar system). In fact, Trouble on Titan starts off with an essay by Nourse explaining that the attraction of Titan for him was that so little was known about it that he could set almost anything there and not have to fear contradiction from scientists.
It's the same…
drorzel | August 16, 2007One final vacation picture: what with all the snorkeling and boat-chartering and hiking, I was starting to worry that I might seem too cool to be a physicist. There was a chance that I might meet somebody, and not have them realize immediately what I do for a living.
At the same time, my Northern European heritage doesn't exactly put me in a great position for dealing with intense tropical sun. After a day or two, I noticed that my scalp was strting to sunburn, through my hair. So I needed a hat of some sort.
I decided to kill two birds with one stone, and looked long and hard to find a hat…
drorzel | August 15, 2007Michael Nielsen, who's so smart it's like he's posting from tomorrow, offers a couple of provocative questions about the perception of a crisis in funding for basic science:
First, how much funding is enough for fundamental research? What criterion should be used to decide how much money is the right amount to spend on fundamental research?
Second, the human race spent a lot lot more on fundamental research in the second half of the twentieth century than it did in the first. It's hard to get a good handle on exactly how much, in part because it depends on what you mean by fundamental…