Analytical Conference Dynamics

As I mentioned in a previous post, I recently had the pleasure of attending the Lake Louise Winter Institute, Which is a conference in Banff, organized by University of Alberta. Billed as a conference on “Fundamental Interactions,” about 75 people were in attendance ranging from Theory to CLEO to ILC, and a fair representation from neutrino, cosmic ray and dark-matter scientists. I learned a ton about neutrino mass studies and hadron spectroscopy. Mornings were principally reserved for three one-hour-long lectures, afternoons were free for skiing etc, and evenings from 19:30-22:15 were reserved for several short 15 minute talks. All talks were given in the same hall. My talk was eighth from last in the whole conference, and I wagered with a colleague that his talk would be better attended. There was ensuing debate about the effects and causes of conference truancy. Thereafter, I sat in the back corner of the hall and counted those present during the opening remarks of each talk.

Was I missing anything? Not really. During 90% of my counting the speakers just wasted time by restating their names, affiliations, and titles of their talks, which are normally announced by the convener anyways. I was always done in time to read the overview slide. I’ll spare you the data from the morning sessions, which were inhomogeneous, and were subject to edge effects of attending scientists travel arrangements. These kinds of effects are not amicable to study.

On the plot above you see three curves, representing the average attendance vs. day in yellow, and two averages for those talks before and after the coffee breaks. Two trends should be highlighted, specifically that average attendance decreases as a function of time, and that the attendance after coffee is significantly lower than before. After making these observation, I then compiled the following plot:

Here one can observe an increase of all kinds of truancy as a function of time. Measured observables include

• “Coffee Break Dropouts”-the difference of the pre and post coffee average attendance
• “Late Arrivers”-The difference between first and second talks
• “Coffee Straglers”[sic]-the difference between the first and second talks after the coffee break
• “Early Leavers”-the difference between the last two talks.

While no theoretical predictions have been made in this work, it is hoped that this study will motivate future advances in this field, and Vava owes me 5CAD.

Spinoff adds up Ringdown

I love interchangeable parts. This kind of feature guarantees not only that the potential of intentional development is nearly fully utilized, but that the efforts of miscreants fools and misguided souls can be put to good use by society. While anything requiring LISA to be observed doesn’t really qualify as good use, I have no qualms with GR in general.

As every time you skype transatlantic and get seamless connection, who do you thank? CERN? Telcoms? HEP is a marginal part of Internet development these days, and Telcoms are guilty of preferentially throttling traffic in order to cut their costs. Thank the pirates and pornographers, who arguably accounted for about 75% of Internet traffic in 2007. If it wasn’t for these bitpushers compulsive need for pop songs, pre-releases and peepshows, Telcoms wouldn’t need those nice wide switches, and wouldn’t pay for them.

Why do I think of this now? Because when armies of pre-teens of all ages want absurdity crammed in their senses in a highly aggressive market with razor-thin profit margins, what are they doing? When they demand that programmers weekly crank out something that not only is new, but looks new as well? They’re relentlessly pushing advances in computing. This requires fast and loose programming, with lots of layers of indirection to encapsulate objects for team collaboration. This requires more triangles, color and shading than a person with a mid-range output device can detect. This requires big, evil processors, processors like a pack of rabid jackals. This requires the PS3. I haven’t owned a gaming system since the Genesis, and probably never will again. I don’t care about how “real” some stupid game looks or feels, but when I see someone take one of these computational warheads and jams it full of hardcore science, I get a bit misty.

In El Reg today, they write about how Sony donated 16 PS’s to U.Mass for numerical relativity. On the project page they write “Overall, a single PS3 performs better than the highest-end desktops available and compares to as many as 25 nodes of an IBM Blue Gene supercomputer.” Get some. These aren’t modded. The code was optimised for the processor, but any good numerical mage does this. This isn’t some feasibility study. This is a potential signal if LIGO can drop their noise floor. This is taking a toy, and using it as a research machine. This is taking humanity’s undying love for wasting time, and redirecting it towards advancement.

I wonder what St. Augustine would have called misdirected sloth…

I quite like the first life, thank you very much

I read somewhere the other day about Second Life, an apparently popular virtual reality online, in which you can meet and chat to people, move about, buy things and even hold physics conferences. The last one is really why I bothered – in the same week I read about physics connections made through Second Life I also found a Second Life group on the Nature Network. So I thought that I’d better have a look. I agonised for a while over the choice of an appropriate name (and I think that I’m proud of what I finally chose), and then set about exploring. The introductory location is on an island, and the disadvantage of this is that you can fall in to the surrounding water. Fortunately you don’t drown, so you can have a bit of a swim and then climb out again. Then my computer crashed and I gave up for the day. I tried again just now and I managed to buy a chain mail shirt (gotta be useful, right?), before it all slowed down and started responding like a reluctant dog being led to the bath. When it finally relaxed and speeded up, I found that I had fallen into the water again. After a few more attempts which all ended in the cryosphere, I gave up. If it won’t run even with all the other programs switched off and nothing fancy enabled, I guess it’s trying to tell me something. Something along the lines of “No MacBook Pro? Not even a dual-core processer? Pah. We don’t need your sort around here”

So I won’t get to the virtual physics conference, but maybe since I’m in sunny California and it’s February, I’ll go surfing instead. Real surfing. With real people. I may yet emerge from my first life crysalis to face the second stage, but for the time being it’s quite nice in here. Now, where did I put my wetsuit?

Signal to Noise Problem

I wasted an hour on Google today, coincidentally looking for a signal to noise extraction method. Why you ask? Because the CDF/D0 collaborations decided to name the thing the “Matrix-Element Technique” Thanks yall. searching “Matrix Element” returns 100% of your papers, and combining with technique or method returns 50%. I finally found a thesis describing it, and guess what: I’m fairly sure its just multiple discriminant analysis. Sure, they generate the discriminant table with s-matrix elements, and convolve the detector smearing, but that’s like renaming the process of baking “egging” just because one recipe calls for eggs.

Speaking of which, who named root? Most HEP work machines have a /root directory on them. Luckily root is centrally managed, so I can search it fast, but I wonder if the Linux community gets slowed down searching for help forum entries by all the CERN garbage.

The Beginning of the Blog!

Hello everybody, and welcome to the the new blog! I see there’s already a post, thanks Homer!

 

Although there are already a small menagerie of physics blogs out there, I thought the world could use one with physicists at the beginning of their “careers”. Hence, this blog is made up of grad students and postdoc(s) only. We offer a unique perspective, etc, etc, but really we’re just more fun than the rest of those <i> other </i> physics bloggers. In forming this blog, I tried to ask and invite friends of mine who were: 1. ridiculously cool and 2. from some diverse areas of physics. Without further adieu, here is “Imaginary Potential” :

 

Helen Czerski is a postdoc at UCSD. She does bubble physics. She got her Ph.D. at Cambridge University, where I consistently beat her in squash (though it should be said that she was actually Cambridge’s #2 badminton player). She used to do explosion physics, which made for ridiculously cool demonstrations, but changed to bubbles because of moral qualms. That’s just the type of gal Helen is. She is also the world famous inventor of the “Einstein Flip” (http://news.bbc.co.uk/2/hi/science/nature/4148943.stm).

 

Homer Wolfe is one of my earliest collaborators. We started our groundbreaking union in 2002 with the barnburner “The Taylor Expansion of a Riemannian Metric” (http://web.mit.edu/guarrera/www/final.pdf, available exclusively on my website). After that, our collaborations have mostly consisted of getting drunk and yelling obscenities at each other. He’s finishing up his Ph.D. in experimental particle physics at DESY.

 

Homer Reid is the second and final Homer in my life. He’s finishing up his Ph.D. at MIT in something that involves “large-scale DFT and QMC-based electronic structure calculations,” whatever those are. As his website (http://homerreid.ath.cx/) will attest to, he’s a man of many talents. Also, before I knew him, I had “referenced” solved textbook exercises from his site more than I care to admit. In his spare time, he enjoys progressive house music and cuddling.

 

Tom Jackson is a theoretical condensed matter physicist, getting his Ph.D. at Yale. I met Tom back in 2003 while we both suffered though Part III in Cambridge. He used to have an excellent blog in operation, but now when I go to the address, it seems to be in chinese.  I’ve seen Tom use the exact same costume to portray andy warhol and carl sagan, both perfectly. Tom is the kind of man who is consistently hilarious and impeccably dressed.

 

Bonna Newman is finishing up her Ph.D. at MIT in experimental atomic physics. Together, she and I lead the Women in Physics Ambassadors program here. She does all the work while I reap the glory. This essentially means that all single available women at MIT physics are constantly throwing themselves at me. Bonna’s hobbies include controlling the physics department behind the scenes and flying planes.

 

I’m David Guarrera and I do string theory at the Center for Theoretical Physics at MIT. I am very much in the midst of my Ph.D. Like, there’s not even an end in sight. I used to write a blog,but it died when I got too lazy. I’m hoping that having more than one blogger here will solve this problem. 

 

Anyway, that’s us. I am humbled and honored to be blogging with these fine physicists, and I look forward to years of insightful commentary and worldwide physics blog fame. 

Recognizing Music

Yesterday I was flying back from a conference in Banff and picked up a copy of New Scientist during a protracted lay-over. The issue features several articles on the cognitive characteristics of music. The thing I found most interesting was how the researchers attempted to classify the essential properties of music, so they could isolate individual effects in people, animals, etc.Maybe the cleverest thing is what they labled as irrelevant, ie, absolute pitch. They point out that in all cultures which have names for notes, notes which differ by an integer multiple of frequency (one or more octaves higher or lower) have the same names. Many cultures have different choices for semitone relative differences, though. They then point out that rhesus monkeys can recognize two songs which are only shifted by one or two octaves as the same song, but sequences shifted by any other amount are not recognized. This makes sense, considering that most things which produce what we call single notes produce some amount of harmonics. Identifying notes an octave apart seems almost unavoidable.

They don’t discuss how people identify two pieces of music as being the same, other than to say that if people have a condition called Congenital Amusia, they cannot recognize “familiar” songs without lyrics. If there is static, a different singer, or an arrangement with some differences, most people can tell that two songs are the same. Specifically, I want to know how a computer or a courtroom, can decide how two songs are the same. The reader should recall the VH1 behind the music where Vanilla Ice sang the difference between the bassline in “Under Pressure” by Queen/Bowie, right before singing the hook in “Ice Ice Baby” There is a difference, note for note. You can hear that they are different, but the court decided that they were very, very similar.

So I was avoiding my thesis a few weeks ago by using a MusicBrainz client to label my mp3’s. It works pretty well, but it tried to identify two different takes of a song (I forgot which one, but I think it was Yardbird Suite) as the same. I’m not sure if this is from users mislabeling two distinct songs with the same name, or if they really have similar signatures in the classifier. The MusicBrainz database doesn’t just identify two songs as the same if the files are the same, it computes a “fingerprint”, which is a number that hopefully encodes the “important” parts of the music. There are many fingerprint possibilities, but MusicBrainz currently uses TRM. Looking at their website, they apparently use the MusicBrainz database, which is user generated, as a fee service for royalty enforcement for internet media. Wow. No technical real info on their webpage, sadly. I’ll do some emailing and see what I can dig up. How far are we from software being able to identify the song Yellow, whether it be done by Coldplay or Richard Cheese?

Testing the H2O

I want to blog!   In the mean time, have a look at this picture to see some of my bubbles…

Hello again, world

According to this link, WordPress renders LaTeX equations for you right out of the box, which sounds too good to be true. Let’s see: . OK, dropping in manual paragraph tags (with </p>) works but is ugly. To Do: get author bylines working, fix link sorting order.does this do a paragraph break?
how about double-enter?

ret-double-enter 
double-ret-enter