E successfully defended his thesis today. Besides not wanting to see someone fail, I was rather nervous, because E is the first student of my advisor. In other words, I had no proof that my advisor is able to get a student through the MS thesis. Although I had no reason to doubt that, it is comforting to have proof.

Part of what I like about grad school is the thesis defense. My program has very little community, so I’m always amazed to see that people come out for the defenses and that people do wait anxiously to see the defender succeed. It’s like a weird family; even if people don’t appear to care about each other, perhaps they truly do. I also like learning about physics theory. I feel like come away from everyone’s research learning something new.

On another note from the past two days, I found out that two jobs I had applied for in 2006/2007 are up again in the Boston-area. They upped their ante from last time; the minimum requirement is an MS and one of them has an even more complicated process.  I have to write a teaching statement and submit three recommendations. While I am indeed applying for both jobs, the cynic in believes that I will be overlooked for a PhD. In this job market, I would believe that they could get a PhD. *sigh

Answering the question “what does a physicist do?” can be difficult.  Even the much more modest question “what do you do?” is pretty hard.  Over the course of my relatively brief physics theory career, I have studied sonar, traffic patterns, cloud formation, parasite epidemics, low-temperature magnetic structures, and the electrical properties of DNA, to name a few things.  These topics have seemingly nothing in common, but they represent only a small sampling of the kinds of research you could find in the physics theory department of any major university.

And really, these subjects don’t have much in common.  But that’s okay, because physics theory isn’t really a topic.  It’s more of an approach, or a set of strategies for problem solving.  Someone trained in physics theory is not valuable because they have learned a lot of useful information, but because they have acquired a way of reasoning that is useful for solving complicated problems.

Acquiring new ways of thinking is what physics theory is all about.  In this post I want to illustrate the value of a “physics theory approach” to a problem by discussing an example where reasoning without it can get you a very wrong answer.

Not long ago I read Matt Ridley’s The Red Queen: Sex and the Evolution of Human Nature.  It was a very interesting book, full of complex and important ideas.  But in my mind too many of its conclusions were based on “common sense”; which can be a dangerous thing.  An idea that seems correct often is, but is certainly not guaranteed to be.  There are plenty of strange and counterintuitive phenomena out there, and their explanations cannot be rooted out by common sense.  Sorting strange fact from sensible fiction takes quantitative reasoning, and that’s what physics theory was designed for.

Somewhere around the fourth chapter of The Red Queen, the author starts talking about factors that can influence the gender of an unborn child.  During the course of his discussion, the author mentions that “merely by ceasing to breed once they have a boy … people would have male-biased sex ratios at birth.”  At first sight, the idea seems sensible.  After all, if every couple decided to stop having children once they had a boy, then every family would have at least one male child and maybe the result would be a male-biased gender distribution.  But on second thought, maybe the opposite should happen.  If everyone keeps having children until they have a boy, then you could have families with 9 girls and only one boy.  They should bias the gender distribution in the other direction, right?  So which is it?  Will a society produce more boys than girls simply by considering them to be more valuable?

To construct an argument that could be physicist-approved, we need to come up with a quantitative prediction for how many boys and girls would result from a society where couples have children until they have a boy, and then stop.  Let’s enumerate all the possibilities.  For a given couple, the sequence of their children could be {boy}, or {girl, boy}, or {girl, girl, boy}, or {girl, girl, girl, boy}, … and so on.  What is the probability for each of these sequences?  The probability for a given child to be either a girl or a boy is 50% (or 1/2).  So the probability of the outcome {boy} is 1/2.  The probability of the outcome {girl, boy} is 1/2 * 1/2 = 1/4.  For {girl, girl, boy} it’s 1/2 * 1/2 * 1/2 = 1/8 (or 12.5%).  And, in general, the outcome with n children has the probability .  We can make a diagram of all possible outcomes that looks something like this:

A diagram of possibilities for a couple's children. Bottom (blue) paths represent a male child, which ends the sequence of children. Top (pink) paths represent a female child, which cause the couple to continue having children. Each blue line has a percentage indicating the likelihood of that sequence.

Every couple will have one boy.  But how many girls, on average, will they have?  Well, according to our chart, there’s a 50% chance they will have no girls, a 25% chance they will have one girl, a 12.5% chance that they will have two girls, and so on.  Summing all possible outcomes gives

(average number of girls per family) =

You can plug the first eight terms or so into your calculator to get a good approximation to the answer, or you can remember what you learned about infinite series from calculus.  Either way, the answer is exactly one.  That is, nothing happens to the gender distribution: on average, every family has one girl and one boy.

If you think this was a fun problem, you can try to see what happens when you modify the “child birth rules” a little bit.  For example, maybe every couple stops either when they have their first boy or when they have 5 children total.  Or if every family keeps having children until they have two boys (the “tree” of possibilities is a little more complicated here, but you can still draw it out).  You’ll find that nothing changes the inevitable: your cultural values have no effect on the ratio of male to female babies.

This answer seems obvious in hindsight, but it really wasn’t.  We needed quantitative reasoning to be our King Solomon, judging between a number of different sensible arguments.  Of course, I’m not saying that non-quantitative arguments are never valuable or correct; they very frequently are.  It’s just that physics theory has trained me not to trust them.

And in case you’re wondering, yes, I did have the audacity to contact Matt Ridley and inform him of the error in his book.

Nadie conoce como ocurre la transición entre mecánica cuántica y mecánica clásica conforme el número de grados de libertad de un sistema crece. Cada mecánica tiene su escala, la cuántica, microscópica, la clásica, macroscópica. ¿Qué pasa en la escala intermedia o mesoscópica? Para saberlo lo ideal es estudiar objetos mesoscópicos que presenten propiedades cuánticas y clásicas simultáneamente. ¿Hay objetos (casi) macroscópicos que presenten propiedades cuánticas? LaHaye y sus colegas han dado un paso de gigante para lograrlo acoplando un viga nanomecánica vibrante a un cubit superconductor. Por ahora solo han demostrado que el acoplamiento funciona. ¿Cuándo serán capaces de demostrar que la viga, cual gato de Schrödinger, se encuentra en dos estados vibratorios simultáneos? Tiempo al tiempo. Nos lo cuenta Pertti J. Hakonen, Mika A. Sillanpää, “Condensed-matter physics theory: Coupled vibrations,” News and Views, Nature 459: 923-924, 18 June 2009. El artículo técnico es M. D. LaHaye, J. Suh, P. M. Echternach, K. C. Schwab, M. L. Roukes, “Nanomechanical measurements of a superconducting qubit,” Nature 459: 960-964, 18 June 2009.

La decoherencia es considerada la clave para entender el proceso de transición entre la física cuántica y la clásica. Lo “cuántico” de un sistema se diluye conforme interactúa con el ruido presente en su entorno (incluso el vacío es suficientemente ruidoso). ¿Cómo reducir este ruido? Trabajando a muy baja temperatura. Los dispositivos superconductores son sistemas macroscópicos dominados por la mecánica cuántica. LaHaye y sus colegas han demostrado que una unión (diodo) Josephson formada por un pequeño corte de pocos nanómetros en un hilo superconductor presenta propiedades parecidas a un átomo cuando interactúa con un campo electromagnético en el régimen de las microondas (como los teléfonos móviles). LaHaye y sus colegas le llaman átomo artificial (en realidad es un bit cuántico o cubit, con sólo dos estados cuánticos bien definidos).

¿Cómo estudiar las propiedades cuánticas de un sistema clásico mesoscópico? Acoplando el sistema mesoscópico a un átomo artificial y “leyendo” sus propiedades cuánticas en este último. LaHaye y sus colegas han estudiado las vibraciones de un resonador nanoelectromecánico (una micropuente de nitruro de silicio con sus extremos fijos capaz de vibrar con una frecuencia de resonancia de 60 MHz) acoplándolo a un átomo artificial (cubit tipo Josephson), gracias a colocarlo a solo 300 nm (nanómetros). Las vibraciones del resonador nanoelectromecánico se pueden medir mediante el cubit (midiendo por  ejemplo su capacitancia). Los autores creen que el sistema también opera a la inversa, las modulaciones de las propiedades del cubit afectan a las vibraciones (fonones) del resonador micromecánico. Cuando el cubit se encuentre en un estado de superposición (simultáneamente en 0 y 1), ¿estará el resonador micromecánico en dos estados de vibración simultáneamente?

Un cubit que controla un “gato” de Schrödinger. Cada día más cerca. En menos de una década, este campo de investigación logrará estudiar en laboratorio la transición de lo cuántico a lo clásico.

holy shit, again i skip another month! meaning that i skipped may ahah. aka mah brinklesday

but it’s june now…and school ended two days ago! (monday), therefore finals have ended and regents have started. i have english regents (pts 1 + 2) to take as well as italian and physics theory. i took the pt 1 for english today, and the second tmrw. i’m kinda scared…though i think i did okay today. yes! i know for sure that i’m not ready for either italian nor physics theory – both of which are next week. but one thing is definite…JUNIOR YEAR IS FUCKING OVER! which means…that i slave away to my growing (not so much) portfolio over the summer, i make pretty, and it comes out like a gorgeous third child hopefully by somewhere in fall/earlyearlyearly winter of senior year. even worse, i still have no idea which college i want to go to, even though i’m open to pretty much anywhere that would take me…COMMUNITY COLLEGE! <3 lmao jpjp. but my mom wants me to go to SYRACUSE <–one of the many SUNYs. it’s upstate, meaning that it’s not in the city (manhattan, etc) but that’s okay. she wants me to major in ecology or something. i want to go into sculpture though, but the major downside would be the difficulty of making a living off of sculpting. apparently, sculpture’s brother (or sister, whatever) architecture is more successful…but the involvement of physics theory! (jesus christ) and the extreme years and tests that i would have to sacrifice to get a degree, etc. totally not my road. so my mom suggested landscape architecture, which would include the design of gardens and public areas, i suppose. which isn’t half bad, because i could throw some of my sculptures in the park and whatnot. diggin’ it oh, and the major in ecology would have some influence on my knowledge in placement of wildlife in the gardens…<–um, okay. i figure that my biology grades would totally fail in majoring in ecology, but if my mother has that kind of hope…whatever. i have three future occupations: 1) sculptor/landscape architect (??) 2) starbucks barista (think about all the coffee on discount! <333 like zomg haha) and 3) HOBO…i think the latter is a win.

and so, i haven’t done that much in the times that have passed…okay so maybe a bit. i’ll try to sum it up in as few words as possible. or even better, another list!

1) went to the YOUTUBE downloaded event in manhattan. loved it. can’t stop bragging about it hahaha. met SMOSH, MICHAEL BUCKLEY, KEVJUMBA, and many others. am now currently following all of them on twitter. /purlywhirls! hook me up…

2) celebrated my birthday with my sister’s friends, because CURLS and SNEEZE ( lol, they’re not my only friends, just closest) were “out of town.” wasn’t bad, as my sister’s friends are pretty awesome. we saw STAR TREK which was also pretty awesome. that was the second time i’d seen it got some nice presents, too (<3)

3) attended the ASTHMA WALK in manhattan (yeah alright, i live in manhattan hahah <–not bragging! just honesty. swear ;D) with my mom and our neighbor. was pretty interesting, except didn’t walk all the way. they’re more lazy than i am, lol

4) just stepped on a thumbtack. it was terrible, hahha.

and so yeah, i think i’ve pretty much covered everything! and as for news to come, i’ve got all those regents coming up (meaning tomorrow and those next week), my cousin’s graduation to attend tomorrow night, my other cousin’s wedding to attend on saturday afternoon, some reading class starting next week, and work (as camp counselor again!) at this horrid camp. so yeah, i’m stock full of shit for the next few months and so. will be constantly updating through twitter, so if i don’t write (love how i’m pretending that people actually read this lolol) follow me on twitter. i feel like i’m forgetting something, can’t remember what…oh well. i’m DONE!

Thursday, October 04, 2007

Hello, gorgeous readers! To begin today’s blog, let’s start with the Mobius Strip. You can make your own! It’s easy! Take a simple strip of paper. Normally, one could fold the strip around to make a ring such that the end corners of the strip would align so:

A__________________C

B__________________D

Just twist one end to create the arrangement

A_____/……………\_____D

B_____/……………\_____C

and make a ring.

If my explanation makes no sense (which it normally will not), Google Mobius Strip. Some genius will make it seem like arts and crafts. In any case, you’ve just made a one-sided object, reader. Make sense? If it doesn’t try drawing a line along the Mobius Strip down the center. You will cover all of it without taking your pencil off the strip or going around an edge. Now, on to business.

I have made a wondeful discovery. It seems farfetched, but it could be the answer to many problems in physics theory. First, consider the Zero Dimension. How does it work? It’s an infinitisimally small point. The reader should be able to recognize a point, and that its expansion to another point creates the First Dimension. First dimensional constructs called lines can be expanded to other lines to create planes. Planes can be expanded to form volumes. Volumes can be expanded to create what we will call “shifts.” And so on. Those are all familiar concepts. Now consider going the other way from the Zero Dimension. That’s right: negative dimensions. I prefer the term “Antispace.”

Much like how negative numbers had to be accepted as the numbers that counterpated positive numbers to produce 0, we should treat Antispace as the form of spacetime that combines with traditional spacetime to produce points (The Zero Dimension). Let’s start small. Consider a line and an antiline. Say that a particle could travel either path. At this moment, the particle will collapse to nothing. Keep in mind that nothing exists. Well, that’s a nice concept, but how do antilines work? They expand on the Zero Dimension, as geometry would tell us, except they are arranged the “other” way. This is called hypersymmetry. The “other” way is clearly impossible to imagine. The reader should view the situation like the Electromagnetic Spectrum, where the are wave mechanicslengths above and below what he or she can see. Now that we’ve established antilines, we can make antiplanes, which have “another” orientation. In fact, for every traditional spacial-temporal dimension, there is a “negative” counterpart. Keep in mind this idea could (and indeed will) involve the other kinds of opposites as well, such that there can be ^-lines, <-lines, >-lines, etc. (C.. 1.) For the best physical example I can give of negative dimensions, consider what you did above with the Mobius Strip. Of course you didn’t travel into “other” space, but you still reduced the sides of the object, similar to reducing dimensionality.

As much as I hate to admit it, PrinceJonathan Pruitt may have mentioned something credible. He once asked in my class about the 2.5 dimension. Everyone laughed, especially since the idea spawned from his playing Viewtiful Joe. I, as well, thought, “Proposterous!” Today I have come to reconsider. A 2.5 dimension is simply the “bending” into the third dimension. While it is true that dimensions are dimensions and are much like integers (Ha! We can say integers now that there are negative dimensions!) in the instances where travel breaks into higher spacetime, the transitions are fractional dimensions. Imagine the 0.5 dimension for a second. Along a 1-dimensional line, we could travel two ways. In the 0.5 dimension, we could travel only one way. Never the other. This leads me to believe the Universe as we see it should be labeled 3.5-D, as we can travel through time, but in only one way.

These ideas open up the field for not only imaginary dimensions, but also ethereal dimensions. As some of you may know, ethereal numbers have the property that when multiplied by 0 they do not equal 0. The first ethereal is u (the Arabic symbol noon, if I could type it). 0 x u = 1. Let’s dive into our memory banks and pull out the old formula F = ma. Say a force of 1 N is applied to a massless object, such as a neutrino. What happens? Typically, we would say it doesn’t move, but by this classic formula, we see that it moves with an acceleration of u. This is into an ethereal dimension, mind you, and since the ethereals behave like 0 in some regards, it appears no acceleration occured.

We now have an interesting model for our Universe. It resembles a giant “cone.” Well, that is if we use only binary oppositivity, but you get the idea. At the center is the Zero Dimension, and from it frow 11 dimensions both ways (or 26, or infinite, depending on you dimensionality theories). When creation of a universe occurs, it inflates both ways. This explains why we don’t see antimatter naturally. It exists in Antispace! We have the power to artificially “oreint” matter to go the “other” way, so as to create antimatter. It is well known that matter and anitmatter obliterate each other upon contact, but what really happens is the return to the Zero Dimension.

Today, we united many new ideas with old ones to give ourselves a reasonable new idea about how our Universe works. If something puzzled you about this blog, post a confused comment or send me a message and I will explain. Until next time, thanks for reading my crazy ideas!

We finally finally finally submitted the paper that describes my thesis research to a journal, so it is now publicly available:

http://arxiv.org/pdf/0906.2983v1

(and totally incomprehensible to non-particle physicists — sorry!).  Notice that on this paper, the writing of which involved a lot of blood sweat and tears on my part, I am not the first author but the 71st!  That’s how it goes in particle physics theory, or at least with the CLEO collaboration.  The CLEO detector actually started taking data the month before I was born  — so this paper is the result of six years of work by me (in collaboration with another graduate student and our advisors) and decades of work by the hundreds of people who have been a part of the CLEO collaboration.

I was very lucky to get to work on this particular study — it’s one of the most important results that the collaboration has produced in the last several years.  The primary purpose was to test a technique called lattice QCD, which is a way of calculating effects of the extremely tricky strong force.  The theorists who use this technique basically assume that the infinite universe is a finite grid of points.  The punchline of our results is summarized in the figure at the top of page 16.  The blue and red points are the experimental data points I spent 6 years producing and the colored band is the Lattice QCD prediction — and they actually agree pretty well!

Another exiting aspect of this submission is that it is the 500th paper submitted by the CLEO collaboration!   That’s more than any other particle physics theory collaboration has ever produced.  Not bad for an experiment that was operated (at least by particle physics theory standards) on a shoe-string budget.

If there is one thing that drives me crazy, it is limitations. Can’t stand ‘em. I’m all about finding the ceiling and punching it ’til a large enough hole forms for me to wriggle through.

Thanks to the new 4×4 wave mechanicsrunner, I now don’t have to decide when I leave the house whether I’ll need my swimsuit when I leave the house because water is now my bitch…

This week’s entry takes a look at the three minds who advanced the science of astronomy and challenged the norms of the day.  This countdown isn’t so much about ranking on a scale, but simply listing them.  I found it difficult separating the three I list today because they all worked off of each other.

Nicolaus Copernicus, Galileo Galilei, Johannes Kepler
Astronomers, Physicists, Mathematicians

Copernicus was the first astronomer to openly challenge the idea of the geocentric universe.  His ideas would be the creation of heliocentric cosmology and is often credited with being the starting point for modern astronomy.  Before Copernicus, Ptolemy’s geocentric model, which has earth in the center with the sun, moon, planets and stars on spheres which surrounded the earth, was widely accepted as truth.  Copernicus’ work would result in much controversy long after his death.

Galileo is credited with improving the telescope (invented by Hans Lippershey) and giving it better optical power.  With this telescope, he observed and discovered four of Jupiter’s moons (Io, Europa, Callisto and Ganymede), which he named after his future patron and his (patron’s) three brothers.  They would be renamed the Galilean Satellites in honor of the man himself.  His Copernican beliefs would eventually land him under house arrest by the church of the time.

(If you would like, I will go further into the astronomical [and astrological] belief system of the day and why many astronomers were arrested by the Church.  I do not feel that this series is the place to discuss religious and political views of the 17th century.  Let me know in your comments.)

Kepler was a German mathematician and astronomer who challenged Galileo’s assertion that planetary orbits were perfect circles.  He did help to verify Galileo’s discoveries with an improved refracting telescope.  Kepler noticed that it was impossible for planetary orbits to be round because of anomolies in their orbits.  At first, under the eye of Tycho Brahe, he reasoned that Mars’ orbit was egg-shaped (with the sun at the center), but all calculations failed.  Then he tried to calculate it as an ellipse, and it worked.  This results in planetary aphelion (furthest distance from the sun) and perihelion (closest distance to the sun).

I admit that I glossed over much of the story here, but I have mentioned the biggest and most prolific discoveries of each astronomer.  All of these men, and others not mentioned are important to next week’s entry in the countdown.  Thanks for stopping by, I hope you’re still interested in learning.