a mash up of two old, bad physics theory jokes. who could ask for anything more, really?

also, i couldn’t figure out how to express indifference with chris in panel 2. i figure “…” is pretty hard to say, but for now they’ll have to deal.

La escala de integración más alta posible para un transistor es utilizar una única molécula. El problema de este tipo de transistores monomoleculares es la presencia de estados cuánticos espurios para la conductancia que penalizan su funcionamiento. Una manera de evitar estos efectos es utilizar contactos superconductores. Investigadores franceses han logrado el primer transistor monomolecular fiable basado en una molécula del fulereno C60 entre dos electrodos de Alumino/Oro cuyo único inconveniente es que funciona a una temperatura por debajo de 1 Kelvin. El artículo técnico es Clemens B. Winkelmann, Nicolas Roch, Wolfgang Wernsdorfer, Vincent Bouchiat, Franck Balestro, “Superconductivity in a single-C60 transistor,” Nature physics theory, Published online 25 October 2009 [versión gratis en ArXiv, que no incluye la información suplementaria disponible aquí].

1.1 Motion

1.1 Motion -worksheets

Kinematics

Speed

Velocity and Acceleration

Distance–Time Graphs

Velocity–Time graphs

The Equations of Motion

Dynamics

Scalars and Vectors (1)

Scalars and Vectors (2)

Dynamics

1.1 Motion -video tutorials

Motion in One Dimension

Motion in Two Dimensions

1.1 Motion -videos

physics theory 2.2.2 – Graphing Distance vs Time

1.1 Motion -animations

Vectors & Scalars

Las clases de complejidad clásicas y cuánticas se relacionan entre sí de una forma complicada que todavía no conocemos en detalle y por ahora todo son hipótesis. Las clases P y BQP son las clases de problemas resolubles de forma eficiente (polinómica) en ordenadores clásicos y cuánticos, resp. Las clases NP y QMA contienen los problemas de decisión que creemos que son más difíciles para ordenadores clásicos y cuánticos, resp., para los que existen algoritmos eficientes, clásicos y cuánticos, resp.,  que permiten decidir si una solución es correcta o no. Un artículo reciente en Nature physics theory ha demostrado que las clases QMA, NP y P colapsarían (serían iguales entre sí), resolviendo la conjetura P versus NP con una igualdad, si se puede resolver de forma eficiente la simulación de sistemas cuánticos descritos por la teoría del funcional densidad (DFT). Por ejemplo, si un modelo concreto, el modelo cuántico de Hubbard, se puede simular en tiempo polinómico. Nadie cree que esto sea posible, pero carecemos de una demostración, todavía. Nos lo cuenta el experto en la teoría de la complejidad cuántica Scott Aaronson, “Computational complexity: Why quantum chemistry is hard,” Nature physics theory 5: 707-708, 2009, haciéndose eco del artículo técnico de Norbert Schuch & Frank Verstraete, “Computational complexity of interacting electrons and fundamental limitations of density functional theory,” Nature physics theory 5: 732-735, 2009.

La clase de complejidad del Protocolo Merlín-Arturo (MA) es la clase de problemas de decisión resolubles por el protocolo siguiente. Merlín tiene  recursos computacionales ilimitados y envía a Arturo una demostración de tamaño polinómico que prueba que la respuesta es “sí.” Arturo puede verificar dicha prueba en la clase BPP (en tiempo polinómico con un algoritmo probabilístico). Si la respuesta es “sí” existe una demostración que Arturo aceptará como correcta con una probabilidad mayor que 2/3 y si la respuesta es “no” todas las demostraciones serán aceptadas por Arturo con una probabilidad menor que 1/3.

La clase de complejidad cuántica del Protocolo Merlín-Arturo (QMA) es la versión cuántica de MA y corresponde a un Merlín que envía una mensaje con una prueba cuántica que Arturo puede verificar en la clase BQP (en tiempo polinómico utilizando un algoritmo cuántico). Si la respuesta es “sí” existe un estado cuántico (demostración) que Arturo aceptará como correcta con una probabilidad mayor que 2/3 y si la respuesta es “no” todos los estados (demostraciones) serán rechazados por Arturo con un probabilidad mayor que 2/3.

El modelo de Hubbard describe un gas de electrones fuertemente acoplados por potenciales de Coulomb en la retícula de un sólido y permite comprender la transición entre un material conductor y uno aislante. La técnica matemática más utilizada para simular este modelo físico es la llamada teoría del funcional densidad (density functional theory). El nuevo artículo demuestra que si dicho problema se puede simular de forma eficiente, las clases de complejidad QMA y P serán iguales. Esto implica un gran avance en dos frentes. Por un lado, en la propia teoría de la complejidad de algoritmos cuánticos. Y por otro lado, impone un límite fundamental a la propia teoría del funcional densidad ya que una demostración de que P =!= NP (lo que todo el mundo cree) implicaría que nunca podremos simular eficientemente problemas “aparentemente” tan sencillos como el modelo de Hubbard incluso utilizando ordenadores cuánticos.

Esto sorprenderá a muchos ya que la mayoría pensaba que la utilidad más importante de los ordenadores cuánticos (cuando los haya) será la simulación de sistemas cuánticos. Pero si un sistema cuántico tan sencillo como el modelo de Hubbard es tan complejo de simular en un ordenador cuántico como en uno clásico, dicha ventaja se cae por su propio peso. Los avances en computación cuántica no cesan y cada día nos sorprenden más a los que somos aficionados a este “arte,” a esta ciencia.

6302603    พอลิเมอร์ฟิสิกส์    Polymer physics theory

บทนำของฟิสิกส์ของพอลิเมอร์ผลึกและอสัณฐาน สมบัติอีลาสติกสมดุลของวัสดุยาง วิสโคอีลาสติก ทรานซิซันของของเหลว-แก้ว สัณฐานวิทยา การตรวจสอบลักษณะและพฤติกรรมเปลี่ยนรูปของพอลิเมอร์ผลึก

(Introduction to the physics theory of amorphous and crystalline polymers. Equilibrium elastic properties of rubbery materials.Viscoelasticity. The liquid-glass nad glass- glass transitions. The morphology, Characterization, and deformation behavior of crystalline polymer.)

(6302603 จุฬาลงกรณ์มหาวิทยาลัย)

Safe and away.

Twice in one day I have heard references to Starfish Prime. First in my plasma physics theory course and second in a paper on electromagnetic resonances in the earth-ionosphere cavity.

So I looked it up.

Starfish Prime was one in a series of high altitude nuclear tests. This particular one was detonated over 400km, well into the ionosphere. The EM pulse wiped out many low earth satellites, it destroyed electronics in nearby Hawaii and lunched a bunch of radioactive particles into space along the earth’s magnetic field lines.

The one good thing it did was introduce a lot of radioactive tracers into the inner radiate belt, thus allowing for the lifetime of particles in the belt to be measured.

Otherwise the thought of high altitude nuclear tests is a bit worrisome.

6302706    พอลิเมอร์ฟิสิกส์ขั้นสูง    Advanced Polymer physics theory

พอลิเมอร์ที่เป็นแฟรคตัล กฎการยกกำลังของพอลิเมอร์ พลศาสตร์พอลิเมอร์ในของเหลวแบบเจือจางและเข้มข้น ทฤษฎีโมเลกุลของสมบัติทางวิทยากระแส ทฤษฎีรีนอเมอไรเซชั่น กรุ๊ป ระบบขนาดนาโนของพอลิเมอร์

(Fractal polymers; scaling law of polymers; polymer dynamics in dilute and non dilute solutions; molecular theories for rheological properties; introduction of renormalization group theory and nanoscale systems of polymer.)

(6302706 จุฬาลงกรณ์มหาวิทยาลัย)

Tomorrow my students have their first midterm. Some of them were thankful to have a practice, some of them- well, not so much. Unfortunately, I’m afraid some of them won’t take the tips and advice that I’ve given to them to heart (I have a few “too cool for school” types). These are actually things that I noticed affect some people near and dear to me or things I’ve learned the hard way.

• Study ahead of time. No brainer, but I’ve seen this happen numerous times
• Do your homework. You just create extra stress by trying to learn things a few days before the exam when you
• Actually do the physics theory problems like you would on the exam. Just looking over doesn’t help matters. You have to actually figure and struggle a little. Watching the teacher do examples is not learning. I find some students think that watching me repeatedly do examples will make things click. It more than likely will not. I probably could do examples until my hand bleeds and I die, and there’s a good chance that they would not learn the topic at hand that well. Note taking, in my opinion, can be passive.
• Sleep well before an exam. Cramming the night before (or period) rarely helps matters and just adds to stress.
• Try not to worry too much after you take the exam. It is literally out of your hands, and you more than likely need some time to recover and work on other schoolwork.
• If you are concerned now about your grades, speak up! I think grades are like financial debt. It is bad when you are in bad places with them, but you cannot do anything about it until you acknowledge that. Also, like credit card companies or loan people, most professors/teachers are willing to work with students and help them figure out what to do and how to improve their grades. However, they aren’t going to be favorable with that if you are doing this last minute.
• Believe you can succeed. Thinking you can’t do something is defeating, because you have already convinced yourself of that. Try to think that you can weather the class/exam.
• There is light at the end of the tunnel. As much as I hope people enjoy school and class, I recognize that people end up taking classes that they don’t like, either because of requirements or because the class turned out differently than expected.
• You have to keep your eye on the proverbial prize. You may hate the class/professor/topic, but you’re in a class and you should at least be concerned about passing so that you don’t lower your GPA/not meet requirements to graduate/etc. At the end of the day, your lack of progress in a class only affects you.
• Be nice to those around you. Professors and teachers like helping people who have a good attitude, not the students who are hostile or apathetic. You don’t have to be genius to be liked by many people; effort and the right attitude means a lot. Even if you don’t love the person, you should definitely be nice. Yelling at them, treating them poorly, etc. is really just unprofessional (would you yell at your boss?) and doesn’t help your case for getting help or advice. No one likes dealing with nasty people.

Does anyone else have tips to succeed at school? I know to some people these sound corny, but I think you have to keep all these things in mind.

2102587 ฟิสิกส์และเทคโนโลยีของสิ่งประดิษฐ์กึ่งสารตัวนำ physics theory And Technology Of Semiconductor Devices

เทคโนโลยีการผลิตไอซี การปลูกผลึก การสร้างชั้นอิพิแทกซีในเฟสของไอ การสร้างชั้นอิพิแทกซีในเฟสของเหลว การสร้างชั้นอิพิแทกซีด้วยลำโมเลกุล การสร้างชั้นออกไซค์ด้วยความร้อน การแพร่ซึมในสภาพของแข็ง อิออน อิมพลานเตชัน การทำขั้วโลหะ การถ่ายแบบ ฟิสิกส์สารกึ่งตัวนำ สภาพไม่สมดุล การฉีดพาหะ ทฤษฎีผิวของสารกึ่งตัวนำ คุณสมบัติของระบบซิลิกอน ซิลิกอนไดออกไซค์

(Integrated circuit fabrication technology: crystal growth, vapor phase epitaxy, liquid phase epitaxy, molecular beam epitaxy, thermal oxidation, solid-state diffusion, ion implantation, metallization, lithography,etc; semiconductor)

(2102587 จุฬาลงกรณ์มหาวิทยาลัย)

It is nearly impossibly to discuss theoretical physics theory without talking about Quantum Theory. Almost any book tackling the subject of string theory (aka the theory of everything) relies on the pillar of Quantum Theory.

What is Locality?

It struck me today that the most fascinating and strangest things about quantum particles is they totally ignore locality. To understand locality first think about another ‘ity’: Causality. Causality is basically the relationship between cause and effect. You know the famous saying, “Every action has an equal and opposite reaction.” Causality is practically pre-wired into our brains. Anything that defies causality defies logic. In other words how can something happen and there not be a consequence. Or even the other way around, how can there be a consequence with seemingly no cause?

Locality takes the relationship of cause and effect one step further. If you want to push a ball down a hill, you need to physically push it. If you don’t push it, the ball has no reason for rolling down the hill. Just wanting the ball to roll down the hill isn’t going to do anything. So you go over to the ball and you push it and you get your desired result. This is the essence of locality. In order for something to happen you have to cause it to happen locally. To cause that something to happen you have to physically cause it to happen. However long it takes you to get to the ball and push it is how fast you caused the ball to start rolling down the hill. Now, lets take this a step further.

Say for arguments sake that you’ve gained the ability move at the speed of light. If you wanted to then you could cause something to happen almost instantly. Using the example above, if you want the ball to roll down the hill you still have to push it; however, since you move at the speed of light, it takes you very little time to get to the ball and push it. The key idea here…is even though you all of a sudden have the tremendous ability to move at the speed of light you still don’t ignore locality. In other words “so what”, you move at the speed of light..that doesn’t mean you don’t have to physically be there to start the reaction.

So it’s logical to come to the conclusion that: In order to cause something to happen extraordinarily far away, it will take you an increasingly extraordinary amount of time (based on how far it is) to cause it to happen.

Defying Locality.

Well that is exactly the opposite of the way quantum particles work. Say for example you have a quantum particle. Particle XY. Particle XY is infinitesimally small and has certain ‘properties’. Another interesting thing about Particle XY is it has a sort of ‘twin’ particle. Say it’s called Particle YX. The names of the particles and the properties for the moment don’t matter. What does matter is that these two particles are on the opposite side of the universe! Say Particle XY has a color property that can change. What would happen to Particle YX when Particle XY changed to the color blue? Locality would logically tell us nothing would happen..why would a particle on the other side of the universe change colors? Well as strange and ’spooky’ (as someone quite famous put it) as it may seem, that is exactly what happens. Particle XY changes color so billions of light years away Particle YX also changes color instantaneously. How is that possible? Is there some underlying connection between these two particles?

Let’s delve one more step (I promise) deeper! If things seem strange already, it’s about to get much much stranger. The only reason Particle XY changed color is because we looked at it. Particle XY is minding it’s own business. It has a color property and it can be either blue or red, BUT it hasn’t chosen a color yet. And it might never choose! All of a sudden we observe Particle XY. It immediately chooses a color, blue in this example, and on the other side of the universe Particle YX changes it’s color to blue as well. So let’s summarize what we have right now.

Make sense?

Particle XY can change its color to blue or red. It won’t pick which color it wants to be until we look at it. Once we look at it, it chooses to be blue and it’s twin Particle YX, on the other side of the universe, copies it and also changes to the color blue.

If you’ve followed this far you must think I’ve either made this up, or accidentally mixed my science fiction reading with my theoretical physics theory reading. Well neither is true and in fact, the way these imaginary particles behave in my example is precisely how quantum particles behave in the real world.

Quantum particles defy locality. No matter how far apart two ‘associated’ quantum particles are, they can effect each other immediately with no regards to locality.

Prove it!

Firstly, particles have a property called ’spin’. A particle can spin about an axis in either clockwise or counter-clockwise motion. This is scientifically proven. It is possible to measure this spin and direction with something called a detector.

Imagine for sake of explaining this that you have 1 billion particles (I chose an extremely large number to prove a point statistically, it could be any large number). Split the particles in half and number them.

Now each of these ’sets’ of particles came from the same place (actually they all came from the same place). You have an atom and when this atom loses energy it releases two photons (the circles in the picture above). One of the photons goes left and the other goes right. Now we set up two detectors. The detectors can detect one of three axes and the direction of motion along only that axis. (Don’t worry about why they can only detect one axis, it’s far too involved and doesn’t truly have any effect on understanding this concept)

Here’s where you need to pay attention. It’s okay if you don’t get it the first time, it took me a while to grasp this, and then even longer to simplify it into a blog post.

If the particles were truly random than below is what you would expect to see after significant trials.

Each particle, in this example, shows motion in one direction 1/3rd of the time, and motion in the other direction the other 2/3rds of the time. So this means:

Five times out of Nine the detectors should both show the same result. Regardless of which axis they were detecting.

Guess what…yup you guessed it. This is not what would happen at all if you were to actually run this experiment. In fact, and this has been reproduced in labs numerous times, the detectors agree far less than that. They actually agree 1/2 the time.

So if we expect the detectors to agree 5 out of 9 times and they only agree half the time, what happened?

The problem is we expected the results to be totally random. We expected that the particle going to Detector 1 would have one result totally different and independent than that of particle two. What actually happens is half the time one detector picks up motion on an axis in clockwise direction so the other detector regardless of randomness detects the same direction on that axis! It’s almost as if the first particle faster than the speed of light changed what the second particle would ’show’.

I’m confused, but let’s sum it up…

Our universe is non-local. On the quantum scale particles can effect other particles. This happens when the particles are what is called “entangled”. The entire universe is comprised of these entangled particles.

I’m not expecting everyone to walk away from this experiment asking the same questions I did after reading about this conclusion. However, if this got you thinking at all..explore these ideas further and keep an open mind.

Sometimes our brains are simply wired to understand and accept things a certain way because that’s how we visualize and conceive them; however, that’s not always the truth.

The above is a summary of the well known and studied theory and experiment proposed by John Bell in 1964. I’ve aquired expansive knowledge in reading books by numerous physicists/authors including Brian Greene, Steven Hawking, Michio Kaku and Leonard Susskind. If you find this stuff interesting and want to read more-polished- work, I suggest picking up a copy of any of the numerous books written by each of these men.