Important Definition and 506 Threads

So I'm taking quantum mechanics and I'm within the threshold of getting an A in the class. My professor assigned a problem set that we can either do for extra credit OR for honors in the class. Most "honors" physics classes at my university are kinda a joke in that they just require you...

I am really not all that intelligent and fairly new to the whole mathematical equation solving thing. So please bare with me, I came to the conclusion instead of reading the daily paper I will read daily articles, as I am reading I am unfamiliar of course with the symbols being undefined in the...

When reading tips on various websites of how to "study physics" I always see they bring up exercise as being one of the key things to success. But, is it really that integral to one's success? I'm quite skinny and frail, and I've noticed most of my professors and other classmates aren't in shape...

Guys, i would be really greatfull if someone help me with this because i really don't know how to deal with this math problem: Find the maximum and minimum values of f = x^(1/4) + y^(1/3) on the boundary of g = 4*x+ 6*y = 720. Please help me someone, i am desperate from this :(

hello all, I'm a physics major who's finishing up my second year as a physics major. I'm finishing up the 3 introductory physics course sequence and also the 4-semesters of calculus courses. In my community college, I was able to rank 1st on my physics courses and in the top 5 of my math...

hello everyone. I'm trying to plan my courses for next year, and I figured that I have room to take a foreign class (plus it's a requirement for me to graduate). now, I'm trying to decide to which one to take. i really want to learn mandarin, if nothing else matters, that is what I would...

Hey PF, I'm in a bit of a tight spot with respect to classes next year, and essentially I have to choose between: 1) Taking Statistical mechanics in fall, then abstract algebra I in spring (then representation theory in junior year spring) 2) Taking abstract 1 in fall, representation theory...

Creativity? Math Intellect? Other?

yeah, sort of, but I am unsure. So Is that possible, that supernova explosion of a star will cause another ray of fast moving stuff like photons, which is focused, so it has damaging effects far away from the stellar system? like for example there re at least 1000 of such stellar systems...

First, let me apologize for my bad English, it's not my native language. Most areas of math for me aren't really an issue. I'm actually quite good at it. But there's one thing I absolutely despise and also something I'm very bad at: geometry. I was planning on studying theoretical physics...

Is LISA the only option in detecting gravitational waves? Anyone have some insider info on the talks about cancelling, going with smaller scales, or just a general update on the situation? What else could LISA do other than observe that gravity waves are actually present? and what would it...

Dear Forum, let's consider a certain load. The load has its own internal structure (resistors, capacitors, etc...). I would think that to give the load the most power, we need to provide the load terminals with the largest voltage. The current in the load will then be a consequence. Power...

Hi, I know that (at least I have been told by advisers at my school so weather it's true or not idk) that if you sat in your room and hibernated and studied nonstop every single day and had a 4.0 but some other person didn't have as high of a average but did other stuff that they would select...

I've seen and heard some scary things when it comes to graduate school applications and for all I know, these could be complete rubbish. On the off chance that these claims are indeed correct, I'd like to know. In general, when a physics/math department is looking at applicant profiles, how...

Which paper or papers do you think will contribute most to future research in Loop-and-allied quantum gravity? Since the poll is multiple choice, it's possible to vote for several papers. Abstract summaries follow in the next post. http://arxiv.org/abs/1112.6391 Curvature invariants...

Alright, I know I'm kind of shaky when it comes to proving elementary things rigorously. I'm looking for for the most elementary (in the sense of using least possible mathematical knowledge) proof that x < \tan x, {} {} \forall \frac{\pi}{2}>x>0 Geometrically ? I can't prove...

http://www.theregister.co.uk/2011/09/22/cern_coverity/"]CERN's[/PLAIN] boson hunters tackle big data bug infestation It's the software or the science that's been wrong One's analysis when processing experimental data must account for possible errors in the tools used to identify and detect...

I am trying to find authority that the gap between the turbine wheel and the housing is important to the performance the turbocharger will be able to add to a diesel engine.

How the distance between upper and bottom wishbone is important. I design 3D model of tilt light car and I have problem with 3d model because I can't place the top front wishbone high. In technical view and dynamic aspect, what's happen if I place the top front wishbone lower, decrease its width...

Hi everyone, So, I'm currently in my second year (undergrad) of university studying nanoscience/physics in Canada. I try to think about my future career fairly often, so that I can do my best to make good decisions. However, I'm beginning to get the feeling that I'm not truly "mastering" the...

Hello every body .. What Is Heat Run Test??

Question on torque(center of mass being important I think) Homework Statement I have a lab report due tomorrow, and I have it all done except one calculation, but it confuses me. The center of mass on my meter stick on a stand is 50.1 cm, or .501 meters. For part B, we changed the...

I've heard it said that 'we don't really understand turbulence', and that it is one of the biggest outstanding problems in classical physics right now. (Or at least Feynman thought so back in his day) But what is there to understand about turbulence and why don't we understand it? I thought...

As far as I understand plutonium production is mainly a function of the spesific burn-up. A low burn-up of under 1000 MWd/tU is preferred to produce weapongs-grade plutonium. The higher the burn-up the more pu-240 and other plutonium isotopes that makes production of weapons a bit more difficult...

I know very little about history and other social sciences/humanities and I intend on learning more about these. Initially, I was going to approach this by reading into anything that interests me. This is proving to be a little hard because I know next to nothing about what's happened! :$...

Homework Statement Find the equation in the general form of the sphere described: Center (1,4,-3) radius square root of 26. Homework Equations None The Attempt at a Solution Well I need to find the center of the sphere to be able to right the equation. Given the radius, which...

What maths topics, eg calculus, trigonometry etc, are important for EE? Thanks AL

My son, a high school senior, is on the verge of applying to college. The potential problem we are encountering is that he thinks he'll want to study astrophysics, but his top college choices are mostly small, liberal arts schools that offer neither astronomy or astrophysics as a major. And...

Above all, the most important thing in science, the thing that gets everything started is asking the RIGHT questions. Isaac Newton did this better than anyone. For example: asking what cheese is the moon made of and then conducting experiments to determine if it was Swiss, American or...

I'm currently studying transistor amplifiers and It is not entirely clear how impedance relates to amplification. For the emitter follower configuration, the book I'm reading implies that low output impedance means high voltage gain and, for any amplifier in general, high input impedance is...

I've been reading Mechanics of Landau Lifgarbagez. They state that "not all integrals of motion are of equal importance", and that "there are some whose constancy is of profound importance"...these ones are conserved for the motion. What confuses me is that I thought that's what an integral of...

How important is it for a physicist have an understanding of analysis?

Why is frequency response an important characteristic of an amplifier? in this situation we are using a transistor and had to calculate gain using specified frequencies and the resulting voltages through our circuit. My understanding of contemporary electronics is not as strong as i...

This is a matter of life and bruising. (The official website(s) are no help, since there's an official one for each camp.)

Hi, I am currently applying to graduate school. My list right now contains all of the top schools for condensed matter and a few "safer" schools but I am wondering if I should try to expand my list further. In undergrad, I attended a middle ranked university, and graduated dual Physics and...

Homework Statement In a friction lab to determine the static and kinetic coefficient of friction, there is a block on a flat slope attached to a string which pulled down by a hanging mass. The lab question is: Why is it important to make sure that the string attached to the block is level...

Of the twenty candidates, please choose those you think will prove most significant for future research in Loop-and-allied quantum gravity. Since the poll is multiple choice, it's possible to vote for several papers. Abstract summaries follow in the next post. http://arxiv.org/abs/1109.6538...

I'm a third year physics student interested in grad school. My marks are ok (85% average), and I should be able to get a letter of reference for grad school based on a 4th year Honours project. How important is a summer research position to a grad school application? I can probably get a...

Why normal subgroups are very important in group theory? what's so good about them? I know that normality plays an important role in defining a simple operation on co-sets of a group and it also plays an important role in defining the quotient group, but what I'm curious to know is the history...

Hi, what do you think are the most important Feynman diagrams (or probably better: what do you think are the most important processes in particle physics)? Thanks, Quantum Cosmo

My professor highly recommended to us that we take a technical writing course because apparently it looks really good on the resumes. What is your opinion on this? This applies for any Electrical/Electronics Engineers/Technicians.

Entanglement – the order of measurements can be important. I try now with some formulas - hope it's reasonably understandable: First known substance - unless I am floundering in it: I imagine that the p - photons is measured first (p1) and meets a PBS (0) (x = horizontal and y = vertical)...

Do the employers care about the bachelor? For example if two persons, one with applied mathematics bachelor's and other with physics bachelor's, both have the same master's, can they get the same jobs? I'm asking this because people with bachelor's in applied mathematics usually get hired for...

Hi folks :smile: I have an experiment in which I take an image of a flame. I then run a software routine that tells me what the concentrations of OH (hydroxyl) is at different heights above the flame. I first have to give it a calibrated image of a flame with known data and it then is able...

Hi, I'm trying to make a list of Physics problems that were "the problem" of their day. I want things like the precession of the perihelion of Mercury or the anomalous magnetic moment of the electron. I'd appreciate it if you could name and briefly describe any interesting problems that were...

And what's considered modern mathematics? I always thought it was 1960s+. Around 50 years ago till now is what i considered modern math. Anyway, how important is topology? I've heard people say "the idea of evolution to biology is the same as the ideas of topology to mathematics." So is it...

I'm totally confused...i don't understand conic sections. Why do these curves so special? They are described as results of a cone cut by a plane and the equations are constructed from the distances from a point and directrix. We find evidence of these curves everywhere-in projectiles, in...

If you follow some of my posts, you probably already know that I am a big advocate of Bell's Theorem. I thought I would share a little exercise that shows another aspect of why it is important. Deposited today in the preprint archive was the following article: Waves, Particles, and...

We get a lot of questions on PF as to "what happens when you vary foo". I'd like to talk a bit why it's important to specify what you're holding constant when you "vary foo", by referencing elementary partial differential equations. I realize that this approach might not reach the maximum...

I would challenge the tradition of viewing Bohr as the most important quantum physicist. I think all of the modern physics, in a nutshell, is "relativistic quantum field theory". Thus, we need to choose between two people: the author of Lagrangian formulation OR the author of Hamiltonian one...