Pure Definition and 499 Threads

This is how one poster tried to explain it to me but for people who have only taken a basic physics course in college it leaves a lot wanting. "If a system is in a pure state, and you know what the pure state is, then your knowledge of the system is complete, and all uncertainty is quantum...

Homework Statement Suppose a wheel with radius R is resting on a non-inclined surface. A torque \tau is applied to the wheel center. In an attempt to prevent wheel from spinning, the ground applies a static friction force to the wheel at the contact point (parallel to the surface), then the...

Hi everyone! Thank you clicking on this thread. I am a community college student seeking to transfer by the end of this upcoming spring semester. I plan to major in math; my main goal is to become a high school teacher or community college professor. Only recently did I find out that...

Hi! This is my first post in this forum, hopefully I will get some guidance :) Long story short, I am pretty much set in doing a double major in Chemistry and Mathematics. The thing is, I'm really having trouble choosing between Applied Maths and Pure Maths major. I have completed my...

I have been in state of confusion in choosing one out of these. Since I am more interested in learning the basic phenomenons and understanding why and how nature works I get distracted from the engineering course in electronics which I am currently into. Early as high-school students I loved...

Let's say you prepare a pure state in a single electron at a time double slit experiment meaning the electron interferes with itself, then you hit the electron with a one photon at the sides (serving as environment) causing decoherence, so the double slit setup decohere and becomes mixed state...

Is there a way to write p1 |v1> + p2 |v2> if it is not a pure state but a mixture? thanks.

Hello, How can one go about acquiring an effect of soundlessness on the brain? For example, as earplugs are to hearing capacity, the affect would be on the mind and brain.

Greetings Physics formus, I am a high school learner currently in my final year of schooling. I have decided that pursuing a double major in math and computer science would be a good option for my tertiary studies, as, my passion lies in the Mathematical Sciences. However, I have not decided on...

So, as I have stopped focusing on physics and shifted over to math I've found myself much more motivated, happier, and relaxed. Furthermore, I am much better at it. I have not taken any math classes that have been as difficult as the basic E&M physics classes (for me). I have made such a...

Hi folks, I just have a question concerning whether it is possible to produce an ensemble of individual electrons in pure single-particle spin states. I'm assuming it is possible, but sometimes one hears that strictly speaking all electrons are entangled with one another, which would mean...

Main reason why semiconductor is used and not a "pure" metal for detec Hi, I have question regarding why semiconductor is preferred in the field of radiation detection. I have read that they can be doped and their conductivity can be manipulated, but I can't see why this is not possible...

I do not know if this question relates to this division and would appreciate if it would be moved to proper division. I want to buy a piece of fine, pure, highly doped semiconductor with dimensions approximately: 7 cm X 7 cm X 1 cm (2 in. X 2 in. X 1/2 in.) It supposed to be just fine and...

Hey guys, I was reading about thermal states and now I have a doubt: is a thermal state always a mixed state with density matrix ρ=exp(-βH)/Tr(exp(-βH)), or is there also a pure thermal state? Thank you

Hi, I love the cognitive sciences. Indeed, for the last few years, what's been motivating me to work hard in school has been almost exclusively my dream to lead a life deeply mired in the mysteries of the mind/brain. I haven't gone a waking hour in an extremely long time when I haven't thought...

I have recently completed my first year of Eng. Physics taking the standard math courses: Calculus, Linear Algebra 1 and 2, Multivariable Calculus and Numerical Analysis. Recently though I have been self studying Rudin's "Principles of Mathematical Analysis"/Abbott on my own and I enjoy this...

Hi ! Here is the article I'm talking about: link tl;dr - Positrons are created from colliding photons head on . I am looking for other research that supports this direct translation of Energy --> Matter . It doesn't necesarrly have to be labrotory tested, could be theoretical as well ...

I need some advice, I've just finished my 2nd year at UCL studying the Bsc in mathematics. I've so far really enjoyed my course and I'm hoping to go on to do a phd somewhere. Now, like everyone else, I want to go to the best place possible. So far, my grades are fairly good, every exam...

Homework Statement Two cyclists are in a race. One cyclist knows that he is slower, so he cheats: he removes the faster cyclist’s bike chain. The cheater starts from rest immediately with acceleration 2.5 m/s2. The faster cyclist has to take 3 seconds to replace her bike chain. She then...

I will become a professor regardless of what major i choose except for maybe engineering. My major will be either ChE, Pure math or Physics. I am currently taking the prequisites for all of these majors so i can change at anytime. With pure math it may be hard to compete for a position against...

Consider a hypothetical particle with no mass (like a neutrino or photon, in that sense), but with pure charge. Consider this pure charge being accelerated in an electric field. Is there any meaning in associating kinetic energy to this charge as it accelerates to a region of lower...

Homework Statement A solid sphere of radius R is given a translation velocity vo on a rough surface of coefficient of kinetic friction=coefficient of static friction=μ. After what time does the sphere begin pure rolling? Also find the the angular velocity and linear velocity of the sphere at...

http://arxiv.org/abs/1306.4035 Graviton scattering amplitudes and Pure Connection Formulation of GR Gianluca Delfino (Submitted on 17 Jun 2013) We show how the recently introduced "Pure Connection Formulation" of gravity provides a natural framework for approaching the problem of computing...

What's the Difference B/n Applied vs. "Pure" Maths? Hello. I'm a soon-to-be new university student and am taking this summer to learn all I can about various subjects, majors, and career opportunities. I've been reading up a little bit this week on math majors and have come across what...

I'm in my last year of school and starting a mathematics degree at a British university this Autumn. I've always liked mathematics, especially 'pure' side of mathematics. I love poofs and always enjoyed solving puzzles and brainteasers for fun. Some of my favourite topics of maths are geometry...

Are systems ever in a pure quantum mechanical state? If they are, is it possible to know the precise pure QM state? The example I am thinking of is the spin of an electron. If we measure the spin about the "z-axis" and find the result to be "up" then we say the electron is in the pure state...

Hi everyone, I have the option to take a vector calculus class at my uni but I have received conflicting opinions from various professors about this class's use in pure math (my major emphasis). I was wondering what others thought about the issue. I appreciate any advice.

Hi! Let's say in mathematica I declare this function t[x_,y_]:= (x'[s]+y'[s])^2 Now I can call it with L=1; t[(#^2)+L &, (#^3)+L &] if I call it this way it will remplace the # with s and evalute the derivative. Now let's say I wana do this for for every L from 1 to 10. so i got...

The best instate college in my state for mathematics is Georgia Tech. However, it does not have a pure mathematics degree. Can I still go to grad school for pure mathematics as an applied math major? Will it prepare me for pure mathematics?

Homework Statement a) A pure resistance and a pure inductance are connected in series across a 100 V(rms) AC line. An AC voltmeter gives the same reading when connected across either the R or the L. What does it read? (Note: Meters read rms values.) b) The magnitudes of R and L are...

Hello Wizards! I need to produce specially pure iron shapes for a research project. As you may know, pure iron is hard to find. Small pure iron bars are the easiest. Is it possible to melt and cast these small pure iron bars into other shapes, without the iron losing its...

Homework Statement Finding shear in terms of r My problem, is that i want t o find the shear force and if i want take a section , i need to know the reactions, but i can't find the value of reaction in terms of r I attached the problem (look at A) and my solution(in which i wasn't able to...

suppose a rigid ball roll on a rigid level with constant velocity , the friction on the contact surface decrease the forward velocity but increase angular velocity , how do you explain this paradox?

suppose a rigid ball have pure rolling with constant velocity on rigid level without friction , is it possible ?

Hello again PF, I now need to decide whether to pursue an engineering physics or pure physics degree for my undergrad, I've been accepted to both, but am unsure what would be the better fit for me. I obviously like the extra job security that an engineering degree would carry with it, but I'm...

what do we mean by "pure gravity" 1-what we mean by "pure gravity" and "gravity coupled to matter"? 2- why pure gravity characterized by c=0 (c: central charge), and what is the conceptual meaning of central charge regards

I am interested in being a cryptographer after college. I want to get a double major in pure mathematics and computer science with a minor in two foreign languages (I'm thinking french and russian). After I get my graduate degree I plan to go to graduate school to get a masters degree in...

hi what is a pure quantum state and a mixed quantum state? I looked up the internet but I did not quite understand. For pure quantum state I have read that they can't be written down as a mixture of other states? are entangled states pure states?

Homework Statement Show that \int_{\gamma}\ f^*(z)\ f'(z)\ dz is a pure imaginary for any piecewise smooth closed curve \gamma and any C^1 function f whose domain contains an open set containing the image of \gamma 2. The attempt at a solution I have tried to approach it from some...

I was not too sure what to title this but I just skimmed through a thread with the same title so I just used this. I am not sure whether to go into math or physics. I would prefer math but how will I ever know if I "know" something. This is a troubling thought that discourages me from math. On a...

I am currently stuck between the two choices. I have to pick my majors soon, as I am going to third year. I originally wanted to go into theoretical physics, but now I am leaning more towards theoretical Computer Science. I have always loved Physics, but I am just more at home in Computer...

Hi all, I am new to this forum =) I did physics and now I'm planning to apply for graduate studies in pure maths. I know it's relatively easier the other way (maths to physics). I never had any proof-based mathematics courses but I've been reading pure maths books (such as books of...

Hi I am a physics major and I am trying to double major in math,I will be taking a differential equations course for pure math students this semester. I need advice on a good textbook in Differential Equations for pure mathematicians that will build up a great intuition for proofs and will have...

Hi all, This post will be long, but I hope in giving more relevant information, the replies will be more helpful. Apologies for the length, and thanks for reading, given now. I'll state the question here though to avoid you having to search for it: Does it make any real difference whether...

Do you know Good undergrad schools for Pure math and/or physics theory? Please Help. Hunting for colleges, I'm a definite pure math or theoretical physics major. To give you an idea of my academic standing: MIT would be a stretch, U Penn is a mid reach, Brown is a low reach, Northeastern is a...

Like the title says, I'm curious why sine waves are often referred to as "natural" or "pure" oscillations. Why not some other oscillating function? As an example of the type of idea I'm referring to, the wikipedia "Sine Wave" article says: To me, the argument that it sounds pure because...

Is it correct to say that as photons have no mass they are pure energy and have no mass equivalent according to E=mc^2? In a particle collision involving photons, conservation of momentum can not be used as photons are mass-less. Is that also correct? A proton in a linear accelerator can...

I want to get my undergraduate in Pure math (I've taken and will take some additional CS courses). My question is, would I still be a competitive candidate for a PhD program in computational biology? (mathematical modelling of biological/behavioral/social systems) or should I really get my...

Assuming I finish my study with a BSc or MSc, what are your ideas on the best way to move into more pure maths? I was thinking that getting employed by a company and working out a way for them to pay for it would be good idea, but even so which courses are probably the best? Would I have to...

Beer´s law does not apply if there is any scattering. In a pure absorber, if 1 layer absorbs 50 % of incident light and scatters 0 % then 2 consecutive layers transmit 25 % of light and absorb 75 %. And so on exponentially. 9 layers of pure absorbers would transmit 0,195% and absorb 99,8 %...