Knowledge Definition and 383 Threads

Are two electrons identical in every way? I think that's what we know so far, but is there any research that proves/doubts this or any reason to expect why it should or should not be the case? I ask because no two things in (the macroscopic) world are absolutely identical, and so I wonder if...

I have been advised that the questions that I ask in another thread in the Chemistry Forum may be better assessed by those who frequent the General Physics Forum. I would be much obliged if you could take a look at the following link, and provide any thoughts, feedback, ideas that you may...

If this is the wrong place for these sorts of musings, I greatly apologize and I would be profoundly obliged if someone could point me in the right direction. Otherwise, on with the question. I have repeatedly heard it said that the number of chemical species and, by extension, the...

How well do you know your dictator literature? Test yourself by matching the literary sample to the dictator that authored it: A. Saddam Hussein B. Kim Jong Il C. Ayatollah Ruhollah Khomeini D. Muammar al-Qaddafi E. Joseph Stalin #1 #2 (edited to eliminate giving away the...

Interesting physics relative velocity problem with some trigonometry mixed in. Homework Statement Agent 007 has just stolen some blueprints from Dr. No, whose henchmen are now in vigorous pursuit of Mr. Bond. He sees his best chance of escape: a wooden boxcar. In a moment, James is in...

I see more and more that any professor or REU program wants one of three skills: programming (which I am in the process of obtaining), fabrication/machining/welding(which I know very well), or electronics knowledge, the latter which I do not have and have no idea even where to start. I know...

I want to one day become a Engineer but I also want to have the level of in depth knowledge about theoretical physics that a physicist would have I have applied to University and have so far been accepted for Medical Physics,(Ryerson) Electrical Engineering, (Ryerson) Space Engineering, (York)...

Homework Statement I want to create a structure that will hold information about the below environment,a knowledge base.So I'm trying to define predicates to encode every state of the problem; some of them will be atemporal predicates, which don't change as time progresses, and some will be...

hi, i have only basic knowledge of number theory, but would like to know a hell lot, like maths major level or something(especially about fractals). is there any good site where i could? and please don't suggest wikipedia.

I've been thinking... I don't know that much mathematics. I'm just saying. It seems to me that nowadays, every branch of mathematics has been accounted for. Forming a basis are things like geometry, topology, algebra, analysis, etc. Then you mix all these together and you come up with...

I want to know about the thresholds of particles observed when colliding two matter particles together in fermilab or CERN i.e the pion production threshold is 290 MeV, what other thresholds are there? What is the complete list of thresholds according to the energy provided? "Is there a...

Reading around the subject, I get the impression that it is impossible to have full knowledge of the polarisation angle of a photon. For example is a linearly polarised photon passes through a vertical polariser it is said to be "vertically polarised" on exiting the polariser, but in fact all we...

Homework Statement hi guys here are some MCQ on current ... my questions are also in the pic please help

I'm a physics undergrad and doing some undergrad study on QFT, and I found that Lie algebra is often invoked in texts, so I decide to take a Lie algebra this sem but I've not taken any abstract algebra course before.The first day's class really beats me because the lecturer used many concepts...

These days, it seems that we all rely on trial and error in order to predict the biochemical reactions of new drugs (say, we want a drug to be a ligand, but we have to rely on trial and error to predict whether or not it will actually fit - plus - we also need trial and error to determine the...

Hello, this is my first post. Anyway, when I was in high school I did not have my priorities in order so I missed out on my math education. About a year ago or more, I started reading a brief history of time. Now today I have read all the hawking books as well as several that covered...

At one point, biology helped physics unravel the conservation of energy. I believe the same will be true for nanotechnology. My prediction: as nano-engineers constantly push to control over atomic level of nature, it will help unravel certain traits and behaviors of atoms...and thus aid...

I am now a third grade undergraduate student. I do fair job in my studies. Now I have been in a theorectical condensed matter group in my university to learn how to do researches. But after a whole year, I still find that when I want to run into a topic, say Berry phase, or higgs mechanism, I...

I’m planning on going back to college and I need to take the following math course in a month and a half when the new Spring semester begins: MATH 150 Calculus with Analytic Geometry I Limits, continuity, differentiation and integration of elementary functions and trigonometric functions...

Now I'll be the first to admit I understand, for all practical purposes, close to nothing of theoretical physics. But I came across an article on "phys org" titled "Scientists Glimpse Universe Before Big Bang"(http://www.physorg.com/news/2010-11-scientists-glimpse-universe-big.html). Now from...

[Edit by Ivan: Discussion moved from another thread] This thread has been dead for almost a year. Not to sound too harsh, but your "knowing they exist" is no different to me "knowing they don't exist". Do you have evidence to back up your claims or do we have to take your word? It's...

Hello, This is my first post and if anyone can direct me to any links that would help I would appreciate it, but I'm having trouble understanding this on my own. I am developing a game with a physics engine and the scope I have in mind would require these calculations. I understand some of...

Hi, i have just started studying quantum computing. i found it very interesting and i was wondering to dedicate my thesis on it...BUT...i suffer a lack of knowledge about classical computing devices (i'm not talking about the classic works on logic by Turing and Church and so forth)...so..can...

Sorry, latex is being weird. I'm currently trying to come up with a way to find an equation that satisfies: s=\int_a^b \sqrt{(f'[x])^2+1} \, dx Which is arc length and G=\int_a^b f[x] \, dx which is area under the curve where A and s are known values, and f[a]=A, f[b]=B...

I have looked at the faculty of many Biomedical Engineering programs, and I have noticed that there are many professors that do research in like, Biomaterials, Tissue Engineering, Biomechanics.. stuff like that.. But they have degrees in things like Biophysics and physics, Chemistry and...

Hi, in mid-terms when I have to hand exercices weekly and have to prepare for examns (in Physics), I often feel overwhelmed by the amount of information. Very often when I go to a lecture I don't feel motivated because I am a couple of lectures behind. I really hate skipping things or scanning...

What exactly does this mean? I have a paper due in Biology, where I had to read a research paper on Clathrin Coated Vesicles and answer some questions. Well that was kind of easy, until I got to the end and it asked "How do the findings in this paper contribute to the scientific body of...

This is not really a homework/textbook/coursework problem. It's something I ran into while studying physics, and I haven't been able to solve it. The rules seem to say that this is the correct forum for something like this, but I can't be certain. If this is misplaced, please move it to the...

hello people i would like to say that i am just 18 years old i am from greece i was always really interested in physics but unfortunately my school didnt give us the knowldges we should have i really love physics and especially quantum physic so i know the basics but i would love to earn more...

I am interested in building replacements for every single body part and bodily function, (with a sort of non biological replacement, more electrical and mechanical.) in order to support the brain. I know that the brain is the least understood body part, but my wonder is just how understood is...

I'm currently an undergraduate who has just completed a year of physical chemistry. I don't feel like I understand quantum mechanics as well as I could. It's probably because my knowledge of classical mechanics stops at basic Newtonian mechanics. I don't know E&M that well either. I would like...

A friend of mine (an old man in his 70's) watched the History Channel shows on The Universe and the Big Bang Theory and all that and asked me - "so what if the universe started with a big bang? what good does it do me by knowing this fact? why worry about all this stuff in the universe when...

Hi, I am going to be starting to teach the IB Physics program in a few months so wanted to get up to speed on it. What is the level of knowledge required? I am currently teaching the physics syllabus in the irish system. The practicals that are to be done? How many should be done? is there...

Homework Statement [PLAIN]http://img411.imageshack.us/img411/4412/sssa.jpg Homework Equations The Attempt at a Solution Actually I have very basic knowledge of university physics and math, so the only things I've done are calculating Hamilton equations (I hope correctly)...

After all, many of you have probably read/experienced dozens of books/papers/articles about many subjects. Not just science, but social science, whatever cultures you happen to be interested in, and the communities you grew up in. And of course, most people you talk to will only appreciate your...

Here are some physics quizzes I just made if people are into that: http://www.sporcle.com/games/Maverick197/branches_of_physics http://www.sporcle.com/games/Maverick197/defunct_theories_in_physics

metaphorical line between "knowledge" and "belief"? where do you draw the metaphorical line between "knowledge" and "belief"? and is there even a difference? Even the best of our scientific knowledge is a series of assumptions based on our observations of our tiny fraction of the universe...

I confused how memetics works.. Could you share your knowledge?

I took the following excerpt from "Surely You're Joking, Mr. Feynman!" I'd just like to know if this kind of 'fragile knowledge' as Feynman puts it, is preventable? Or can only certain gifted minds do this sort of thing? I don't consider myself able to do this kind of thing at ALL, so is it...

Hi All, I am a computer programmer who has studied computer science and electrical engineering .It is my desire to combine my programming skill and EE background to design systems that potentially constitute mechanical parts( controlled by circuit and firmware...) .The problem is ,I have no...

Hello, One topic I would like to discuss here is the comparison of our understanding and knowledge of the cosmos, matter, energy, evolution and the existence in general WITH that of the other "civilizations" if they exist elsewhere in the cosmos. I am just curious...if someday we visited...

A question for those of you who know about the distribution of dark matter in the galaxy: Do we know how "clumpy" dark matter is? Can we tell yet whether dark matter is distributed about as densly as a gas or whether it's possible that there are the equivalent mass distributions that might...

Hi PF, I am an undergrad who recently started getting much more involved in his research (basically I am a HEP code monkey). Anyways, most of the technological aspects of the work were completely unknown to me, I started from scratch. And I found that, looking for the answer to one glitch...

Hello. I am a college freshman. All the sudden I understood that school taught me fragments of mathematics, not the whole thing. Different low-grade teachers that would teach us to solve a lot of simple problems fast for tests like SAT instead of learning mathematics. I want to become a...

Humility makes one focus on what is not known and so keeps increasing ones knowledge. Pride makes one focus on what is known and thus stagnates ones knowledge.

Hello! I am going to do bachelors in theoretical physics in next year,so I want to know what kind of computer knowledge needs for theoretical physics (I mean even fast typing programming) Thanks Have a nice day and happy x'mas!

Hello everyone, and happy holidays. I had a question that recently popped into my head as I am in my last three semesters of my undergraduate university. Some background, I am thinking of applying for a professional Masters degree (2 yrs long) before finding work in industry. But I was...

I decided to take a math course based solely on proofs, no such courses are in my undergrad requirements and i thought it would be interesting experience. It seems like physicists have a working knowledge of mathematics rather than a really deep knowledge of it. I realized this after trying...

I realize this may be kind of strange, but as it turns out, I've experienced a good introduction to topology (at the level of Munkres) before taking a rigorous class on analysis. With a month-long winter break in my near future, I'm wondering if anyone could suggest a text on real analysis that...

hi friends,i wonder if anyone can give me a link to a good layman book about the latest advancements in physics ,pertaining to explaining our existence and the forces behind it,and please no cosmology issued or big bang stuff,just applied physics to creation.thanks:wink: