Theories Definition and 466 Threads

At what level (graduate, PhD, etc...) do people start learning theories, such as String Theory and Loop Quantum Gravity?

Apart from evolution and intelligent design what other serious origin theories are there?

Hi, I'm new to this forum and I thought I'd ask for some help with my research paper. Well I am a Senior in Highschool and I take IB (International Baccalaureate [Google it]) courses which are basically super advanced courses. Anyway, one of the requirements is that I write a 3,500-4,000 word...

In physics there has been a sequence of three theories of motion, each superseding its predecessor: Newtonian dynamics, SR and GR. Insights from GR cast the predecessors in new light. With the new insights the predecessors can be reframed in such a way that the transitions between them become...

Here R^4 is a flat 4-dimensional space, and M is a 6-dimensional Calabi-Yau manifold; and the other side, R^10, is a flat 10-dimensional space. Is there any careful talk and reference about the equivalence of theories in those two spaces above? Great thanks.

In the perception of General Relativity a Black hole can form in which anything (including light) is trapped inside the horizon of the Black hole and can never escape, because nothing can exceed light speed. However, still something escapes the Black hole, which is the presence of the...

With one, we have 5, what about more than one? What are they? What are the importance of these, phenomenologicaly saying?

The LHC is probably the last of the large accelerators so should the main contenders for the title of the theory of everything (if such a thing exists) now, at the dawn of the LHC start up, clearly state what findings would a) prove their theory b) support their theory & c) eliminate their...

I need a topic for a physics research paper on Physics Theories that have been found to be incomplete/inaccurate. Anyone out there that can throw an idea to me? Thank you for your time! Justin

Jun3-03, 03:02 PM C0mmie "... logic is not an attribute of the universe, but instead is our means of understanding the universe, while the universe itself has nothing to do with logic. For expample, imagine a person who for the first time in his life is exposed to Heisenberg's...

Would it be sufficient for the validation of a string theory if it could make the same predictions as those already validated under QM and GR? Would it be necessary for such a theory to make additional predictions that could be tested at available energies?

Can someone explain how Hardy's Paradox is resolved? As well, what could someone infer from this regarding both Copenhagen Interpretation and Bohm's theory?

In Quantum Field Theory, there are 'infinity' problems: At extremely short distances the energy quanta increase so much that infinities would occur. In order to overcome this a cut off is imposed that postulates that quanta cannot possess energy above some arbitary high value. This works...

Einstein"s theories of relativity and the resulting E = MC^2, although extremely important to physics, was not his greatest insight. His idea that time is not fixed, that it can run infinitely slow or possibly infinitely fast was the most important. If there was a Big Bang, that suggests at...

Is Geography a science? It is comprised of theories, Laws (well Rules realy), hypothesis, some Math equations, aspects of Physics Chemistry and Biology. Also there is still much to be learned from it.

Hi everyone.. I'm supposed to find the pros and cons of major and minor theories on how the universe began. The only things i have so far are the big bang and creationisme..but i can't think of anything else! Help ! =(

Im looking for a good resource that clearly explains the problem of Gribov ambiguity. In particular, I want to know 1. Why the problem only arises for non-abelian theories 2. Why restricting the functional integration to field configurations where the Faddeev-popov determinant is postive...

How do "deterministic" Bohmian/Pilot Wave Theories Handle These? We are fortunate to have Demystifier and several others on this board who are very involved in research into Bohmian Mechanics/dBB/Pilot Wave theory. I have a couple of questions I am hoping someone can discuss. (I will use...

How much leave do phd scholars in physics get annualy? Is it it not possible to do research work at home,incase the student is ill and wants to be in his comfort zone during bad times? Btw if i choose a theoretical physics topic will i be free from learning computer related stuff with...

Is every first order theory with finitely many axioms automatically complete? An axiom schema like that of ZFC's separation counts as an infinite number of axioms.

Im trying to learn about instantons at the moments from Cheng and Li's book. It seems to suggest that instantons only occur in theories that are non-abelian. Why is this so?

Aspiring author looking for theories... Hi :) I'm looking for some information / theories for a sci-fi book I'm working on. I have no medical or biology background so I'm kind of starting from scratch with this. I'm specifically looking for theories regarding parasites, virus's, things of...

http://www.symmetrymagazine.org/breaking/2009/02/19/most-extreme-gamma-ray-blast-also-probes-quantum-gravity/Fermi%20Observations%20of%20High-Energy%20Gamma-Ray%20Emission%20from%20GRB http://www.nasa.gov/mission_pages/GLAST/news/high_grb.html...

Why is it that general relativity and quantum mechanics are so different and that physicists are having difficulty combining them. Please give me a simple answer. I scoured the whole net and each website has its own opinion.

Is it true that classical theories tend to treat matter 'in the limit' of large N, or it encodes matter in N_A as N_A(m_e,e) say, and chiral theories need to include \hbar which classicality sees as \{G(h),c\} ? We use 'mass-free' theories that treat charge and spin momentum in circuits =...

How much weight if any, should be given to public opinion to scientific theories that are, let's say difficult to prove, and could have significance effects globally.

Eternalism and Presentism -- theories of time The topic of this thread emerged from this thread, A problem with time travel Originally posted by Maxtm How do I know that you're not just a closet presentist masquerading as an eternalist? :smile: Your statements don't make any sense to me...

Sifting through ArXiv and other sources, I've found many documents on the topic of String Field Theory, perhaps the most extensive being by Thorn, 1989*. This brings up the question: Will String Field Theory evolve in popularity and perhaps outshine the more traditional String Theories? With...

Questions: Where can I obtain the most advanced published papers regarding valid unification theories? If there are none, which published papers will get me closest when combined in their respective categories? Comment: It is obvious to me through speculation, physical laws have yet to...

Topological Strings = 3 Superstrings = 10 Bosonic strings 26 Tensionless strings = arbitrary Do you know of any others that could fit in other dimensions not listed above?

I was just wondering, what math is needed to fully understand the mathematics of general relativity, quantum mechanics, and string theory? Can you be specific in naming them? For example General Relativity Algebra Calculus I know there has to be more than that but that was an example...

Ok, I haven't studied the subject at all (yet), but a professor of mine was explaining some of the theories behind string, brane, etc. to me. So bear with me here; I'm confused by this idea that came into my head earlier: If there are an infinite number of universes where every possible...

Can any of you think of examples of physics theories that were at one time rejected by the scientific establishment but later were accepted? Can you beat these examples? • Heliocentrism (Galileo in particular) - I don’t count this since he was primarily rejected by less scientific groups. •...

What theories do exist that predict compatibility between two people? Sometimes I talk to people and I think there is just no connection. Or they are just too boring. I recently read something about transaction analysis. It's not quite communication theory, but it seemed to sort of grasp why...

What about the Arp' s theories? I' ve seen the photos of the Stephan's quintet. What about them? Seems that the quasars are near other objects that look to be nearer to us than the quasars.

The online version of my local paper, as do many, has a place to post an opinion addressing most of the days articles. People make posts and then argue back and forth. It doesn't take long until the conservative wing nuts begin going off of the deep end. From todays article about Obama...

The propagator for gauge bosons in a spontaneously broken (non-abelian) gauge theory in the R_\xi gauge is (see Peskin and Schroeder eqn. 21.53) \tilde{D}^{\mu\nu}_F(k)^{ab}=\frac{-i}{k^2-M^{ab}}\left[g^{\mu\nu}-(1-\xi)\frac{k^\mu k^\nu}{k^2-\xi M^{ab}}\right]\,, where M^{ab} is the gauge...

Hey there Why did the big bang happened? what made it happen? what is the cause of the big bang? Could be vacuum fluctuations? Or a collision between different branes or universes? Could be some sort of a creator? What is the most proved and most appropriate theory that talks about...

Quantization of Gauge theories ?? Hi , i am trying to learn the math formalism of Gauge Theories as far as i know they begin with the 1-form A= \sum_{i} T^{i}A_{\mu}^{i} where 'T_i ' are the generators of the Lie Group then we define the 2-form F= dA + (1/2)[A,A] and the...

hey everyone, My names aaron and I am a year 12 student studying physics. We have to learn about both the wave and particle theories of light, and i just have a few questions. I have read that light behaves as if it has a mass, and although we can't actually 'weigh' the light we believe its...

hello everyone! i've got a very special question on the gauge invariance (gauge group: SU(N), non-abelian) of the kinetic term in the lagrangian. is it invariant for any representation? i only know, that for the fundamental rep. this is true. to be more specific: the usual kinetic term...

dear all, I am eager to read the "Gauge Theories of the Strong and Electroweak Interaction" wriiten by Manfred Böhm,Ansgar Denner,Hans Joos. But in my country, there's no the book. If you have the ebook or know the web sites to download it, please send it to my email(wuleihnu@yeah.net). Thank...

Hi all, Can you help me come up with toy field theories to practice calculating cross-sections? I'm not considering theories with derivative couplings like scalar electrodynamics. The interaction vertices I'm aware of are \bar{\psi} \gamma^\mu A_\mu \psi (QED), \bar{\psi}\psi\varphi...

Hi everyone. This is my first post so at this point I want to thank all of you for your terrific and interesting and informative forum on cosmology. I understand, and agree with, not getting into non-mainstream theories not published in peer-reviewed journals in this discussion group that...

I am an Italian physicist working in the field of condensed matter and non-relativistic quantum mechanics. Unfortunately my background in general relativity is very poor. In the last few monthes, as a hobby I am trying to learn a little bit of general relativity. Besides reading textbooks on...

In quantum mechanics there has been more different interpretations than religions trying to explain the "creation" it seems. I remember when Afshar Experiment was conducted John G Cramer immediately used the results to advocate his own pet theory while saying Copenhagen and MWI was falsified...

Hi , i have this question - it's not an idea , and it's not a theory indeed , it's merely a question - we all know that the theory of relativity is inspired by maxwell theory of electromagnetism , from which the constancy of speed of light in any frame of reference is derived . and we know that...

Why in every single text about GUT theories only the left spinors are used? Why use the conjugate of the spinor instead of the spinor itself? Is it just a another historic definition? Thanks

Maybe this is a dumb question. I'm a bit tired right now. :smile: What is a "theory" in mathematics, and what kind of statements can we call "axioms"? To be more specific, is "group theory" a mathematical theory, and if yes, what are its axioms? Should I think of the definition of "group"...

I don't know much about sociology but I am somewhat curious about the discipline. I'd like to start a little discussion on sociology where I hope you all will inform me about the subject. What theories have sociologists proposed? What hypotheses have they came up with? What hypotheses have...