Theory Definition and 1000 Threads

I think everyone would agree that linear current is simpler than circular current. So please tell me honestly, which one do you think is more fundamental? Considering that a loop is made up of closed lines, I think the answer is obvious. What is painful is, in mainstream electromagnetism, the...

The hypothesis is that the anomalous ionization noticed near galactic centers is due to dark matter particles colliding to make an electron and positron. This would produce distinctive gamma rays detectable by the next generation of telescopes.

Hi, my name is Rod. I'm interested in theoretical physics. I wanted to get feedback on a theory and that's why I'm here.

I don't know why, but I purchased Quantum Field Theory As Simple As Possible by Andrew Zee. I actually like it (not so much his other book Quantum Field Theory In A Nutshell). The purpose of this post is to mention that while math is required, it is nothing beyond a HS or even advanced middle...

I am studying to get a BS in Materials Engineering. I am learning a ton of useful skills (MATLAB, spectroscopy, materials testing), but I miss the theory in the math / physics classes I took during my first couple of years. I don't know if I would like physics or math more, I like them both. I...

Usually we look at a system of ODEs of the form: $$\dot{x}=f(x,u,t)$$ $$y=g(x,u,t)$$ Why not look at systems where the controller also changes with time, i,e functions of terms ##\dot{u}##? I took quite a handful of Control Theory courses and yet as of yet never seen one incorporating this...

While searching the internet for milestones in physics, mainly for those that led to the standard model, I came to ask myself why general relativity cannot be modeled by a gauge theory. Searching for "Relativitätstheorie als Eichtheorie" brought up a dissertation from 1990 titled: "Die...

New to Western music theory.... About this concept of chord progressions -- is it that there is a large set of "officially approved" chord progressions for a given key (eg C major), and someone composing a melody will typically select a progression first, and make the melody conform to it? Or...

Hello everyone. I have the following questions: 1. How and why did the theory of quantum gravity begin? 2. What is the objective of those who are dedicated to this research?

I'm bored out of my mind and while watching a PBS spacetime video I had an idea. What if black holes are hosts to universes in between the singularity and the event horizon ? It's 3am so pardon my lack of precision, but chatGPT did formulate my idea pretty well in this conversation : Link to...

C2 means the speed of light squared so Mass traveling at the speed of light times itself becomes energy. That would mean we could travel up to.34,500,000,000 miles per second before breaking down into pure energy. So we should be able to travel faster than the speed of life. Did I miss something?

propose and perform novel optical experiments, especially double slit experiments

A mathematician friend told me that the major tenets of information theory can be established through knot theory. Is that the case? Thanks.

I have no formal eduaction in the science field. My brain just naturally never stops. I absolutly love math, programming, and hard problems. I see things differently and can connect the dots to seemingly different issues buidling relations that are grounded in reality. I am very much a realist...

Hello , I have the theory from the books shown below where we can change the polarization of an incident wave. suppose we have TEM wave where E field is in X direction. so if n1=1 (vacuum) and n2=sqrt(4) )=2 FR-4 phi=(1-2)*(2*pi*lambda*0.25)/lambda=pi/2 so by this logic after quarter wavelength...

Hi, my name is Kurt. I'm interested in unifying everything. Glad to have found this place.

In Peskin's textbook, the coupling factor is given by a constant in the interacting field theory. The scattering matrix ##S## is given by the time-evolution operator, ##\exp(-iHt)##, in the limit of very large t, i.e., ##t\rightarrow \infty##, as expressed in Eq. (4.71). In my mind, the...

A few years ago I took a course on QC from the mathematics department. But I didn't see a direct connection to QFT, it seems QC is more connected to QM than to QFT. But I may be wrong I am just a novice here. Maybe a good title for a PhD dissertation... (now just to fill the details) so much...

Hello ,I have the following resonator Its very intresting. I need to simulate it .Is there some theory regarding this resonator ? so i could control it and see which modes could be made from it? Thanks.

https://www.amazon.com/Student-Friendly-Quantum-Field-Theory/dp/0984513957?tag=pfamazon01-20

It is a giveaway. https://www.amazon.com/Quantum-Field-Theory-Standard-Model/dp/1107034736/?tag=pfamazon01-20

Cost me a fortune when the dollar was so high in the eighties :rolleyes: ##\ ##

Hello everyone, I saw a very interesting video and I am confused. Can a monkey really write so accurately if given infinite time? Doesn't this prove the superiority of randomness over creativity?

Hi, I start my PhD education, actually offically it was one and a half month. And ı didn't decide to choose to experiment or theoric. Maybe, if you know or study this field,help me to decide. What is this two field advantages in STEM? If ı choose theoric, ı can find a job? Thanks for your answer...

I have come across the following paper (arxiv preprint link, it looks like it is published in Phys Rev D) that claims to have found a consistent quantum field theory of tachyons, overcoming three issues which have been said in previous literature to make such a theory impossible...

If we could have one day theory of everything thing, would we be able to explain why there is something rather than nothing and would we be able to know why there are physical laws?

Are there currently professional physicists who work on Einstein’s quest to unify the gravitational field and the electromagnetic field (as classical fields), or has this idea been completely abandoned? Is it simply a hopeless endeavour?

"The Price of Abandoning Dark Matter Is Nonlocality" (Deffayet, Woodard) written in response to "What is the price of abandoning dark matter? Cosmological constraints on alternative gravity theories" (Pardo, Spergel) In a nutshell, as explained after equation 34, by adding a nonlocal...

So I have the solution here and trying to understand what happened at the beginning of the second row! How did we get the exponential $$e^{i(\omega_m - \omega_0 ) t' }$$ ?

Would it be possible for Black Holes to undergo nuclear fusion of materials with very high atomic numbers (above 118 or the majority of known atoms) in their singularity, producing any signs, including photons across the spectrum? Furthermore, I was thinking aloud and wondering, what prevents...

let n be a positive integer show that if n is square then σ(n)( the sum of all divisors of n )is odd.

I'd like to hear your professional opinion on and experience with using Quantum Field Theory for the Gifted Amateur by Tom Lancaster and Stephen J. Blundell as a self-study textbook. Thank you.

Someone wrote to me that the atomic bomb didn't exist and was probably a hoax. T They said that in World War II German scientists declared the bomb impossible. German scientists were the best in the world so the bomb must be fake.

I am reading a hebrew translation of the popular book by Michio Kaku on HyperSpace. It seems Superstring Theory will never be refuted since if it's a theory of everything then you need infinite energies since the universe is infinite, and we can never get a from finite machines infinite...

Hi guys, I am a first year IB student and I need to give hand in my research question for the extended essay today, the only thing is that I don't really know what I could do it on. The extended essay is basically a 4000 word research project. I was going to do it on photoelasticity, but when I...

Answer: The energy of a system with H and Cl atoms at varying distances can be represented by a curve that shows the potential energy of the system as a function of the distance between the two atoms. At very large distances, the potential energy is zero because there is no interaction between...

In interpretations of quantum mechanics there are two types of physicists: those who care about ontology and those who don't. The ontologists, or realists, want to know what is the world made of. The non-realists, on the other hand, think that this question is not relevant to physics. Usually...

Hi, I am trying to learn relativistic classical field theory as a preparation for studying quantum field theory. I am currently reading chapter 13 i Herbert Goldstein's Classical Mechanics edition 3, but I think that this book is a bit too brief and does not fully derive and explain the...

Hello All, Not sure if this belongs in general math but lets start here and see where it takes us. In mathematics, a combination is a way of selecting items from a collection where the order of selection does not matter. As an example , say we have digits 1 to 10. And we want to select 3...

Hello : I apologise for my last post about the titanic , I didn't think it will be considered conspiracy theory , although I see it as a good science post Best regards Hagop

Can you please express this theory mathematically or through equations? Destiny is the automatically predestined chain or course of events spread throughout the universe that originated from the first cosmic event called the Big Bang. It automatically determined when, where and exactly what...

hello i would to get some help with my homework. 1. true 2. i dont know 3. true 4. i dont know 5, false 6. i dont know about 2,4,6 i really have know idea what to think I really appreciate help

Hey guys, i need insight on the highlighted part...the steps before this are quite clear: where is the ##\dfrac{3}{4}M ## coming from? and how to show the argument does not work for ##n=-3##? i should be able to check on this ...later. and why is the Norm of say; ##ϒ =a+c\sqrt b## taken...

TL;DR Summary: Book: Neoclassical Theory of Electromagnetic Interactions - A Single Theory for Macroscopic and Microscopic Scales I've found the book of Babin & Figotin: Neoclassical Theory of Electromagnetic Interactions - A Single Theory for Macroscopic and Microscopic Scales. I like their...

I’ve been trying to solve this for ages. Would really appreciate some hints. Thanks

Does matter (like electrons) diffract at the single slit and create an interference pattern on the screen? If it's not why? Isn't that violation of Bohr's Theory?

What is the Schrodinger equation in QFT? is it the nonrelativistic approximation of a Klein-Gordon scalar field? or Is there more? I have read that the Schrodinger equation describes a QFT in 0 dimensions. I accept every answer