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Questions tagged [unified-theories]

The tag has no usage guidance.

-7
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1answer
46 views

Is there a unified field?

Does the same force that holds the electron in orbit around the proton hold the Earth in orbit around the sun.
0
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1answer
106 views

Why Einstein's unified field theory is believed not to work?

In his later life, Albert Einstein was trying to extend his general theory of relativity to incorporate electromagnetism and other fundamental forces with it, something he himself called "The theory ...
-1
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0answers
33 views

What is so special about strings in string theory? [duplicate]

I mean to say that why have we kept ourselves stuck at strings. If strings explained stuff that particles couldn't a membrane explain more physical phenomena? I have just started learning about string ...
3
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1answer
62 views

Is Gravity still considered to be part of the “Superforce” which existed at the instant of the “Big Bang”

My limited understanding of the Big Bang is that all the Fundemental Forces (Electromagnetic, Weak Nuclear, Strong Nuclear and Gravity) were originally part of a "Superforce." As the universe cooled ...
1
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1answer
53 views

Faraday's Law and the Law of Inertia

Faraday's Law can be stated qualitatively as : Any loop (of wire) opposes/resists the change of magnetic flux through it. The Law of Inertia states that any physical object resists its change in ...
12
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5answers
2k views

Why do we say there are four fundamental forces instead of some other number? [duplicate]

In my physics textbook (and in popular science culture) it is stated that there are four fundamental forces: electromagnetism, strong, weak, and gravity. But Wikipedia tells me that there is a ...
1
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0answers
41 views

Classification of $E_6$ symmetry breaking

Is there a good reference which details the various ways of breaking $E_6$ into smaller groups using Wilson lines? I'm looking for a list of discrete (Abelian) symmetries, e.g. $\mathbb{Z}_5$, and the ...
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1answer
77 views

Relation between electroweak force and gravity? [closed]

I'm really stuck on the following idea. For gravity to in any way be 'unified' with the electroweak interaction wouldn't it need to include a model whereby the electron somehow tunnels to within the ...
5
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1answer
80 views

Why did physicists in the 1950s and 1960s suspect the weak and EM interactions were at some level the same interaction?

Around the 1950s and 1960s there was a lot of work in particle physics motivated by two issues - finding a workable quantum field model for the weak interaction, and finding a model that unified the ...
2
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1answer
134 views

Mathematical challenge for unification of gravity and electromagnetism in classical theory?

I am trying to better understand the mathematical foundations of a possible reconciliation between quantum field theory and gravity in general relativity. However, before the application of the ...
1
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0answers
62 views

Attempt to understand the Kaluza-Klein theory

I'm currently doing an internship on Kaluza-Klein theory. by reading some articles, I don't understand some things that seem easy to authors for example : In this article https://arxiv.org/abs/gr-qc/...
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0answers
99 views

Einstein's last attempt

Are there any good sources on Einstein's attempt to unify general relativity with electrodynamics, a unified field theory, before he died?
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0answers
34 views

Can we say the concept of wave and particle unifies in quantum mechanics?

I read this concept of unification in Physics like the unification of electromagnetism and weak interaction, unification of magnetic field and electric field by Maxwell. In this light of knowledge I ...
0
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1answer
40 views

Attributing direction as well as metrical structure to space - What did Einstein mean?

In notes from a lecture on The Concept of Space delivered by Einstein - 6 June, 1930 - it was reported: … he himself had faith that the idea of attributing direction as well as metrical structure ...
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1answer
125 views

Is String Theory the end of (currently known) physics? [closed]

Assuming that String Theory were true, does it explain all the currently known physics? Or are there anything that is known to exist and that even String Theory would not be able to explain?
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1answer
91 views

Who are the present 'superstars' pursuing significant breakthroughs toward a Theory of Everything (TOE)? [closed]

What are the main problems remaining to create a Theory of Everything (TOE) and who are some of the main contemporaries pursuing the TOE?
0
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2answers
151 views

Einstein's attempts at a unified field theory

Does anyone know where to find an English translation of Einstein's papers re his attempts to unify electromagnetism and gravity? Einheitliche Feldtheorie von Gravitation und Elektrizität and ...
2
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1answer
61 views

Why can increasing energy, the weak force and the EM-force become a similar force?

When the heat of the universe was much higher it seems that the weak force and the EM-force was combined into the electro weak force. For a layman the EM-force and the weak force look quite different,...
6
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3answers
340 views

Why to unify gravity with the other forces if gravity isn't really a force?

As I understand, the Theory of General Relativity says that the force of gravity doesn't exist. The planets move in elliptical orbits because the spacetime is curved by the mass of the sun, not ...
5
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4answers
2k views

Why is there a need to unify quantum mechanics and general relativity and what is meant by such a unification?

If general relativity (GR) describes gravity as a fictitious force, then shouldn't it be easy to quantize gravity in the sense that the spacetime distortion of a body changes in discrete values as a ...
1
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1answer
111 views

Why did Kaluza need to invent a new theory to unify general relativity and electromagnetism?

Wikipedia (and many other sources) say that by extending the number of spacetime dimensions from four to five, Kaluza–Klein theory unifies general relativity and electromagnetism into a single theory. ...
1
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1answer
66 views

Splitting the Fundamental Forces

So one interesting idea in physics is that at higher energy levels, fundamental forces fuse together (ex: Electricity and Magnetism into Electromagnetism) and (Eletromagnetism + Weak Force -> ...
0
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0answers
89 views

Is it true the Michio Kaku has completed a unified field theory started by Einstein by making use of string theory? [duplicate]

This professor has a few documentaries available explaining science to the layman like myself and he showed an equation no longer then a sentence that he says unifies all the know forces and particles ...
1
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0answers
47 views

What is the minimum set of hypotheses which the present physics is based on? [duplicate]

Based on nowadays human understanding, what are the most fundamental hypotheses or principles in present physics which could deduce all other formula/theorem/details/applications?
9
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1answer
485 views

How did Einstein plan to Unify Electromagnetism and Gravity?

I'm asking the question on this site because I'm more concerned with the physics and philosophy of unification than historical details I know that Einsteins description of gravity includes curvature ...
5
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4answers
199 views

Does any unifying theory explain why nature is Chiral?

I'm currently studying particle physics and find the experimental fact that massless particles are always left-handed quite surprising.In fact, the need to add projectors in the lagrangian seems not ...
3
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3answers
1k views

How does string theory try to Unite Quantum mechanics with General relativity?

I've always thought that the reason we had trouble unifying Quantum mechanics and General relativity is: Quantum mechanics is defined "on" space time and time doesn't vary because of energy. Time is ...
5
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4answers
198 views

Reformulating QFT to exclude space-time basis

This is, I guess, a pretty loose or general question and so I hope it's ok to post in this forum. But I suppose this is what science is all about: asking and seeing what happens. It is just personal ...
3
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1answer
243 views

Why does the Standard Model not unify $SU(3)$ and $SU(2)\times U(1)$?

I am struggling with the definition of a unification. I read this question and i am wondering why the standard model is not unifying strong and weak force according to the given definition of a ...
10
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2answers
665 views

Are the fundamental forces unified in a black hole?

Regarding the question of unification of the forces it is usually presented the following diagram: So it seems the matter of whether the forces are unified or not relates to how high the energy is. ...
2
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2answers
207 views

Massless particles in a universe with compact extra-dimensions

One common idea behind many extensions to the Standard Model (such as String Theory or Kaluza-Klein Theory) are small or hidden "Extra-Dimensions", that are compactified. According to my ...
3
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0answers
142 views

Modifying Heisenberg's Unified field theory with gravity

How would Heisenberg's unified field equations (as presented in "Introduction to Unified Field Theory of Elementary Particles" by Heisenberg) be represented if gravity is incorporated? Would it result ...
2
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2answers
154 views

Is it possible that there is a 5th force or is it proven that there is no other force?

I heard about in high energy the 4 fundamental forces can combine. They were not separated until $10^{-11}$ seconds after the big bang and as the univers gets cold, they begun to seperate. Is it ...
32
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1answer
2k views

What does it mean to say that “the fundamental forces of nature were unified”?

It is said that immediately after the Big Bang, the fundamental forces of nature were unified. It is also said that later they decoupled, becoming separate forces. Indeed, if we look at the list of ...
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1answer
248 views

Geometric interpretation of mass [closed]

I have a question about the definition of mass. In general relativity mass is closely related the curvature of spacetime, which indicates that mass might be interpreted as a geometric concept (maybe ...
5
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1answer
169 views

Is there a path to go from GR, to Gravitational Waves, to Gravitational Particles (Gravitons), to Quantum Gravity?

The articles on the subject often say : a part of the mass of the 2 celestial bodies became energy for gravitational waves after merging : E(gravitational waves) = (M1 + M2 - M_merged).c^2 ...
5
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4answers
146 views

Is there a theory where there are (recursively) infinitely smaller particles?

So I read that electrons are just points, with no mass, and furthermore, protons look like they have some "size" but that's really 3 "point-like" quarks. We first thought atoms were the smallest ...
1
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1answer
309 views

How do physicists develop theories? [closed]

I'm wondering about the way physicists develop "unified theories" and models about the universe, like string theory, or quantum mechanics. People (on this forum for example) often say things like "at ...
0
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1answer
97 views

Unification: what does it mean for the forces to become equal?

The Coulomb force constant $k_c$ has si-units of $Nm^2C^{-2}$. The gravitational force constant $G$ has si-units of $Nm^2kg^{-2}$. What does it mean that at very high energies these forces become ...
5
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2answers
216 views

What is it exactly that conflicts when trying to unify all 4 fundamental forces? [duplicate]

Everyone knows that there are 4 fundamental forces: Gravity Electromagnetic Weak Strong At school and university you're taught that no one has been able to unify these 4 fources. However, not a ...
1
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1answer
91 views

Is it possible that there is more than one entirely correct unified field theory? [closed]

As we approach a more and more solid limit to the data we can get in physics, we find that there are multiple possible explanations (although they are not whole). Is it possible that instead of a ...
1
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1answer
236 views

Why didn't we have inflation when the theory of everything and GUTS broke symmetry?

I asked this in astronomy and they suggested I ask it here. Inflation seems to have occurred when the symmetry breaking of the electroweak occurred. But do we know of any reason why we did not have ...
2
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1answer
80 views

Can anyone explain to a novice physicist whether there is a gravitational-electromagnetic symmetry?

I am trying to understand how the four fundamental forces relate to one another and to a theory of everything. As I understand it the unified force that is thought to exist at very high energies gets ...
2
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0answers
522 views

Are there any good books about Grand Unified Theories?

I'm starting to get a little desperate, because I can't find any introductory treatments of Grand Unified Theories (GUT). So far the only books I found are Mohapatra Unification and Supersymmetry ...
2
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0answers
155 views

Evaluation of the anomalous dimensions of fields in SUSY $SU(5)$

The general formula for the anomalous dimension can be found in Martin΄s review article (hep-ph/9709356), on page 62 relation (6.5.4). In the case of $SU(5)$ and especially in the paper of Kobayashi, ...
0
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2answers
236 views

A model that unifies the strong, EM, weak and gravity forces?

Does there exist such a model that explains the force clusters (their origin, relations between them): the strong, EM, weak and gravity forces?
25
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3answers
3k views

Can all fundamental forces be fictitious forces?

After reading many questions, like this and this, I wonder: is it possible to consider also the other fundamental forces, the electroweak interaction and the strong interaction or ultimately the ...
4
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2answers
160 views

Unification of the electroweak theory

Can the electroweak theory be described by the spontaneous symmetry breaking of $SU(3)$ to $SU(2)\times U(1)$?
3
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0answers
578 views

Heisenberg's Unified Field Theory

While searching in the Internet, I came to know about Werner Heisenberg's attempt to obtain an Unified Field Theory (see the book Introduction to Unified Field Theory of Elementary Particles). But ...
4
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4answers
1k views

How are theories in physics validated against existing knowledge in practice?

Often you hear people mention how most attempts at Unified Theories haven't "accounted for all the experimental observations". The question is, how do you know you have accounted for all of the ...