Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [terminology]

Use this for questions relating to the proper use of physics terminology or nomenclature.

1
vote
1answer
64 views

What is a homogeneous magnetic field?

What does it mean when one says that a magnetic field is a homogeneous magnetic field?
-1
votes
0answers
22 views

Radii of binary [on hold]

Where to find a picture showing what these radii mean?
1
vote
1answer
18 views

“Monochromatic” vs. “Impulse” Force (What are the meanings of these terms?)

In a paper I am reading (linked below), the following is stated: The transient motions of the sphere and the gas bubble in the elastic, incompressible, inviscous medium are investigated in response ...
2
votes
1answer
87 views

Why is the Fermi Golden rule called so?

I was studying time dependent perturbation theory and this rule came under the case of constant (weak) perturbations. I understood the rule and the derivation but what I cannot understand is that is ...
-1
votes
0answers
21 views

Semantics problem with physics definition [closed]

Definition of current: Rate of flow of electron then, " The electric current is flowing" would be a wrong phrase due to the above definition if we replace the current in the above phrase with Rate ...
-1
votes
0answers
26 views

How to define events in special relativity [duplicate]

See my answer to this question: What is an event in Special Relativity? I'm not actually sure of this answer. What I do know is that: equations of motion (dynamical laws of physics), the minkowski ...
0
votes
3answers
52 views

What would be the minimum velocity of a particle performing S.H.M.?

We were asked a simple question on a test: What is the maximum and minimum velocity of a particle performing an SHM? Note here that we're talking about a generic standard SHM here. If the maximum ...
0
votes
0answers
44 views

Weyl Spinor components

In Schwarz's book on QFT, he writes that in the Weyl representation, we can write the spinors into two component $\psi_L$ and $\psi_R$ each of which are as he always say are "two components" ...
1
vote
1answer
33 views

Define System of particles

What really is a system in physics? In laws of motion a system contains particles with same acceleration but when I studied conservation of linear momentum i found that system is just a collection of ...
-4
votes
0answers
32 views

Why we use word particle in 1PI diagrams? [duplicate]

What does mean particle in the name of 1-particle irreducible diagrams? particle
0
votes
0answers
10 views

Minor loss coefficient

I want to know the difference between ´dividing line flow´and ´dividing branch flow´ for a tee fitting. I am designing a cooling system and it would really help me to calculate the head loss.
0
votes
1answer
63 views

What is an anisotropic harmonic oscillator?

I can't find any explanation of it anywhere in the internet. How is it different from an isotropic harmonic oscillator?
0
votes
2answers
45 views

Is second harmonic generation a special case of high harmonic generation?

That might be a strange question, but while I was researching for these topics, I never found an explicit statement that would answer that question. (That might be because of the different ...
10
votes
4answers
433 views

Is the term “quantum fluctuation” an aide to understanding? [closed]

I would like to ask if anyone has found a tight enough way to define the term "quantum fluctuation" so that it can become a useful rather than a misleading piece of physics terminology. Terminology ...
1
vote
1answer
49 views

Meaning of the subscripts $L,R$ for the two component Weyl spinors $\phi_{L,R}$

For a Dirac spinor $\psi$, its chiral projections are $\psi_{L,R}$ are defined as $$\psi_{R,L}=\frac{1}{2}(1\mp\gamma^5)\psi.\tag{1}$$ Acting with the chirality operator $\gamma^5$, we find $$\gamma^5\...
0
votes
0answers
8 views

Terms in photometry

Difference between luminous energy, illumination , luminous flux ,luminous intensity. Also describe how these terms are related with each other and please specify units as well.
0
votes
2answers
194 views

What is the $\,\phi=0\,$ gauge called?

In electromagnetism textbooks, the gauges most often talked about are the Lorenz gauge and Coulomb gauge. Sometimes it's convenient to work in a gauge in which there is only the vector potential $\vec{...
1
vote
1answer
87 views

Action angle variables and Action

Action given by principle of least action ($S$) and action variable given by action angle variable theory ($J$) are same?
-1
votes
1answer
77 views

Uncertainty Principle - Accuracy or Precision? [closed]

While discussing about the Uncertainty Principle, some books use the word 'accuracy' and some other books use the word 'precision'. Some even use them both interchangeably. For instance, in Griffiths' ...
0
votes
1answer
36 views

What is a quasistationary approximation

I was reading an article which states : The linear-stability analysis for this system can be performed in complete generality; but it will be best for purposes of this review to go directly to ...
0
votes
1answer
73 views

What is the difference between resolving power and dispersive power of grating?

Are there any differences between resolving power and dispersive power of grating?
0
votes
0answers
43 views

Is there any consensus on what is meant by Lagrange's equations of the first kind?

Is there any consensus on what is meant by Lagrange's equations of the first kind? Joos and Freeman define them as follows: Coordinates are given in terms of a rectangular Cartesian coordinate ...
0
votes
2answers
42 views

What is the difference between “uniform” distribution and “even” distribution?

I was reading a question in mechanics where it was written that mass of the rod is evenly distributed, but it was supposed to be "uniformly distributed". What is the difference between "uniform" ...
0
votes
0answers
20 views

What does it mean for something to interact with a mean field?

I think I just don't understand what a mean field is very well except that it's sometimes used as an approximative technique.
0
votes
0answers
15 views

What's the difference between a convection and a polarization electric field?

In the ionosphere and magnetosphere communities, studies frequently refer to the "convection electric field" and the "polarization electric field". What is the relationship between them, and what are ...
4
votes
0answers
42 views

When was the phrase “beta function” of renormalization first used?

My question is a historical one: when was the phrase "beta function", as it pertains to the renormalization-group equations, used in physics? I am talking about this beta function: $$\beta_g\equiv \...
0
votes
1answer
77 views

What is the difference between a quadrivector and a 4-vector? [closed]

What is the difference between a quadrivector and a 4-vector? Why is the square of a 4-vector equal to $t^2+x^2+y^2+z^2$ while the square of a quadrivector is equal to $t^2-x^2-y^2-z^2$? Aren't they ...
0
votes
1answer
74 views

What is a fuzzy space?

Can someone give a down-to-earth explanation of what is a fuzzy space? (As known from M-theory and noncommutative geometry)
0
votes
2answers
67 views

Terminology for how bendable an object is and what affects the bendable-ness of an object

I was wondering what the term is for how bendable an object is. Also, does this feature vary depending on the thickness of the object? Say, for example, I want to know how bendable a ruler is. Does ...
1
vote
0answers
59 views

What is meant by finite harmonic oscillator?

What does it mean to take finite harmonic oscillator, In research article "http://iopscience.iop.org/article/10.1088/1367-2630/17/11/113015 ", we were finding effective number of cobosons in ...
1
vote
1answer
39 views

Should the rest frame of a lab positioned on a gravitating body be considered an inertial frame in special relativity or not?

In Newtonian Mechanics, the rest frame of a lab on the Earth is considered to be (approximately) an inertial frame. The fact that a thrown ball is not moving on a straight line corresponds to the ...
-2
votes
2answers
93 views

Why is quantum mechanics called quantum *mechanics*? [closed]

At least a few books have "Quantum Mechanics" in their title, e.g., Sakurai's Modern Quantum Mechanics. However, I don't think measuring spin, which is "the" way of introducing quantum mechanics, ...
0
votes
0answers
32 views

Who first used the terminology of “on-shell” and “off-shell”?

By 1915 Klein and Hilbert dealt with the issue (and I do not claim they were the first). They distinguished between what follows for GR purely from the geometry of spacetime (notably, the first ...
0
votes
0answers
38 views

Difference between ideal gas and perfect gas?

I tried seaching it in the internet but I didn't understand anything. I know the definition of ideal gas. But I don't understand what perfect gas is. Can you help me, please?
1
vote
1answer
44 views

What is a hypercomplex quantity?

An extract from the book "Quantum Mechanics and the Path Integrals" by Richard P. Feynman and A. R. Hibbs: We can state the correct law for $P(x)$ mathematically by saying that $P(x)$ is the ...
1
vote
2answers
116 views

What is meant by the absolute scale of the neutrino mass?

In this review titled "Pieces of the Flavour Puzzle" the author Ferruccio Feruglio wrote in the introduction that "The origin of the parameters in the flavour sector of the Standard Model (SM), ...
1
vote
1answer
49 views

Is there a standard convention for whether the term “handedness” refers to helicity or chirality?

I was under the impression that the "handedness" of a massive spin-1/2 particle refers to its chirality rather than its helicity. This answer, this one and Srednicki's QFT textbook seem to use the ...
1
vote
1answer
69 views

Models in physics [closed]

As I said in another question I am just a physics enthusiast so I am sorry for my very poor knowledge. What is meant by models in physics? what is their function and why physicists imply them? Are ...
1
vote
1answer
36 views

What is the term for the light-sensitive metals in the photoelectric effect?

Can anyone please tell me the term used to refer to metals such as those used in photoelectric effect which can generate a current from light?
0
votes
1answer
39 views

Adiabatic Availability?

In the textbook "Thermodynamics: Foundations and Applications" by Elias P. Gyftopoulas and Gian Paolo Beretta (Dover). In chapter 5, on page 73 (section 5.3) the book says: Adiabatic availability ...
2
votes
1answer
28 views

How to concisely state 'atmospheric conditions' without being ambiguous with STP?

I'm conducting an experiment in an open system, so the temperature and pressure is equal to that of the atmosphere at that time. However, it is not equal to STP conditions of $273 \; \mathrm{K}$ and $...
0
votes
1answer
51 views

About the quadratures method

in the Classical Mechanics (2nd. Ed.) book of Herbert Goldstein, p. 75 it says: "Equations 3-18 and 3-20 are the two remaining integrations, and formally the problem has been reduced to quadratures..."...
0
votes
0answers
17 views

What are the differences between magnetometers, teslameters and gaussmeters?

What are the differences between magnetometers, teslameters and gaussmeters? I think that teslameter and gaussmeter are the same thing, but I am not sure about that either.
1
vote
1answer
77 views

What is the wave field functional?

I was reading on some QFT and I came across the following paragraph: In the same way that a generic state $|\psi\rangle$ of a particle can be described by giving its overlap with all the possible ...
2
votes
2answers
79 views

Modes in optical fibers

I am trying to understand the modes in step-index optical fibers and I saw that they say the electric field distribution in the core and cladding is as bellow. my question is that which component of ...
6
votes
4answers
258 views

Shouldn't “speed of light” really be “speed of electromagnetic waves”?

Since all electromagnetic waves travel at the speed of light ... shouldn't its name be Speed of Electromagnetic wave?
0
votes
2answers
315 views

If an object moves at constant speed, does it necessarily have constant velocity? [closed]

If an object moves at constant speed, does it necessarily have constant velocity?
1
vote
0answers
25 views

Is there a term for the study of asteroids?

I'm trying to find the name for the academic specialty of studying asteroids, but I can't seem to find any. For example, there is a distinct wikipedia page for "Planet" vs "Planetary science". Is ...
0
votes
0answers
12 views

What is gradient-flow modified operators in thermal gauge theory?

This is going to be a very "soft-question". I do not fully understand German, so I am not sure if "Korrelationsfunktionen mit Gradientfluss modifizierten Operatoren bei endlicher Temperatur in ...
1
vote
2answers
32 views

What are pre collisions and post collisions in forces and momentum?

What are pre collision and post collision exactly? I assume it is before collision and after collision. I can not find an answer on google.