Questions tagged [terminology]

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

Filter by
Sorted by
Tagged with
1
vote
1answer
111 views

Have there been more distinctive names suggested for neutrino mass states $\nu_1, \nu_2, \nu_3$?

The different mass states of neutrinos are generally named $\nu_1, \nu_2, \nu_3$. By comparison, the names of quark mass states (up, ...
12
votes
5answers
31k views

What is sound and how is it produced?

I've been using the term "sound" all my life, but I really have no clue as to what sound exactly is or how it is created. What is sound? How is it produced? Can it be measured?
0
votes
1answer
26 views

Abelian and non-Abelian holonomies

I read the article Geometric Manipulation of Trapped Ions for Quantum Computation, and it mentioned “Abelian and non-Abelian geometric operations (holonomies)”. I know what is holonomy, and what is ...
2
votes
0answers
313 views

Effective Field Theories of QCD

Recently, I am studying the online course Effective Field Theory provided by MIT OCW. Prof. Stewart gives a nice picture to summarize the effective theories: As a newbie in this field (I only have a ...
1
vote
1answer
122 views

Spring constant, but intrinsic to material, not rest length

If you have two metal springs that are coiled in the same way, but one is twice the length of the other, the spring constant will be half as large for the longer one. That makes sense of course. What'...
3
votes
1answer
940 views

What is a Witten diagram?

Recently I heard the terminology of Witten diagram. Studying QFT, I frequently see Feynman diagrams and use them to compute scattering amplitudes, one-loop corrections and so on. In string theory ...
0
votes
0answers
31 views

Are there names for Helium (He) emission lines like the Lyman/Balmer/Paschen series in Hydrogen?

Just wondering if helium emission lines have names like hydrogen lines. For instance the Balmer series is: $$H_{\alpha}, H_{\beta}, H_{\gamma}, H_{\delta}...$$ The Lyman series is: $$L_{\alpha}, ...
29
votes
6answers
3k views

Is the Big Bang defined as before or after Inflation?

Is the Big Bang defined as before or after Inflation? Seems like a simple enough question to answer right? And if just yesterday I were to encounter this, I'd have given a definite answer. But I've ...
-1
votes
1answer
45 views

What do we really mean by the word “light”? [closed]

Does the term "light" refer to any electromagnetic wave or just the visible spectrum?
0
votes
0answers
16 views

What is an electrified channel?

I've been asked to create a sketch of an electrified channel. I've never heard of this terminology before. I tried to Google it and it came up with either guitar related answers, or a few about ...
1
vote
1answer
20 views

What is the difference between longitudinal chromatic aberration and spherochromatism?

In lens design textbooks, a distinction is often made between longitudinal chromatic aberration and spherochromatism. (See for instance Kingslake's lens design book.) What is simple way to understand ...
1
vote
2answers
53 views

“Energy transfer” and “Energy transport”

Are the terms "energy transfer" and "energy transport" sometimes or always interchangeable? My own surmise is that the term "energy transfer" is slightly more general: "energy transport" refers to ...
0
votes
1answer
30 views

Pseudotensors for describing physical quantities

I have been reading about tensors from Mathematical methods for Physics and Engineering, by K.F. Riley, M.P. Hobson and S.J. Bence. And there are a couple of things i am not getting. On page 949 (...
-2
votes
3answers
84 views

Symbolizing frequency as $v$

In my school textbook $v$ is symbolized to the frequency of the wave. Is that correct? I also saw this convention used in Chemistry: The Central Science By Theodore L. Brown, H. Eugene LeMay Jr
2
votes
2answers
72 views

What does `weakly gravitating' mean?

When relativists like Bousso (see for instance https://arxiv.org/abs/hep-th/0203101) talk about `weakly gravitating systems', what sense of weak gravity is usually meant? (1) Post-Newtonian ...
1
vote
2answers
138 views

What is meant by “collective behavior” in the definition of plasma?

"Plasmas are many-body systems, with enough mobile charged particles to cause some collective behavior ." [M.S. Murillo and J.C.Weisheit Physics Reports 302, 1-65 (1998)]. In the above definition ...
-1
votes
1answer
1k views

Is displacement vector fundamental or derived quantity?

We know that we have 7 fundamental quantities (all scalars) and length is one of them. I classify velocity as a derived quantity. What about a position displacement vector? How do I classify ...
20
votes
5answers
2k views

Should it be obvious that independent quantum states are composed by taking the tensor product?

My text introduces multi-quibt quantum states with the example of a state that can be "factored" into two (non-entangled) substates. It then goes on to suggest that it should be obvious1 that the ...
2
votes
2answers
160 views

Origin of vectors with physical meaning

I was reviewing notes of physics, and i realized that something about the mathematics of vectors was wrong in my head. Suppose a vector is $\vec{A}=5\textbf{i} + 3\textbf{j}$, and other $\vec{B}=7\...
4
votes
0answers
64 views

Difference between an electron wiggler and an undulator?

Both wigglers and undulators use periodic magnetic fields applied to stored relativistic electron beams to produce intense beams of UV or X-rays that can be used in a wide range of condensed matter ...
3
votes
1answer
158 views

Nomenclature of nuclear excited states

I read in an online portal about $^{112}$Sn nucleus making a transition from $0_{g.s}^{+} \rightarrow 2_{1}^{+}$ state. Also, some higher excited states were named as $0_{2}^{+}$, $3_{1}^{-}$, etc. ...
0
votes
1answer
33 views

What is a pseudopure state?

In the paper titled "Experimental Implementation of the Quantum Baker’s Map" by Weinstein et al. (Phys. Rev. Let. 89 (2002)), the author says something like [...] the pseudopure state corresponding ...
1
vote
1answer
152 views

What is the different between Poisson Nernst–Planck and Poisson Navier–Stokes in the Electrolyte?

I am now studying about electroosmosis flow phenomena which is governing by the Navier-Stokes equation and Poisson equation. By combine these two equation we can describe the electrolyte flow velocity ...
0
votes
2answers
169 views

Tensors defined by transformation laws are tensors at a vector space or tensor fields?

In Physics it is common to see tensors defined by transformation properties relating components of the object in different coordinate systems. There is, however, two ways we can think of a tensor: a ...
1
vote
2answers
64 views

Difference between Oscillatory motion and vibratory motion

What is the difference between oscillatory motion and vibratory motion. I have read in my book that "If the amplitude of oscillatory motion is extremely small,the motion is called vibratory motion". ...
0
votes
2answers
107 views

What is the name of the formula?

What is the name of this formula? $$ G_{\mu\nu} = 8 \pi T_{\mu\nu} $$
2
votes
1answer
86 views

What is Snell's window?

Why is it that an underwater observer can see only a circular "window" and also can't see anything above the separating surface? Does the "window" depend on the depth?
0
votes
1answer
300 views

Difference between yaw angle and slip angle

What's the difference between slip angle and yaw angle (speaking about cars)? It seems they both are the angle between the actual direction of travel and the direction towards which it is pointing.
0
votes
0answers
32 views

Interaction picture counter rotating terms

In the interaction picture, we often do the rotating wave approximation where terms like $e^{i(\omega_1 + \omega_2)t}$ are ignored because they represent rapidly oscillating terms which ends up ...
18
votes
9answers
6k views

The instant an accelerating object has zero speed, is it speeding up, slowing down, or neither?

This problem is from Khan Academy. Specifically for the blue point circled in red, the answer is that at this blue point, the object is neither speeding up nor slowing down. When I think about the ...
21
votes
7answers
3k views

Terminology confusion - “particle”

I am confused about the word "particle" being used in academic contexts. Some professors at my university are adamant on the fact that particles do not exist, and only fields, as per QFT. One of them ...
1
vote
1answer
979 views

Is 'Boltzon' an accepted name for particles following Maxwell-Boltzmann (MB) statistics?

In my curriculum during one of my statistical mechanics visiting lecture classes, our teacher was referring comparatively macro particles following MB statistics as "Boltzon". But I have searched ...
0
votes
2answers
438 views

What is the difference between sound and vibration?

As far as I know, the only difference between sound and vibration is that sound propagates but vibration does not. In most cases, they are the same. Please help clarify these concepts.
5
votes
3answers
413 views

Meaning of the term “phase” in chemistry and thermodynamics

I have some doubts about the definition of the term “phase” in chemistry and thermodynamics (is the meaning the same?). The "textbook" definition is: "A phase is a form of matter that is uniform ...
1
vote
1answer
194 views

Bound states and the meaning of 'off shell'?

there are a couple of similar posts here on StackExchange about bound particles being off shell in QFT. From posts on other sites, I've been told that the idea of off shell particles doesn't apply to ...
0
votes
1answer
1k views

What is a stoquastic Hamiltonian?

Recently, I've often read about the term 'stoquastic Hamiltonian'. But I couldn't find a precise definition anywhere. I found that the Ising-Hamiltonian is a stoquastic Hamiltonian, but that does not ...
0
votes
0answers
38 views

In what sense $Z_\mu^0$ is orthogonal to $A_\mu$?

I am reading Standard model. Please explain in what sense the $Z$-boson $$Z_\mu^0=(g^2+g^{\prime 2})^{-1/2}(g A^3_\mu-g^\prime B_\mu)$$ is an orthogonal linear combination of the photon $$A_\mu=(g^2+...
1
vote
1answer
71 views

What is a gauge (for someone who has not studied gauge theory)? [duplicate]

I am taking a Quantum Mechanics II course and we were studying the relativistic corrections to the hydrogen atoms in perturbation theory. I was looking at the assignment, and a question is as follows: ...
26
votes
3answers
15k views

What's the difference between inclusive and exclusive decays?

For example, why is the semileptonic $B$ decay $B \to X\ell\nu$ inclusive? I can't find any definition of these frequently used terms, strange.
0
votes
2answers
280 views

What's the relationship between probability amplitudes and amplitudes of a wave?

Amplitudes or probability amplitudes are the complex coefficients of the linear combination of states which represent other quantum physical states. The amplitude of a wave can be interpreted as a "...
1
vote
1answer
59 views

What is the area of physics/science called that deals with fundamental limits of computation?

I am interested in learning about the fundamental limits of computation and in particular would like to read textbooks on the subject if they exist. My background is in maths and computer science - I ...
8
votes
5answers
2k views

What is the term for hose fluctuating movements during flow?

What do we call it when water flowing through a flexible hose causes it to act like snake movements if the hose were disturbed? Can this movement be explained by the Coriolis force?
0
votes
0answers
383 views

Confusion between curvilinear and rectilinear coordinate

This is perhaps an elementary question to ask, but it is important for me. I am confused between curvilinear coordinates and rectilinear coordinates. Are these two same things? (Synonym of ...
2
votes
3answers
80 views

Understanding quantum mechanics “picture” terms

I was reading various sources and a have some questions. The "Schrödinger picture" is the same thing as "Schrödinger wave formulation"? Is "Heisenberg picture" the same thing as "Heisenberg matrix ...
2
votes
1answer
246 views

Classification of field types in QFT

In Classical Field Theory fields are sections of bundles over spacetime. In particular we almost always consider vector bundles. Some examples are: Scalar fields: these are sections of the trivial ...
5
votes
5answers
7k views

Is 'restoring force' a particular type of force?

I have a question about the restoring force in elastic band or rope which confusing me for a long time. As I was told in high school physics, for an elastic band (or spring), if Hooke's law holds, we ...
1
vote
2answers
108 views

Formal name for the “pianology” objection towards contemporary particle physics direction of research?

In a popular science book, an interesting objection towards the current direction of particle physics was stated. I tried to search for more on this, but got nowhere. Since I assume this is not an ...
0
votes
4answers
449 views

Are bosons matter?

The title explains the question. Are bosons matter? As I have seen, there are three answers to this question: No, only fermions are matter. Yes, but only those with mass. Yes, all bosons are matter. ...
5
votes
4answers
365 views

Is there a scalar acceleration?

Distance is paired with Displacement and it seems to be a bigger idea than just the magnitude of Displacement. Speed is paired with Velocity. I have always thought that there is not such pairing with ...
0
votes
2answers
173 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?