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

learn more… | top users | synonyms (1)

1
vote
0answers
84 views

Motivation For Definitions [closed]

I noticed in my physics textbook that we define certain relationships to be true. I can see how this is considerably helpful in deriving other relationships from these definitions; for instance, take ...
1
vote
1answer
464 views

What's the common consensus on the meaning of “physical change”?

I'm doing a textbook problem that shows a "molecular level" view of some matter, little colored balls, before and after, and there are, among the four questions, two that say: 1) Did a physical change ...
1
vote
0answers
581 views

What is the relationship between Luminosity, Intensity, and Flux?

I am always confused by the terminology: In high energy particle scattering, and in particular, in the context of collider physics, what is the relationship between luminosity, intensity and flux? ...
1
vote
1answer
281 views

What does anthropic mean as in Anthropic principle? [closed]

I'm reading a book about string theory, and it describes anthropic principle. Idea is clear to me, I understand this principle describes certain constants in modern physics that are so fine tuned as ...
1
vote
0answers
101 views

Is putting a charged balloon up to a neutral wall polarization AND temporary induction, or just polarization?

Is putting a balloon that is charged up against a wall and having it stick polarization AND charging by temporary induction, or just polarization?
1
vote
0answers
526 views

What is a boundary condition for capacitors/dielectrics?

I am extremely confused about what boundary conditions are. One minute ago I was solving easy capacitor questions and the next minute I am being asked boundary condition questions and there is no such ...
0
votes
2answers
69 views

When referring to weights and mass of weights in a physics laboratory, do we use the term mass or weights?

What terminology is used to refer to weights/ mass/ weight of mass/ mass of weights when referring to the mass of weights in a physics report? My question is more of the weights that we use in the ...
0
votes
4answers
45 views

Can the term «shadow» pertain to anything else than light? [closed]

Can the term shadow pertain to anything else than light? Feel free to interpret this question in the widest sense possible.
0
votes
3answers
100 views

What does the term 'equation of motion' refer to?

What does the term equation of motion refer to? If I am asked a question of the form 'What is the equation of motion of this object?', what should I write?
0
votes
3answers
100 views

Commutator summation notation

I have the relation $ e^L M e^{-L}=\sum_{n=0}^\infty \frac 1{n!} [L,M]_{(n)}$ where $L$ and $M$ are operators. What does the subscript $n$ after the commutator bracket denote?
0
votes
1answer
223 views

Ultrarelativitistic particle - what kind of a particle is this?

I have heard many times that we can treat a moving particle as a: classical particle non-relativistic relativistic particle ultra-relativistic particle While I know equations for 1, 2, & 3, I ...
0
votes
3answers
106 views

Is my conceptual understanding pertaining to heat & temperature correct?

From what I've understood: Heat is the total sum of kinetic energy translational energy possessed by individual atoms in an object. Temperature is the average kinetic energy translational energy ...
0
votes
3answers
62 views

Ideal, isotropic fluid and stress tensor

An ideal fluid is the one which cannot support any shearing stress. It also doesn't have viscosity. My question is what does it mean by a fluid to be isotropic? Is an ideal fluid necessarily isotropic ...
0
votes
3answers
99 views

What is the 'normal/standard' formulation of quantum mechanics called?

I know of at least three equivalent formulations of QM: The "normal/standard" one, dealing with Hilbert spaces and state vectors. The Feynman path-integral formulation. The Wigner-Weyl phase space ...
0
votes
4answers
271 views

Can physics (ever) explain intrinsic properties of nature? [closed]

I may be totally off with this quite abstract (?) question(s). But still, here are some closely related sub-questions: Is there a list of currently "known" intrinsic properties of nature? How ...
0
votes
3answers
181 views

Equation $H(q,p)=E$ is the equation of motion or energy-conservation law?

I do not completely understand, why do we consider Hamilton–Jacobi equation $H(q,p)=E$ as equation of motion, whereas it is looks like energy-conservation law?
0
votes
1answer
60 views

Why oobleck does not obey Newtonian dynamics? [duplicate]

In the following post we can see that some guys are walking on Non-Newtonian fluids. As far as I know that, we can not predict the exact amount of strain if we predict some forces. therefore the curve ...
0
votes
1answer
124 views

What is this simple mechanism called? [closed]

I often build with Lego and use this mechanism: It converts the rotational movement to linear by making the stick between the two blocks go back and forth. What is this mechanism called?
0
votes
1answer
81 views

Definition: Coupling [closed]

What does it mean to say that 2 fields are coupled? More generally, what does "coupling" mean?
0
votes
3answers
187 views

What is the name of the equation which led to the Schrödinger one?

What is the name of this equation: $$\frac {d^2\psi}{dr^2}+k^2\psi=0?$$ (I want a Wikipedia link for this equation, but I don't know what its name is.) Point: In this equation, the wave function ...
0
votes
2answers
254 views

Why equivalence principle is principle and not law?

We can prove that the inertial mass and the gravitational mass should be the same (equivalence principle) from the $f=mg=ma$ then $g=a$, so we have equivalence law! But why we said equivalence ...
0
votes
1answer
286 views

Spectroscopic notation $s$, $p$, $d$, $f$, $\ldots$

$s$ is sharp, $p$ for principal, $d$ for diffuse, $f$ for fundamental. Where do all those term come from? I do not see any link with the corresponding shapes.
0
votes
2answers
221 views

Identifying hue, brightness and chroma of color and reaction time

If someone knows how identify hue, brightness, and chroma of color, please let me know. I am a PhD student at Educational Linguistics UNM.
0
votes
1answer
25 views

Forgotten word meaning susceptability to direction

A little over a year ago, I encountered a descriptive word with respect to experimental physics, describing the phenomenon in which calibrating an instrument from one direction will yield a different ...
0
votes
3answers
77 views

Eternal Black Holes

What is the definition of an eternal black hole? Studying white holes and the term appears in relation to this field of research.
0
votes
1answer
54 views

Is 'grapheme' a substance or a typo?

While reading Ref. 1 I came across the sentence Below we focus on the physics of ideal (single layer) grapheme. I did google search 'grapheme' but the results tended towards a completely ...
0
votes
1answer
69 views

Is charge transfer from A to B positive or negative?

I see this term pop up a lot -- for instance "charge is transferred from atom A to atom B", but it's never specified whether they're talking about positive or negative charge. I know electrical ...
0
votes
1answer
33 views

The meaning of “heralded photon”

I am not a native English speaker, and I have just started to study physics in English. However, I came across the term heralded photon while I was reading a review article about optical quantum ...
0
votes
2answers
80 views

What is the principle of equivalence in thermodynamics?

I've been searching for this for a while. There is a principle of equivalence in general relativity: http://en.wikipedia.org/wiki/Equivalence_principle But I need the principle of equivalence in ...
0
votes
2answers
2k views

What is Curie-Weiss temperature?

What is Curie-Weiss temperature? What is the difference between Curie-Weiss temperature and Curie temperature?
0
votes
1answer
65 views

Reason for the convention about polarization states

I'd like to know if there is a special reason for limiting convention of polarization state to waves that can be split in just two components of equal frequency.
0
votes
2answers
147 views

Is an electric lamp a transducer? [closed]

Silly thought. A transducer, by definition, is a device that converts variations in one form of energy to another. An electric lamp converts electricity into visible light - the brightness may vary ...
0
votes
2answers
60 views

What is the difference between leptons and baryons?

I am learning about the formation of the first atoms and, from what I am reading, before heavy particles, like neutrons and protons could form, there were already other types of particles, called ...
0
votes
3answers
77 views

Kinematic Viscosity

How would you define kinematic viscosity? What does it physically represent? Around the Internet I've found it defined as just a ratio, and that's it. I saw in an answer that I can think of it as ...
0
votes
3answers
168 views

About the postulates of quantum mechanics and self-adjointness

I am a freshman trying to understand the very basics of quantum mechanics but I met barriers at the beginning. What really matters is the postulates of quantum mechanics and their relationship with ...
0
votes
3answers
53 views

Image angle illusion [closed]

I am not sure whether this question on-topic here. (please suggest to migrate if this is off-topic) What is the phenomenon/illusion (or something else?) known as where in a photo of a person, the ...
0
votes
1answer
30 views

Can Allan variance be generalized such that the “Oscillator model” is not presumed?

The definition of Allan variance, $\sigma^2[ \tau ]$, which relates to "stability of clocks" is described on the Wikipedia page as being derived in terms of an "Oscillator model": "The oscillator ...
0
votes
1answer
26 views

What are “finely subdivided” substances?

As in the title, what does it mean for a substance to be finely subdivided, or finely grained? For example: It is only in the cases for which the ratio area/volume is very large (for example, a ...
0
votes
2answers
72 views

Changing from potential to kinetic energy

During a conversation with a friend, I began to wonder if there's is a term for the transformation of potential energy to kinetic energy, and vice versa.Is there a term for the process of converting ...
0
votes
1answer
54 views

If the axis of rotation is fixed, is it ok to say clockwise torque?

I know that the direction of torque is along the axis of rotation, but would it be acceptable to say, for example considering a vertical thin rod in the x-y plane with a force acting on the bottom end ...
0
votes
1answer
223 views

What is the difference between a battery and a “polarized” charged capacitor?

I know that the main difference between the two is that a battery can provide a constant voltage whereas a capacitor's voltage decreases as the charge stored decreases. But what about the internal ...
0
votes
3answers
24k views

What is the difference between phase difference and path difference?

I have learnt that path difference is the difference between the distance travelled by two waves meeting at a point. If that is path difference,then how will one know what is phase difference and how ...
0
votes
1answer
202 views

Is the speed of light related to the mass of the universe?

If the mass of the universe were cut in half, would it affect the speed of light? Would it be twice as fast? Would it stay the same? Do we have instruments that are sensitive enough to measure the ...
0
votes
2answers
111 views

What is “species” in the context of an electrochemical cell?

From the Wikipedia entry on Electrochemical cell (http://en.wikipedia.org/wiki/Electrochemical_cell): An electrochemical cell consists of two half-cells. Each half-cell consists of an electrode, ...
0
votes
1answer
115 views

Oscillon and soliton

I want to know the major difference between oscillon and soliton in terms of radiating energy with respect to time and position. And what about their localization?
0
votes
3answers
258 views

Is it true that an isolated fundamental particle does not decay?

Is it true that an isolated fundamental/elementary particle does not decay? It seems logical to me.
0
votes
4answers
224 views

Isotropy and Noise

If you have a field which value is just Gaussian noise plus a constant do you call it isotropic? there is no preferred direction however it is not "the same" in all directions if "the same" means ...
0
votes
1answer
643 views

Wave packets v.s. wave trains

Could someone please explain the difference between a wave packet and a wave train? I have rummaged around online but have not been able to find a definitive definition.
0
votes
1answer
379 views

Energy versus free-energy diagram

Energy versus free energy diagram. I haven't been able to find an adequate definition of these two terms in relation to each other. Could someone point me in the right direction, please? From Borrell ...
0
votes
1answer
144 views

Name for phasor model of light

I'm looking for the name of the model of light "exploring" every path to a given point, and reaching that point with a probability proportional to the square of the resultant phasor's amplitude. (Yes, ...