Use this for questions relating to the proper use of physics terminology or nomenclature.
Questions tagged [terminology]
2242 questions
10
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Is there a difference between a postulate and a principle in physics?
Is there a difference between a postulate and a principle in physics?
Both seem unproved statements taken as true. If thats correct, why the different names?
galmeida
- 407
- 3
- 12
7
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2 answers
What's the difference between constitutive laws and governing equations?
I'm studying about the finite element method in a class but I don't come from a civil engineering background. Anyways, it hasn't been made clear to me what the difference between constitutive laws and governing equations are. To me they both relate…
bmillare
- 257
3
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1 answer
Question about physical principles
How are principles created i.e. how is it decided that something qualifies as principle?
What is the difference between a principle, a law and a theory?
Were there any principles that were proved to be wrong or are principles always right? For…
please delete me
- 283
2
votes
2 answers
Does physics have some division schema which divide physical amounts into these two classes?
Does physics have some division schema which divide amounts into these two classes? :
A) amounts which can be counted by natural numbers (for example many units can be counted by number of electrons, photons per second etc.)
B) amounts which cannot…
user3123061
- 189
2
votes
1 answer
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 $1 \; \mathrm{bar}$.
How do I state my conditions…
George Tian
- 165
2
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1 answer
Why there are reduced properties?
In physics we frequently encounter with quantities that are 'reduced'. But why?
Why there are reduced Planck constant, temperature, pressure etc?
esilik
- 143
1
vote
1 answer
What are "packets"?
Paraphrased from Wikipedia:
Infrared sensing in snakes depends on a kind of natural thermography, by which tiny packets of cellular water are raised in temperature by the infrared radiation.
What is "packets" refering to in this is example?
5ives
- 25
1
vote
2 answers
Identify equation in "Men at Arms" by Pratchett
Does this (possibly corrupted?) equation look familiar to anyone?
$$ \mathrm{10^{-3} ( M_e / M_p ) \alpha^{6} \alpha^{G} - ^{1/2}N \approx 10N} $$
The equation is from the fiction novel Men at Arms by Terry Pratchett, first published in 1993, part…
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vote
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Theorem or Conjecture?
I understand the definitions "theorem" and "conjecture" in mathematics, but I wasn't sure for physics. I mean, if it's proved mathematically, it's a theorem, otherwise it's a conjecture. But for physics (i.e. when the idea is meant to correspond to…
user12345
- 2,283
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vote
0 answers
Found a weird piece of lab equipment?
My physics teacher found a weird piece of equipment in his classroom that was dated to the 70's. The item in question has no identifying marker except for "Carolina Biological". He has contacted the company and they told him it was a ring launcher.…
Nikolas
- 11
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Equivalent of the word "Attitude" for the other three DoFs
When discussing the physical state of a thing (e.g. a satellite), you can refer to its attitude state (which, to me, consists of its attitude and its derivatives/rates) and its.... non-attitude state (which, to me, consists of its position and its…
iAdjunct
- 111
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vote
1 answer
Doesn't linear motion include curvilinear and rectilinear motion?
From some Portuguese language textbooks, I learned the following definitions:
linear motion (movimento linear): motion along a line;
rectilinear motion (movimento retilíneo): motion along a straight line;
curvilinear motion (movimento curvilíneo):…
Leonardo Castro
- 175
0
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2 answers
Is Ansatz compared to Solution like Hypothesis compared to Theory?
I wonder how you would describe a correct use of the term "ansatz" in English physics literature? In German, "ein Ansatz" simply means "an approach". Could we say, in the context of theoretical physics, that an ansatz stands to a solution like a…
user373714
- 23
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Why do we say we "drop" perpendicular lines
I often see problems or hear people talk about problems where they say that one "drops" a perpendicular line. This YouTube video at 9:30 https://www.youtube.com/watch?v=GKYBX3KM7CY specifically prompted me to ask this question because he says "so…
Jack
- 517
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Single word to describe "homogeneous" and "isotropic" matter?
Is there a single word to describe materials which both have a homogeneous and isotropic permittivity and permeability?
There are just too many "homogeneous and isotropic materials" and "homogeneous and non-isotropic materials" in my text. And it's…
user224659