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Questions tagged [models]

DO NOT USE THIS TAG just because the involved physics is based on a model. All physics descriptions are inherently model-based. This tag is reserved specifically for addressing model development, validity, simplification, or other meta-model questions.

DO NOT USE THIS TAG just because the involved physics is based on a model. All physics descriptions are inherently model-based, so this tag is not useful for questions about applying or understanding a specific model. Rather, this tag is reserved specifically for addressing model development, validity, simplification, other meta-model questions, or the nature of models within physics.

393 questions
4
votes
1 answer

Are there microscopic theories, which work, but which wrongly predict macroscopic behaviour?

Motivated by this question (and the P. W. Anderson article linked in that question, which I came across here somewhere today and just read) I wonder about something, which is somewhat bordering an inverse idea of effective field theories: Can a…
Nikolaj-K
  • 8,443
1
vote
2 answers

Does a scale model with 1/2 the linear length have 1/8 the mass?

If a scale model has 0.5x the original length in all directions, should its mass be 1/8th of the original mass?
DarkLightA
  • 1,422
1
vote
1 answer

Simple mobile - From data points to model?

Here is some background : I'm taking part in a programming challenge in which you control a racing pod that has to go from checkpoints to checkpoints to win a race. You are allowed to specify the thrust (in [0;100] ) of the pod and a target point. I…
Furrane
  • 113
0
votes
4 answers

What is a theory?

I was reading brief history of time by hawking and there I stuck on this line “A theory is a model of universe or a restricted part of it and a set of rules that relate quantities in the model to observations we make.” What is it saying? Please…
cOnnectOrTR 12
  • 143
0
votes
2 answers

How to model a water plant valve

I'm looking for a mathematical model of resistance in valve. Some relation between drop of pressure $\Delta p$ and volumetric flow rate $Q$. I got this tip from some colleague to use formula for resistance of tube written below: \begin{equation} R…
user50222
  • 179
-2
votes
2 answers

Is there a way to represent whole objects in a formula?

In physics I always see formulas with variables representing properties of objects like (this is a simplified example): F = a bodies force. m = a bodies mass. a = a bodies acceleration. But why do I never see variables representing whole objects…
Richard Bamford
  • 97