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6

Yes. Ordinary quantum field theory is as wrong as Newtonian gravity for not including GR effects. That is to say, it is a perfectly fine theory inside its domain of validity, which in this case means pretty much everything below the Planck scale, just as Newtonian mechanics is valid for speed much less than the relativistic scale (the speed of light). ...


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here's an answer from Dr.Richard Feynman http://www.feynmanlectures.caltech.edu/II_01.html#Ch1-S1 You know, of course, that atoms are made with positive protons in the nucleus and with electrons outside. You may ask: “If this electrical force is so terrific, why don’t the protons and electrons just get on top of each other? If they want to be in an ...


1

in short, it is a fitting issue ... Many theories may solve a hierarchical classes of problems. ex for gravitation : newtonian mechanics ( NM ) and GR. Both work well always otherwise in critical cases where GR is necessary. All what NM does is well handled by GR but not the reverse. On another hand, GR is more complex than NM. When one has the choice ...


1

A "theory" is nothing more than a recipe to describe a natural phenomenon. There can be many theories to describe the same thing, just as I can use different words to describe the same object. Theories can be very different from one another for several reasons. They can describe the same exact phenomenology with different formalism (different words for the ...


0

Because a theory only covers what is known at the moment. In the future new features and behaviour may be discovered to apply in certain situations. A new theory must then be made that covers the old theory AND the new discoveries and takes it all into account. For example, the original Bohr model of the atom as electrons in circular orbits orbiting the ...


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My experience with the type of system you've described is that it does not follow the Poiseuille equation your friend gave you. That equation better fits low flow rates of viscous fluids through tubes of small diameter compared to their length. The pressure -flow behavior is best fit with an empirical based quadratic model: $$\Delta P = K_2Q^2 + K_1Q$$ As ...


1

The model is good as a probability model for quantum mechanics, up to the "superposition", where you say: Nobody knows where is the red and the black card, so each card is red or black with the 50% of probability. In other words each card is red and black at the same time (superposition). No , just the state of the card is unknown, it is not half ...


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Valves come in various trim sizes and shapes. The valve trim is the component in the valve body that moves up and down in the port to change the flow rate of water (or other fluid) based on valve position. If you get valve information, call the vendor, and tell him what valve size and valve trim you have, he can give you a chart that details flow rate vs ...


5

This actually extends beyond just computational approaches and applies to experimental approaches also. And it's not at all a trivial problem to address. Generally speaking, we construct a model of some physical system -- either computationally or experimentally -- and we make certain assumptions to simplify the problem. In your circuit example, maybe we ...



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