How to interpret the movement of air in nose in the two parts of breath : inspire and expire in terms of the 4 interactions of nature, gravitational, electromagnetic, weak, strong interactions ?

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    $\begingroup$ That's really just fluid dynamics. No need to go deeper than that $\endgroup$ – Hilmar Oct 1 '19 at 20:55
  • $\begingroup$ Sure but how to make connection to the only 4 fundamental interactions of nature ? $\endgroup$ – Mathieu Krisztian Oct 1 '19 at 21:48
  • $\begingroup$ Gravity has an impact on what atmosphere you breathe. The rest is E&M through chemistry... $\endgroup$ – Jon Custer Oct 2 '19 at 0:42
  • $\begingroup$ Lungs expands and compress. That pushes on air molecules. They push in other air molecules. Which push in other air molecules... Every time a push takes place, we can zoom in to the nano scale and see that a "push" between molecules or atoms is just electromagnetic repulsion $\endgroup$ – Steeven Oct 2 '19 at 5:07
  • $\begingroup$ Electromagnetic interaction would explain pushing the molectules but not pulling molecules when we breathe. Pression is not a fundamental law of particle physics. I search how to reduce pression to fundamental interactions $\endgroup$ – Mathieu Krisztian Oct 2 '19 at 6:27

You have to realize that different mathematical models are used in differing frameworks. The mathematics modeling is appropriate to the framework, and the forces and assumptions used in the models differ. There is a hierarchy though:

Take thermodynamical models:the hierarchy is: thermodynamics with its laws, which emerges from classical statistical mechanics with its laws, which emerges from quantum statistical mechanics with its laws, which emerges from single particle quantum mechanics with its laws.

Laws, principles, postulates are different from level to level to enable to pick the correct mathematical solutions , except conservation laws of energy, momentum and angular momentum.

Fluid dynamics that describe the motion of air depend on the gravitational field that your nose exist, but do not affect the input output of breath, as pressure is a constant where you are. Electromagnetic theory is enough to explain the motion of muscles, although quantum theory is also necessary to explain temperature (black body) and energy supply. (biological and chemical reactions at the quantum level). In this sense the electromagnetic interaction plays the main role.

The weak interaction is not needed macroscopically. The strong interaction keeps the nuclei of atoms in air and your body but is not taking part in the fluid motion.

So even though weak and strong exist so that atoms in your body and the fluid air have the behavior you observe, it is not an effect that affects the motion of the fluid.

So the concept to keep in mind is the concept of "emergence" when thinking of different levels of interactions.

  • $\begingroup$ Anna has the key : emergence in physics. I thought all could be reduced to the 4 fundamental interactions. Is it not the case ? $\endgroup$ – Mathieu Krisztian Oct 2 '19 at 6:25
  • $\begingroup$ If we did not have these four interactions the world as we know it would not exist. Weak interactions limit the numbers in the periodic tabe l(by introducing instabilities) , strong interactions keep the nuclei on the stability curve and give stable nuclei so that stable atoms can be formed with the electromagnetic forces, and gravity allows the atmosphere to exist. But as I stated, the various levels of our world are emergent from the lower ones, the lowest being the elementary particle, in a complicated mathematically way. $\endgroup$ – anna v Oct 2 '19 at 7:43
  • $\begingroup$ Sure and I try to understand how high level world works from low level world. This is the sense of my question with an example of pression that attract or repulse air by unknown force. Il people would use electromagnetism to push molecules then how to attract them. Molecules charges don t change. People are eluding my question $\endgroup$ – Mathieu Krisztian Oct 2 '19 at 16:58
  • $\begingroup$ electricity and magnetism can be both attractive and repulsive at the macroscopic matter level. There are spill over fields in the atoms and molecules that generate positve and negative electric field regions,, as well as magnetic fields. $\endgroup$ – anna v Oct 2 '19 at 18:40
  • $\begingroup$ Sure but this does not explain why air changes of direction during the breathe since the charge will not change of sign during breathing $\endgroup$ – Mathieu Krisztian Oct 3 '19 at 6:38

The movement of air into is not because of any force exerted on it. The lungs in our body have a diaphragm which essentially controls the volume of the lungs. When we are about to breath in, the diaphragm contracts and the lungs become an region of low pressure as compared to the atmosphere. Hence the air moves from high pressure to low pressure.


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