If the electromagnetic force is so much stronger than the gravitational force at any distance, then why do we have stars, planets, galaxies in our universe?

We learn that electromagnetic force is stronger than the gravitational force.

We know for a fact that electromagnetic force is much much stronger than the gravitational force. Orders of magnitude stronger.

(How did we come to know that? Take the two equations of both the forces and play with them. You will find the factor of strength. And how did we calculate the strength of electromagnetic force? That is an interesting deep question!)

The simple meaning behind it is that, take any two objects and keep them some fixed distance apart. Now in textbooks, you will often see everything kept 1 meter apart. That is just for ease of calculations and defining stuff. Then take any two charges, any combination – positive positive, positive negative, or negative negative – and keep these two charges the same distance apart as we did with the two objects above. Measure the gravitational force in the first case. Measure the electromagnetic force of attraction or repulsion in the second case.

What you will find is, the electromagnetic force is mind-blowingly strong! And at any distance. Even if you conduct the above measurements with the distance equal to billions of light years! To be precise, $10^{36}$ times stronger.

Then everything should repel each other.

All the matter has protons and electrons right? So even if in an atom, the electron is attracted by proton and vice versa, in case of multiple atoms, the electrons should repel the electrons of other atoms, and the protons should repel the protons of other atoms. Correct?

So by our above logic, if electrons should repel other electrons, and protons should repel other protons, then why do we have atoms that clump together by force of gravity? (As gravity between protons-protons and electrons-electrons is infinitesimally small). Why does gravity dominate on the large scale? (Notice, we said large scale. Why not the small scale too of atomic level?)

But in reality, in our universe, the stars do form. And the planets do form. And sometimes, life forms too! So there must be something wrong with our considered logic above. We must be leaving out something.


The galaxies do form


Stars and galaxies

The stars do form


The planets do form

The planets do form

This is how you think about concepts. You learn something like the relation between the strength of the electromagnetic force and the gravitational force. You then either conduct real experiments or conduct thought experiments based on theoretical results. And then you try to predict what will happen or what should happen in previously not considered cases like we did above. 

You then come across some startling results that your experiments give you. And like in our above case, they are clearly wrong. So the results must also collaborate with the observed phenomenon! This should make us realise that we committed some mistake somewhere in our considerations above.

We want you to think what it is that we did not consider and write us your answers at contact@edofox.com. Or in the comments below.

Stay curious!

Here’s a hint:

Think about the neutrality of atoms. Or consider the fact that electrons will attract the protons of other atoms and protons of other atoms will attract the electrons of other atoms. So what will this force of attraction do with the force of repulsion we considered above?

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