I found this interesting note in one of my textbooks,

The enormous strength of the electromagnetic force compared to gravity is evident in our daily life. When we hold a book in our hand, we are balancing the gravitational force on the book due to the huge mass of the earth by the 'normal force' provided by our hand. The latter is nothing but the net electromagnetic force between the charged constituents of our hand and the book, at the surface in contact. If electromagnetic force were not intrinsically so much stronger than gravity, the hand of the strongest man would crumble under the weight of a feather! Indeed, to be consistent, in that circumstance, we ourselves would crumble under our own weight!

What does this mean?


I think the part about electromagnetic force being exponentially stronger than gravitation got through to you!(An easy way to picture this is how static electricity can lift up things against the pull of the earth!) About the feather,the way you are able to support the feather against the gravitational pull of the earth is because of the electromagnetic forces exerted by your hand on the feather and vice versa. If these were much much weaker something as little as a feather would be able to crumple your hand, that is if it hadn't already been crumpled by gravity before that!

I've read in The Briefer History of Time (Stephen Hawking), that even very slight changes in the strength of the fundamental forces can cause great imbalance. If the electromagnetic force was stronger, atoms wouldn't be as stable as they are, and if it was weaker, atoms might not form at all, so the chances of life existing would be zero!

If there was a sudden change, hypothetically, this instant, the whole world could possibly crumble. But if that actually was the case we wouldn't even have been here.

  • $\begingroup$ Suppose that I place a mobile phone vertically on a table and get my hand as close as possible to one side of the mobile, then by the repulsion of the charged particles in my hand and in the phone, the phone supposed to fall down horizontally on the table, but I observed that it is not happening? $\endgroup$ – RogUE Nov 8 '14 at 14:06
  • $\begingroup$ Hi Rogue: I believe what you're not getting is this: you know when you "touch something"? Ie when one piece of wood pushes another piece of wood. in fact, fundamentally, that is achieved by electromagnetic force. That's what "ordinary, hard solids" are - what you're feeling is fundamentally the electromagnetic force. they are not talking in the quoted passage about anything at all to do with "electricity", static cling, etc. Just "normal everyday solids". $\endgroup$ – Fattie Nov 8 '14 at 14:56

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