Thinking about the space between the subatomic particles in atom -- and how small they are relative to their atom's size -- isn't it rather convenient that the strength of those forces that govern the way they dance around... tend to keep us floating about 4,000 miles above the center of the earth? That's a lot of earth and it's a long way down. Imagine YOU trying to hold up all that weight. You'd probably give up in a day. I call it luck.

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    $\begingroup$ Is this a serious question? $\endgroup$ Commented Jan 31, 2012 at 6:38

1 Answer 1


You may call luck that the various physical constants for the interactions which lead to forces , (gravitational, electromagnetic, strong, weak) hbar and c have the values they do. Others call it the anthropic principle, as we would not exist as observers except for a narrow range in combination of these constants. Most physicists are pragmatic and accept them as is.

But you should read more about physics, since what is holding us up from the center of the earth is not in particular the strong force, but the electromagnetic. Anything we see, touch, smell, hear, taste ( five senses) depends on the electromagnetic force, not the others. The others are a necessary framework that cradles us, but we see/sense the world through electromagnetism and store the information in our heads through electromagnetic interactions.

It is the electrons on the atoms of the ground that are repelling the electrons in the atoms of our shoes and feet so as not to fall through to the center of the earth. Like those russian babushka dolls which are nested withing each other, the other forces are nested and of course equally necessary for the existence of nuclei and therefore atoms, and the existence of livable planets, but as first in human relevance, it is electromagnetism that reigns supreme.

  • $\begingroup$ So the force that pushes atoms away from one another, and prevent them from overlapping, is the electromagnetic force? $\endgroup$
    – blink
    Commented Jan 31, 2012 at 5:40
  • $\begingroup$ Yes, it is the electromagnetic force that prevents atoms to interpenetrate. $\endgroup$
    – anna v
    Commented Jan 31, 2012 at 6:55
  • $\begingroup$ This is misleading. "hbar and c" are dimensionfull constants, they can be set to anything. $\endgroup$ Commented Aug 21, 2013 at 16:53
  • $\begingroup$ @Dimension10 Can you elaborate? In our given system they have a given value. It is not an arbitrary one. $\endgroup$
    – anna v
    Commented Aug 21, 2013 at 16:57
  • $\begingroup$ @annav: I meant that there's nothing special about these dimensionful constants having these values, they are only what= they are because, of the units that humans use. $\endgroup$ Commented Aug 21, 2013 at 16:58

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