This may be a stupid question but I was wondering why, if I break a stone or any other object in two parts, and then I try to put these two parts together they don't stick to each other. I mean, the bonds that were keeping those atoms together have been broken so whenever they are put next to each other they should theoretically attract each other back..? Thank you

  • $\begingroup$ @IvanNeretin Hmm. Well, I am not even sure what actually happens to the bonds when the object gets broken. do they rearrange themselves or they stay exactly as they were? if they don't move then your could be a valid answer :-) $\endgroup$
    – MeV
    Jul 17, 2017 at 17:09
  • 1
    $\begingroup$ Paraphrasing what Feynman once said: Suppose you snap a block of pure copper. If you were to somehow prevent any impurity/oxide layer from developing at the newly formed surfaces, and if you were to bring the blocks together again... they would stick. It's because there is no way for the copper atoms to "know" that they belong to different blocks. : This was an interesting piece of insight, so I thought I'd share it with you ;) $\endgroup$ Jul 17, 2017 at 17:31

1 Answer 1


Depending on the chemical nature of the stone, the bonds may rearrange themselves to be quite content with their new situation, or they may be left dangling for a while. In the last case you should be able to put the halves back together, given the following conditions:

  • The dangling bonds do not react with the components of surrounding air;
  • The break-up surfaces remain very clean (no debris from the fracture, no dust in the air);
  • You can put the parts together with atomic precision.

Each of these conditions is unlikely enough in itself. And if any of them fails, then the stone will behave as usual, that is, remain broken.


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