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How electrons and protons and atoms make a whole object

  1. Oct 2, 2016 #1
    heisenbergs uncertainity says that we can never predict the position and velocity of a particle exactly simultaneously. that is we can never be sure where an electron or a proton would be seconds from now. its all about probablity.

    then how can these particles together form something like we humans or the objects around us which arent like these constituent particles?
     
  2. jcsd
  3. Oct 2, 2016 #2

    mfb

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    No, it says those quantities do not even exist exactly simultaneously. It is not a limit of our measurements.
    The uncertainty is tiny, and irrelevant for macroscopic objects. As an example, the position of electrons in an atom is uncertain - but you can still be certain that the electron is part of the atom. And atoms are too tiny to see them (with light).
     
  4. Oct 2, 2016 #3

    ZapperZ

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    Not sure how your first paragraph relates to your second. I don't see the logical connection between the two.

    The HUP says that, UPON A MEASUREMENT, our accuracy to predict a certain value will depend on how well we can predict the other corresponding value. But this effect, as mfb has stated, is VERY, VERY small. Otherwise, we will have seen it all the time and it won't be that unusual.

    Now, unless you have a microscopic creature that continually spy on what your electrons and other sub-atomic particles are doing in your body all the time, these particles are NOT being continually measured and observed, which means that HUP is not directly in play when you just leave it alone.

    Zz.
     
  5. Oct 3, 2016 #4
    Even in an atom, the position and momentum of the electrons are uncertain, and wavefunction for position looks like a cloud, so we talk about an electron cloud. The total energy is known, but the potential energy and kinetic energy of an electron in the cloud are uncertain.
     
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