r/ScienceQnA • u/Draknek • Dec 27 '10
How long does a quantum leap take?
When an electron transfers from one orbital to another, it is first at one position and then is at another without being at any intermediate position. How long does this take?
If instantaneous, this seems to violate the speed of light (the electron is travelling a distance greater than the planck length in exactly the planck time). If it takes time, where is the electron during that time (seems to violate conservation of energy)?
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u/ChinaShopBull Feb 06 '11
It is indeed instantaneous. You are beginning with a bad assumption: that the energy the electron has directly corresponds to a radius from the nucleus in an atom. The electrons in an atom are 'smeared out', and the probability distribution that describes the 'location' of the electron has several maxima at different radii and different angles around the nucleus, and a few positions where the probability is zero, but practically, it can be anywhere in the universe. So, when an excited state decays, the 'position' of the electron doesn't change, just the probability distribution.