Watching The Electrons

You’ve all heard of electrons I assume. Particles within atoms that, among other things, determine the sorts of chemical reactions those atoms can take part in but more importantly without which much of modern life – and the mysteries of the world wide web and internet through which you are reading this missive – could not take place.

They are usually represented as moving in circles around an atom’s nucleus (see some of the pictures here.)

They don’t. The circles are just an easy way to picture how far away from a nucleus they are and how much energy they have.

More accurately they occupy certain volumes of space (orbitals) around the nucleus. Which is to say that the probability of their being in that volume is more than 99%.

This is an outcome of quantum mechanical calculations on electrons and their properties.

One of the ramifications of Heisenberg’s Uncertainty Principle was that you could never know simultaneously both the position and velocity of an electron. If you knew one’s speed you did not know its position, if you determined its position you couldn’t know its speed.

One of my lecturers when I was a student thought that this was unlikely and called the Uncertainty Principle, “the Phlogiston Theory of the Twentieth Century.”

Well, it seems that physicists are now able to watch electrons moving in real time.*

Though the details are quite dense (and probably incomprehesible to anyone without a background in Chemistry or Physics) it’s a measure of how sad I am that I found this information irrationally exciting. It deals more with movement of electrons between orbitals of different energy than of electrons within their orbitals. It doesn’t violate the Uncertainty Principle.

* Thanks to Guthrie at his blog for bringing this to my attention.

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