Quote Originally Posted by Rollo View Post
The Sea of Dirac.

It explains anomalous negative-energy quantum states of relativistic electrons - and also predicts the positron.
In quantum mechanics we can only talk about the probability of finding an electron; that gives us position and zero size.

The smallest sea in the world is 0.0nm across.
That's a very ingenious answer, I'm impressed (and would not have thought of it in this context myself). Unfortunately it is not a real sea but a theoretical model and I'm looking for a real one.