Fish-shop Window

Is the glass of water half full or half empty? It doesn’t matter, actually – the water molecule has some really fun properties. It behaves differently from most other liquids, and this window shows an example of this.

It used to be possible to recognise a fish-shop by the water it had running along the inner surface of the shopfront window as cooling. The ability of water to stick to itself and at the same time stick to other substances means that it can run along a vertical glass surface. The phenomenon depends on the surface tension and adhesion of the water, which are consequences of the water molecule being a dipole with weakly charged plus and negative sides.