Rules inside the museums

In the last weeks we have visited several museums and old palaces with amazing sculptures and paintings inside of it and in all these ocassions the pleasure of taking pictures have been denied to us, but exactly why is this? One would think of many reasons but as always there is a scientific explanations for this. Light is an important factor that contributes to the damage of the painting. Light is composed of energetic particles called photons. The energy of the light varies with the wavelenght, the kind of light that damages the painting is the ultraviolet light that comes out when you take a picture.

The energy of the light can interact with the chemicals present on the paintings by exciting the outer electrons and therefore changing the conformation of the molecules by causing radicalic reactions whitin the surface of the paintings and making it so britltle that it cracks at the end. A big consequence of this is the fading of the pigments and dyes when exposed to the ultraviolet light. The light speeds the cracking caused by the addition of varnishes. The energy of light causes the bonds between the monomers of the cellulose constituting the paper to break, this is what causes the cracking. To prevent this kind of damage the museums reinforced their windows with a plastic material that absorbs UV light.

Another thing that is prohibited in the museums is to smoke, and again there is a scientific explanation for this besides the respect that you owe to other visitors that do not enjoy the smoke as much as you do. Dust and sand particles can damage the painting by altering the tone of the colors. Tobacco particles have the same effect and they are even harder to remove especially if the painting is not varnished.