Abstraction from the perspective of Art and Science

While visiting the museum of Modern Art in Paris I was constantly thinking on what is the meaning behind all these art work which really does not easily convey the theme behind it. 

In my opinion art could be divided into two distinct categories the antique art (for e.g. renaissance paintings) vs the modern art. Antique paintings convey the theme directly, for example paintings such as Monalisa convey the depiction of European woman's portraits with its mystery smiles etc. The theme in general here could be human nature and its mystics. However, modern art is very very abstract in its nature. Many of the paintings I saw had just rectangles painted in the same color as the wall they were showcased on. Or one rectangle with a tilted side superimposed on a triangle. This the geometric perspective. Then there were many creations which used day to day objects such as a leather bag, a spoon etc. And then there were so many more which I could not understand. 

In Science too, abstraction is the theme. Science is all about asking abstract questions and then trying to find an answer to them. So the theme here is exploration of the observed abstraction and understanding why the observed facts are the way they are. So this is more of a top down approach where one starts with abstraction and then divulges into it. 

Modern art differs in this aspect I think where the big picture itself is so much abstract that most of the time understanding the theme being conveyed becomes an abstraction in itself, because the theme usually rests on the personal context of the creator. And it is not universal as in the case of the Science. Understanding an Art Work could therefore have too many dimensions from its creators perspective. The abstraction in Science gets conveyed using the method of publication of theory or experimental results. The focus here is to be as simple in conveying the abstract idea so that it makes sense. A modern art creation also differs here because it defies the sole purpose of simplicity by being extremely abstract in its nature. 

And there could be many more arguments like this ...