Chapter 9: Contribution in Physics
Imam Jafar al-Sadiq (A.S) made many discoveries in physics which no one had even dreamt of before him and no one could think of after him. One of the laws worked out by him is about opacity and transparency of materials.
He said that materials which are solid and absorbent are opaque, and materials which are solid and repellent are more or less transparent.
When he was asked about the thing which is absorbed by an opaque material, he replied "Heat"
Today this theory is one of the Laws of Physics. How wonderful it is that in the 2nd century A. H., he could enunciate such a new and unique theory.