Here is a Youtube video that captures the voice of the great physicist Albert Einstein explaining his famous equation, e=mc2.
There are a number of implications for Buddhist thought. First of all, the interchangeability between matter and energy seems to support the notion that things do not have inherent characteristics. If a seemingly solid thing like a lump of matter could be interchangeable with energy, then matter itself does not have what is normally conceived of as having, namely its spatial shape, its mass, its solidity, and so on. It’s only a short route from this to the claim that all things are but “empty” as Nagarjuna said. Whether something is matter or energy perhaps depends ultimately on *our* point of view. Language and conceptualization have a magical way of “creating” something out of what is essentially “nothing.”