Wed, 22 Nov 2006
Energy
Next on the list of things that people believe that aren't true is the belief that Einstein's formula E = mc2 proves that everything is really energy. There's two problems here. There's a misunderstanding of what energy is. Most people think of energy as an immaterial substance. For physics it is not, it is a property of a system, just as your height is a property. For physics both mass and energy are properties of systems. It's even more nebulous than that. For physics energy is defined as a differential, meaning that only a difference in energy levels is physically significant and the absolute amount of energy in a system is irrelevant. What Einstein showed is that the total amount of mass and energy in a system is conserved, but one can be converted into another. It's like a stick. When you lay it down it's one inch high and one foot long. But when you stand it up it's one inch long and one foot high. But neither the length or the height of the stick is the stick or its stickiness.
I think it's important to understand that even physics, thought of as the most fundamental science, doesn't talk about the substance or essence of things, it talks about their properties, because it's their properties that are observable and measurable. What things actually are is a question for philosophy. An electron has a mass and charge, but what is it that has the mass and charge? It was questions like this that drove me to Buddhism, where I got to ask similar questions about the mind. What is the mind, other than the ephemeral thoughts and emotions that pass through it? So the question didn't change, only its location did.
