Matter is only energy stored in a certain form. So, all energy is matter and all matter is energy. Energy, theoretically, could be turned into matter and matter is continuously being turned into energy all around us in the form of chemical reactions.
The general trend is for all complex matter to break down into simpler forms of matter and, eventually, into energy.
Matter is generally defined by empirical science as the monistic substance that everything in the universe is composed of.
We often think of matter as physical or solid, but at the smallest levels of observation, matter appears to have no such properties.
The largest studies of matter are done in cosmology and astrophysics while the smallest studies of matter take place in particle and quantum physics as well as the more philosophical or mathematical studies in string theory.
There is currently a discord between those studying the quantum world and those studying the cosmological world.
It is interesting that we find the "solid" or "physical" world is overwhelmingly empty space.
It is the nuclear and electromagnetic forces that prevent us from being able to pass through other matter.
It could be that the world of matter we observe is an illusion, a hologram, and organizational forces are merely the rules and regularities of the natural environment we find ourselves in.
We have some reason to posit this type of reality; namely, the fact that particles can communicate instantly and over vast spaces.
Generally, we believe that matter is composed of atoms, which are made of sub-atomic particles such as protons, neutrons, and electrons.
Protons and neutrons are, themselves made of quantum particles.
Whether or not we will discover another layer of particles is open, though many researchers believe that quarks constitute a bottom layer of physical or material reality.
The graphic to the left of this page is meant to depict an abstract atom, with energy and light eminating from the center.
