So energy apparently equals mass times the speed of light squared. According to Einstein anyway. I was taking an objective look at this theory or whatever it's called just now and I got to wondering...what exactly does Einstein mean by "energy" and what does the speed of light have to do with it? I'm no physicist, but it seems to me that the speed of light is just some random number and I'm hazy on what how he defines "energy." Does he mean total potential work possible from a piece of matter? If so, how does he know it's not infinite? I mean, aren't there physics theories out there that say that this sort of pattern of things revolving around things goes infinitely small. By that I essentially mean, there are particles within an atom's components acting in the same way that the earth does in the relation to the Sun in the solar system, to the center of the galaxy, and then the universe and all that. Yeah, please forgive my lack of physics knowledge, but I just thought I'd try a skeptics view at this stuff for kicks. Thanks in advance for your patience and replies. I was sitting on the toilet just a minute ago thinking that perhaps nuclear fission isn't a result of an immense amount of energy existing within a single atom, rather just due to the contagiousness of a single loose proton. by that i mean a single atom might not have an unbelievable amount of energy, rather a loose proton has the ability to cause a massive domino effect in the same way an army of trillions red ants would be more potent a weapon than one bear, but that doesn't make a single ant more deadly than a bear. i hope that makes sense...and again, please excuse my ignorance. another way to look at it: while an atom involved in a fission reaction can cause an immense impact on the atoms around it, that same single atom, if it is completely isolated from any other atom and was split the same way, would be unable to affect the surrounding atoms. it seems to me that the energy within a single atom is dependent on its surrounding environment which it can effect and it seems to me that there is always a way to increase the impact the same atom can have on its surroundings, whether that be by placing atoms around it in a certain way or varying temperature or whatnot. maybe not infinite with there being certain physical constraints, but the energy is certainly varied based on the atom's environment. this is based off the definition of energy i found off another website and stated two paragraphs up. the potential amount of work capable of a whatever. following the same logic, the amount of work that can be done by a single carpenter can be varied based on giving him manual tools vs power tools. increasing the usefulness of the supplies. is the energy of this carpenter changing here? i mean, it seems to me that in this case, there is no maximum limit to his "energy" as there are probably an infinite number of ways utilizing technology and more efficient ways of working to increase his productivity. but in the end it's the same guy. i dunno. it just doesn't make much sense to me that the potential energy of anything is finite.