In the world of Pokèmon, creatures cute and fearsome are forced to fight one another by their trainers for personal amusement. But its fun, and the little buggers are left relatively unharmed (aside from Gary's Raticate, may he rest in peace), so hey, no harm no foul, right? And considering that this universe was able to spawn said creatures, it must operate on a slightly different set of rules, right? Yet one specific aspect of the universe tends to break a law that, for the most part, is held constant. That aspect is Pokèmon evolution, and the Law of Conservation of Matter.
While animals in real life are known to grow over a long period of time, Pokèmon can go from a small, 10 kg fish to a raging, 235 kg dragon in a matter of seconds, an almost 2300% increase in mass. This has to break the Law of Conservation of Matter, right? Well, as a recent Game Theory video points out, it might not. To sum up the video's theory, which uses the same example, during evolution, the 'mon absorbs matter from the surrounding environment, until it has enough materials to become said giant dragon. However, the video assumes that the 'mon absorbs specific compounds, and as such, shouldn't be possible, due to the low density of certain resources in most areas. However, the video fails to notice one specific alternative:
Einstein's Theory of Mass - Energy Equivalence.
According to Einstein's theory, mass and energy can be related with the equation: E = mc2. Assuming that Pokèmon uses this principle in evolution, they would only need to store enough energy to convert to the required mass, which also explains two things: the flash of light during evolution, and evolution via stone/location. The flash of light could be released during the process as extra energy lost in kick-starting the process, while evolution stones and locations could contain large amounts of energy which specific 'mons have catalysts for, allowing for them to evolve without the need for a long energy gain process. Heck, even trade evolution could be explained, being the 'mon is temporarily converted to energy, and the transfer could supply a large amount of energy which essentially catalyzes the evolution.