Everyday experience leads to a mistaken understanding about the nature of our world. We get the sense that most phenomena are continuous. We think that a playground swing can swing ever more slowly until it gradually and continuously comes to rest. We assume masses can vibrate just a little bit, and can gradually, and continuously be damped to rest - or be made to move more vigorously in a similar, gradual fashion. We get the idea that planets can orbit at any distance (and with whatever orbital energy) from the sun or that ping pong balls can rotate at any finite rate. Experience and experiment leads to these conclusions only until the systems of interest become very small, or our measurements become very precise. [br][br]When we observe very small systems on the order of the size of molecules, the world behaves very differently than what we perceive in our macroscopic world. It becomes obvious that [b]vibrations and rotations, as well as the associated energies of motion, are discrete[/b]. If you are not familiar with the term discrete, it is to be contrasted with continuous. Mathematically we have discrete Riemann sums versus continuous integrals. You can climb a continuous ramp, or discrete stairs. [br][br]What physicists have found is that the world is actually full of discrete phenomena, without exception. Even the translational speed of objects moving through open space is in principle discrete in a finite space. This literally means that if you could attach a speedometer to anything moving in our universe, that the speed increases or decreases in little jumps as things speed up or slow down, and not gradually, as it seems. I hope you find this troubling and ridiculous sounding. Problem is that it's true. [br][br]The impression that we get of the world being continuous is therefore in error. The error arises in our observations of the macroscopic world only because the "steps" are so small that we don't see them in our ordinary, macroscopic world, and instead perceive the steps as continuous "ramps".[br][br]The steps about which we are speaking are called[i] quanta[/i], from the Latin quantus, which means "how much". The singular of quanta is one quantum. One quantum plus one quantum gives two quanta. [b] In nature, everything is quantized, or made up of discrete quanta.[/b][br][br]There is another misconception here as well. We get the idea that the world is made of both physical objects (or particles) as well as wavy things - like light perhaps. It turns out that the [b]particles literally are the quanta of the wavy fields that exist in nature[/b]. In other words, the smallest possible waves in nature are the things that we mistake for particles. The "particles" are quanta of unfamiliar matter fields such as the lepton field or the baryon field. This will warrant more discussion. Let's look at the first hints that nature gave us to lead to these conclusions.