In school today we were discussing the concept of "Matter Waves", and how all matter has a certain wavelength depending on its speed and mass. Because speed is determined relative to the observer this means that the wavelength of matter is dependant on the velocity of the observer. I'm not sure what implications this has, and I'd like to discuss that, especially with people who understand physics a bit better than I do. Also, is this the commonly refered to concept in "Quantum Physics" that so many people refer to to try to prove that the world is subjective, or random, or what not, or is that more closely related to Heisenburg's Uncertainty Principle, or something else entirely?