Today in AP Chem, we began to discuss the behavior of electrons, most specifically, in regards to light and light energy. Most of what we looked over was old news from Physics last year, as far as the relationships between speed of light, frequency, and wavelength. However, this equation brought back some ideas that we looked at last year:
We often times looked at this equation in Physics-B to analyze matter-wave duality, since light behaves both as a wave and as a particle, known as a photon. Light is transmitted in waves, like energy, but also carries momentum due to the fact that it possesses particle properties (the mv of the equation above).
I always found it rather humorous last year when we did practice problems involving the wavelength of a rather massive object, clearly not a sole form of energy travelling in waves - such a problem I recall involved a bowling ball. Let's find the wavelength of myself, shall we?
Let's say I am strolling along one day at about .5 m/s (I am not sure what speed the typical human travels at). My mass is approximately 58 kg. Using Planck's constant and the equation above, my "human wavelength", as I like to call it, can be calculated:
wavelength = 6.63e-34Js/(58kg*0.5m/s) = 2.286e-35m
So, what does this mean? Well... basically nothing. Said "wavelength" has such a small magnitude that it is insignificant. A human is obviously a human, and not energy. This equation comes into play at the quantum level of physics. Since light is soooooooo tiny compared to a human, such changes between wave and particle properties can be detected: thus, light is able to have momentum, yet also travel in transverse waves. Could you imagine a human performing double slit diffraction? Neither can I. Those would have to be two interesting looking slits.
Basically, I just think that matter-wave duality is pretty cool. Who knew, years ago, that light could live in both the realm of wave and particle? Oh well, just something to think about.
Until next time, Fizzix Community, until next time.