It states that any complex sound wave can be decomposed into a number of sine waves of different frequencies, each with a different strength, stacked on top of each other or superposed. This is Fourier's theorem, after French mathematician Jean-Baptiste Joseph Fourier. The sound wave from, say, an orchestra is extremely complex, but amazingly, it can always be broken down into a combination of many simple sine waves of different frequencies. The sound wave for a simple pure tone, like a middle C, is a sinusoidal wave, with the frequency determining the pitch of the tone. That shape determines what the wave sounds like to our ears. You can describe a sound wave just as the intensity of the wave as it passes by. So let's choose a type of wave that's a little more intuitive, sound waves. However, it turns out that something like the uncertainty principle arises in any wave mechanics. See, quantum mechanics is a type of wave mechanics. To understand the origin of the uncertainty principle, we don't need to know any quantum mechanics, at least not to start with. It's, instead, a statement about how much information we are ever able to extract from a quantum system. The uncertainty principle exists alongside this observer effect. Try to perfectly nail down a particle's position, and we have complete uncertainty about its momentum.Īnd it's not just because our measurement of position requires us to interact with the particle, therefore changing its momentum, no. We cannot simultaneously know both position and momentum for a quantum system with absolute precision. The uncertainty principle is most often expressed in terms of position and momentum. If we fully unravel this idea, we'll be on the verge of tackling things like Hawking radiation.īut as you'll see today, in that unraveling, we are led unavoidably to Heisenberg's uncertainty principle. The vacuum itself can be thought of as constructed from the sum of infinite possible particles. The universe we experience seems to be constructed of singular particles with well-defined properties, but this intuitive, mechanical reality is emergent from an underlying reality in which the particles that form matter arise from the combination of an infinity of possible properties. See, the apparent weirdness of the uncertainty principle hints at an even weirder underlying reality that gives rise to it. We've discussed it in earlier videos on quantum mechanics, but it's time we looked a little deeper. It expresses the fundamental limit on the knowability of our universe. 13 00:00:33,750 -> 00:00:36,990 One of the most difficult ideas to swallow in quantum mechanics is Werner Heisenberg's famous uncertainty principle. Today, the humble sound wave is going to open the door to really understanding Heisenberg's uncertainty principle, and ultimately, quantum fields and Hawking radiation. Sometimes intuitive, large-scale phenomena can give us incredible insights into the extremely unintuitive world of quantum mechanics.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |