字幕列表 影片播放
-
Quantum mechanics is weird, right? But did you know that some of its supposed peculiarities
-
are not unique to quantum physics but are just properties of waves in general?
-
Take the uncertainty principle - it says that the better we know where a particle is, the
-
less we know about how fast it's going. There's a limit to how much we can know! But this
-
isn't just quantum weirdness - it happens all the time with normal everyday waves!
-
Remember that the frequency of a wave is how close the wave crests are to each other - a
-
low frequency wave doesn't have nearly as much oomph as a high frequency one!
-
And the position of a wave is… well, where the wave is… mostly. So where exactly is
-
a wave? It's spread out everywhere, right? Ok, but for a wave pulse it's pretty easy
-
to see where the wave is. So now that we know where the pulse is, what's it's frequency?
-
Well, a localized pulse doesn't really "wave", so we can't measure the frequency of its crests!
-
And that's the uncertainty principle in a nutshell - you can either know where a wave
-
is or where it's going, but not both at the same time!