The second one of the TED-Ed lessons I wrote about quantum physics has now been published: What Is the Heisenberg Uncertainty Principle. This is, again, very similar to stuff I've written before, specifically this old blog post and the relevant chapter of How to Teach [Quantum] Physics to Your Dog.

As usual, I tried but probably failed to do justice to other interpretations in the "Dig Deeper" references I sent; outraged Bohmians should feel free to comment either here or there with better explanations.

Again, it's really fun to see the images the animators found to put to my words. I love the mustache-hat-guy in this one.

In other notes, over 18,000 people have watched yesterday's video lesson on particles and waves. As I said on Twitter, that's more views than there have been students enrolled at Union during the 14 years I've been teaching here. (We bring in something on the short side of 600 new students every year, and there were three classes here when I arrived, so I've been a faculty member through at least part of the careers of around 10,000 Union students.) Which is an interesting bit of perspective...

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I taught high school chemistry for some 30 years and explained the uncertainty principle this way

Immagine a magic box partially filled with ping pong balls. You cannot see into the box but can put your finger into it to count the number and position of the balls. But in doing so you move the balls, some a little and other more so. So by the mere fact of counting the balls, you are uncertain of their position even though you may have a rough count as the number of balls in the box.

I enjoy these videos. I'd love to see something like them... and accordingly longer... that included the wave function perspective (i.e. the math) behind it at the same time.

David@1 - That explanation succumbs to the common problem with most explanations of the Uncertainty Principle. That is, it implies the uncertainty is due to a disturbance based on trying to measure the properties. While this is the angle from which Heisenberg originally came at the problem, it turns out that the Uncertainty Principle is a much more fundamental concept in quantum physics, and applies *even when no measurement is being done*. It's not "the disturbance of being measured" that causes the uncertainty (which is what your finger-moving-the-ball analogy implies), the uncertainty is an intrinsic property of quantum objects.

Really, please do (re)watch Chad's video. It's only 5 minutes, and it does a good job of explaining things without succumbing to the misleading standard explanation that the Uncertainty Principle is somehow about measurement.