Abe Recommends: Magnets

My brother Abe sends me a lot of cool videos and articles about science: recent research, new inventions, educational materials, or the work of grad studentswho aresharing presentations of their findingson YouTube.This week he sent me this great video, explaining why iron is magnetic and how magnetic materials work, which actually has a surprising explanation:



Noah: So what is this exactly?

Abe: It's called MinutePhysics. It's a collaboration between several awesome YouTube educators: Henry Reich and another guy, Derek Muller, whoruns a channel called Veritasium. You'll see that there'sanother video produced by Veritasium that follows from this one.

Noah: Cool. So what caught your attention with this?

Abe: Well, Henry Reich is amazing. Both channels are really good at explaining things. Thisexplains how electricity and magnetism are related to each other due to general relativity. That’s an amazing feat of education.

Noah: Yeah, and in a very short amount of time, too. It's only about six-and-a-half minutes long.

Abe: Exactly. They're able to convey complex ideas to a lay audience without talking down.

Noah: Yeah, I saw that "How Far Can Legolas See?" video.That could be really cheesy unintentionally. But it's actually levelheaded and straightforward enough to be not so, you know, like catchy for its own sake.

So why the magnets video in particular? Is it because of Insane Clown Posse? [WARNING: That link goes to a YouTube video thatcontains some profanity]

Abe: Well, among MinutePhysics'videos, this magnetism one blew my mind the most. Their explanation thatmoving charges + relativity = magnetism�"I never knew that and it's kinda awesome.

Noah:Yeah, it's kind of crazy how stuff we think of as being high-level physics (since it's not mechanical and Newtonian) sort of has a really big influence on seemingly mundane phenomena.

Abe: I remember learning the “right-hand rule” in high school physics and thinking it didn’t make any sense. How come electric and magnetic fields always act perpendicular to one another? A charged particle moves through a magnetic field and the field exerts a force on the particle that’s perpendicular to both the magnetic field and the particle’s velocity. Why? How does that make any sense? They're able, like that rule, to make a complicated subject simple and understandable. But rather than just giving you a tool for getting the right answer, they explain to you whyand how the phenomenon operates.

Noah: What do you think about their use ofdrawings? You seem to gravitate to stuff that has some cool animation-type elements, like RSAnimate and similar series.

Abe:I like the use of the medium (video) as a teaching tool. I always felt like my college education would have been a lot better if I wasn't learning from limited media like PowerPoint slides and diagrams in books. Motion is intuitive to people.

Noah:That's really interesting. Why do you think that is?

Abe: Well think about it: vision makes up a huge percentage of our overall sensory input�"I think it's something like 85%. And most of the world we see is in motion. In fact, I know of a great video that suggests that motion is important for us to be able to make sense of vision.

Noah: That's cool. But,I mean, it's magnets�"how exciting can they be?

Abe: Well, magnets are the topic of a lot of pseudoscience. And as much as I laugh at ICP, I never actually knew how magnets work.

Noah: Really? I learned about them from MacGyver when I was, like, three years old: