Deep Shit: The magnetic force

I am working on some changes to the site right now that will hopefully bring you a bit more of the things you’d like to read, and at the same time, give me a great outlet for telling you some interesting things about Star Wars and science — two of my very favorite things. I will get into the details of what that all means in another post down the road, but I thought it would be fun toss an idea out to you for one of my new columns.

My wife came up with the name for this column after I told her that I want to share some of the extra things that I research when creating my Sciencing the Shit Out of Video Games column on GameSkinny. I usually spend a day researching any one post. I usually try to approach any of the ideas from different angles, so the resulting column is usually only about 10% of the information that I have actually gathered on the subject. But there is so much fascinating stuff to be discovered when you combine science and video games. Although I will likely not be able to share the other 90% in this column, but it does give me an outlet to share, and hopefully, you enjoy it, too.

In this week’s Sciencing the Shit Out of…, I talked about Alolan Raichu. Although Pokemon was never really my thing, there might be child or two in my house who are really interested in it, and who might be excited about Pokemon Sun and Moon hitting the shelves soon. When I saw the gifs of Alolan Raichu, I loved the look and the idea that he floated on his tail. However, I didn’t like the idea that he used telekinesis to float himself on his tail. I’ve actually never really liked that TKs could float themselves. So I looked at a couple of alternatives. Both of them were hoverboards. They are similar to each other, but worked in two very different ways. I think after you finish reading, you’ll understand why I chose to focus on the Lexus board.

The Lenz effect

The Hendo hoverboard was probably the first hoverboard we thought about in 2015 — the year of Back to the Future 2. The great thing about this board was that it actually floated above the surface of the earth and had zero friction. It seemed to not require anything to stay afloat. Although it was bulky, we knew it was just a prototype, and it would likely get thinner and more streamlined at its final release. Unfortunately, it doesn’t work exactly the way we want it to, regardless of how thin it ends up.

The Hendo hoverboard relies on Lenz law, which was discovered by German physicist Heinrich Lenz in 1834. Wikipedia says that Lenz law is this:

“The direction of current induced in a conductor by a changing magnetic field due to Faraday’s law of induction will be such that it will create a field that opposes the change that produced it.”

If you’re not a physicist, that probably means nothing to you, so I will breakdown simply for you in relation to the Hendo hoverboard. If you drop a magnet through a conductive material it will create an opposing magnetic field which will cause resistance. In practical application, if you drop a magnet through a copper tube, it will drop more slowly than a piece of iron of the same mass. The same kind of field is generated if you spin the magnets around in a circle, and that’s how the Hendo board works.

There are two rotors on either side of the board, spinning. The magnets are arranged in what’s called a Halbach array, which creates a higher magnetic current on one side over the other. (More on this later.) This will increase the resistance on the bottom side of the board, giving the board more ‘lift.’

Here’s the big catch with the Hendo board and why it’s not as amazing as we want it to be: The board has to be placed over a conductive surface, like copper, in order to work. The two rotors spin, and when placed over the copper sheet, they float. It requires a spinning motor and a highly conductive surface to hover over. Sorry, you can’t hover over concrete.

halbach_array_field

A Halbach array

The GameSkinny article talks about the the Lexus hoverboard, in pretty good detail. However, I did leave out some related but not wholly relevant information about the track itself. Besides the supercooled conductive material in the hoverboard itself, the track is laid out in a Halbach array with extremely powerful neodymium magnets.

The basic breakdown for a Halbach array is to place two poles of the same ‘spin’ next to each other. There is usually a lot of resistance, and the magnets have to be held together physically. However, this is the source of the lift generated by the track, and it is extremely powerful. In the Lexus video, it’s demonstrated by the magnet flipping the coin. The coolest thing is that you can likely make one of these at home with some powerful magnets and a hot glue gun, but wear goggles just in case one of the magnets goes flying.

Thanks for reading Deeper Shit. If there are any video game tropes that you’d like to see me science the shit out of, let me know in the comments here or on GameSkinny. Also what are your thoughts on hoverboards? Do you think we will ever see one that doesn’t use some trickery like a metal track? Let me know your thoughts about this or about this column in general in the comments below, and I will talk you again next weekend.


About Larry

view all posts

Larry writes for many different gaming news websites, including Massively, GameSkinny. You can catch him weekly on Gamebreaker's The Republic and read from his Star Wars fan site Hyperspace Beacon.