If you want a strong magnet, the obvious answer is to buy one. However, for a variety of reasons, you might want to combine several smaller magnets. There are a few ways to do this, but the Halbach ...

If you want a strong magnet, the obvious answer is to buy one. However, for a variety of reasons, you might want to combine several smaller magnets. There are a few ways to do this, but the Halbach ...

Now I know why that particular combination of sensitive to magnetism and not sensitive didn't happen naturally during Earth's long gestation. We never would have gotten anything done. It might beat ...