FYI: What's the lightest metal on Earth?

If you answered 'any lump of metal somebody else is carrying,' then you're sarcastic.

If, on the other hand, you answered 'metallic microlattice,' I'm thinking you probably already watched the video.

The challenges of materials science often boil down to some combination of 'make it lighter, cheaper, stronger.' Cut down the material's weight, and we can cut down the cost to ship it, to fly it, to make it, to throw it away when we're finished. Make the material stronger, and we can use less of it for a longer time and can push harder with or on it.

It seems that every time we start to think that we can't make strong materials from less material, somebody comes along to prove us wrong. According to a Popular Science post...

The key structural component is a series of hollow tubes. In a study published last November in Science, the researchers exposed a light sensitive liquid to UV light through a patterned mask, which created a three-dimensional photopolymer lattice. They then deposited a layer of nickel-phosphorous onto the polymer lattice, which was then etched. The remaining structure was a macroscopic material with hollow tubes as the base structural elements. The resulting material had a density of .9 mg/cm³. By comparison, ultralight silica aerogels are 1 mg/cm³.

I've held aerogel. I've let another ASM master teacher (cough-Becky-cough) break my aerogel, and to think that this material is lighter than aerogel is pretty impressive.

I'm putting the video after the jump because it auto-plays. Click through to watch.