What is Life?

This might sound like a philosophical question, but I intend it more like a scientific question.  We’ve discussed this somewhat before, like in our post about the universe’s habitable zone, but I want to focus in a little closer on what life really is, on what makes one thing alive and one thing not alive, how we might go about defining the difference, and whether what we call life deserves the distinction we have hitherto applied.

Strength: Toughness Versus Hardness

This post is primarily intended as an educational one, to discuss some of the terminology and thought-processes involved in materials science, but it was inspired by world-building considerations. As you may recall, if you've been following along with what I've been reading (and my regular book reviews), I recently read a book called The Substance of Civilization, which detailed how the materials to which our species has had access have shaped the course of cultural evolution over the past ten thousand years. It prompted me to think in more detail about choice of materials and construction techniques in world-building.