A tiny diamond ball is pressed into a piece of metal: that's how you test a material's hardness. But what happens inside, right under that ball? Scientists took an alloy of molybdenum, tantalum, and tungsten and looked into the thick of its atoms.
The experiment was repeated in a computer, modeling millions of atoms. The model showed: when the ball presses on the metal, atoms don't scatter: they shift in layers, like a deck of cards. But the shift isn't random: it depends on how the crystal is oriented. Press on one face, and defects spread in a neat cross. Press on another, and the metal deforms unevenly, creating weak spots.
This means you can make a part from this alloy stronger simply by choosing the right way to cut it from the blank. For turbines and reactors running at hellish temperatures, that's no small thing.
The hardness of this alloy was tested with a ball just hundredths of a millimeter across: it leaves a dent less than a thousandth of a millimeter deep, but that dent tells you how strong the whole material is.