Tonight, my husband beckoned me out onto our deck at 9:30 pm to look at the stars and listen to...something. He wouldn't tell me what it was; just cautioned me to keep still and listen. Very soon, I heard a timpany-like wave of sound that reminded me of a doppler or ultra sound machine--a kind of whoosh, whoosh that was other-worldly. "That's the sound of cracks in the ice propagating," explained my engineer-spouse. (We were overlooking our pond, which, for the first time all year, had frozen solid enough for ice fisherman to patiently wait for a bass to trigger their tip-ups. I must have heard it at various points in my life, but I never heard it like that, in my own backyard with the stars blazing overhead. (To hear what it sounds like, click here.