A visit to a peat bog will make you rethink everything you know about the surface of our planet. A bog is land, sort of, but not in the solid-ground sense you’re used to. If you try walking across one’s surface, you may feel the soft organic muck known as peat undulate beneath you — or you may sink into it yourself. From the surface, it’s hard to know whether the waterlogged peat extends 3 feet...

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