Beech cupules. The husk can have a variety of spine- to scale-like appendages, the character of which is, in addition to leaf shape, one of the primary ways beeches are differentiated. The nuts are edible, though bitter (though not nearly as bitter as acorns) with a high tannin content, and are called beechnuts or beechmast. The name of the tree (Latin "fagus", whence the species name; cognate with English "beech") is of Indo-European origin, and played an important role in early debates on the geographical origins of the Indo-European people. Greek φηγός is from the same root, but the word was
Photonics mast Photonics mast A photonics mast (or "optronics mast") is a sensor on a submarine which functions similarly to a periscope without requiring a periscope tube, thus freeing design space during construction and limiting risks of water leakage in the event of damage. A photonics mast replaces the mechanical, line-of-sight viewing system with digital equipment, similar to a digital camera array, and it has fewer locational and dimensional constraints than a traditional periscope. Unlike a periscope, it need not be located directly above its user, and it requires only a small pressure hull penetration for cabling. This allows the photonics mast