[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Deep beneath the geysers and hot springs \Nof Yellowstone Caldera Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,lies a magma chamber produced by a \Nhot spot in the earth’s mantle. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As the magma moves towards \Nthe earth’s surface, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,it crystallizes to form young, \Nhot igneous rocks. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The heat from these rocks drives \Ngroundwater towards the surface. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As the water cools, ions precipitate out \Nas mineral crystals, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,including quartz crystals from silicon \Nand oxygen, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,feldspar from potassium, aluminum, \Nsilicon, and oxygen, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,galena from lead and sulfur. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Many of these crystals have signature \Nshapes— Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,take this cascade of pointed quartz, \Nor this pile of galena cubes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But what causes them to grow into these\Nshapes again and again? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Part of the answer lies in their atoms. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Every crystal’s atoms are arranged \Nin a highly organized, repeating pattern. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This pattern is the defining \Nfeature of a crystal, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and isn’t restricted to minerals— Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,sand, ice, sugar, chocolate, ceramics, \Nmetals, DNA, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and even some liquids have \Ncrystalline structures. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Each crystalline material’s atomic \Narrangement Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,falls into one of six different families: Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,cubic, tetragonal, orthorhombic, \Nmonoclinic, triclinic, and hexagonal. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Given the appropriate conditions, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,crystals will grow into geometric shapes Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that reflect the arrangement \Nof their atoms. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Take galena, which has a cubic structure \Ncomposed of lead and sulfur atoms. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The relatively large lead atoms Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,are arranged in a three-dimensional \Ngrid 90 degrees from one another, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,while the relatively small sulfur atoms \Nfit neatly between them. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As the crystal grows, locations like these\Nattract sulfur atoms, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,while lead will tend to \Nbond to these places. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Eventually, they will complete the grid \Nof bonded atoms. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This means the 90 degree grid pattern \Nof galena’s crystalline structure Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is reflected in the visible \Nshape of the crystal. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Quartz, meanwhile, has a hexagonal \Ncrystalline structure. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This means that on one plane its atoms \Nare arranged in hexagons. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In three dimensions, these hexagons are \Ncomposed of many interlocking pyramids Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,made up of one silicon atom \Nand four oxygen atoms. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So the signature shape of a quartz \Ncrystal Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is a six-sided column with pointed tips. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Depending on environmental conditions, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,most crystals have the potential to form\Nmultiple geometric shapes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,For example, diamonds, which form deep\Nin the earth’s mantle, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,have a cubic crystalline structure and can\Ngrow into either cubes or octahedrons. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Which shape a particular \Ndiamond grows into Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,depends on the conditions where it grows, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,including pressure, temperature, \Nand chemical environment. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,While we can’t directly observe growth \Nconditions in the mantle, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,laboratory experiments have shown some\Nevidence Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that diamonds tend to grow into cubes at \Nlower temperatures Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and octahedrons at higher temperatures. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Trace amounts of water, silicon, \Ngermanium, or magnesium Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,might also influence a diamond’s shape. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And diamonds never naturally grow into the\Nshapes found in jewelry— Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,those diamonds have been cut to \Nshowcase sparkle and clarity. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Environmental conditions can also \Ninfluence whether crystals form at all. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Glass is made of melted quartz sand, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but it isn’t crystalline. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That’s because glass cools \Nrelatively quickly, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and the atoms do not have time to arrange\Nthemselves Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,into the ordered structure \Nof a quartz crystal. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Instead, the random arrangement \Nof the atoms in the melted glass Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is locked in upon cooling. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Many crystals don’t form geometric shapes Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,because they grow in extremely close \Nquarters with other crystals. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Rocks like granite are full of crystals, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but none have recognizable shapes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As magma cools and solidifies, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,many minerals within it crystallize at the\Nsame time and quickly run out of space. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And certain crystals, like turquoise, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,don’t grow into any discernible geometric\Nshape in most environmental conditions, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,even given adequate space. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Every crystal’s atomic structure has \Nunique properties, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and while these properties may not have\Nany bearing on human emotional needs, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,they do have powerful applications \Nin materials science and medicine.