字幕列表 影片播放 列印英文字幕 Scientists have discovered a new form of ice using diamonds, x-rays, and a bunch of ultra-powerful lasers, and this new ice could tell us more about the inside of planets. I know that sounded like science-themed mad libs, but I promise you it’s true. The first thing you should know is there are way more known iterations of ice than you probably expected. The kind you’d find in your freezer or in your drink is called ice I. Actually, there are two forms of Ice one, that kind is called ice Ih, the h stands for “hexagonal” after the hexagon shape the frozen water molecules form which differentiates it from the more cuboidal shape of ice Ic. Wow, two forms of ice? Ice, ice, baby. Can it get any crazier? Oh, yes it can. It can get crazy 17 more times, because including this newly discovered form of ice, we’re up to 19 total crystalline arrangements of H2O. Water can form so many different lattice structures in part because of the molecule’s bent shape plus its hydrogen bonds to other water molecules which can lead to complex arrangements. But our newest confirmed form of ice, called ice XVIII, is something altogether different. Instead of being like the ice in your fridge, white and cold, it’s black and hot. It was first predicted by a computer model from 1988. The simulation suggested a new form of ice occurs at high temperatures and pressures, above 2000 kelvin and above 100 gigapascals. For reference, water at the deepest point on the ocean floor is under about 1000 times less pressure. These conditions rip the hydrogen atoms off their oxygen partners, losing their electrons and essentially becoming positively charged protons. The oxygen atoms are packed into a cubic lattice, while the freed protons flow around them like a liquid. This high concentration of flowing ions should actually conduct electricity about as well as other semimetals like arsenic or graphite, just using freely moving protons instead of electrons. Predicting this superionic form of ice on an old computer is one thing, but observing it is quite another. In order to create this form of ice, scientists compressed water between diamonds to build up the pressure. Then they blasted it with lasers, 6 of them in fact. They couldn’t hit it with one big blast because that would put it over ice XVIII’s predicted melting point. Instead, they used timed pulses which explosively vaporized the diamond containing the water and caused a massive spike in temperature and pressure. In order to see what was happening inside the water at the exact moment pressure peaked, scientists shot 16 more laser beams at an adjacent piece of iron, which vaporized and sent X-rays through the water. Basically, it was a flippin' laser jamboree up in there. Based on the diffraction of the X-rays, the scientists confirmed the oxygen atoms formed the nanometer sized cubic lattices predicted by computer models. All of this is very interesting to planetary scientists, because the conditions for ice XVIII are probably right inside ice giant planets like Uranus and Neptune. Ice XVIII’s structure and properties could explain some odd phenomena of these planets, like the shape of their magnetic fields. Earth and most planets in the solar system have a magnetic field like a bar magnet with two poles, and the magnetic poles line up well with the axis of rotation. This is likely due to conductive fluids inside the planet swirling with the planet’s rotation. But ice giants have magnetic fields that are more lumpy, with multiple poles and no correlation with how the planet spins. An interior made up of ice XVIII would mean the planets have a solid-ish core that wouldn’t really churn, with a thin shell of flowing ionic water above it that could account for the odd magnetic field. There’s still plenty more research to do though, because ice giants probably have other molecules like methane and ammonia in the mix that could change how the water behaves deep below the surface. And technology has advanced enough to take a snapshot of the oxygen atom lattice, but we still haven’t seen the flowing hydrogen ions. I guess that means we gotta shoot more lasers. Sweet. Thanks for watching, if you liked this video subscribe and check out another I did on a new phase of matter that’s solid and liquid at the same time. For you Vonnegut fans out there, yes there is an Ice IX, but good news, it will not destroy the planet. That’s all for now, see you next time on Seeker.
B2 中高級 最新形式的水是熱的、黑的,等等什麼? (The Newest Form of Water Is Hot and Black, Wait What?) 6 1 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字