Physicists Discover the Most Complex Forms of Ice Yet

Ice comes in more forms than what you’ll find in a freezer or a glacier.

冰的形式比冰箱或冰川中的冰更多。

Since 1900, scientists have observed more than 20 phases of ice, many of them shaped under extreme conditions.

自 1900 年以来，科学家们观察到了 20 多个冰相，其中许多是在极端条件下形成的。

The growing list includes hot ice and even ice that conducts electricity.

不断增加的清单包括热冰，甚至导电冰。

Ice is the name for any phase of water that is solid and crystalline, meaning that it has a repeating molecular structure.

冰是任何固态和结晶水相的名称，这意味着它具有重复的分子结构。

Over the past decade, computer simulations have predicted tens of thousands of possible forms of ice.

在过去的十年中，计算机模拟已经预测了数以万计的可能的冰形式。

Though uncommon on our planet, exotic ice may exist in off-Earth environments, from cold and amorphous comet tails to the hot and crushing cores of icy planets.

尽管在我们的星球上并不常见，但奇异的冰可能存在于地外环境中，从寒冷和无定形的彗尾到冰行星的炽热和破碎的核心。

Ice comes in many more forms than the cubes in your water glass.

冰的形式比水杯中的立方体要多得多。

Scientists have found about 20 phases of ice, including hot ice and bendy ice and ice that conducts electricity.

科学家们已经发现了大约 20 种冰相，包括热冰、弯曲冰和导电冰。

And according to simulations, there could be many more out there.

根据模拟，可能还有更多。

As physicists put water to the test with improved experimental techniques, they keep finding surprises.

当物理学家通过改进的实验技术对水进行测试时，他们不断发现惊喜。

“You take water, and just the way you compress it — a little bit faster, a bit slower, up and down, at the right timescale — and then you can find this completely unexpected behavior,” said Marius Millot , a research scientist at Lawrence Livermore National Laboratory (LLNL) in California.

加利福尼亚州劳伦斯利弗莫尔国家实验室 (LLNL) 的研究科学家马吕斯​​·米洛特 (Marius Millot) 表示：“你取水，按照你压缩它的方式——快一点、慢一点、在正确的时间尺度上上下移动——然后你就会发现这种完全出乎意料的行为。”

Abandoning old assumptions and applying new techniques, scientists have discovered three new kinds of ice in the past year, including two of the most complex ice phases ever seen.

科学家们放弃了旧的假设并应用了新技术，在过去的一年里发现了三种新的冰，其中包括有史以来最复杂的两种冰相。

“It seems a remarkable time at the moment,” said Chris Pickard , a physicist at the University of Cambridge.

“目前看来这是一个非凡的时刻，”剑桥大学物理学家克里斯·皮卡德说。

“They’re really finding a lot more of these structures.”

“他们确实发现了更多这样的结构。”

The shape of water makes it exceptionally versatile.

水的形状使其用途广泛。

Its molecular structure can assemble in many possible configurations.

其分子结构可以以多种可能的构型组装。

Each water molecule looks like a central unit with four arms spread apart by the electromagnetic force.

每个水分子看起来就像一个中心单元，有四个臂在电磁力的作用下分开。

The central unit is an oxygen atom.

中心单元是氧原子。

Bonded to it are two hydrogen atoms, and sticking out like extra limbs are two pairs of leftover free electrons.

与它结合的是两个氢原子，像额外的肢体一样伸出的是两对剩余的自由电子。

In the most common form of ice, these building blocks combine to form a cagelike hexagonal structure.

在最常见的冰形式中，这些构件结合在一起形成笼状六边形结构。

The spaciousness of this arrangement makes typical ice less dense than liquid water.

这种宽敞的布局使得典型的冰密度低于液态水。

This is why ice floats, and why bodies of water freeze from the top down, allowing underwater life to survive the winter.

这就是冰漂浮的原因，也是水体从上到下结冰的原因，使水下生物能够度过冬天。

Put water under pressure, though, and its shape can compress and overlap in a seemingly endless bounty of possible patterns.

然而，将水置于压力下，它的形状可以压缩并重叠，形成看似无穷无尽的可能模式。

Because it can take so many different forms, “the physics and the chemistry of water can be completely different” from one environment to the next, said Livia Bove , a physicist at the Swiss Federal Institute of Technology Lausanne.

瑞士洛桑联邦理工学院的物理学家利维亚·博韦 (Livia Bove) 表示，由于水可以采取多种不同的形式，因此“水的物理和化学性质可能在不同环境下完全不同”。

“It’s topologically beautiful.”

“它的拓扑结构很美。”

In 2018, an international research group from Europe and Japan created an ambitious computer simulation of the dynamics of water molecules that aimed to predict undiscovered forms of ice.

2018 年，来自欧洲和日本的一个国际研究小组对水分子动力学进行了雄心勃勃的计算机模拟，旨在预测未被发现的冰的形式。

The result was a catalog of over 75,000 phases, each characterized by a slightly different way that the water molecules could fit together when subjected to a different combination of temperature and pressure.

结果是一个包含超过 75,000 个相的目录，每个相的特征都是在不同的温度和压力组合下，水分子结合在一起的方式略有不同。

Livia Bove’s team recently discovered a type of “plastic” ice that’s thought to exist in the cores of icy moons.

利维亚·博夫（Livia Bove）的团队最近发现了一种“塑料”冰，人们认为这种冰存在于冰冷卫星的核心中。

In reality, scientists don’t expect to find anywhere near that many phases; just because a structure is mathematically possible does not mean that it will form in nature.

事实上，科学家们并不期望找到那么多相。仅仅因为一个结构在数学上是可能的并不意味着它会在自然界中形成。

“There is always a bit of uncertainty associated with claims of the existence of new phases when they are solely based on simulations,” wrote Federica Coppari , a physicist at LLNL, in an email.

LLNL 的物理学家 Federica Coppari 在一封电子邮件中写道：“当新相的存在仅仅基于模拟时，总是存在一些不确定性。”

Some phases would require a ridiculous amount of energy to form.

有些相需要大量的能量才能形成。

Others are so fragile that they would collapse immediately.

其他人则非常脆弱，会立即崩溃。

Scientists try to narrow their predictions down to just those that seem viable.

科学家们试图将他们的预测范围缩小到那些看起来可行的范围。

“It filters down to fewer of them,” said Pickard, who worked on the simulation.

“它会过滤到更少的人，”参与模拟的皮卡德说。

“But the reality is, we don’t exactly know how to place that filter.”

“但现实是，我们并不完全知道如何放置该过滤器。”

To discover the forms that ice actually takes, scientists head to the laboratory.

为了发现冰的实际形态，科学家们前往实验室。

In 2018, Yong-Jae Kim was a postdoc at the Korea Research Institute of Standards and Science (KRISS) studying how room-temperature water turns to ice under extreme pressure.

2018 年，Yong-Jae Kim 是韩国标准与科学研究所 (KRISS) 的博士后，研究室温水在极端压力下如何变成冰。

The experiment involved squeezing a drop of water between two diamonds and studying its changing molecular structure with high-speed imaging and other analysis techniques.

该实验包括在两颗钻石之间挤压一滴水，并通过高速成像和其他分析技术研究其分子结构的变化。

Going through the data from the experiment, Kim noticed what at first looked like a mistake.

在查看实验数据后，金注意到乍一看似乎是一个错误。

For just a few tens of milliseconds, the ice seemed to lose its structure, dissolving into a mess of molecules before transitioning to its next phase.

在短短的几十毫秒内，冰似乎失去了结构，溶解成一堆分子，然后转变为下一阶段。

Kim worried that sweat or dirt had contaminated the water.

金担心汗水或污垢污染了水。

“At that stage, I felt more anxious than excited,” he said.

“在那个阶段，我感到焦虑多于兴奋，”他说。

He shared the observation with the rest of his team, but he ran out of time to follow up on it.

他与团队的其他成员分享了这一观察结果，但他没有时间跟进。

In 2025, researchers at KRISS ran an improved version of the same experiment using Kim’s diamond system and managed to re-create the strange structure.

2025 年，KRISS 的研究人员使用 Kim 的金刚石系统进行了同一实验的改进版本，并成功地重新创建了这种奇怪的结构。

It was so complex that at first it looked almost random.

它是如此复杂，以至于乍一看几乎是随机的。

“But step out,” Kim said, “and we see the structure macroscopically.

“但是走出去，”金说，“我们会从宏观上看到结构。

It has a periodicity.”

它有一个周期性。”

You take water, and just the way you compress it — a little bit faster, a bit slower, up and down, at the right timescale — and then you can find this completely unexpected behavior.

你拿水，按照你压缩它的方式——快一点，慢一点，上下，在正确的时间尺度上——然后你就会发现这种完全意想不到的行为。

Marius Millot, Lawrence Livermore National Laboratory

马吕斯·米洛特，劳伦斯·利弗莫尔国家实验室

The researchers took their setup to the European X-Ray Free-Electron Laser Facility in Germany, which houses a laser that accelerates electrons through a 3.4-kilometer-long tunnel and then sends them through special magnets to produce bursts of X-rays.

研究人员将他们的装置带到了德国的欧洲 X 射线自由电子激光设施，该设施配备了一台激光器，可加速电子穿过 3.4 公里长的隧道，然后将它们发送通过特殊磁铁以产生 X 射线爆发。

“The brighter the beams of X-rays, the better pictures you get of your crystal structures,” Pickard said.

“X 射线束越亮，您获得的晶体结构图像就越好，”皮卡德说。

The scientists shone high-powered X-ray laser beams through the ice and measured how the beams scattered.

科学家们用高能 X 射线激光束照射冰层，并测量光束的散射情况。

Most phases of ice send the rays bouncing in just a couple different directions, since their crystal patterns repeat after a few molecules.

大多数冰相都会使光线在几个不同的方向上弹跳，因为它们的晶体图案在几个分子后会重复。

But this sample sent the light along roughly 15 different paths.

但这个样本沿着大约 15 条不同的路径发送光线。

When the scientists analyzed the images, the number of molecules in the crystal pattern came to a whopping 152.

当科学家分析这些图像时，晶体图案中的分子数量达到了惊人的 152 个。

The team’s observation of the structure earned the phase of ice an official Roman numeral name, ice XXI.

该团队对该结构的观察为冰相赢得了官方的罗马数字名称，ice XXI。

What’s more, the new phase was a total surprise.

更重要的是，新阶段完全令人惊讶。

The team scoured the tens of thousands of phases predicted by Pickard’s group in search of a match, but they didn’t find one.

该团队搜索了皮卡德团队预测的数万个阶段来寻找匹配，但他们没有找到。

The repeating structure of ice XXI, it turned out, was beyond the size at which the simulation capped its search.

事实证明，XXI 冰的重复结构超出了模拟搜索的上限。

“They basically found something much more complicated than we did,” Pickard said.

“他们基本上发现了比我们复杂得多的东西，”皮卡德说。

Unbeknownst to the KRISS team, a group from Okayama University had actually predicted the structure in a different, narrower simulation also created in 2018.

KRISS 团队不知道的是，冈山大学的一个团队实际上在 2018 年创建的另一个更窄的模拟中预测了这种结构。

The more focused simulation predicted two additional phases of ice that are still undiscovered.

更集中的模拟预测了另外两个尚未被发现的冰相。

The researchers at KRISS and Kim, now at LLNL, had not set out to discover a new phase of ice.

KRISS 和现在在 LLNL 的 Kim 研究人员并没有打算发现新的冰相。

Rather, they wanted to investigate another of water’s strange properties, related to how it transitions from phase to phase.

相反，他们想研究水的另一种奇怪特性，与水如何从一个相转变到另一个相有关。

The classical theory of phase transitions predicts that any system will return to its lowest-energy state.

相变的经典理论预测任何系统都会返回到最低能量状态。

But water does not always follow predictions.

但水并不总是遵循预测。

Chris Pickard worked on a simulation that created a catalog of more than 75,000 possible forms of ice.

Chris Pickard 进行了一项模拟，创建了超过 75,000 种可能的冰形态的目录。

For example, Kim’s sample did not respond to being squeezed by the diamond device by jumping straight to its most stable state, which at that level of pressure would be a form called ice VI.

例如，Kim 的样品在被金刚石装置挤压时并没有做出反应，而是直接跳到最稳定的状态，在这种压力水平下，这种状态将是一种称为冰 VI 的形式。

Instead, it hopped from water to ice XXI, and then to ice VII.

相反，它从水跳到冰 XXI，然后跳到冰 VII。

These in-between phases are called metastable states, and their existence demonstrates that some phase transitions happen in steps, rather than all at once.

这些中间相称为亚稳态，它们的存在表明某些相变是逐步发生的，而不是一次性发生的。

Water’s metastable states support a theory of phase transitions called Ostwald’s step rule, named for Wilhelm Ostwald, a German physical chemist and a peer of Albert Einstein.

水的亚稳态支持一种称为奥斯特瓦尔德阶跃法则的相变理论，该理论以德国物理化学家、阿尔伯特·爱因斯坦的同行威廉·奥斯特瓦尔德的名字命名。

(Einstein was initially rejected for a job in Ostwald’s laboratory, but the two later became friends, and Ostwald eventually nominated Einstein for the Nobel Prize.) Ostwald’s step rule suggests that systems transition to the closest and easiest-to-reach phase state rather than the most thermodynamically stable one — and that they sometimes then get stuck.

（爱因斯坦最初被奥斯特瓦尔德实验室的工作拒绝，但两人后来成为了朋友，奥斯特瓦尔德最终提名爱因斯坦获得诺贝尔奖。）奥斯特瓦尔德的步进规则表明，系统会过渡到最接近和最容易达到的相态，而不是热力学最稳定的相态，并且有时会陷入困境。

“It’s a nicely paradoxical thing that sometimes the easiest [state] to form is the one that’s the least stable,” Pickard said.

皮卡德说：“有时最容易形成的[状态]却是最不稳定的状态，这是一件非常矛盾的事情。”

A group led by Hiroki Kobayashi of the University of Tokyo has already followed up on the discovery of ice XXI, as reported in a preprint article , by re-creating it using different techniques.

正如预印本文章中报道的那样，由东京大学的 Hiroki Kobayashi 领导的一个小组已经通过使用不同的技术重新创建了 XXI 冰的发现。

In the process, they discovered a nearby phase — now dubbed ice XXII — that is even more complex, repeating its pattern only every 304 molecules.

在此过程中，他们发现了附近的一个相——现在被称为“ice XXII”——更加复杂，仅每 304 个分子重复一次其模式。

At lower temperatures, the group also came up with a way to reliably produce ice IV, a metastable phase of ice so elusive that it has earned the name “will-o’-the-wisp,” after the ghostly lights that lure travelers in folk tales.

在较低的温度下，该小组还想出了一种可靠地生产冰 IV 的方法，这是一种难以捉摸的亚稳态冰，以民间故事中吸引旅行者的幽灵般的光芒而得名“鬼火”。

As scientists observe more metastable states, they are collecting evidence that this application of Ostwald’s theory accurately describes how phase transitions work, not just in ice but in other kinds of crystals, including those used in medicine.

随着科学家观察到更多的亚稳态，他们正在收集证据，证明奥斯特瓦尔德理论的这种应用准确地描述了相变的工作原理，不仅在冰中，而且在其他种类的晶体中，包括用于医学的晶体。

Changing the phase of a pharmaceutical drug can change its effectiveness, something factories need to protect against.

改变药物的相会改变其有效性，这是工厂需要防止的。

“Sometimes drugs can turn from one [phase] to another and then ruin the whole batch,” Pickard said.

“有时药物可能会从一个[阶段]转变为另一个阶段，然后毁掉整批药物，”皮卡德说。

Ostwald’s theory helps predict when that might happen.

奥斯特瓦尔德的理论有助于预测这种情况何时会发生。

In 2025, Bove’s team in Lausanne discovered a smaller but in some ways stranger metastable phase of ice.

2025 年，Bove 的洛桑团队发现了一个更小但在某些方面更奇怪的冰亚稳态相。

In a study published in Nature , they reported the first observation of plastic ice VII.

在《自然》杂志上发表的一项研究中，他们报告了对塑料冰的首次观察七。

This is a variation of ice VII, a high-pressure phase of ice, that appears when the ice is heated to around 500 degrees Celsius.

这是冰 VII 的一种变体，冰的高压相，当冰被加热到 500 摄氏度左右时就会出现。

Federica Coppari and Yong-Jae Kim study the properties of matter under extreme conditions.

Federica Coppari 和 Yong-Jae Kim 研究极端条件下物质的特性。

In plastic ice, water molecules retain their solid crystal structure but spin rapidly in place.

在塑料冰中，水分子保留其固体晶体结构，但在原地快速旋转。

This motion is difficult to observe; hydrogen is practically invisible to X-rays, which in water molecules deflect only off the atoms of oxygen.

这种运动很难观察到； X射线几乎看不到氢，而水分子中的X射线仅偏转氧原子。

“If you can’t see the hydrogens, then you can’t really tell if the water molecule is rotating,” Pickard said.

“如果你看不到氢，那么你就无法真正判断水分子是否在旋转，”皮卡德说。

So in addition to using X-rays, Bove’s team adopted a different technique: They sent a stream of neutrons into the hot ice.

因此，除了使用 X 射线之外，Bove 的团队还采用了一种不同的技术：他们将中子流发送到热冰中。

“Those neutron techniques are so powerful,” Millot said.

“这些中子技术非常强大，”米洛特说。

“You can look at the molecules and see if they vibrate, if they rotate, if they vibrate and rotate.”

“你可以观察分子，看看它们是否振动，是否旋转，是否振动并旋转。”

The rotating molecules in plastic ice VII give the ice some elasticity, like a gentle trampoline.

塑料冰 VII 中的旋转分子赋予冰一些弹性，就像一个轻柔的蹦床。

Plastic ice VII is believed to exist inside the cores of icy moons and is thought to be an intermediate state that ice passes through before becoming a hotter form called superionic ice (or ice XVIII), first discovered in 2019 .

塑料冰 VII 被认为存在于冰冷卫星的核心内部，并且被认为是冰在成为称为超离子冰（或冰 XVIII）的更热形式之前所经历的中间状态，于 2019 年首次发现。

In this form, hydrogens fully break free of their bonds to oxygens, allowing the ice to conduct electricity.

在这种形式下，氢完全脱离了与氧的键，使冰能够导电。

Research like Bove’s shows that observing more of water’s phases might require using new experimental techniques or combining several different ones.

像博夫这样的研究表明，观察更多的水相可能需要使用新的实验技术或结合几种不同的技术。

Scientists are currently working on new methods to up the pressure they can apply to water.

科学家目前正在研究新方法来增加对水施加的压力。

“The final pressure that we are aiming for is really high,” Coppari said, “more than twice the pressure at the center of the Earth.”

科帕里说：“我们目标的最终压力非常高，是地心压力的两倍多。”

We live on the planet of water, but we’re still learning what water can do.

我们生活在水星球上，但我们仍在了解水的作用。

“The more we look and the better the experiment becomes, the more surprises we find,” Millot said.

“我们看得越多，实验就越好，我们发现的惊喜就越多，”米洛特说。

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《Quanta》杂志对评论进行审核，以促进知情、实质性、文明的对话。

Abusive, profane, self-promotional, misleading, incoherent or off-topic comments will be rejected.

辱骂、亵渎、自我推销、误导、语无伦次或偏离主题的评论将被拒绝。

Moderators are staffed during regular business hours (New York time) and can only accept comments written in English.

版主在正常工作时间（纽约时间）有工作人员，并且只能接受英文评论。