evaporation

Picture a tiny hole in a sheet of graphene: a single missing carbon atom. It used to be thought that a water molecule splits apart at this defect only on its own, in dry gas. But if liquid water is sloshing all around, everything changes.

In the dark chamber of the trap, thousands of charged particles dance under electric fields. At first they move freely, like a crowd in a square, but cool the cloud and the dance slows: ions begin to sense each other, their steps become constrained.

The camera captures not a race but a dance of atoms. In vanadium dioxide, the transition from an insulating to a metallic state occurs within trillionths of a second, yet until now no one had seen exactly how the vanadium and oxygen atoms move. Now, ultrafast electron diffraction has captured this route frame by frame.

A hydrogen bubble on a platinum electrode behaves like a swimmer trying to surface, but every time it almost breaks free, something below grabs its legs. In the lab, high-speed cameras captured this behavior: a millimeter-sized bubble hangs near the surface, even though buoyancy pulls it upward with a force thousands of times stronger than surface tension can hold.

In a pot on the stove, water starts to churn from the bottom long before the whole thing boils. Bubbles of steam rise from the base even though the burner itself hasn't heated up yet.

Swimming season opens when the water feels tolerable. But everyone has their own threshold: one person shivers at twenty degrees, another swims comfortably at fifteen. Scientists decided to figure out where this difference comes from. They compared a swimmer's body to a house trying to keep heat in while a cold wind blows outside.

Plasma is a gas in which electrons are stripped from atoms and roam freely. Sometimes, regions where electrons are almost absent spontaneously appear in such a gas; they are called holes. It is like a whirlpool forming in a stream, pulling everything around it in. But exactly how such a whirlpool is born has long remained a mystery.

A drop of saltwater dries on a table. The salt doesn't settle just anywhere: crystals first appear at the rim, forming a ring, like coffee grounds at the bottom of a cup. Everyone who has seen the stain left by a dried droplet knows this behavior. But what if the droplet contains swimming bacteria?

In a vast hall, billiard balls are scattered about. At first they lie sparsely, each on its own. Then someone adds more, and suddenly the balls compress into dense clusters. This is a phase transition — the moment when matter abruptly changes its state. Physicists have long described such a picture with the hard-sphere model: particles are identical balls that cannot overlap.

Water turns to ice at zero degrees — sharply, with no intermediate states. Something similar happens to complexity when we take a random quantum state of an entire system and look only at a part of it. As long as that part occupies less than half the system, its complexity grows smoothly. But as soon as the fraction crosses 50%, a jump occurs.

In the first moments of its life, the Universe resembled a boiling cauldron. As it cooled, phase transitions occurred — much like steam turning into water, but instead of molecules, the very state of space changed. In this cauldron, bubbles of the new phase were born, akin to bubbles in a pot coming to a boil.

Dark matter is the invisible scaffold that holds galaxies together. But how did it come to be? The standard answer: particles of dark matter once stopped colliding and "froze out" in the amount we see today. However, there's a trickier path — UFO, or ultra-fast freeze-out. Here, everything is like coffee that cools down and then heats up again as you carry it through a cold corridor.

If you squeeze water between two glass plates so that only two layers of molecules fit, it becomes something between a liquid and ice. At room temperature, molecules in such a trap still move but arrange themselves into a semblance of a crystal lattice.

Water plunges into an abyss, but part of it shoots back up — churning and foaming at the very edge. That's roughly how gas behaves as it flows onto a supermassive black hole when its stream becomes too dense. In a new study, scientists traced this picture using computer simulations.

A chef pours hot sugar syrup onto a cold table, and it sets into crystals. That's roughly how engineers pictured metal solidification: the liquid instantly becomes a scatter of crystalline grains. But close-up imaging revealed an extra stage wedged between liquid and solid.

Spread a handful of coins on the table. Each coin is a possible outcome: heads, tails, or something else. If we know how chaotic this set is (its entropy), which combinations of probabilities will we encounter more often? It turns out the answer depends on how much chaos we allow.

River water often swirls into funnels. But in semiconductors, the foundation of microchips, electrons at low temperatures and high purity also turn into a fluid. If you create a circular cavity, vortices appear, just like in a river backwater.

A ship gliding through water constantly rubs against it, like a palm against a rough surface. This friction eats fuel and slows progress. One way to reduce it is to blow air under the hull: water stops sticking to the hull, and drag drops. But air is finicky: sometimes it helps, sometimes it hurts.

In a solid piece of tin-lead alloy, the layers of the two metals lie like pages in a book. When heated from one side, the layers don't melt uniformly but in whimsical tongues and fingers. Scientists studied this process using a transparent alloy that can be seen through under a microscope and compared it with a computer model.

An aluminum pot on the stove melts at 660 degrees Celsius — everyone knows that. But what happens if you heat aluminum a hundred times hotter? The liquid starts to boil, and here's the puzzle: at what exact temperature does that happen?

A copper crystal is squeezed in diamond anvil cells. As pressure mounts, a battle unfolds inside the material between two states: one prepares electrons for superconductivity, the other hinders their pairing. Scientists tracked this struggle using ultrashort laser pulses.

Water can be ice, liquid, or steam. Physicists call these states phases. In theory, each phase has its own measure — a way to describe how likely it is. But not every measure you can imagine occurs in nature. Some phases are real, while others are just mathematical illusions. Scientists have found a simple criterion that separates reality from mirage.

Ordinary window glass may seem frozen forever, but inside, atoms never stay still. In amorphous germanium telluride (GeTe)—a material used in rewritable discs and non-volatile memory — physicists have for the first time directly tracked how atomic bonds stretch and bend in trillionths of a second.

Water deep within the Earth is compressed more than a thousandfold compared to the surface. Even there, it continues to flow, but its internal structure changes. Researchers measured how water resists flow and compression as pressure rises from zero to 1.6 gigapascals — equivalent to placing a 16-ton weight on every square centimeter.

Water in a pot, when heated, doesn't boil: it turns into ice. That's roughly how ultracold atoms behave in an optical lattice — a light-based crystalline grid that holds atoms in place. Scientists simulated this system on a computer to understand how order changes as temperature rises.

An ordinary heat engine is like a mill between the hot and cold banks of a river: the greater the drop, the stronger the current. Here, the drop is tiny, just one or two degrees, but water can still turn the wheel. The secret is that water is made to boil not by heating but by a sudden drop in pressure, so steam bursts out even from barely warm liquid.

In a superconductor, electric current flows without loss, like water through a perfectly smooth pipe. But if you place such a material in a magnetic field, vortices appear inside — tiny whirlpools where superconductivity is destroyed. As long as these whirlpools stay put, current flows freely.

A coffee drop on a table dries and leaves a ring — coffee particles gather at the edge. But if charged nanoparticles float in the drop, the picture becomes richer: the deposit cracks like mud in a dried-up puddle. Physicists studied how the particle charge and the surface on which the drop dries change these cracks.

In a glass of soda, bubbles merrily rise to the top. But if you freeze the water, some bubbles end up trapped in the ice. How do they get there? After all, ice grows, pushing gas aside, but it doesn't always manage to.

A piece of material glows blue. Heat it up, and the glow turns green, as if someone flipped a switch at a traffic light. That's how the new luminescent thermometer described in the paper works. Inside the material are terbium ions — a rare-earth metal that knows how to shine. At room temperature, they emit blue light.

A drop of oil in water behaves like a tiny ball: it seeks the spot with the least energy. If a wall is nearby, the drop often sticks to it, just as a raindrop spreads on glass. In a mixture of two immiscible liquids, such as polyethylene glycol and dextran, tiny droplets of one liquid form inside the other.

Helium on graphite behaves like an acrobat who simultaneously slides along a tightrope and holds a pose.

A thin stream of water flows down a cold inclined board and, before your eyes, turns into an ice ridge. At first, the water paves itself a straight icy path, as if reinforcing its own banks. Then the trickle starts to meander, and the ice quickly spreads sideways. Finally, the ridge stops growing outward and begins to thicken, smoothing out irregularities.

In superfluid helium, a state where liquid flows without friction, quantized vortices spontaneously arise: microscopic funnels resembling whirlpools in ordinary Water, but governed by quantum mechanics.