compression

Many materials behave like finicky ice: at one pressure they melt, at another they turn harder. Superconductors in the cuprate family are no exception. Their ability to carry current without loss depends on how tightly the crystal lattice is squeezed. In a new study, physicists traced this dependence for the compound Bi-2223.

The race for fusion energy is like trying to bottle a lightning bolt. For decades, physicists have struggled to recreate on Earth the processes that power the Sun. The main challenge is getting light nuclei to fuse despite their mutual repulsion, while extracting more energy than was spent heating and confining the plasma.

The proton is not a solid ball but a tiny prison. Inside it, three quarks are locked up, and the gluon field keeps them from escaping — something like invisible threads that only grow stronger if the quarks try to move apart.

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.

A flat sheet with slits in a flow of water or air behaves like self-adjusting blinds. The pressure opens the gaps, and each strip of material tilts, turning into a miniature wing. Thus, even a sheet placed perpendicular to the flow generates not only drag but also significant lateral lift.

Splitting water into hydrogen and oxygen with electricity is an age-old dream of clean fuel. But tiny gas bubbles stand in the way: they cling to the electrodes like foam on the side of a soda glass, interfering with the current's work. Each bubble is a tiny plug, blocking part of the surface where the reaction should occur.

Thick honey spreads slowly across a plate. In such a world, where friction suppresses inertia, motion is governed not by force but by viscosity. This is how many soft materials behave: polymer gels, colloidal suspensions, the contents of living cells.

An ordinary wire heats up when current flows through it. A superconductor doesn't. But almost all known superconductors require either very low temperatures or enormous pressures, like those deep inside planets. Scientists have long searched for a material that avoids these extremes.

A printer that prints not with ink but with metal and ceramic is now a reality. Scientists took an ordinary drop of water containing dissolved metal salts and made it deposit copper, zinc oxide, or nickel hydroxide onto a surface — all with precision down to millionths of a meter. The secret lies in electricity.

A superconductor crystal is squeezed in a small cell, like clamping it in a vise, but with water to distribute the pressure evenly. Pressure up to 1.08 GPa (about a hundred times greater than in a car tire) barely changes the temperature at which the material loses resistance.

The usual way to freeze a living cell is like trying to put a spacesuit on it: you first need to get a protective substance inside, but while it's crossing the membrane, the cell can burst from salt imbalances or get poisoned by the chemicals.

The space between two closely spaced surfaces is far from empty: it's a seething "quantum glue." Within it, quantum fluctuations continuously pop in and out of existence: microscopic bursts of energy in electromagnetic fields that, according to quantum theory, give the vacuum a dynamic structure.