cluster

Two ink reservoirs stand on opposite sides of the cell junction. From them, two types of monomers flow onto the membrane, and when they meet, they form viscous droplets of complexes. The droplets barely move, but the free monomers dart around as fast as perfume molecules in a room.

Deep inside a neutron star, where matter is compressed to the density of an atomic nucleus, neutrons form a superfluid and protons form a superconductor. A neutron vortex is a quantized vortex in the superfluid, akin to a miniature whirlpool that cannot stop spinning.

Water droplets shoot out of a nozzle one after another, like cyclists on a narrow track. The faster ones catch up with the slower ones and merge into larger drops. This simple mechanism is called ballistic aggregation, and until now it had only been observed on cosmic scales: this is how dust particles stick together to form planets.

Usually, the complexity of systems, from satellite motions to heart rhythms, is assessed with averaged entropy (a measure of unpredictability, as understood by Boltzmann). But that's like evaluating the ocean only by wave height: the average figure hides the full richness of underwater currents.

The early universe expanded at a breakneck pace: this phase is called inflation. But how exactly did it do it? Some models describe the expansion as a steep exponential surge, others as a more gentle power-law motion.

The carbon nucleus was long imagined as a uniform ball of protons and neutrons, evenly mixed like dough. But physicist George Gamow suspected otherwise: particles inside might group into tiny, sturdy blocks — helium nuclei, or alpha particles.

In nuclear physics, the belief long reigned that two neutrons cannot form a bound state — they attract too weakly and immediately fly apart. However, on the surface of neutron-rich nuclei, where the matter density drops to a thousandth of normal nuclear density, the situation changes dramatically.

At first glance, the atomic nucleus is a cramped communal apartment where protons and neutrons (together called nucleons) live by strict rules. Each occupies its own orbit, like electrons in an atom, and on average everything looks orderly.

A handful of rice thrown into a glass of water scatters — the grains spread apart. Now imagine each grain propels itself forward with stubborn persistence and bounces off softly upon collision. Such particles are called active: they spend their own energy to move, like bacteria or microscopic robots.

Gravity is like a stretched trampoline: massive bodies press into it, making other bodies roll toward them. This shared curvature of space, gravity, affects everyone, but it doesn't convey secret messages.

A cold cloud of atoms is like a swarm of fireflies drawn to one another. The attraction between atoms tries to pack them into a single dense ball. But quantum jitter, the unavoidable motion of particles, keeps the ball from collapsing. When the attraction is strong, the cloud breaks into separate clumps.

A galaxy cluster is like a busy intersection where galaxy-cars race through a headwind of hot gas. This wind, called ram pressure, strips galaxies of their cold gas — the fuel for star formation. Astronomers from the SAMI survey traced how this happens in hundreds of galaxies across eight nearby clusters.

In the dense, star-forming gas cloud W44, the ALMA telescope has spotted eight tiny clumps racing at enormous speeds. In position–velocity maps, each one looks like the letter V, just like the previously discovered 'Bullet'. This resemblance hints at a common origin.