Hao Wang

A meteorologist looks at a map where clouds gather in flocks, like birds before a storm. Each spot on the radar could be a future downpour or just noise. Earth system forecasting is like trying to assemble a puzzle with thousands of pieces that keep changing shape.

1550 supernova flashes and millions of galaxies — that's the statistics of the DESI survey. This dataset allowed, for the first time, a suspicion: the repulsive dark energy has a hidden counterweight.

The universe is expanding faster and faster, like yeast dough in the kitchen. This expansion is helped by dark energy — the cosmic sugar. Ever since astronomers like Adam Riess noticed the acceleration in the late 1990s, they've been searching for the cause.

When you pluck a guitar string hard, it doesn't sound a single note but several at once — the fundamental tone and overtones. Physicists have pulled a similar trick with light: they aimed an infrared laser at a crystal, and the crystal lit up with sixteen colors at once, from invisible heat to hard ultraviolet.

An ordinary laser beam carrying quantum keys trembles at the slightest movement, like a flashlight in the hand of a running person. The drone vibrates, the rover shakes, and the code falls apart. The authors figured out how to align the polarization of light (the direction of its oscillations) on both ends of the line on the fly.

Among magnets, there are quiet masters of disguise. An ordinary magnet attracts paperclips and has two poles — north and south. But there are materials that are internally arranged like a magnetic chessboard: their atoms are aligned in a strict order, yet externally the material behaves neutrally, as if no magnet exists at all. Such substances are called altermagnets.

In the crystal Rb1-xV2Te2O, the spins of vanadium atoms arrange in a checkerboard pattern: each spin is surrounded by opposite spins. This pattern is called G-type antiferromagnetism. Neutrons passing through the sample scatter off this pattern and reveal its geometry, like light from a flashlight shining through blinds casting stripes on a wall.

In 2017, detectors picked up a tremor in space — gravitational waves from the merger of two neutron stars. At the same moment, telescopes saw a flash. For the first time, one event spoke in two languages at once: light and gravity.

For decades, two independent methods of measuring the rate at which galaxies are flying apart, the Hubble constant, have given conflicting numbers. The situation resembled a room with two thermometers showing different temperatures.

Ever since Edwin Hubble discovered the fleeing of galaxies, the law of expansion of the Universe — Hubble's Law — has been a cornerstone of cosmology.

Picture a room where hundreds of people are talking at once while you strain to hear a pin drop. That is essentially how physicists with the PandaX-4T collaboration listened for silence inside 3.7 tonnes of liquid xenon.