time resolution

A particle enters a silicon wafer like a courier arriving in an unfamiliar city: it must not only deliver its signal but also leave an accurate record of when it arrived. The 3D sensor on the Timepix4 chip makes that record to within 245 picoseconds, and it pinpoints the meeting spot to just 7 micrometers.

A protein is like a tiny machine that switches on and off on command. The command arrives when another molecule sticks to it, like a key in a lock. The protein then changes shape and passes the signal along. But exactly how the signal travels inside the protein has long been a mystery.

Inside a fusion reactor, plasma rages — a gas heated to millions of degrees. There are no direct windows, and cameras and sensors quickly fail. Engineers see only fragments of information: a few sensors at scattered points. It's like trying to grasp a symphony from the sound of three microphones in a vast hall.

In the constellation Scorpius, 3,000 light-years from Earth, a dead star steals matter from a living one. A white dwarf in the system IGR J17014-4306 — a superdense carbon-oxygen ball with the mass of the Sun but the size of Earth — siphons hydrogen from a normal companion star.

A charged particle streaks through a silicon sensor, leaving behind a trail of free electrons. The time it takes for this charge to be collected at the electrode depends on how deep in the crystal it was born. A particle entering head-on carves identical paths through neighboring pixels: their signals arrive almost simultaneously.

A silicon detector is like photographic film, but instead of light, it senses charged particles. When a particle flies through the silicon, it knocks out electrons, and we see a signal. But how do you look inside the detector itself and see where the electric field is strong and where it's weak? One way is to use a laser.

In giant accelerators, particles zip through detectors in billionths of a second, and telling one from another requires a stopwatch of incredible precision. The new µRWELL-PICOSEC detector acts as such a stopwatch: it captures the moment a particle passes with a precision of 48 picoseconds: that's 48 trillionths of a second.

The camera that hunts for tumors works like a highly sensitive camera: it catches the faint glow from a substance that accumulates in diseased cells. In conventional machines, the light is born in a crystal — a solid piece that resembles glass. But a crystal doesn't always convey exactly where the light flashed, so the image comes out slightly blurry.

A regular camera captures the world as a series of frames: twenty-four, sixty, or even a hundred images per second. That's enough for filming a falling drop, but inside a living cell, events unfold a thousand times faster. Protein molecules carry cargo, membranes bubble, ions slip through channels — all in fractions of a millisecond.

A particle zips through silicon in billionths of a second, and the sensor manages to click, recording the exact time. This isn't science fiction; it's the result of testing the MiniCACTUS-v2 prototype at CERN in July 2025. The best result: 48.88 picoseconds — in that time, light travels just 1.5 centimeters.

When a particle zips through a transparent material faster than light can travel through it, it leaves behind a faint blue flash, just as a jet breaking the sound barrier creates a shock wave. This Cherenkov radiation fires instantly, with no delay, making it perfect for ultra-precise timing in the world of elementary particles.

Light can be more than just a stream of particles; it can be a wave with a specific shape over time. Sometimes this shape changes so rapidly that capturing it is like photographing a bullet in flight. Scientists have devised a way to measure such fleeting quantum states of light. For this, they use a device called a balanced homodyne detector.

A ruler made of light: that's one way to describe a new method for measuring tiny time delays. In 1987, Chong Ki Hong, Zhe-Yu Ou, and Leonard Mandel noticed that when two indistinguishable photons hit a beam splitter simultaneously, they always exit together from the same port.