decibel

In the 1980s, the DARPA speech recognition challenge settled the debate between statistical methods and hand-written rules, setting a common standard for the entire field.

The cosmic dawn is hidden behind a dense veil of time. To see beyond it, you need to catch the radio signal from clouds of neutral hydrogen — the so-called global 21 cm signal. But it is so faint that the receiver's own noise drowns it out.

A sound signal is conveniently represented as a complex number: its modulus (amplitude) reflects loudness, while its argument (phase) indicates the wave's position in time: its instantaneous shift.

Cosmology is the music of the spheres, and the Hubble constant once seemed like a reliable metronome.

Comparing two scents is easy even without knowing their ingredients, just tell if they're alike. This everyday principle became the foundation for a new class of Bell inequalities, reimagining tests of the spooky connection between particles. Previously, you had to measure precise properties, like spin direction, but the authors showed that simply comparing outcomes is enough.

A speck of glass floats in a laser beam. Air molecules, photons, even Earth's gravity give it little pushes, and by watching its jitter, you can tell what pushed it. But every measurement has a limit: the particle's own noise hides weak signals. Quantum mechanics sets that limit, but it can be bypassed.

Inside the receiver of a telescope aimed at the oldest glow in the universe sits a tiny thermometer chip. It's so sensitive that the heat from a single photon can warm it noticeably. But to hear that whisper of heat, you need a middleman — an amplifier that doesn't add its own noise.

In a quiet lab, a device the size of a microwave oven sits on a table. Inside, a coil glides smoothly up and down while a computer reads electrical signals. This is the tabletop Kibble balance — a machine that links mass to quantum constants. Previously, such balances occupied a whole room and required a team of engineers.