wavelet analysis

Waves on the water's surface usually break against any obstacle — a rock, a piling, an island. But what if you arrange obstacles so cleverly that the wave barely notices them? In a new study, scientists assembled a pattern of many points on the water, arranged according to special mathematical rules, and sent waves through them.

You could send a short radio pulse toward a black hole and wait for the reflected echo. Intuitively, the shorter the signal, the better it would probe the finest details of spacetime right at the horizon: that region from which even light cannot return.

Physicists have achieved three-dimensional Anderson localization of electromagnetic waves — a phenomenon where waves become permanently entangled in a random labyrinth of metal particles and cease to propagate.

The lungs are not two bags but millions of tiny sacs where air enters and blood flows close by. To see how they work, doctors sometimes use MRI without contrast: the scanner picks up weak signals from the tissues themselves. But these signals are like a radio in a thunderstorm — breathing is irregular, pulse jumps, and the image falls apart.

When two atomic nuclei collide, the outcome depends on their energy and the angle at which the fragments fly apart. Typically, such calculations demand enormous computing power, and accuracy hits a wall due to approximations.

To spot a dim star above a brightly lit city, astronomers subtract one image from another — removing the glare of streetlights. They do the same with living neurons: their faint flashes drown in noise, but if you subtract everything unchanging, only they remain.

Thousands of kilometers of fiber-optic cables lie on the ocean floor. They carry internet traffic, but the cables themselves sense the slightest vibrations in the water and the seabed. If you listen closely to such a cable, you can hear a blue whale singing or the ground trembling thousands of kilometers away.

The heart beats, and on a paper ECG strip, each beat looks like a sharp spike with two humps: a quick rise, then a smaller wave, then a descent. A doctor looks at such a strip and sees the rhythm, but the shape of each spike, how exactly the muscle contracted, is hard to discern, especially if the recording lasts a full day. This new method turns that strip into a colorful carpet.

Radio telescopes scattered across the globe pick up waves from distant black holes. But two telescopes placed almost side by side see only a blurry blob — fine details are beyond them. Usually, such pairs are considered useless and discarded. But that's a mistake: even a blurry blob holds clues.

An electrocardiogram is like a musical score, where each note is a heartbeat. A doctor hears the melody and spots the off-notes — arrhythmia. But listening to the score for hours is tiring, so a smart monitor is placed by the patient's bedside.

The climate of the United States is not a straight line creeping upward. It is an orchestra without a conductor, where every violin and every drum plays its own part, and together they create an intricate pattern of warm and cold, wet and dry years.

An orchestra plays a complex piece, and each group of instruments enters on its own schedule. The violins might slow down while the woodwinds keep the same tempo, and the percussion might suddenly burst into a roll. The conductor hears everything at once, but pinpointing the exact moment when the flutes, not the cellos, changed rhythm is nearly impossible.