waveform

A handful of pebbles drops into a pond: each one sends out ripples. If the pebbles are different, the ripples will be different too: some sharp, some smooth. But when you look at the water from a distance and see only a small part of the ripples, all those differences blur together.

A stone drops into a pond, and ripples spread across the water. In the same way, massive bodies generate gravitational waves, except it's space itself that ripples. So far, these waves have been caught by giant detectors that barely flinch as a wave passes through. But what happens on the microscopic scale, inside a tiny piece of matter?

In the familiar picture of the world, an event is a point on the map of spacetime: 'here and now,' with no size or internal structure.

Right after the Big Bang, space cooled unevenly. In some places, folds could have formed — threads of energy as thin as a hair but incredibly dense. Physicists call them cosmic strings. They oscillate, collide, and emit gravitational waves — ripples in the fabric of space itself.

The early Universe was like a rapidly cooling ocean. At colossal temperatures, everything was one — quarks, electrons, forces all blended into a symmetric 'steam.' But as it expanded and cooled, this steam condensed, phase transitions cascading one after another like water turning to ice.

The spiral of water draining into a sink spins faster and faster toward the center. In an ordinary black hole, that funnel ends in an infinitely sharp point — a singularity where the laws of physics break down. But this new work considers a different picture: the funnel doesn't taper to a needle but ends in a smooth, swelling bubble.

Space is full of invisible waves — ripples in the fabric of spacetime left behind by cataclysms like black hole mergers. An ordinary black hole swallows everything without a trace. But there are hypothetical exotic objects — ultradense clumps of matter without an event horizon (a surface from which not even light can escape).

The merger of two black holes is not just a silent dance, but a grand act after which spacetime itself vibrates for a long time. These damped oscillations — quasi-normal modes — are like the ringing of a gigantic bell. But there is another echo: barely perceptible, almost ghostly.

In the ocean of space, every storm of birth or merger of supermassive black holes generates ripples — gravitational waves traveling at the speed of light. Over billions of years, these waves superimpose, merging into a low-frequency hum, like a distant surf.

The mystery of dark matter has puzzled physicists for nearly a century. Among the candidates for its role are primordial black holes (PBHs), born in the fiery embrace of the first moment after the Big Bang.

A tightrope walker spirals over an abyss, each loop drawing closer to the center. Their path is not a smooth glide but a series of sharp jerks and pauses. That is roughly how a tiny black hole behaves when it is pulled toward a supermassive neighbor.

Light passes through a crumpled film — and comes out slightly altered. In much the same way, gravitational waves born in the early universe feel the lumpy distribution of galaxies and dark matter.

Gravitational waves from a tiny body falling into a black hole work like an X-ray image. Only instead of a bone, they illuminate the curved spacetime itself.

Drop a pebble into a pond — ripples spread across the water. In much the same way, a massive body circling a black hole perturbs the fabric of spacetime, generating gravitational waves. But what if the pond itself isn't flat, but has hidden folds — extra dimensions invisible to the eye?

Astronomers listen to the cosmos like an old radio: they twist the knob not to find a particular station, but to catch any unusual noise. This approach breaks the mold: instead of hunting for gravitational waves using memorized patterns, they catch everything — without bias.

A fundamental string plucked at the moment of the Big Bang doesn't just hum a single note — waves run along it, and occasionally tiny loops peel off. These loops, like tuning forks, begin to ring at their own frequency, producing a very high-pitched sound.

A stone drops into a pond, and ripples spread across the water. If a protruding branch blocks the ripples' path, part of the wave reflects, and part bends around the obstacle. Gravitational waves, ripples in spacetime itself, behave similarly when passing by galaxy clusters or black holes.

Usually, black holes inch closer gradually, circling in a tightening spiral. This dance births a long ripple of gravitational waves — a tremor in the very fabric of spacetime. Detectors LIGO and Virgo routinely catch such mergers. But GW190521 is the exception.

Back in the 1960s, physicist Joseph Weber tried to catch gravitational waves using aluminum cylinders: they were supposed to tremble like tuning forks from the ripples of spacetime.

Einstein and Rosen imagined a bridge connecting two sheets of reality. Wheeler gave it a name — wormhole, and Thorne with Morris proved: the tunnel is traversable if you fill it with exotic matter.

A stone falls into a well, and a second later, a splash. A star falls into a black hole, and disappears beyond the horizon, leaving only a ripple in space. But what if the bottom of the well is not a dead end but a passage? In the usual picture, matter compresses into a point of infinite density — a singularity.

A black hole collision isn't just a burst of gravitational waves; it also leaves a lasting trace: an eternal curvature of spacetime — gravitational memory. Like a boat on water leaves a lingering wake, the cosmos 'remembers' the catastrophe.

The symphony plays, but a barely perceptible wrong note has crept into the score. This is roughly how physicists search for deviations from general relativity in the 'sounds' of the universe — gravitational waves from merging black holes.

The term 'wormhole'—coined for physics by John Archibald Wheeler in 1957—still teases the imagination. It's a hypothetical tunnel through curved spacetime, connecting distant regions of the Universe or even different universes.

The trembling of space sounds like an orchestra. Gravitational waves caught by the LIGO and Virgo detectors tell of black hole collisions. Sometimes the music carries off-key notes — tiny deviations from Einstein's score. They might whisper of new physics or simply of dust on the bows.

Gravitational wave detectors work like sensitive microphones, picking up the trembling of space from distant cosmic catastrophes. When two black holes merge into one, the newborn object rings like a bell, and that ringing is a unique 'voice' of gravity.

A tuning fork, once struck, makes neighboring strings vibrate. Much the same happens with a cloud of ultralight particles (also called axions) around a rapidly spinning black hole. The hole, like a motor, spins up the particles, and they begin to emit gravitational waves — a trembling of space itself.

Gravitational waves are ripples in space, born, for example, when pairs of supermassive black holes spiral around each other. To catch them, scientists monitor pulsars — dead stars that emit radio pulses with clockwork precision.

Gravitational waves are ripples in spacetime curvature that imperceptibly stretch and squeeze everything around. But the Moon, like a bell, catches these waves: as a gravitational wave passes through it, it makes our satellite vibrate.

When two black holes merge, the newborn hole rings like a bell, emitting gravitational waves. In the past, only the fundamental tone of this ringing was captured. But analysis of the GW250114 merger showed that the signal hides extra faint vibrations — nonlinear overtones.