acoustic oscillations

The night sky is full of rings and bubbles, but in the radio band they look different. In data from the Australian radio telescope ASKAP, a structure has surfaced that resembles two soap bubbles blown from the same straw.

The Sun has quiet regions where the magnetic field is barely visible. But even there, sound waves find loopholes to rise higher. These loopholes are magnetic tubes that expand upward like funnels. Inside them, sound travels more freely.

In the first moments after the Big Bang, the universe resembled a boiling cauldron. According to one hypothesis, dark matter, the invisible substance that holds galaxies together, could have been born there.

When two black holes merge, ripples spread across the fabric of spacetime — gravitational waves. But what if one of them isn't a run-of-the-mill black hole but something else — an exotic compact object?

In the first fractions of a second after the Big Bang, the universe was a stage of rapid change. A stretched rubber sheet that cools quickly becomes covered with microscopic cracks. A similar process on a cosmic scale could have given rise to cosmic strings — ultra-thin but super-dense threads of energy stretching across the entire universe. These strings are not just defects in space.

The first moments after the big bang: space expands rapidly — physicists call this period inflation. Inside this swelling fabric, like soap bubbles in a stream of air, regions of new vacuum begin to form — a first-order phase transition. Most bubbles pop or merge as soon as they appear.

The universe rang piercingly in its first moments. During the inflation epoch, when space expanded faster than light, energies were monstrous — trillions of times higher than in the Large Hadron Collider.

In the first moments of its life, the universe resembled a boiling cauldron. Matter wasn't spread evenly — clumps and voids were brewing within it, and their violent motion gave rise to a trembling of space itself: gravitational waves.

Light from quasar J0744+2052 traveled to us for almost 12 billion years. Along the way, it bumped into hydrogen clouds that snatched individual lines from the spectrum — like a comb sifting through delicate frequencies. Astronomers call this pattern the Lyman-alpha forest in spectroscopy.

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.

In the first moments after the Big Bang, cosmic symmetry breaking divided the hot plasma into regions with different vacuums — the lowest energy states of a field.

Plasma is not just hot gas; it's an entire orchestra of charged particles, each group playing its own part. Heavy ions (atoms that have lost electrons) set the slow rhythm, while light electrons dart around ten thousand times faster.

Picture the early Universe as an unimaginably large bell. Inflation — the era of rapid expansion, dreamed up by Alan Guth, strikes it, sending a wave rippling across the fabric of spacetime.

In the first moments after the Big Bang, the Universe was not a silent void but a seething cauldron of plasma, threaded with sound waves. As the temperature dropped, the cosmos underwent phase transitions — spontaneous reorganizations that gave birth to bubbles of a new phase.

Imagine a river at a rapid: the current accelerates until no wave can go against the flow. So it is with gas near a black hole: reaching the speed of sound, it locks itself in — an acoustic black hole is born, a twin of the gravitational abyss. Here the event horizon is woven from a flow faster than its own sound.

The early universe resembled an overcrowded hall where heavy particles collided and decayed at a deafening pace. Among them could have been scalar leptoquarks — particles that simultaneously latch onto a quark (a building block of matter) and a lepton (such as an electron).

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.

In the first moments after the Big Bang, the universe was a boiling cauldron. But then, according to a new hypothesis, it suddenly cooled dramatically — far more than previously thought. In this icy world, dark matter particles, like tiny pendulums, froze and did not begin their oscillations.

In a thin sandwich of semiconductors, light creates pairs, an electron and a positive hole, that stick together like a ball on a rubber band. Normally, such pairs, called excitons, quickly emit light and vanish. But there are others, dark ones, that live hundreds of times longer because their internal structure forbids them from easily giving off energy.

Right after the Big Bang, space rippled with gravitational waves, like those from a thrown stone. These tremors in the very fabric of the cosmos, predicted by Alan Guth, stretched across the entire universe. The ripples slightly compressed primordial matter in some places and thinned it out in others.

Axions are hypothetical elementary particles introduced in 1977 by Roberto Peccei and Helen Quinn to resolve the so-called strong CP problem in the Standard Model of particle physics.

After the Big Bang, dark matter and ordinary matter (mostly hydrogen) went their separate ways in terms of speed. Their gravitational pull acts like a bow gliding across a string: when frequencies match, resonance occurs, and sound waves start to rapidly grow in ordinary matter.

Imagine a vast lake at night, perfectly still. You can't see waves, but you hear them lapping evenly on the shore from all sides. That's what astronomers call the gravitational-wave background — a constant hum from distant black hole mergers. But what if the splashing were slightly louder on one side?

Each vowel sound is a distinct shape of the mouth, tongue, and throat. When you say 'ah,' 'ee,' or 'oo,' not only does the air inside your head change, but so does the way radio waves pass through it. Researchers peered into this process using MRI scans taken right during speech and built a precise computer model of the head — from bones to soft tissues.

In the first moments after the Big Bang, the cosmos resembled a giant cooling pond. Just as water, when freezing, becomes covered with a network of cracks, so the cooling universe could have cracked — not into ice, but into the thinnest filaments of pure energy. These filaments are called cosmic strings.

In a disk of gas and dust around a young star, dust particles behave like sand grains in a stream of water: the gas flows faster, the dust lags behind, and friction arises between them. This friction can rock the magnetic waves that run through the disk. The galaxy is full of such disks: it is precisely in them that planets are born.

A sheet of graphene one atom thick hangs in the air like a taut bedsheet. Heat waves, vibrations of atoms that physicists call phonons, ripple across it. Previously, it was thought that these waves quickly scatter due to strong interactions, and heat transfer is poor.

After the Big Bang, the Universe simmered as a fiery 'soup' of fundamental particles. Expanding and cooling, the soup gradually 'solidified' into protons and neutrons — much like crystallization. Had the solidifying been instantaneous, like a lake cracking in a deep freeze, the fabric of spacetime would have convulsed.

The universe wasn't born in silence. Primordial gravitational waves — ripples in spacetime — still carry the echo of that event. Scientists try to hear it in two ways. Low 'notes' are captured in the Big Bang's afterglow — light emitted 380,000 years later.

The standard cosmological model describes the birth of the universe as an explosion from a singularity — a point of infinite density and spacetime curvature.

Ahead of the bow shock that Earth creates in the solar wind, giant bubbles of rarefied gas sometimes appear. Inside them, particle density drops by factors, and electric fields start to tremble like a plucked string.

A star like the Sun hums like a bell: sound waves inside make its surface tremble ever so slightly. From this trembling, astronomers, like doctors reading a pulse, infer the star's temperature, density, and age. But the Kepler telescope spotted an oddity: many stars that spin fast and are covered in spots show no trembling at all. It's as if they've lost their voice.

In its infancy, the universe was a hot, plasma-like mixture of particles. Microseconds after the Big Bang, as it cooled, the temperature fluctuated slightly.

Ultrasound in a liquid is like shaking a bottle of soda vigorously: shake it, and bubbles appear. In science, this is called cavitation, and the bubbles don't just float around: they are born, grow, and collapse with tremendous force.

The Sun constantly emits a stream of charged particles, mostly hydrogen — the solar wind. Sometimes the Sun ejects dense blobs of magnetized gas, inside which calm usually reigns. But in 2000, scientists noticed two regions inside one such cloud where the gas was churning.

In the first moments after the Big Bang, the cosmos was like a pot of boiling broth. In it, like lumps of flour, dense clumps of energy — oscillons — curdled and swelled. They grew, gained strength, and soon took over the expansion of the Universe.

A magnetar's crust cracks in milliseconds. A deep shift generates seismic waves that run across the surface and shake the magnetic field. This starquake is like an earthquake, but on a neutron star with a field a quadrillion times stronger than Earth's.