primordial magnetic fields

Light from the hottest stage of the universe has been traveling toward us for nearly 14 billion years. This is the cosmic microwave background — a faint glow filling the entire sky.

In the first moments after the Big Bang, the universe expanded at an incredible rate — a phase known as inflation. Even the vacuum was restless back then: quantum jitters shook the fields like wind rustling through a wheat field.

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 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.

Ever since Edwin Hubble discovered the fleeing of galaxies, the law of expansion of the Universe — Hubble's Law — has been a cornerstone of cosmology.

In 1981, Alan Guth proposed a scenario of cosmological inflation — a lightning-fast expansion of space that stretched quantum fluctuations to the scale of entire galaxies. Since then, cosmologists, like archaeologists, have been excavating this event from the structures of the Universe.

In the scorching plasma of the infant Universe, right after inflation, conceived by Alan Guth, the kinetic dominance epoch reigned.

The universe is filled with invisible dark matter. Just as a drop of water, as it evaporates, leaves behind a tiny salt crystal, so too can a black hole evaporate, leaving behind a minuscule stable remnant.

The universe is expanding, and its history features two puzzling episodes that don't fit into a simple picture. The first is a brief period in its youth when everything flew apart faster than expected, as if someone had floored the gas pedal. The second is today's acceleration, as if the same pedal were pressed again, but more gently.

Black holes come in lightweights, born from dying stars, and supermassive ones at galactic cores. The missing intermediate link had been hiding. Fast radio bursts, cosmic signals lasting milliseconds but carrying the energy of days of sunlight, helped crack the case. Think of these bursts as cries from the depths of the universe.

Ancient light, traveling 14 billion years, reaches us from all directions. At first glance, it looks perfectly smooth, but if you look closely, tiny fluctuations appear, like ripples on a still pond. Those ripples aren't random noise; they're an encoded history of the universe.

In the seething cauldron of the early universe, the vacuum, like a supercooled liquid, could boil with bubbles of a new phase. For a long time, physicists pinned their hopes on these bubbles as a source of primordial black holes (PBHs)—ideal candidates for dark matter.

A handful of copper coins scattered on a triangular grid freezes into a strange order when a current is passed through them. That's roughly how tiny magnetic arrows, electron spins, behave in a crystal with the rare name Y-capellasite.

Globular clusters are dense 'balls' of hundreds of thousands of stars that orbit the center of the Milky Way. Some were born in our Galaxy, others were captured when the Milky Way swallowed dwarf satellite galaxies. They can be distinguished by chemical composition, but astronomers now have a new tool — dynamical age.

A vast, dark cloud of gas stretched across the young universe. Inside it, like invisible fingers, magnetic field lines left over from the very birth of the cosmos threaded through. These fields act on charged particles, pushing them together, like a gentle breeze gathering fallen leaves into piles.

A tiny black hole the size of an atomic nucleus floats in the hot soup of the early universe. Normally, such a little one should quickly evaporate, releasing energy like a drop of water on a hot skillet. But if space is more complex than it seems and contains hidden dimensions, everything changes.

In a large gas cloud where stars are born, the magnetic field lines are roughly aligned in one direction, like the fibers in a piece of felt. But look inside, into the dense clumps that will eventually become stars, and the picture changes: there the lines are twisted every which way, like a ball of yarn after a kitten has played with it.

Eight red giants — bloated old stars like the future Sun — are not behaving by the book. Their surfaces oscillate steadily, like a bell, but within this chime there are glitches: some tones are missing, and the rhythm breaks. Scientists suspected an invisible hand inside — a magnetic field — and tried to calculate its strength.

Around young stars, disks of gas and dust swirl — the building blocks for future planets. Inside these disks, dust grains don't just fly randomly: they align along invisible lines of gas flow. Recently, astronomers noticed that dust grains in such disks behave like badminton shuttlecocks — always turning their long side into the wind.

In the first moments after the Big Bang, the universe was not empty and quiet but filled with hot plasma, particles, and magnetic fields. Among the particles, there may have been axions — light, nearly elusive dark matter candidates.

The James Webb Space Telescope has spotted tiny, unnaturally bright red objects in the early universe. Their light outshines by a hundredfold what you’d expect from ordinary galaxies of that era.

In the first instants after the big bang, the universe was a quantum vacuum where pairs of particles and antiparticles, virtual "guests" from physical nothingness, spontaneously appeared and almost immediately annihilated.

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.

A powerful laser strikes a tiny target, and it instantly turns into a cloud of scorching gas — plasma. Within this cloud, magnetic fields spontaneously arise. Like invisible hands, they prevent heat from freely escaping the hot core.

In the cold gas clouds where giant stars are born, everything is churning with motion. Gas compresses, swirls, and fragments into clumps — the future stars. For a long time, it was thought that the magnetic field brought order here: like invisible threads, it stretched clumps perpendicular to itself. But new observations showed the opposite.

Somewhere above our heads, every second, a proton accelerated to energies millions of times greater than those at the Large Hadron Collider slams into the atmosphere. It strikes an air molecule, and a cascade is born — a wide atmospheric shower of thousands of particles.

In its first moments, the universe resembled dough that alternately rises rapidly and then pauses for a second. During these short bursts, called expansion of the universe with interruptions, even tiny magnetic fields could have grown like bubbles in well-beaten dough.

In the mud at the bottom of a pond live bacteria that carry tiny magnetic compass needles inside them. These needles are chains of magnetite crystals that help the bacteria swim along Earth's magnetic field, like a compass needle, in search of better conditions.

The early Universe was like a construction site where, instead of slowly building floors, they used prefabricated blocks. These blocks were primordial black holes, born in the first fraction of a second after the Big Bang.

Dark matter may not be particles but black holes from the Big Bang era. In the early Universe, which was like a swirling batter, they were like heavy lumps — barely moving, they gathered surrounding matter and spun it into the swift galaxy flows astronomers observe today.

A black hole merger gives birth to a gravitational wave. Sometimes the wave’s path is blocked by a galaxy or a clump of dark matter, predicted by Zwicky and discovered by Rubin.

On a high-speed highway, a steady flow of cars sometimes clumps into a traffic jam because of random slowdowns. In the young Universe, the overall expansion of galaxies after the Big Bang resembled this orderly movement. But each galaxy also performed its own maneuvers — braking or accelerating under the pull of neighboring galaxies.

The Universe is filled with invisible mass, dark matter, which reveals itself only through gravity. One hypothesis suggests that dark matter consists of primordial black holes — objects formed in the extreme conditions just after the Big Bang.

The Universe after the Big Bang was almost perfectly homogeneous. Almost, because tiny density perturbations stretched by inflation became the seeds of galaxies. But what if these same perturbations could give birth not only to stars but also to black holes?

The night of March 4, 2024. The MeerKAT radio telescope in South Africa catches a millisecond pulse: a fast radio burst coming from a depth of 17.4 gigaparsecs. This is light that traveled 10.5 billion years to reach Earth.