A City Map Where the Streets Stay the Same but the Distances Change
Imagine a city drawn on a sheet of paper. The streets are the same, the intersections are in place, but the distances between blocks have suddenly changed.
Luminous Gas Rivers: How Giant Galaxies Are Born
In the early Universe, just one and a half billion years after the Big Bang, three massive galaxies collided in a small volume of space. Their gravitational dance flung out giant streams of cold gas that stretched for 60 kiloparsecs, a distance twenty times the diameter of our Galaxy.
Space Beacons: LST-1 Telescope Begins Tracking
At the heart of many galaxies lies an invisible beacon — a supermassive black hole. As it devours matter, it blasts a dazzling beam of gamma rays into space. If that beam points towards Earth, astronomers see a blazar — a bright but fickle point.
Dark Energy Is Not Constant: A New Look at the Universe's Acceleration
The Universe is a grand highway where galaxies, like cars, are moving apart faster and faster. The gas pedal is controlled by mysterious dark energy.
Refining the Expansion Rate of the Universe with 'Twins' Among Type Ia Supernovae
Type Ia supernovae are the 'standard candles' of cosmology: their peak luminosity is nearly identical, allowing distances to be determined from apparent brightness — the fainter the object, the farther away it is.
Gravitational waves and galaxy maps measure the expansion of the Universe
The Universe is expanding, and every galaxy cluster takes part in a grand dance. The tempo of this dance is set by the Hubble constant, first measured by Edwin Hubble nearly a century ago. Pinpointing the number is tough because you need a ruler that spans billions of light-years.
How quantum fog tests the laws of gravity
An ultracold atomic cloud, resembling fog, hints that gravity might not work as Newton said. On the outskirts of galaxies stars move faster than expected, and MOND theory tweaks the law of gravitation over large distances, removing the need for dark matter.
Seven Years of Watching a Cosmic Mirage
Light from quasar PS J2305+3714 has been traveling toward us for more than eleven billion years. On its way, it passes near a massive galaxy whose gravity bends its path, like a heavy ball denting a stretched sheet. Through a telescope, we see not one quasar but two images — two points of light that are actually the same distant object.
The Universe Stops Being Uniform at a Scale of 138 Megaparsecs
Galaxies in the Universe are not scattered randomly: neighboring ones move in the same direction, like a school of fish, while distant ones each go their own way. Where the boundary between 'together' and 'apart' lies has been unclear until now.
Bubbles After the Big Bang
The universe was born dark and cold, like a room with the lights off. Then someone started turning on the bulbs — the first stars. Around each such star, gas heated up and lost electrons, becoming transparent to light. These glowing regions grew like bubbles in boiling water and gradually merged until the entire cosmos became transparent.
Black Holes 'Weigh' the Expansion Rate of the Universe
Each merger of black holes produces gravitational waves — ripples in the fabric of the universe — predicted by Einstein and first detected with key contributions from Kip Thorne.
Molecules at the Black Hole: Who Sped Them Up
At the center of the distant galaxy NGC 1052, an invisible engine is at work. It accelerates clouds of gas to speeds at which sulfur oxide (SO) molecules begin to absorb radio waves. Astronomers caught this radiation using a network of Korean radio telescopes operating as a single instrument the size of a continent.
Gravitational waves refine cosmic expansion rate
Measuring the universe’s expansion is like timing a race when the track stretches. Neutron star mergers act as standard sirens: their gravitational waves ring out with a known “volume,” so fainter signals mean greater distance.
Dark Matter and Dark Energy: A Slow Reaction
The universe is expanding, and the rate of that expansion is a hot topic in cosmology. Nearly a century ago, Edwin Hubble discovered that galaxies are flying apart, but modern measurements of the Hubble constant, which characterizes the expansion rate, give conflicting values.
Cosmic Vortex: How Void Rotation Reveals the Universe's Composition
330 billion dark matter particles move in a cube 8 h⁻³ Gpc³ across — the arsenal of the AbacusSummit simulations, recreating the evolution of an expanding universe.
Galaxy Rotation in Voids Tests Inflation
In the nearly empty regions of space, galaxies spin in unison, like dancers in the same troupe. This dance creates a difference in light from opposite sides: on one side stretching, on the other compression. This optical shift has become a probe of the first moments after the Big Bang.
The Fading Echo Reveals a Stellar Accelerator
Twenty years ago, an X-ray image of the Arches cluster resembled a photo of a person in thick fog: the cluster itself was drowned in the glow of a neighboring cloud. The cloud acted like a mirror, reflecting hard radiation from the vicinity of the black hole, and that reflection swamped the faint signal from the stars.
Cosmic Beacons That Flash and Fade
An X-ray telescope points at a neighboring galaxy, and sees a point that wasn't there yesterday. A month later, it blazes hundreds of times brighter than the Sun, and a year after that, it fades again. Such points are called ultraluminous X-ray sources, and each one is a close pair: an ordinary star and a black hole or neutron star, whirling around each other.
Dark Energy as a Spring: A Model with No Tuning
In the late 1990s, Saul Perlmutter, Adam Riess, and Brian Schmidt observed supernovae and found: the universe is expanding faster and faster.
A Distant Galaxy Cluster That Wasn't So Quiet After All
A city at night looks quiet from above, but life bustles in its neighborhoods: streets are blocked off, construction is underway, and equipment hums in basements. That's roughly how astronomers now see the galaxy cluster SPT-CL J2215-3537, located so far away that its light has traveled for more than 8 billion years.
Light in Layered Crystals: How 2D Materials Transform Optics
Light passing through a window pane refracts the same in all directions. But in thin layered crystals, it's a different story: light traveling along the layers sees the material differently than light traveling across them. It's as if a sheet of paper were transparent but transmitted light differently along and across its fibers.
A Camera That Can See Tissues Breathe
Cells breathe. They need oxygen, and they take it from the blood flowing through the tiniest vessels. If blood flow is weak or oxygen is scarce, cells start to suffocate. Doctors need to see this as early as possible. But how do you look inside living tissue without cutting it open?
The new device does it in two ways at once.
A Living Database for Solar Cells
Scientific papers are published faster than people can read and organize them. In the field of perovskite solar cells, the main database has been stuck in 2021, even though research is in full swing. Now PERLA comes to the rescue — an autonomous living database that keeps an eye on the flow of publications on its own.
The Quiet Engines of Galaxies
A quasar is a supermassive black hole at the center of a galaxy that devours matter and shines brighter than all the stars around it. Some of that energy goes into radio emission, which, it was thought, could heat or expel cold gas — the raw material for new stars.
How a neural network tells black holes from neutron stars
For years, an X-ray telescope in orbit recorded how binary systems shine, where an ordinary star orbits a black hole or a neutron star. Matter from the companion falls onto the compact object, heats up to millions of degrees, and emits X-rays.
Cosmic Traffic Light: Why a Bright Galaxy Fooled Astronomers
Light from a distant lantern reflects off the surrounding fog, and from the delay of the reflection you can infer the distance. If the fog is uneven, the reflection arrives earlier or later, and the distance comes out wrong.
Invisible Clouds in the Virgo Cluster
In the dense Virgo galaxy cluster, astronomers have spotted six strange clouds of neutral hydrogen — gas that emits no light and is therefore invisible to ordinary telescopes. Radio telescopes can pick it up, but where it came from was unclear.
Dark Dancers: When Dark Matter and Dark Energy Dance Together
Galaxies are flying apart, but the expansion rate measured from the afterglow of the Big Bang and from supernova explosions doesn't match: this problem has been called the Hubble tension. It's like two dancers losing their rhythm because they can't feel each other.
A Galaxy Cluster at the Dawn of the Universe
In the first moments after the Big Bang, the universe was nearly uniform, like smooth dough. But within a billion years, in some places the dough began to rise faster: clumps of hundreds of galaxies emerged, which astronomers call protoclusters. These are the seeds of future giant clusters, the most massive bound structures in the universe.
Cosmic Microwave Background: New Measurements from the South Pole
At the South Pole, where the air is dry and transparent to millimeter waves, stands a telescope that looks not at stars but at the oldest light in the universe. This light is the cosmic microwave background — the radiation left over from the Big Bang, filling the entire sky.
Freezing the Moment: How Photons Stood Still for Precision
Light traveling through an optical fiber is like a runner in a narrow corridor: it can run straight, or it can weave from side to side. The direction of these "weaves" is polarization. Physicists have learned to keep the runner on a straight path: they constantly check its trajectory and gently correct it, not letting it veer off.
Light Beam on a Snap
A flashlight beam in fog spreads out within a couple of meters. Light particles scatter in all directions, like a crowd in a square. But sometimes they can march in formation — without spreading, without mixing. That's exactly the kind of march achieved in a tiny perovskite crystal.
The crystal was placed between two mirrors.
A Cosmic Ruler Without a Ruler
The universe is expanding, but at what rate is a question that has been troubling astronomers for decades. Two methods of measurement give different answers, and this discrepancy is called the Hubble tension. Some look at the early universe through the cosmic microwave background, others at nearby supernovae and Cepheid variables.
A Ring That Lets Light Through
Terahertz radiation sits between microwaves and infrared light. It passes through clothing, paper, and plastic, but not through metal or water. That's why it's used in security scanners and medical imaging. To see the polarization of such radiation, you need a detector.
Light That Gives Itself Away
Light from a star is not just a stream but a wave that can oscillate in different directions. Ordinary light is like a crowd where everyone waves their arms randomly. But after reflecting off dust grains or passing through a magnetic field, some waves align in a single line, like soldiers in a row.
Galaxy Colors Trace the Universe's Pattern
If you spill a handful of colorful beads on the floor, they will land differently: some will clump together, others will scatter into corners. Roughly the same way, galaxies of different colors (blue, green, and red) are scattered across the universe. Scientists decided to measure how 'clumpy' their distribution is using a number called the fractal dimension.
Polarization of Terahertz Waves: A New Compact Spectrometer
Terahertz radiation sits between microwaves and infrared light. It passes through clothing, paper, and plastic but is blocked by water and metal. That's why these waves are used in security scanners and for quality control of materials.
A Lattice That Senses Cracks Before They Appear
Ordinary materials break in silence. First, invisible struts inside them snap, and only then does a crack appear that you can see with your eyes. Engineers at Carnegie Mellon University have taught a material to 'talk' about such hidden damage.
They 3D-printed a lattice resembling honeycomb but with a more intricate pattern.
Warm Emptiness Instead of Dark Energy
In the standard cosmological model ΛCDM, galaxies recede under the pressure of dark energy — an invisible spring. However, different methods of measuring the expansion rate give different numbers, as if the ruler's scale is off.
A Cosmic Beacon from the Depths of Time
Galaxies, like giant whirlpools, sometimes collide and merge. In this chaos, gas compresses, new stars flare up, and a bright radio beacon is born at the very center. Its light — not visible to the eye, but radio waves — pierces through dust and gas like a siren through fog.