Titanium in Cosmic Rays
In the stream of cosmic rays, particles flying toward us from the depths of the Galaxy, titanium is rare. Its nuclei are almost indistinguishable from iron: both are heavy, and both leave similar tracks in detectors.
Cosmic nuclei reveal their energies
High above the Antarctic ice sheet, a balloon with a detector floated for twenty days. It caught tiny particles that had been traveling toward us for millions of years from distant stellar explosions. Now scientists have sorted through the catch and reported how much energy the protons and nuclei of different elements carried.
Extra Electrons in Cosmic Rays
High above Antarctica, a balloon carried an instrument that caught electrons from space. These particles come from distant stellar explosions and other powerful events. The instrument measured their energy, like the force of an impact. And in one energy range, there were more impacts than calculations predicted.
Cosmic Rays in Bubbles: Why Heavy Nuclei Unexpectedly Rise with Energy
The ATIC balloon rose over Antarctica and caught particles older than Earth itself. Among them are atomic nuclei from sulfur to chromium, and the higher their energy, the larger their fraction compared to iron. The standard 'leaky box' model predicted the opposite: heavy nuclei should dissolve like salt in water. But the data stubbornly rose.
Dusty Seasons over La Palma: Thirty Years of Observations
Every clear night, a telescope on the island of La Palma looked at the sky and recorded how much the air dimmed starlight. This was routine work for astronomers measuring stellar positions. But in these records, like in an old diary, traces of a different story remained: the arrivals of dust from the Sahara.
Cosmic Rays Break a Simple Law
High above Earth, a satellite flies, and inside it is an instrument the size of a small wardrobe. It catches particles that have been racing through the galaxy for billions of years and finally slam into the detector. Such particles are called cosmic rays, and they bring news of distant stellar explosions.
Cosmic Nuclei: What They Tell Us About Their Stars
Like long-distance runners, atomic nuclei, from light helium to heavy iron, race toward us across the Galaxy. At the finish line, in a detector on a high-altitude balloon, we see that heavy nuclei arrive a bit more exhausted than light ones. The difference is small, but it repeats from flight to flight.
The Cosmic Ray Knee: All Nuclei Break the Same Way
Cosmic rays are charged particles that fly to us from the depths of the Galaxy. If you plot how many particles arrive at each energy, the line runs smooth, then suddenly drops sharply.
The Threshold Where Light Becomes a Projectile
Light strikes a metal plate, and electrons fly out. This is the photoelectric effect, and it works only if the light has enough energy to cross the threshold that holds electrons inside.
Cosmic Showers Reveal the Composition of Cosmic Rays
At night over the Siberian taiga, a faint blue light sometimes flickers. It's not the aurora borealis but a cosmic-ray shower: a single particle from deep space slams into the atmosphere and shatters into millions of secondary particles. They race toward the ground in a broad front, like a ripple from a stone dropped into water, and make the air glow.
Cosmic Rays: Odd Nuclei Run Faster
Cosmic rays are atomic nuclei accelerated to near-light speeds. They arrive at Earth from all directions, and their composition tells us what's happening in the far reaches of the Galaxy.
A Cosmic Shower of Heavy Particles
Every second, dozens of particles from space fly through each of us. Most are light protons, but there are also heavier atomic nuclei: carbon, oxygen, iron. They are born in stellar explosions and travel to Earth for millions of years. Their energy can be staggering: a single particle can carry as much as a tennis ball on a serve.
A Red Dot Behind the Bullet Cluster: Peering into the Broad Emission Region of a Black Hole
The red dot in the James Webb Space Telescope image is the galaxy Bz5.3, whose light has traveled 12.5 billion years to reach us. It lies behind the Bullet Cluster, whose gravitational field acted as a lens and brightened it by a factor of 3.7.
Levitating Nanospheres Catch Dark Matter Recoils
A silicon sphere 166 nanometers in diameter floats in a beam of infrared laser light. The pressure is below 10⁻⁸ mbar, and the motional temperature is about 10 millikelvin. That is colder than the cosmic microwave background.
Dust Veil Over the Beacon at the Heart of SN 1987A
At the center of the supernova remnant SN 1987A, 168,000 light-years from Earth, hides an object that astronomers have been seeking for 37 years. This is the closest supernova to have exploded in front of modern telescopes, and the only one where the compact remnant has yet to be seen directly.
The Sun as a Free Quantum Pump
Sunlight collected by a Fresnel lens and passed through 20 meters of plastic fiber had a power of just 3 microwatts, a million times less than a typical laser pointer. That was enough to generate photon pairs correlated in position inside a nonlinear crystal. One photon from each pair passed through the object, the second was scanned by a detector, and coincidences built up the image.
A Score for Two Molecules: Permanent Dipoles Conduct Dark States
Two voices in a molecular duet can sound in unison or cancel each other into silence. In physics, such silence is called a dark state: a quantum excitation that does not interact with light and therefore lives unusually long.
The Cosmic Potter: How Rotation and Magnetic Fields Shape a Black Hole
On November 23, 2023, the LIGO, Virgo, and KAGRA detectors caught a gravitational wave from the merger of two black holes with masses of 137 and 103 solar masses. Both fall into the pair-instability mass gap, the range from 69 to 139 solar masses where ordinary stellar evolution leaves behind nothing but expanding gas.
The Invisible Janitor at the Heart of the Milky Way
At the center of the Milky Way, 27,000 light-years from Earth, lives the supermassive black hole Sagittarius A*. It weighs in at four million Suns. It does not flare brightly like quasars; instead, it smolders almost imperceptibly. For a long time, astronomers debated whether it blows a wind. Now we have the answer: it does.
Pilot Photons: Relativistic Bohmian Mechanics Seen Directly
A single photon passes through two slits and leaves an interference pattern on a screen. Quantum mechanics describes this process with a wave function, but what happens to the particle itself?
A Traveling Line: How Photons Lose Energy in a Crowd of Electrons
On October 9, 2022, detectors on Earth recorded a gamma-ray burst of unprecedented power. GRB 221009A was so bright that its radiation ionized the upper layers of the ionosphere, and satellite instruments were temporarily blinded.
The Quiet Supernova: Why Pa 30 Is Silent in Radio
In 1181, Chinese and Japanese astronomers recorded the appearance of a 'guest star', a bright object that shone for six months in the constellation Cassiopeia and then vanished. Today, that spot hosts Pa 30: a nebula with a hot central source ejecting material at 16,000 km/s.
Falling into a McVittie Black Hole: A Plunge into an Expanding Waterfall
A waterfall doesn't ask if you're ready to jump. Its flow accelerates, and at some point even light can't escape back. A McVittie black hole is such a waterfall, but not in an ordinary river; it's in an expanding universe: the water here is space itself, which continuously stretches, carrying galaxies apart from each other.
Red Dots as Gravastars: A Birth Mechanism
The James Webb Space Telescope has spotted a scattering of compact objects in the early universe, nicknamed 'little red dots.' They are too red and too dim to be ordinary quasars, and astrophysicists are scratching their heads over what powers them.
Sky Hotspots: The Senders of Ultra-Particles Identified
Every day, particles with colossal energy enter Earth's atmosphere, like unsigned letters. Their source long remained a mystery. New research shows: these 'visitors' point to nearby galaxies, where from time to time catastrophes occur — collisions of neutron stars, ultra-dense spheres the size of a city but with the mass of the Sun.
Supernovae as Probes of Dark Energy Evolution
Astronomers use Type Ia supernovae — thermonuclear explosions of white dwarfs — as 'standard candles': their peak luminosity was long thought to be the same everywhere in the universe.
Stellar explosions puff up giant gamma-ray bubbles
At the center of the Milky Way, a giant stellar cauldron boils. Massive stars are born and die there: each death is a supernova explosion, hurling clouds of charged particles into space.
Encounter with a Shutter: How a Photon Creates a Fountain of Probabilities
Light consists of portions — photons. Max Planck was the first to understand that light is emitted in quanta. Today, we can guide single photons. When such a photon encounters a fast shutter, it cannot be sliced — half a photon doesn't exist. Instead, a quantum mixture of states with different photon numbers emerges: zero, one, two, three..
How a Whirlpool in a Cup Becomes a Black Hole Bomb
When liquid is swirled in a cup, a vortex with an empty center forms. In this empty core, waves find a trap: bouncing off the walls, they siphon energy from the vortex and grow like a flame along a fuse — each wave stronger than the last, until a surge breaks loose.
Astrophysicists have described the same chain reaction around black holes.
When the Speed of Light Stops Being the Limit
In October 2022, the LHAASO observatory measured the spectrum (energy distribution) of gamma-ray burst GRB 221009A — the brightest on record. Its light traveled for two billion years and was so intense that it disturbed the upper layers of Earth's atmosphere.
Dust Storms on a Rogue Planet
Far beyond the Solar System, a world called VHS 1256B wanders — a giant planet without a star. For a long time, astronomers couldn’t figure out why its brightness jumped by nearly 40% in just a few days. The answer came with the James Webb telescope: it turns out, colossal storms of silicate dust engulf the entire planet.
Cosmic Heavyweight: Neutron Star Sets Mass Record
In a dance with an ordinary star, astronomers have found a true heavyweight — a neutron star with 2.35 times the mass of the Sun. That's more than any other whose mass has been precisely measured. These objects are born when a star explodes as a supernova and its core collapses into a city-sized sphere.
The Last Cry of an Alien Civilization
The galaxy is like a city at night: most windows shine steadily, but sometimes a skyscraper lights up all its lights and then goes dark. Just like that, according to a new hypothesis about planets around alien stars (exoplanet), we might first notice another civilization — by a short but blinding flash that could mark its demise.
Intermediate-Mass Black Hole: The AT2018cqh Flare as a Key to the Missing Link
When a star wanders too close to a black hole, an object with gravity so intense that not even light can escape, tidal forces shred it like dough caught in a mixer's beaters. This event, known as a tidal disruption event (TDE), unleashes a powerful flare of radiation.
A Black Hole's Shadow Betrays Its Spin
In 2019, astronomers unveiled the first-ever image of a black hole's shadow — a dark void encircled by a lopsided orange ring. This is the supermassive black hole at the heart of galaxy M87, 55 million light-years away. The ring isn't just glowing: one side is noticeably brighter than the other, like a campfire burning unevenly, with flames leaping higher on one side.
Proton smashes into deuteron: how speed changes the rules
A proton slams into a deuteron — a tiny bundle of a proton and a neutron. In the past, such collisions were described by equations where time flows the same for everyone, as in everyday life. But when particles are accelerated to near-light speeds, time slows down for them and lengths contract. It's like two runners on a track measuring the distance with different rulers.
X-ray Without a Camera: How to Film a Spinning Engine
An X-ray image is like a photograph taken in the dark with a very short flash: anything that moves comes out blurred. Conventional X-ray detectors are large arrays of millions of pixels, and by the time they read out one frame, the next is already missed. For a spinning turbine or a beating heart, such sluggishness is a death sentence.
A team of researchers sidestepped this problem by ditching the array altogether.
Light Makes a Crystal Conduct Current
A crystal without a center of symmetry is like a staircase where all the steps are tilted in the same direction: electrons, given a kick by light, roll predominantly in one direction. This is how a direct current is born — the photogalvanic effect.
Plasma Brews Herbs in a New Way
Everyone has a kettle in their kitchen, but few brew herbs in water that has just had an electric discharge passed through it. That's exactly what researchers did with neem and tulsi leaves — plants used for centuries in India as natural remedies. First, they 'activated' the water with plasma: they sent a glowing electric discharge through it, like a miniature lightning bolt.
Hiding in Plain Sight: A Nearby Neutron Star
A star 300 light-years away dances with an invisible partner. One side of the star heats up more than the other, as if the unseen dancer is breathing a hot wind onto it. This partner is a neutron star — a city-sized cinder so dense a teaspoon of its matter outweighs Mount Everest.