Antiproton in the Nuclear Halo
The antiproton is a mirror twin of the proton: same mass, but negative charge. When it approaches an atomic nucleus, the particles can annihilate, turning into radiation.
Plastic That Sees Radiation
A dense piece of plastic the size of a coin flashes when an invisible particle hits it. That's how scintillators work — materials that turn radiation into faint light. They're usually made from fragile crystals or expensive polymers. But now there's a simpler option: plain polyurethane, the stuff used to mold furniture foam and shoe soles.
A hospital cyclotron instead of a nuclear reactor
Every year, in the United States alone, doctors perform more than 16 million scans using the radioactive isotope technetium-99m. It lights up the heart, bones, and lungs in images, helping to find tumors or check blood flow. But the isotope itself has a half-life of only six hours, so you can't stockpile it: you need a steady supply.
The Thorium Pendulum: Catching the Atomic Echo
An atomic nucleus usually lives in a single energy state, like a ball resting on the floor. But thorium-229 has a rare exception: the nucleus can get stuck on a tiny step above the floor — the so-called isomeric state. This step is so low that it can be nudged by ordinary light, not just hard radiation.
Antimatter Meets Protons: Particle Birth Seen for the First Time
In a particle accelerator in Beijing, an anti-Lambda hyperon, a rare antimatter particle, slams into an ordinary proton. Instead of simply disappearing, they transform into a whole bouquet of other particles: a positively charged kaon, two pions, and sometimes additional neutral pions. Such transformations for the anti-Lambda had never been observed before.
Antimatter Meets an Ordinary Proton
In a particle accelerator, the anti-lambda particle is a rare guest. It is born on the fly, lives for a tiny fraction of a second, and usually decays on its own. But sometimes it manages to collide with an ordinary proton, and then a whole shower of light particles is born: kaons, pions.
Five Metals in One Spot: A Cathode for Sodium Batteries
Sodium is lithium's neighbor on the periodic table, but it's hundreds of times more abundant in the Earth's crust and much cheaper. So sodium batteries could replace lithium ones in electric vehicles and energy storage.
Antihydrogen in the Light: How an Antiproton Probes the Nucleus
The antiproton is the proton's twin, only with a negative charge. When such a twin approaches a nucleus, it doesn't just bounce off: a whole dance of attraction and repulsion unfolds between them.
An Experiment Where an Antiproton Talks to an Ion
A single antiproton, trapped and cooled to near absolute zero, behaves like a tuning fork that needs a very precise strike to produce a clean note. Catching that 'note' directly is nearly impossible — the signal is too weak.
How to Tell a Pion from a Kaon in a Fireball
In collisions of heavy nuclei, a fireball of thousands of particles is born. Among them are pions and kaons, two kinds of light particles that look very much alike. To understand what happens in this fireball, physicists need to know exactly how many of each particle flew out.
How to Count Atoms More Precisely
An electron in an atom is like a note on a string: it has a set of allowed energies, and the physicist's task is to find these notes. Usually, the space around the nucleus is divided into small pieces and the behavior of the electron in each piece is calculated. The finer the pieces, the more accurate the answer.
Trapping Antimatter: How to Catch What You Can't Touch
At CERN's antimatter factory, antiprotons are born with the energy of a bullet from a rifle. You can't just put them in a box: they instantly annihilate upon touching ordinary matter. So physicists devised a way to catch them in electromagnetic traps — invisible cages made of fields.
The Gamma Angle: How Physicists Catch the Difference Between Matter and Antimatter
Every second, billions of decays happen inside our bodies, and nobody notices. But physicists do: they smash particles in accelerators and watch what fragments they fly into. Hidden in those fragments is the answer to why we exist at all. Right after the Universe was born, there were equal amounts of particles and antiparticles, but today all we see around us is particles.
A Mirror for Antiprotons
When particles collide at enormous speeds, they produce a shower of new particles. Among them are antiprotons — twins of ordinary protons but with the opposite charge. Each of these particles has its own spin, like a tennis ball sent with a twist. But whether antiprotons are actually spun up at birth has never been checked.
Tin Nucleus Reveals Its Size
Two tin nuclei collide at about two-thirds the speed of light. For an instant, a hot, dense cloud forms, and protons fly out in all directions. If you catch pairs of protons and measure how often they fly off in the same direction, you can work out the size of that cloud. This method is called femtoscopy: it works like a microscope for nuclear scales.
Sorting Atoms by Nuclear Spin
Usually, isotopes are separated by exploiting the difference in nuclear weight. That difference is tiny, like sorting grains of sand that differ by one hundredth of a millimeter. The new method ignores weight and instead looks at the nucleus's rotation: its spin.
The laser hits the molecules twice with a short pause in between.
The Atomic Nucleus: Not a Soloist, but a Choir of Voices
The atomic nucleus is not a billiard ball but rather a hazy cloud that constantly changes its contours. Protons and neutrons inside are in continuous motion, and the nucleus can take on many different shapes: elongated, flattened, or pear-like. To describe this quivering diversity, physicists usually picked a few most probable shapes and mixed them, like an artist mixing paints on a palette.
A Positron in the Ring: How Atoms Attract an Antiparticle
A pinch of salt falls into water, and sodium and chlorine ions scatter, surrounded by water molecules. Now, instead of an ion, a positron (an antiparticle, the electron's twin but with a plus instead of a minus) joins the molecular crowd.
Laser Test of Nature's Mirror Symmetry
Ever since Paul Dirac theoretically predicted antimatter, physicists have been hunting for the tiniest differences between particles and their antiparticles.
The Heavy Neutrinos That Never Were
In the first moments after the Big Bang, matter and antimatter should have been created in equal amounts. But today we see only matter — stars, planets, ourselves. Where did the antimatter go? One clue hides in nearly elusive particles: right-handed neutrinos. The usual story is that their decays create a slight bias in favor of matter.
How to Spot Hidden Magnetism by Symmetry
Two teams pull a rope with equal force in opposite directions — the rope doesn't move, and the net force is zero. That's how many antiferromagnets behave: the magnetic moments of atoms are aligned oppositely and cancel each other out.
Invisible Molecule Teaches Chemistry of Space
Two guitar strings are stretched on the same neck. They are almost identical, but one is slightly shorter — and they sound different. That's roughly how the two isomers of ethanimine work: molecules with the same set of atoms but rotated differently in space. Astronomers spotted this molecule in the dense clouds near the center of our Galaxy.
Nuclear Duathlon: Alpha and Beta Decay Combined
An atomic nucleus is like a crowded bus. To free up space, a group of two protons and two neutrons — a helium nucleus, an alpha particle — exits through the front door: this is alpha decay, described by George Gamow as tunneling under an energy barrier.
How a Polyglot Neural Network Uncovered an Atomic Secret: Why Protective Coatings Destroy Solar Cells
Hybrid perovskites are the rising stars of photovoltaics: their efficiency is growing so fast it feels like we're on the brink of a solar revolution. But these materials, like intricate atomic mosaics, are extremely vulnerable — moisture, heat, and light quickly turn them to dust.
Why Technetium and Promethium Are Outcasts of the Periodic Table
In nuclear physics, a puzzle has long been nagging: why among elements lighter than bismuth, only technetium (No. 43) and promethium (No. 61) have no stable isotope at all? All their neighbors in the periodic table can boast at least one long-lived variant, but these two seem to fall out of the general pattern.
Excitons in Copper Oxide: When 'Atoms' Get Crowded
A copper oxide crystal looks like a dark red pebble. But when a short laser pulse hits it, pairs are born inside: an electron and a 'hole'—a place where an electron is missing. Such a pair is called an exciton and behaves almost like a hydrogen atom: the particles circle each other, bound by electric attraction.
How a Magnesium Nucleus Grows a Neutron Coat
The atomic nucleus is usually pictured as a dense ball where protons and neutrons are mixed together. But in some isotopes, neutrons can stick out far beyond this ball, forming a diffuse shell — a neutron halo. This is especially common in nuclei with many more neutrons than protons.
Antiprotons: Bounce or Annihilate?
The antiproton is the mirror twin of the proton: same mass, but negative charge. When it hits matter, it usually annihilates instantly — disappearing in a burst of energy upon colliding with an atomic nucleus.
How to Measure an Atomic Nucleus by Knocking a Particle Out of It
Inside an atomic nucleus, protons and neutrons don't sit still like peas in a pod. Each particle occupies its own orbit — a region of space where it can be found. The larger the orbit, the more 'smeared out' the particle is.