hydrogen

Inside the steel of a future fusion reactor, tiny helium bubbles form, and on their walls a chemical drama unfolds. Chromium and tantalum atoms, like sentinels, take positions at the cavity boundary and change the rules of the game for hydrogen.

On a table lies a handful of coins of the same denomination but different minting. Weigh the whole handful at once and you learn only the average weight, not the story of each coin.

In a molecule, hydrogen sometimes resembles not a ball but a wave that can leak through an energy barrier, like a ghost through a wall. Chemists call this tunneling, and it underlies many processes, from enzyme function to charge transfer in materials. But how exactly does a molecule find its path for such a transition?

Forty light-years away lives a star that went unnoticed for a long time: TRAPPIST-1 emits two thousand times less light than the Sun. But it turned out to have seven Earth-sized planets, three of which orbit in the zone where water could remain liquid. Yet little was known about the star itself, about its chemical kitchen.

A fusion reactor is like a super-hot furnace where plasma reaches millions of degrees. The walls are made of tungsten, the most refractory metal there is. But even tungsten needs protection: fast particles from the plasma bombard the surface and knock atoms loose. These ejected atoms enter the plasma and cool it down, like a spoonful of cold milk in hot tea.

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.

When stars are born in a galaxy, they make hydrogen glow, like a neon sign, but on a cosmic scale. This light could tell us a lot about how many stars are forming, but on its way to us, it passes through cosmic dust. Dust is like a fogged-up window: it dims the glow and alters its color.

In a dense molecular cloud, at the edge of glowing gas, an invisible assembly line is at work. It takes simple scraps — single atoms and light pairs — and glues them together step by step into long carbon chains and rings. The first piece of this assembly line has long eluded our eyes. Now it has been found.

In dark interstellar clouds where new stars are born, chemistry starts with a tiny particle — the trihydrogen ion (H₃⁺). It collides with other atoms and sets off a cascade of reactions that build ever more complex molecules. For a long time, it was thought that the main reaction producing it, H₂⁺ colliding with H₂, only happens in the gas phase.

At a distance of 1900 parsecs, in the constellation Vulpecula, the star V420 Vul pulsates — a Mira-type variable. Such stars, nearing the end of their lives, swell and shed their outer layers. But around V420 Vul, astronomers spotted not just a shed envelope, but something trickier.

In a tight row of atoms, spaced closer than the wavelength of light, a remarkable state hides. The excitation is distributed among all particles so that their radiation cancels itself out. This quantum 'silence' is an ideal vault for a photon: it can be stored there hundreds of times longer than usual.

A flashlight beam cuts through fog. The denser the fog, the more the light scatters and the later it reaches your eye. A similar principle works with fast radio bursts — mysterious, super-powerful pulses from distant galaxies. As their radio waves travel through space, they interact with free electrons — particles stripped from atoms.

A film sliver thinner than a human hair was placed between diamond anvils and squeezed. The pressure climbed — a hundred thousand atmospheres, half a million, a million… Yet the material kept conducting electricity without resistance.

The cosmic dawn is hidden behind a dense veil of time. To see beyond it, you need to catch the radio signal from clouds of neutral hydrogen — the so-called global 21 cm signal. But it is so faint that the receiver's own noise drowns it out.

A young star cluster resembles an orchestra before a concert: each instrument tunes up in its own way, and the overall hum seems like chaos. But if you listen closely, you can pick out individual notes.

Water comes in different varieties. Not just fresh or salty, but also "heavy"—when one of its hydrogen atoms is replaced by deuterium, its heavier cousin. Such water is called HDO, and it's a true cosmic passport: the amount of deuterium in water reveals where and when that water was born.

In an ultrathin sheet of four-layer graphene, electrons can behave like a frozen liquid. When cooled strongly and subjected to an electric field, they stop darting around and line up into a regular pattern — a Wigner crystal. It's similar to how water droplets on a frosty morning turn into ice honeycombs.

Electrons in a molecule are like dancers trying to keep their distance from each other. But when two get too close, their dance hits a sharp snag — a so-called Coulomb hole (a deep dip in the interaction energy).

In a giant cosmic cradle, the Tarantula Nebula, astronomers took a close look at 122 massive stars, each at least 30 times heavier than the Sun. They measured the nitrogen abundance in their atmospheres, and the picture turned out to be unexpected.

In the coastal shallows, where water retreats and returns, life follows the rhythm of the sun. The brownish film on the mud's surface is not just dirt but a dense community of tiny diatoms. By day they get plenty of light for photosynthesis, but when the sun gets too intense, a chemical storm brews inside the cells.

3I/ATLAS burst into the Solar System like an uninvited guest, a gift of fate for hunters of extraterrestrial intelligence. This comet-like wanderer from the depths of the Galaxy flew close enough to be heard in all its details — unlike distant exoplanets.

A sub-Neptune is a planet that falls between Earth and Neptune in size. These worlds are abundant in our galaxy, but their internal structure has been hotly debated. New research shows that in their youth, these planets behave like a sponge soaked with water.

The Martian surface is a place where anything alive quickly dies. Cosmic rays and ubiquitous oxidizers sterilize the top layer of soil. But dig a little deeper, and the picture changes. There, beyond the reach of ultraviolet light, a zone suitable for life may lurk. This zone runs on a strange fuel — radiation.

Previously, Uranus and Neptune were considered ice giants because of assumed thick layers of frozen water, methane, and ammonia. New calculations paint a different picture: deep inside them hides an ocean of hot magma, which under immense pressure has absorbed a colossal amount of hydrogen.

Water in a glass seems simple, but to split it into oxygen and hydrogen with sunlight, it's not enough to just transfer electrons: they also need to 'agree' on the direction of their spin. An oxygen molecule is born with two unpaired electrons spinning in the same direction.

The James Webb Space Telescope peered into a disk of gas and dust around a young star where planets are born, and for the first time spotted ice made of heavy water. This water is not ordinary: in its molecules, regular hydrogen is replaced by deuterium, its heavier sibling.

In the heart of a molecular cloud, a massive star is born. Its ultraviolet light ionizes hydrogen, and the cloud flares in the Lyman-alpha line. But for the photon, this flare is not liberation but imprisonment in a hall of mirrors.

Imagine a packed orchestra, each musician playing their own part, while you try to pick out the quiet voice of a rare flute: its melody drowns in the sound of violins and trumpets. That's what hunting for molecules in interstellar clouds is like: telescopes pick up the 'radio voices' of countless substances, and picking out the signal you want from the noise is no easy task.

Atomic nuclei are wrapped in fluffy electron coats — in such attire, they can't get close enough to embrace. But swap the light coat for a heavy one: a muon, a particle from the standard model, shrinks the cloud by nearly 200 times.

A steel cylinder that has held hydrogen for a long time sometimes breaks not along the usual grain boundaries but right through the crystal grains, leaving a strange pattern, as if the crack chose the wrong road. For a long time, people looked at this and wondered: why?

The cosmic microwave background is the afterglow of the Big Bang, which we see at millimeter wavelengths. But it also has a long-wavelength tail extending into the radio range.

From carbon, nitrogen, oxygen, and sulfur, you can assemble 10⁶⁰ different small molecules: that's a 1 with 60 zeros, more than the stars in the visible universe. Life uses only a tiny fraction of this menu, but not randomly.

Light takes 124 years to reach us. That's how long it takes for the star's rays to bring news of K2-18b — a planet entirely covered by an ocean but wrapped in a thick hydrogen blanket. It's about two and a half times the size of Earth. For a long time, scientists debated: a water world with a dense atmosphere, or a scaled-down Neptune without a solid surface?

Hydrogen is the most common element. Its atoms are like antennas: they emit and absorb light at very specific frequencies. Einstein predicted that spacetime can ripple: these are gravitational waves.

Light in an optical fiber runs along the core, barely escaping outside. But if you get very close, you can feel a faint trembling of the field at the surface — the evanescent wave. It is in this 'light fog' above the surface of a tiny silicon ring that physicists have caught a single rubidium atom.

In the dense gaseous cocoon around a young massive star, streams of matter collide as if in a giant chemical flask. One stream moves relative to us at about 11 kilometers per second, the other at about 5. The telescope at Onsala (Sweden) caught their radio voices and resolved them into hundreds of spectral lines — molecular fingerprints.

Searching for extraterrestrial signals is like trying to hear a whisper at a roaring stadium. The Green Bank Telescope listened to 70,000 stars, but 100 million bursts turned out to be earthly noise — from phones, satellites, microwave ovens.

A thin crack runs through glass. At first glance, the fracture line simply reflects the material's brittleness. But if you zoom in to the atomic level, the picture gets more complex: glass starts to resist differently when the crack accelerates.

The Universe is structured like a sponge: there are dense regions packed with galaxies and gas, and giant pores — cosmic voids. These voids occupy most of space, but their contents have remained a mystery because matter there barely reveals itself. Now astronomers have 'felt' the voids using fast radio bursts — super-powerful pulses from distant galaxies.

In a crystal of water and caustic cesium, oxygen and cesium atoms sit in place like beads in a rigid lattice. Hydrogen atoms behave differently: they are like passengers constantly changing seats. In this layered material, each oxygen is linked to three neighbors via hydrogen bridges, forming a honeycomb-like pattern.