Vue lecture

Particles Seen Emerging From Empty Space For First Time

Longtime Slashdot reader fahrbot-bot shares a report from NewScientist: According to quantum chromodynamics (QCD) -- widely considered to be our best theory for describing the strong force, which binds quarks inside protons and neutrons -- even a perfect vacuum isn't truly empty. Instead, it is filled with short-lived disturbances in the underlying energy of space that flicker in and out of existence, known as virtual particles. Among them are quark-antiquark pairs. Under normal conditions, these fleeting pairs vanish almost as soon as they appear. But if enough energy is injected into a vacuum, QCD predicts they can be promoted into real, detectable particles with measurable mass. Now, the STAR collaboration -- an international team of physicists working at the Relativistic Heavy Ion Collider in Brookhaven National Laboratory in New York state -- has observed this process for the first time. The team smashed together high-energy protons in a vacuum, producing a spray of particles. Some of these particles should be quark-antiquark pairs pulled directly from the vacuum itself, but quarks can never exist alone and immediately combine into composite particles. Quarks and antiquarks are born with their spins correlated -- a shared quantum alignment inherited from the vacuum. The researchers found that this link persists even after the quarks and antiquarks become part of larger particles called hyperons, which decay in less than a tenth of a billionth of a second. Spotting these spin-aligned hyperons in the aftermath of the proton collisions allowed the researchers to confirm that the quarks within them came from the vacuum. The findings have been published in the journal Nature.

Read more of this story at Slashdot.

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Plongeurs d’élite et navire de guerre : le plan de l’US Navy pour récupérer les astronautes d’Artémis 2

Orion US Navy

Les quatre astronautes de la mission Artémis II ont quitté la Terre dans la nuit du 1er au 2 avril 2026 pour un voyage historique autour de la Lune. C’est fascinant, certes. Mais d'ici quelques jours, il va bien falloir les ramener à la maison. Et pour intercepter une capsule spatiale qui tombe du ciel, la Nasa a fait appel à l'artillerie lourde de la marine américaine.

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Fait-il nuit et jour sur la Lune ?

L'humanité s'est de nouveau aventurée autour de la Lune, avec la mission Artémis II de la Nasa. Les astronautes ont pu observer et photographier la face cachée de la Lune. En effet, la Lune vue de notre planète présente toujours la même face. Mais y'a-t-il des jours et des nuits sur la Lune, comme sur la Terre ?

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