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Big Bang nucleosynthesis
In physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than H-1, the normal, light hydrogen, during the early phases of the universe, shortly after the Big Bang. It is believed to be responsible for the formation of hydrogen (H-1 or simply H), its isotope deuterium (H-2 or D), the helium isotopes He-3 and He-4, and the lithium isotope Li-7. Big Bang nucleosynthesis begins about one minute after the Big Bang, when the universe has cooled enough to form stable protons and neutrons, after baryogenesis. From simple thermodynamical arguments, one can calculate the fraction of protons and neutrons based on the temperature at this point. This fraction is in favour of protons, because the higher mass of the neutron results in a spontaneous decay of neutrons to protons with a half-life of about 15 minutes.
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Space & Time News
August 29, 2026
Aug. 28, 2026 NASA’s Roman Space Telescope will combine Hubble-like detail with a field of view 100 times larger, giving astronomers a sweeping new way to explore the cosmos. Its observations could uncover hidden planets, map billions of cosmic objects, and ...
Aug. 26, 2026 NASA has successfully tested a system that allows satellites to navigate without GPS by using other spacecraft and debris as landmarks in orbit. In just three days, FALCON also improved the known orbits of more than 200 space objects completely ...
Aug. 26, 2026 NASA’s Roman Space Telescope is now enclosed inside its Falcon Heavy fairing and nearly ready for launch. Its mission could uncover thousands of exoplanets while helping scientists investigate dark matter, dark energy, and the accelerating ...
Aug. 24, 2026 NASA’s Roman Space Telescope has been cleared for final launch preparations ahead of a targeted August 30 liftoff aboard SpaceX’s Falcon Heavy. The powerful new observatory will probe cosmic expansion, the history of the universe, and distant ...
Aug. 20, 2026 A discarded SpaceX Falcon 9 stage crashed into the Moon on Aug. 5, leaving behind a newly formed crater about 60 feet wide. NASA’s Lunar Reconnaissance Orbiter captured detailed images showing bright and dark streaks of debris blasted across the ...
Aug. 12, 2026 Researchers have found a clever new way to map a part of Earth’s upper atmosphere that is notoriously difficult to observe. Using orbital data from roughly 1,200 Starlink satellites, they ...
Aug. 11, 2026 NASA is assembling the foundations of a future Moon Base through a wave of robotic missions and powerful new commercial landers. More than 20 landings are planned through 2029, testing everything from precision landings and lunar communications to ...
Aug. 10, 2026 NASA engineers have found a clever way to squeeze more life out of Voyager 2, nearly half a century after it left Earth. In an operation nicknamed the “Big Bang,” the team simultaneously shut down certain power-hungry hardware and switched to ...
Aug. 7, 2026 A ten-month Antarctic experiment found that astronauts may struggle not only with loneliness but also with spending too much time around the same people. Frequent contact was linked to greater ...
Aug. 7, 2026 Metal-rich asteroids could one day become hardware stores for Mars, supplying the materials needed to build and repair a growing colony. A new analysis shows that carefully selected asteroids may be reachable with current spacecraft technology. Some ...
July 31, 2026 Scientists have built the first all-optical photonic time crystal, allowing them to reshape the behavior of terahertz light at extraordinary speeds. The breakthrough could open the door to ultrafast computing, smarter communication systems, advanced ...
July 30, 2026 Astronomers may have been listening for alien civilizations in only a small slice of the radio spectrum while overlooking a largely unexplored range of higher frequencies. Using archived data from the ALMA telescope in Chile, researchers conducted ...
Latest Headlines
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Aug. 29, 2026 A major new analysis challenges recent claims that the universe's expansion is slowing, finding that the evidence for cosmic acceleration remains strong. The findings preserve the leading role of ...
Aug. 27, 2026 Astronomers have captured their clearest image yet of Betelgeuse’s long-suspected companion, potentially ending a search that lasted about 100 ...
Aug. 27, 2026 Today’s mysterious gravitational-wave background may preserve clues about how the Universe’s first supermassive black holes formed. Descendants of hypothetical Dark Stars could be responsible for ...
Aug. 26, 2026 A magnetar with an astonishingly powerful magnetic field may have revealed a quantum effect predicted by Werner Heisenberg nearly 90 years ago. Its light shows signs that supposedly empty space is ...
Aug. 26, 2026 A single asteroid impact may explain two of Deimos’s most puzzling features: its huge southern depression and unusually smooth, dusty surface. Simulations suggest a roughly 320-meter asteroid ...
Aug. 25, 2026 NASA scientists found that microbes brought by astronauts could survive in cold, shadowed niches around the Moon’s South Pole, potentially complicating future searches for pristine lunar chemistry. ...
Aug. 24, 2026 A massive test of gravity across the cosmos found that it behaves almost exactly as Newton and Einstein predicted, even across galaxy clusters hundreds of millions of light-years apart. The result ...
Aug. 24, 2026 A faint ribbon of stars around a distant galaxy has become the first globular cluster stellar stream ever identified beyond the Milky Way. Because the stars trace the galaxy’s gravity, researchers ...
Aug. 24, 2026 The Artemis II crew will receive the Congressional Space Medal of Honor after becoming the first humans in more than 50 years to travel beyond the Moon. Their 10-day Orion mission also carried them ...
Aug. 23, 2026 Researchers at CERN have created microscopic versions of the early Universe by colliding surprisingly small atomic nuclei at nearly the speed of ...