Search results
Results from the WOW.Com Content Network
Neither the standard model of particle physics nor the theory of general relativity provides a known explanation for why this should be so, and it is a natural assumption that the universe is neutral with all conserved charges. [3] The Big Bang should have produced equal amounts of matter and antimatter. Since this does not seem to have been ...
All the particles that make up the matter around us, such electrons and protons, have antimatter versions which are nearly identical, but with mirrored properties such as the opposite electric charge.
This imbalance has to be exceptionally small, on the order of 1 in every 1 630 000 000 (≈ 2 × 10 9) particles a small fraction of a second after the Big Bang. [6] After most of the matter and antimatter was annihilated, what remained was all the baryonic matter in the current universe, along with a much greater number of bosons.
Why does the observable universe have more matter than antimatter? (more unsolved problems in physics) In physical cosmology , leptogenesis is the generic term for hypothetical physical processes that produced an asymmetry between leptons and antileptons in the very early universe , resulting in the present-day dominance of leptons over ...
The energy per unit mass (9 × 10 16 J/kg) is about 10 orders of magnitude greater than chemical energies, [89] and about 3 orders of magnitude greater than the nuclear potential energy that can be liberated, today, using nuclear fission (about 200 MeV per fission reaction [90] or 8 × 10 13 J/kg), and about 2 orders of magnitude greater than ...
In November 2010, the ALPHA collaboration announced that they had trapped 38 antihydrogen atoms for a sixth of a second, [23] the first confinement of neutral antimatter. In June 2011, they trapped 309 antihydrogen atoms, up to 3 simultaneously, for up to 1,000 seconds. [24] They then studied its hyperfine structure, gravity effects, and charge.
Despite the low theoretical abundance of lithium, the actual observable amount is less than the calculated amount by a factor of 3–4. [8] This contrasts with the observed abundance of isotopes of hydrogen (1 H and 2 H) and helium (3 He and 4 He) that are consistent with predictions. [2] Abundances of the chemical elements in the Solar System.
The visible matter in the Universe, such as stars, adds up to less than 5 percent of the total mass that is known to exist from many other observations. The other 95 percent is dark, either dark matter, which is estimated at 20 percent of the Universe by weight, or dark energy, which makes up the balance. The exact nature of both still is unknown.