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REMAINING OBSTACLES. “Very strong theorems seemed to exclude any possibility of negative mass particles or objects, or more generally violating the positivity of energy.” https://lnkd.in/daA2SgMy View in LinkedIn

NEW BRIDGES. “By the 1950s, Bondi had built negative mass solutions that respected the equivalence principle.” https://lnkd.in/daA2SgMy View in LinkedIn

LATER CONCLUSIONS. “But rather obviously, these studies had assumed that matter and antimatter had both a positive gravitational mass. Today, the discovery of a repulsive gravity through observations of SN1a supernovae luminosity distance, called Dark Energy, leads us to be more cautious: indeed, what seemed previously impossible, repulsive gravity, is the major topic of interest in cosmology.” https://lnkd.in/daA2SgMy View in LinkedIn

EARLY CONCLUSIONS. “Glashow et al. “concluded again that even if the primordial universe had succeeded in creating a symmetrical world between matter and antimatter, diffusion of matter and antimatter at their domain boundaries would lead, as soon as the Universe becomes transparent, to an annihilation between matter and antimatter in conflict with observational limits, unless the domains of matter and antimatter had a size exceeding several billion light-years, which seems unrealistic.” https://lnkd.in/daA2SgMy View in LinkedIn

INCONSISTENCY. “Indeed, if matter and antimatter have both positive gravitational masses and respect the equivalence principle, matter-antimatter annihilation continues to occur after the Universe has become transparent, leading to a diffuse high energy gamma-ray background, already difficult to justify in the early 1970s, at the epoch of the SAS-2 satellite, and clearly inconsistent with the much more sensitive contemporary satellites, such as the Fermi satellite.” https://lnkd.in/daA2SgMy View in LinkedIn

SEARCH FOR SYMMETRICAL UNIVERSE. “The conclusion of their study, after several years of effort, was that the primordial Universe, at least in the standard cosmological model, does not provide enough time for a matter-antimatter universe to create structures large enough to evade the constraints of the diffuse gamma-ray flux.” https://lnkd.in/daA2SgMy View in LinkedIn

Slug on mushrooms. View in LinkedIn

“THE UNIVERSE is an appearance corrected by a transparency. “ (Victor Hugo) https://lnkd.in/dNRMDkJZ View in LinkedIn

TIME TRAVEL. “And we also know since the early 1990s that building a time machine in general relativity —for example using a wormhole as a time machine— requires violating the positivity of energy. It is therefore natural to test whether antimatter is not by any chance such an “exotic” material.” https://lnkd.in/daA2SgMy View in LinkedIn

SEARCHES. “In the 1960’s and again in the late 1980s, two teams tried to understand whether a symmetric matter-antimatter universe could be consistent with observations.” https://lnkd.in/daA2SgMy View in LinkedIn