The universe should be empty, yet it is full of matter
In short: Physics suggests that for every particle of matter created, an equal amount of antimatter should exist. When they meet, they annihilate into nothingness. If this were true, the universe should be a void. Instead, we live in a cosmos dominated by matter. This mystery is known as Baryogenesis.
The fundamental problem lies in the laws of physics: matter and antimatter are nearly identical, differing only in charge. According to quantum mechanics, empty space is not truly empty but filled with energy and quantum fluctuations that constantly create and destroy virtual particles. Because these pairs appear simultaneously, they should theoretically cancel each other out perfectly, leaving a universe of nothingness.
To explain why matter survived while antimatter vanished, Russian physicist Andrei Sakharov proposed three necessary conditions for Baryogenesis. The first is that the universe must be out-of-equilibrium—a condition met by our expanding, cooling cosmos. The second involves 'C' and 'CP' symmetry violations. While C symmetry suggests laws should apply equally to matter and antimatter, the weak force breaks this rule because neutrinos and antineutrinos possess only one type of spin.
The third condition requires baryon-number-violating interactions—processes where the number of baryons (particles made of three quarks) can change. Currently, we have never observed a process that creates two baryons from one. While some particles like K, B, and D mesons do violate CP symmetry during decay, these interactions are not numerous enough to account for the massive volume of matter we see today.
Theories to bridge this gap remain speculative. One hypothesis suggests antimatter might be moving backward in time, though observed antimatter moves forward. Others suggest mirror galaxies exist elsewhere, but a lack of high-energy gamma rays from
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- Summary by Intellect · source: The Baryogenesis Anomaly: What happened to all the Antimatter?
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