Assertion: dark matter | /r/HasProperty | be proton
Facets:
Source sentences:
text: Big Bang Nucleosynthesis (BBN), which explains the way light elements such as Helium were formed fractions of a second after the Big Bang, tells us abundance of baryonic matter doesn’t account for the total matter content of the Universe inferred from other observations, and that dark matter can’t be just be things like protons and neutrons.