- Theory (explained)---Theory is a contemplative and rational type of abstract or generalizing thinking, or the results of such thinking
- Age of universe---In physical cosmology, the age of the universe is the time elapsed since the Big Bang. The best measurement of the age of the universe is 13.798±0.037 billion years (13.798±0.037×109 years or 4.354±0.012×1017 seconds)
- characteristics---a feature or quality belonging typically to a person, place, or thing and serving to identify it.