The conversation between human and AI assistant.
What do you hypothesize dark energy to be? I don't mean answers like the cosmological constant. What do you think occurs physically?
What kind of observations led scientists to theorize the existence of dark energy?
Observations of type Ia supernovae led scientists to conclude that the expansion of the universe is accelerating, rather than slowing down as would be expected due to the effects of gravity. This observation, along with others such as measurements of the cosmic microwave background radiation, provided evidence for the existence of dark energy.