We Are Not Alone in the Universe, Massey Says

The video discusses the probability of extraterrestrial life, referencing Enrico Fermi's famous question about the absence of contact with other civilizations. It explores the discovery of exoplanets and the statistical improbability of Earth-like conditions being unique in the universe.

Why might we not have heard from extraterrestrial civilizations, according to the text?

What does the text suggest about the conditions necessary for life to exist?