Best of 2024: Where Are All the Aliens?
Conspiracy Theories
Deep Dive
What is the Fermi Paradox?
The Fermi Paradox questions why, despite the vastness of the universe and the high probability of extraterrestrial life, we have not encountered any intelligent alien civilizations.
How many Earth-like planets are estimated to exist in the Milky Way?
Scientists estimate there may be 11 billion Earth-like planets orbiting Sun-like stars in the Milky Way.
What is the Drake Equation, and what does it calculate?
The Drake Equation, formulated by Frank Drake in 1961, calculates the number of intelligent civilizations in the Milky Way capable of emitting electromagnetic signals that we could detect.
What is the Great Filter theory?
The Great Filter theory suggests that there is a point in a species' evolution where it faces an insurmountable barrier, such as a catastrophic event or resource scarcity, that prevents it from advancing further.
What is the rare Earth hypothesis?
The rare Earth hypothesis posits that while Earth-like planets may exist, the specific conditions on Earth, such as the presence of a moon, make it uniquely suitable for life, implying that intelligent life may be extremely rare.
What is the SETI Institute, and what is its mission?
The SETI Institute is a private organization founded in 1984 with the mission to explore, understand, and explain the origin and nature of life in the universe and the evolution of intelligence.
What is Oumuamua, and why is it significant?
Oumuamua is the first known object from another star system to enter our solar system. Its unusual characteristics, such as lacking a coma like a typical comet, have sparked debate about whether it could be an artificial object.
What is the dark forest hypothesis?
The dark forest hypothesis suggests that advanced civilizations in the universe remain undetectable out of fear of being invaded by other hostile civilizations, creating a 'dark forest' of silence and caution.
Why did Michael Hart argue that extraterrestrial life does not exist?
Michael Hart argued in his 1975 paper that the high probability of extraterrestrial life suggested by the Drake Equation meant that if aliens existed, they would have already colonized the universe, and their absence proved they do not exist.
What are some possible reasons for the lack of alien contact?
Possible reasons include physical barriers preventing travel, aliens choosing not to visit Earth, or aliens being too recently evolved to have developed the technology to reach us.
- Fermi Paradox: The contradiction between the high probability of extraterrestrial life and the lack of evidence.
- Three main hypotheses to explain the paradox: we are alone, aliens exist but haven't contacted us, aliens have visited but left no trace.