As Tim Urban says, 'We’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.' So there must be aliens. Why haven't we heard from them? (Read about the Fermi Paradox here.) This blog is a list of answers. I've summed up each one in a line and dropped a relevant quote afterwards, and mostly linked to an article not a paper. Some of the ideas overlap or are sub-categories of each other. I tried to avoid an endless list, but still give different perspectives.
A list of solutions to the Fermi Paradox
A list of solutions to the Fermi Paradox
A list of solutions to the Fermi Paradox
As Tim Urban says, 'We’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.' So there must be aliens. Why haven't we heard from them? (Read about the Fermi Paradox here.) This blog is a list of answers. I've summed up each one in a line and dropped a relevant quote afterwards, and mostly linked to an article not a paper. Some of the ideas overlap or are sub-categories of each other. I tried to avoid an endless list, but still give different perspectives.