In class, I asked you to write down what you thought were the most likely solutions to the Fermi Paradox. Here are the results. As group, you didn't have much consensus, choosing a total of 32 of Webb's 50 solutions. Here are the most popular (those that got more than one vote):

#9 The Stars are Far Away (chosen 6 times)

#36 Continuously Habitabile Zones are Rare (5)

#40 The Solar System is Dangerous (5)

#42 The Moon is Unique (5)

#47 Intelligence is Rare (3)

#18 SETI's search Strategy is Wrong (3)

#39 The Galaxy is Dangerous (3)

#16 We don't Know How to Listen (3)

#26 The Universe is Stranger than we can imagine (2)

#43 The Origin of Life is Rare (2)

#17 We Don't Know the Correct Frequency to Listen (2)

#24 They Have a Different Mathematics (2)

Use these results, or not, as you like.