This reminds me of something British enzymologist J.B.S. Haldane once said, "Reality is not only stranger than we suppose, it may be stranger than we can suppos

This reminds me of something British enzymologist J.B.S. Haldane once said, "Reality is not only stranger than we suppose, it may be stranger than we can suppose." It's unprovable, but perhaps alien intelligence is already "here", existing at some level imperceptible to human faculties. Given the age of the universe, and humanity's relative youth, it's not impossible that an alien civilization could have developed transportation/communication technology far beyond anything we could possible imagine.