In 4 billion years our galaxy will collide with Andromeda; NASA created this animation of what the c

[JohnnyRingo]

30. Clarke is a great writer and an optimist

The galaxy should be flush with intelligent life, but where is it? It's sad that we may be as technologically advanced as a civilization gets before we destroy ourselves through war or depletion of resources, and let's not forget the Robot Apocalypse LOL. Not hard to imagine.

Astrobiologists Dirk Schulze-Makuch and William Bains, reviewing the history of life on Earth, including convergent evolution, concluded that transitions such as oxygenic photosynthesis, the eukaryotic cell, multicellularity, and tool-using intelligence are likely to occur on any Earth-like planet given enough time. They argue that the Great Filter may be abiogenesis, the rise of technological human-level intelligence, or an inability to settle other worlds because of self-destruction or a lack of resources

https://en.wikipedia.org/wiki/Great_Filter