We don’t have a complete enough understanding of time to call something impossible based on it.

Jeez... Kim Stanley, you don’t saaaay... Difficult to colonize planets and even more difficult to colonize other star systems? Do you thithink that it might be even more difficult to colonize other galaxies? Nah, it’ll be super easy...

The third brake light is there because your other two brake lights share a location with an often identically coloured set of tail lights.