Yes, rainbows are beautiful, but are they good for anything? Indeed, they have been very important for science.
It is encouraging to me that someone else came to the same basic conclusion as I did following my observation of a total solar eclipse in India in 1995.
The problem with the early universe is that it was a much more dangerous place.
Perhaps the publisher, Cambridge University Press, thought the title might help sales with a younger, hipper generation.
I was motivated to do this study after two papers were published in 2018 on the difficulty of launching rockets from super-earths.