Basically our thoughts are ruining everything. Like when humans are taught stars are giant balls of gas. To the rest of the universe they aren't but humans think it and destroy alien planets. I think they come to seal us off from the rest of the universe.
The novel is set in the near future (2034–2080), after the solar system has been surrounded by an impenetrable shield (constructed by either aliens or extra-solar humans) known as the Bubble. The Bubble permits no light to enter the solar system, and as a consequence the stars can no longer be seen. This seems to be mere background at first, but in fact it is central to the plot.
In the novel a physical process in the human brain is responsible for collapsing quantum wavefunctions representing systems into particular eigenstates. Human observations of the universe were reducing its diversity and potentiality (for instance, by rendering it uninhabitable to beings that relied on stars being something other than the enormous nuclear fusion-powered furnaces human astronomers have observed them to be). Hence it is suggested that the Bubble was constructed to prevent humanity from wreaking massive destruction on the rest of the universe through the process of mere observation.