on 7 February 2013
I'm not sure I'm a fan of the large number of short stories currently being put out by some established authors. The Crystal Spheres for instance, is not a new story. It's been in a number of anthologies and it can't have taken long to set it up for a Kindle release. At this sort of price you'd be paying £15 or more for a normal paperback collected short stories and so it doesn't seem great value for money.
That said, I love stories that investigate the Fermi Paradox and the Crystal Spheres comes up with one of the more unlikely scenarios. There's not much I can say without giving away the entire short plot, but the whole thing has a very hopeful message alongside the lonliness impossed by the lack of alien visitors.
If you're looking for a longer look at the question, try Stephen Baxter's Space, Time, Origin and Phase Space. The last one is a set of short stories.