The Elastic Book of Numbers, ed. ?, a couple more stories.
I've hit pay dirt! Gold! An oasis in the desert! YES! Okay, I'll stop squeeing and be more solemn about this.

Also, the second story has one of the two coolest stardrive systems ever. My husband agrees that it is indeed very cool. (Why two? I can't decide between this one and the one in Timothy Zahn's "Cascade Point.")

In any case, the first one is Rosaleen Love's "Wanderer 8." Superficially, it's about two people trapped on a space station amid the debris of human existence. This ranges from the prosaic--various spy satellites--to the absurd, such as the freeze-dried and perfectly edible fish. The first-person narrator is quietly, even at times whimsically, accepting of this fate, which is couched in terms of ancient astronomy, of personal mysticism and far-flung speculation. It is, if one can apply the term to a story about this situation, sweet without being cloying, thoughtful without being pretentious. It's a good, solid story and I was happy to hit it.

Now we come to Julian Todd's "Mine the Primes," which--if you'll forgive just a bit more squeeing--blew my brain open with sheer, unadulterated, unflagging JOY. This is framed as a cranky retired mathematician talking to a young hopeful--a young hopeful who is looking for a new series of prime numbers. Because prime numbers are the key to the stardrive--Joe, by the way, says that the accompanying particle physics is extremely handwavy, but the stardrive is so cool that it's justified.

Note: I will tell you straight off that I haven't the faintest background in Complex Manifold Cohomology, but you just need to know that it's a sub(subsub?)branch of mathematics, not what it does. In terms of speculative math, it posits that Goldbach's conjecture has been proved. I believe the story gives the narrator's salient experiences of mathematics without requiring the reader to know the mathematics. (Number theory? Barely dipped my toes in; not a strength of mine even at that level.) Of course, you'd have to get a non-math-major to verify this.

In any case, that's not the whole of the story, although for my money you could sell me a story on that alone. It's also about human greed, and human folly, and a metaphor for other human wasting of resources, and failures to learn from the past. It is cautionary, cranky in tone, and it captivated me utterly. If any of this sounded appealing to you, read this story.

Also, how can I not be tickled by a story with a ship named the Erdos Cup?