Writing hard SF is... well... hard. Any SF magazine or anthology editor will tell you that (unless their guidelines specfically say they are only looking for hard SF) the percentage of hard SF stories that get submitted to them is very small. And the percentage of these that are fully rounded stories with strong character development and an emotional heart is miniscule.
Most time travel fiction doesn't present the time travel mechanism in a way that would satisfy the requirements of hard SF. Pretty much all the time travel works that I can think of (including the really good ones) either offer nothing when it comes to the science behind time travel or provide what is, at best, a bit of a fudge. In a hard SF anthology, however, you've got nowhere to hide. For some bizarro reason, I wanted to see if I could do time travel in a way that that would satisfy hard SF readers. The result was "The Mandelbrot Bet".
I decided to push the time travel sub-genre as far as I could with this story. I'd published another story, "The Jesus Particle", in Cosmos a couple of years ago where the time travel involved was to the end of the Earth. With "The Mandelbrot Bet" I decided to go a step further: to the end of the universe.
The stated aim of of Carbide Tipped Pens was to not only to portray the science as "consistent with current understanding or be a logical and reasonable extrapolation thereof" but also to "emphasize plot, character, science, originality and believability in equal measure". The goal of the anthology is "to not only entertain readers but also to educate and to return the sense of wonder of the Golden Age to a new generation of 21st Century readers".
They are ambitious aims.
So have I even got close to succeeding in rising to the challenge? You'll need to wait. Carbide Tipped Pens is scheduled for publication in 2014.