So while we wait for Sunday's announcement of the actor that will play the next Doctor, let's talk about that stickiest of subjects, Doctor Who canon. We won't discuss whether Dimensions in Time is "in" or Time Crash is "out" (the answer is no and no, by the way) but where this whole notion of canonical stories comes from in the first place: religion!

What does "Doctor Who canon" have in common with religious canon? How does one determine which stories "matter," and does a 50-year-old television series develop a canon in the same way that a 2,000 year-old (give or take) religion did? Rabid Doctor Who fan and New Testament historian Mark Goodacre is the perfect guest for this Time Dilation conversation. No proselytization, just Doctor Who geekery at its finest, placed in a historical context.

And Mark, update your website.