1. Personality Counts
Following a regeneration, the most pressing challenge for a new Doctor is to establish his personality, quirks, mannerisms. Even if you've only seen five minutes of any Brian Cox programme you'll know he says ' Amazing!' a lot. That's the catchphrase sorted, then. Next he'd have to navigate his way through the seemingly neverending selection of outfits in the TARDIS wardrobe. Taking care of course not to slip into his Second incarnation's clothes for fear of overloading the Near-Doppelganger Sensor, he'd face a straight fight between dressing normally ( for him) and ending up looking like a school science technician. Which would add up to a great homage to that ' Robot' moment where the newly-regenerated Fourth steps out in some hilariously inappropriate outfits before settling on his coat, scarf & floppy hat combo, or the Seventh trying on some past choice garments before plumping for that questionable question-mark pullover ( surely up there with the Sixth's ' Amazing Technicolour Dreamcoat' in the dodgy stakes). All the same though, every Doctor has ' that' moment, and Thirteen's could be just as special.
I hope you've really enjoyed reading this, it's been wonderfully enjoyable to write! Feel free to send in your own ideas for blurring the line between ' real' and ' Who' science. Incidentally, who does this image of the First remind you of? If you are/were an avid ' Sky At Night' viewer, answers by postcard. Or hypercube, if you'd prefer. Either way, keep watching the skies.