Oh, I don't really doubt that, but I was never able to watch more than about 10 minutes before I got massive headaches. As far as the access point is concerned, it is called "episode #1".
Actually, you mentioning the good Doctor brings up a good point in this overall topic: what are the ramifications?
See, I don't get into Doctor Who because I usually hate time travel. Pretty much, you can always assume that whatever issues the characters are trying to deal with are likely caused (a probability in excess of 95%) by their own travels through time, which means that any attempts to change the time line are probably going to cause more damage than they are worth.
I mentioned to you in that PM about the Novikov self-consistency principle
. While it really hasn't caught on in real physics, I personally think it is a must for any time travel fiction. The reason why is that it puts limits on what the tech can do, what the characters are going to do with it, and ensures the GM doesn't have to retcon a bunch of changes because a group of kids and their damn dog screwed with time.
That is what I mean by ramifications. Turning that onto the idea of mind uploading, what are the ramifications of this? I can see a few, right now:
1.) The characters are effectively immortal (if you make it wireless, they are entirely immortal, but if you use the idea of an implant, they are far more vulnerable and real death is possible).
2.) AI's exist, but they are actually human minds running on computers. Unfortunately, once you can download a human mind, you should be able to run it on a computer, too, though this could require massive installations and power plants to pull off.
3.) If you have Alternity cybertech, you have mind uploading. Since most of Alternity's cybernetic systems require the use of a nanocomputer, which is capable of reading signals straight from the human brain (one reason I really don't like it), that means you have direct access to human thought via a computer. That means you can download a human mind, and then upload it into a computer or a new cybernetically hooked up body. Now it may take a very long time (probably weeks if not months) to download and upload, but it is doable while staying within the core Alternity rules.
4.) Your population can now literally explode. That is one of the flaws with assumed immortality or life extension technology, that the human drive to procreate (and the drive for physical pleasure) runs head-long into the capacity to have children not for a couple of decades but for a century or more. Yes, you can try to introduce a 1-child policy or social conditioning to discourage the behavior, but that has never worked out in all of human history
(I can't emphasis that enough). Just look at the issues in China over the last decade, and remember that their 1-child policy was only in effect for about 40 years. Such programs are also never going to work at such a large scale, either (tens or hundreds of billions, or about one or two orders of magnitude larger than China's current population).
5.) The social ramifications also need to be considered. Go take a look at Altered Carbon for that. The rich are viewed as "divine" (their wealth only increases, they are immortal, and they have the resources and influence to do damn near anything they want; a god by any other name), people treat their bodies as finite and inconsequential (they are called "sleeves", and most people don't really care what happens to theirs since they can get a new one anyway), and crimes are punished by keeping criminals in storage (no bodies, just their "stacks") for the entire time of their sentence (so yes, you can wake up and it will be 250 years after your trial, and the world has totally changed; did I mention that you also have no control over what body you get?).
Shockingly, time travel and mind uploading are not the only two areas where the ramifications of the tech can be extreme. Gravity manipulation means you can build any megastructure you want (orbital rings
, space elevators
, or even just massive 50-kilometer-tall buildings) with normal materials (steel and concrete, not carbon nanotubes or graphene) because you can negate enough of the mass so that it remains under the structural limits of the object.
So, yes, think long and hard before you go adding new tech to a setting. That's why I personally favor more limited applications of any major technology. In the case of time travel, if it doesn't follow self-consistency, I would never introduce it.