Sciencey Wiencey: Is Regeneration Possible?

Guest contributor Caleb Howells investigates.

One of my favourite aspects of Doctor Who is its whimsicalness. I love the sheer ridiculousness of it sometimes, like the Doctor parking his TARDIS on a cloud in the sky with an invisible spiral staircase leading up to it. It’s completely bizarre and ridiculous and whimsical, and I love that about the show. Because of the very nature of the show, it can go anywhere in time and space, with any scenario you can possibly think of, featuring any sort of character you can think of.

However, it’s not a fantasy show. It’s science-fiction. Soft science-fiction no doubt, but science-fiction nonetheless. So, even though the plausibility of some of the situations and devices is “soft,” they should still all have some basis in reality, however weak. So in a series of articles, I’m going to be looking at some of the main features of the show and investigating how scientifically plausible they are. Let’s start with one of the big ones.

A whole new body?

The style of regeneration has changed over the years, but since it’s been more consistent in the revived series (and I’ve only seen a handful of the classic series), I’ll go with what’s established in that.

The Doctor, when mortally wounded, can initiate a process which, as explained by the Ninth Doctor, changes every cell in his body. So every cell in his body becomes new, which is what restores him to full health and changes his appearance. How feasible is this? This is much harder to say, purely because it’s never really explained how regeneration works. Yes, every cell in his body changes, but how? The way I see it, there are only two possibilities.

It could work like the real world regeneration of some reptiles and fish. To put it simply, stem cells gather at the wound and create new cells. Except for the Doctor’s regeneration, it would need to do this for every cell in his whole body. But seeing as you can’t just create new matter, and the old cells have to go somewhere, the new cells must be created from the old ones (and if there’s any tissue missing, such as would be the case after being shot, more can be taken from the storage organs). The body would rapidly rebuild itself, taking apart and reforming even the cells that aren’t damaged, creating an entirely new body.

However, I see a big problem with this. The cause of the Tenth Doctor’s death. He died due to intense radiation poisoning. Put simply, radiation poisoning is when high energy particles shoot into your body and damage the DNA in your cells, which is what causes all the problems you associate with it, such as deformities.

So, bearing that in mind, there’s a good chance the stem cells would be corrupted by the radiation poisoning. The genetic code would be damaged, thus corrupting the new body created from them, which would completely negate the regeneration and still cause the Doctor to die.

There’s another possibility I can think of which works better with the idea of there being “regeneration energy,” such as what River gave the Doctor in Let’s Kill Hitler. This idea is that the Doctor’s body literally creates truly new cells, not from previous matter. How? By converting energy into matter. I’m sure we’ve all heard the example that if you could get all the energy that a sugar cube is made up of, then it would be enough to power America for quite some time. And that is essentially what a nuclear reaction is. Converting mass into energy. Likewise, it’s also theoretically possible to do the reverse.

River Song said that a Time Lord’s body is a miracle, and if it had the ability to turn energy into mass (an incredible amount of it, at that), then that certainly would justify the statement.

But then what would happen to the old cells? Well, perhaps they burn up in some way, causing the glow that occurs during regeneration. This, in my opinion, makes more sense than the previous possibility.

However, there’s still the problem of controlling it. Let’s assume that this process is controlled by the brain, rather than cells just doing what they know they should. Brain cells contain DNA, just as other cells do, so they would also get damaged by the radiation. However, this is only a problem for cells that replicate, because the damage to the DNA only presents itself when the cell divides, using the corrupted code to make the new cell. So the brain cells will only be properly damaged if the radiation is particularly high. So, is 500,000 rads particularly high?

Yes.

I was going to say that we’ll give the Doctor the benefit of the doubt and say that his brain cells could withstand that, but after looking into it properly, I found that 5000 rads can directly damage brain cells (in a human, that is), rather than affecting the blood cells, which would in turn lead to the death of brain cells. Now, the Doctor has been shown to be able to withstand higher amounts of radiation than humans, but that’s quite excessive, and it was clearly meant to kill the Doctor with no possibility of him surviving it. So I’m saying it would directly damage his brain cells.

In this case, this could also lead to the corruption of the regeneration process (though probably not as much), considering it would be controlled by the brain.

So to recap, the first possibility is: Stem cells are released all over the body. The cells surrounding them self destruct and break up. The stem cells absorb these materials when needed and divide rapidly, filling up the space of the old cells.

The second possibility is: There is a part of the Doctor’s body which stores energy and can convert it into mass when needed (perhaps in his brain). However, after all that I’ve said, I can see no realistic way that this new material can form the new cells without using another structure (a cell) to put them together into a new cell, without the possibility of the DNA of the cell which is putting it together being corrupted, leading to precisely the same problem as the previous possibility.

So, is regeneration possible?

Certainly. But as far as I can see, there’s no sure way for it to give you a perfectly new body if the fatal problem was radiation poisoning, or anything else which corrupts the DNA. There’s always going to be the possibility that the defect will be passed on to the new body, which isn’t consistent with how I feel regeneration is presented in the show.