

Human heart is a Turing machine - cjg
http://igoro.com/archive/human-heart-is-a-turing-machine-research-on-xbox-360-shows-wait-what/

======
wglb
I have two difficulties with the abstract (not having read the entire paper.)
First is while I don't dispute the claim that the heart cells are capable of
turing-machine activities (conveniently forgetting the infinite tape as noted
by cjg), it isn't evident that the heart's activities are limited to what the
turning machine can compute.

The second thing that i am wondering about is that the heart, like any
physical oscillator, is a dynamic system, and as such, is chaotic. This seems
to be an important question regarding the modeling. Chaos theory won't tell
you that your heart won't stop, in fact, it won't give you any comfort that it
will be immune to slight changes in its environment, say with increased salt
content.

And the turing-complete claim about the game of life is clearly for grids that
have no bounds. I suspect that there are not an infinite number of states that
the heart and all its cells can encompass. Thus the heart is not a Turing
machine.

So I am not seeing any added value of this Turing result that isn't already
better described by Chaos theory.

------
cjg
Of course, it's nonsense because a heart isn't infinite...

~~~
barrkel
PCs aren't infinite either, but that doesn't help compilers prove halting /
non-halting during analysis. A few GB of memory, never mind internal and
external storage, is more than enough state space to be equivalent for proof
purposes.

~~~
eru
Or at least big enough, to make our models apply.

The real world is also not made up of smooth stuff --- atoms pop up when you
look to close. But engineers are using differential equations without too many
problems.

