A problem for "Web as distributed programming paradigm"

Clay Shirky clay@shirky.com
Fri, 24 Aug 2001 12:22:49 -0400 (EDT)


> If the the answer above is right, then REST is NOT a programming
> paradigm; it is merely an IPC protocol.

I'll argue that there is no "mere" about this. 

In fact (WARNING: THIS POST IS LEAVING EARTH), I'll argue that IPC is
more than a hack, its a fact of life, woven into the fabric of the
universe. 

One of the really interesting questions in biology is why cells are the
size they are. An elephant has order 10^15 cells, a nematode worm has
order 10^2 cells, but the cells themselves are roughly the same
size. At a certain point, it was evolutionarily more efficient to grow
by having multiple cells than having the same number of cells grow
larger. 

Now one of the ramifications of this is that cells need some way to
pass information between one another, if they are to act in concert,
and a common theme in this information passing is that there is a
membrane, and inside the membrane there is a really rich chemical
environment with all sorts of processes going on all the time, but
between any two cells there is a really limited set of information
channels. To take one obvious example, the huge preponderance of the
chemical work that goes on in the brain goes on inside the neurons
themselves, while the information that passes between neurons is all
done with just a few ions, Na+, K+, and Ca++.

So, although the majority of chemical work is going on inside the
neuron membranes, the complexity of the brain itself is a product of
the system as a whole, both the local neuron state and the 'mere' ion
(IPC) channels.  Whatever it is those neurons are doing, they are not
thinking -- it takes neurons plus synapses (local processing plus IPC)
to think.

So we have a system where membrane-bound units with simple IPC create
complexity at a level _above_ the unit, and this theme is repeated up
and down the scale. Within cells there are organelles -- mitochondria,
nucleus, Golgi apparatus -- that are themselves membrane-bounded with
reduced channels of information flow, and the membranes of these cells
have two cells walls, between which the chemical reactions are
different yet again.

On the way up, organs are membrane-bounded as well, and communicate
through a reduced set of chemical signals, and organisms are
membrane-bound. Most of the biological complexity in an ant colony
goes on inside the ants, while inter-ant communication goes on with
only a handful of pheremones and a bit of antennae rubbing. And yet
the behavior of the ant colony cannot be explained by the complexity
of the ants alone. As poor an IPC channel as pheromones are, it is the
individual ants plus ant IPC that make the ant colony.

Even outside the biological world, systems recapitulate this
membrane+restricted channel all the time. Alphabets and money are two
of the best IPC channels we've ever thought of. Now I'm not claiming
that REST is the right instantiation of the Right Answer, but I am
willing to say that not only is IPC not going to be displaced soon by
a distributed computing paradigm, IPC is not going to displaced ever,
because it is a true thing about the universe, not just a placeholder
hack.

-clay