බුද්ධිමතුනට
මේ බුද්ධියේ තවත් කතාවක්. අපි ඊනියා වාස්තවික ලෝකයක් ගැන හිතන එක නවත්තන්නේ නැහැ.
2023 අප්රේල් 15 New Scientist සඟරාවෙන්
Physicist David Wolpert on how to
study concepts beyond imagination
There is probably a
plane of knowledge beyond the grasp of human minds. But mathematician and
physicist David Wolpert says it is still possible to explore this unimaginable
realm
I
LIKE to think my dogs experience the world in the same way I do. They seem
excited when I ask if they want to go to the beach – their favourite place –
and when I ask if they are hungry, they reply with a delighted tail wag. But
until recently, I hadn’t paused to wonder whether a dog can even understand the
concept of a question.
I
was prompted to ponder this after a conversation with David Wolpert, who is based at the Santa Fe Institute
in New Mexico. Wolpert is a polymath who has turned his hand to many
disciplines over the years, including artificial intelligence, physics,
economics and computer science. Recently, he has taken a deep dive into questions
of intelligence and its outer limits.
In
a video call, with my dogs sitting behind me, Wolpert talked me through some of
his latest work, which centres on the nature of human intelligence. He points
out that, just as dogs and other animals lack our appreciation for logic, there
are inherent limits to human knowledge too. Wolpert isn’t the
first to talk about unknown unknowns, but, in a recent paper, he approached
this topic from a different angle: trying to pinpoint weaknesses in our
reasoning so as to identify some of the things we can’t know.
It
is both exhilarating and decidedly tricky territory to navigate, but Wolpert
says these are some of the most profound questions in science. We have to
consider them now, he says, because the artificial intelligence revolution is upon us –
and machines may not have the cognitive limits that we do.
Abigail
Beall: You recently produced an essay arguing that there must be something
lacking in our ability to understand the universe. What prompted you to write
it?
David
Wolpert: It started when I was involved in an event at the Santa Fe Institute,
where I work. There was a presentation looking at how it is that our brains,
which were designed for operating in the savannah, can also be good at other
things. This is a very old question. I was asked to write an essay responding
to this puzzle. As I was considering my response, I kept running into a
different, more fundamental question.
Consider
the collection of all cognitions, thoughts or perceptions that are beyond the
ability of any human to have – what will we ever be able to say about those?
For example, can we even know if they exist? If so, can we say whether the
number of cognitions or thoughts that we cannot have is larger than the set of
cognitions or thoughts that we can have?
I
wrestled with the title for that essay and eventually called it: “What can we know about that
which we cannot even imagine?” But I still don’t like that because
“what we cannot imagine” is almost by definition ineffable.
Are we as clueless as a paramecium when it comes
to certain questions?
What
conclusions do you reach about the limits of human thought?
I
present examples of how, responding to the original question about the
evolution of human brains, one runs into that second, more fundamental question
about things we can’t imagine. Then, in addressing the second question, I
conclude that there are vastly more possible cognitions than can ever be
formulated in human language. This set of cognitions, by definition, cannot be
formulated, never mind investigated.
So,
there must be some way in which our ability to understand the universe around
us fails.
I’ve
long been adamant that we must always be on the lookout for inadvertently
assuming that human thought is fundamentally privileged in some
way. We already know that we are bad at making judgements about ourselves. For
example, studies show that people tend to rate themselves as being better at
driving than average. This can’t be true for everyone, but we all believe it.
This problem of implicit self-aggrandisement extends far beyond that, though.
It is also deeply wrapped into the foundations of all analysis by academics.
How do
we avoid falling into this trap?
Think
about a paramecium, a very simple, single-celled organism. It’s not just that
it wouldn’t understand any questions I ask – it wouldn’t understand the concept
of a question. We need to put ourselves on the other side and say: we are the
paramecium, what is beyond us?
Nicolaus
Copernicus – the Renaissance astronomer who was the first to argue that Earth
orbited the sun – is my religion, in a certain sense. I’m always on the lookout
for how we might be completely wrong and aggrandising ourselves, just like we
did when we thought that Earth was the centre of the universe. It struck me
that language is a great example of such self-aggrandising. Maybe, by
investigating the limitations built into human language, we can avoid falling
into at least this instance of the trap.
In
what way does language limit us?
What
distinguishes us from the dogs behind your left shoulder? Communication. We
tend to think of language as one of our great achievements as a species. But
when you think about it, language is just finite strings of a finite set of
symbols – that’s what sentences are – and as a mathematical structure, that is
extraordinarily restricted.
This
applies to maths too, by the way. Many people have said that the world is even
more mysterious than we can think, but they’ve not really tried to quantify
that. When I tried to do this, I found that mathematics is an extremely rich
structure that actually points at types of maths that it itself says it cannot
describe.
So, we
know there are levels of intelligence that are currently unfathomable to us.
Are they permanently off-limits?
I
find a very low likelihood that, by the end of this century, the human genome
will be the only storage system for intelligent life on Earth. I think CRISPR gene-editing technology means scientists
are going to make babies who don’t need sleep, who have IQs of 200, who have
gills – whatever you can imagine. Some religions are going to be deeply
challenged by it, there will probably be wars about it. But CRISPR is out of
the bottle – our DNA is going to be mucked around with. There will be disasters
and mistakes at the start, but eventually they’re going to come up with
something new that will be self-propagating. So I don’t think humans as they
are currently configured are where intelligent life stops on Earth.
What
about intelligent machines?
One
of my previous lives was in machine learning. Everybody is now debating whether
there will be a single, monolithic artificial general intelligence that can reach
our level. Would it understand things in the way that we do? The measure is
always us.
I
think the premise here is completely mistaken. The question is not “will these
intelligences be able to emulate us and just add a little more?”, since such
machines will be doing things differently. The question is: “what will their
actual capabilities be?”
Everybody
seems to have forgotten the mantra that a lot of power comes from distributed
systems, and this is key in thinking about what the capabilities of intelligent
machines will be.
What
are distributed systems and why are they interesting?
Think
of the “flash crash” of 2010, an event in which stock
markets fell by trillions of dollars in minutes before recovering most of their
value in about half an hour. It was caused by a lot of bots that do automated
trades. On their own, these bots are based on simple if/then programs, but they
somehow interacted collectively to suddenly cause the entire market to
nosedive. The market slowly crawled its way back to where it was, so this
wasn’t like the much more protracted economic downturn that began in 2007. But
to this day, nobody can understand what went on. No new regulations have been
put in place to try to prevent a repeat, because nobody knows exactly why it
happened. It is described in the scientific literature as having been like some
kind of alien ecosystem that we don’t understand.
Now,
imagine something like that, but with artificial intelligence systems like
AlphaGo that are practising and learning across the whole web. What sort of
vastly more complicated versions of the flash crash ensue when the bots are
replaced by these kinds of machines? It’s not going to be some human-like
intelligence any more, it’s going to be different. It’s hard not to believe
that, in some ways, it will be vastly more powerful.
Between
CRISPR and distributed, interacting AIs, I can’t imagine that, by the year
2100, we will still be “the most intelligent creatures on Earth”. Our progeny
will be here.
Let’s
imagine those kinds of intelligences have arrived. Would they ever be able to
explain how they think to us?
My
whole shtick in all of this is that I can’t conceive of how that could happen.
I mean, it might be that what emerges will be a type of intelligence coming
from something I haven’t thought of. People talk about the wood wide web, all trees talking to one another. It
might be that somehow we will gain the ability to converse with the trees or
with, say, cetaceans or something – who knows, I’m just riffing now – and maybe
they can actually provide us with an answer using means that I can’t even
conceive of.
It
might turn out that tree roots can tickle our toes while the cetaceans blow
bubbles in particular patterns in a swimming pool right next to us and somehow
we have a deep epiphany. Maybe it’ll be a neuro-prosthesis. There could be
other ways. I can’t conceive of them though. I can’t see how I could provide
such details to the paramecium – but again, that’s the whole point.
Abigail
Beall is a features editor at New Scientist
