Monday, May 30, 2011

True uploads of minds are impossible for finite beings

Elder Daughter, Son-in-Law and their daughter MJ were over for a week, including MJ's first birthday. Utterly delightful but lots of family visits, including going to Cornwall to see my mother so over the time we saw all our descendants and living ancestors. Hence no time to blog!

Very interesting e-correspondence continues about the ability to simulate/upload human minds. The idea is that sometime in the future we could upload our mind into a computer, and then (perhaps) download it again.  The key points for me are as follows:
  1. The brain is not a Turing machine: more generally organisms are not Turing Machines (Denis Noble has a great talk about this). So even if all the other obstacles could be overcome (impossibility of completely accurate measurement both for practical and Quantum reasons etc..) an “upload” is fundamentally and qualitatively different from a real human.

    Only an omnipotent being, not limited by Heisenberg, could do an upload properly, into a new, non-digital body. Which is basically the Christian teaching about the resurrection.
  2. The brain may indeed act statistically in some senses, but individual neron firings do matter, they are not a simple sum, and there is massive feedback and cascading. So it has chaotic dynamics and quite a large Lyapunov exponent (indeed not obviously bounded). This means (for anyone who may need reminding) that the error term in the hypothetical simulation will grow as exp(At) for a fairly large A.  Therefore however small the error between the real and simulated brain starts at, after a relatively small t it will be binary in the sense that Brain 1 would have done X and Brain 2 would not.
  3. The suggested exact imaging of the brain is also impossible. Even a nanobot in every neuron would be unable to observe every synapse in detail, and to understand exactly what is going in a synapse you have to "look at" the exact state of eg the Ca++ ions binding to the syapototagamin, which is beyond the capabilities of even the smallest nanobot. Furthermore any nanobot could only transmit a finite quantity of information to the supposed simulation in a given time, and since the brain state changes continuously it would never be possible to synchronise the two systems. Not to mention the problem of interactions between the nanobots and the brain, power dissipation, errors etc..  Neurons are highly complex wet analog systems, they are not logic devices at all, they only approximate to them.
  4. Not only are there are fundamental physical and biological reasons why it won't work, I cannot see how any company could get ethical approval for the necessary clinical trials. And without this there wouldn't be enough of a market to develop the hypothetical sensors.
  5. My attention was drawn to Deutsch's fascinating 1985 (!) paper which proves that any finite physically realisable system can be perfectly simulated by an (abstract) Quantum Computer.  What he shows is that "every element of a certain countable dense subset of G {the set of physically realisable unitary quantum systems with finite numbers of degrees of freedom} can be computed {in the sense of there being in principle an abstract quantum computer that could compute that set}. But every point in any open region of a finite-dimensional vector space can be represented as a finite convex linear combination of elements of any dense subset of that space. It follows {since he has also shown that in principle if two sets can be Quantum-computed so can any linear combination of these sets} that Q can perfectly simulate any {unitary} physical system with a finite-dimensional state space."

    Now this is an interesting result, but we have to understand that what Deutsch means by a physical system is one in which measurement/wavefunction collapse doesn't occur. So for Deutsch the brain never makes decisions: there is a "world" in which each neuron fires at a particular time and another one in which it doesn't.  Whether or not one finds this ontology ridiculous what is very clear is that it is completely incompatible with the concepts needed to describe brains, thoughts, uploading or anything like that.  The moment you can ask questions like "did I do this?" or "do I remember this?" then these Quantum Computers break down as "prefect simulators": they can only tell you probabilities.

    The other secondary problems are that Deutsch needs infinite precision coefficients in his quantum computers for perfect simulation of another system, and that his computers are abstract and not necessarily physically realisable.
  6. It was also pointed out that there is a contradiction between Chaos Theory and Quantum Mechnanics. This is a deep issue and probably relates both to Quantum Gravity and the Measurement Problem. QM is known to be incomplete because it can neither account for gravity nor measurement. The Copenhagen interpretation (followed by the great majority of physicists over 50) says there is a not-yet-understood process whereby the system decides which (eigen)state it's in when it is measured, and a QM system is only linear/unitary up to the point at which it is measured. Deutsch and the Everett crowd say that there is no decision, just n new parallel universes one for each eigenstate.
  7. Finally my attention was drawn to the latest paper from Penrose and Hamerhoff. What I jokingly refer to "Beale's Law of Biological Systems" is the fundamental principle that "Biological systems are almost always more complex than you think - even when you allow for the fact that they are more complex than you think" Whether or not their ideas about OrchOR and Microtubules turn out to be correct in detail, the fundamental point is that the brain is much much more complex than AI types suggest. What is certainly true is that even tiny fluctuations in the behaviour of the microtubules can be enough to change the firing behaviour of neurons. And as Hava Siegelmann showed in  1995, you don't need special physics to get the brain beyond the Turing limit.

    I did suggest in the same journal that the discoverability of scientific laws may place a strong constraint on them, and this offers a meta-explanation of why consciousness and the laws of physics might be connected.

Wednesday, May 25, 2011

Scientists beliefs in God and about Science/Religion

Been incredibly busy so no time to blog.

PNAS paper has been accepted subject to some very minor amendments which we are making. Should be in final final form next week.

Fascinating long e-discussion with Nobel Laureate required a detailed response partly because he cc’d his last to a number of other world-class scientists. Eventually made a short email then a detailed response (4pp) which addressed all the points he made. That way the cc’s people could look if they wanted but were not burdened.

The basic points I made were:
  1. Although they are in a minority, there are some outstanding scientists who are sincerely religious (Amongst Nobel Laureates I could name Hewish, Phillips and I believe Martin Evans)
  2. There is a fundamental difference between (A) "I do not believe in God" and (B) "there is an irreconcilable conflict between science and religion."
  3. Unless an organisation is explicitly committed to (B) it is unreasonable to complain if it takes actions that are incompatible with (B).
  4. Any form of persecution for people’s views on religion should have no place in science.
  5. Perhaps it would be constructive to focus on what we can agree about in this area, with respect to academic freedom and reasonable debate.
The data on scientists religious views are quite interesting.

The only scientific study of religious beliefs amongst scientists at elite universities in the US of which I am aware (Ecklund and Park 2009) found the following:

Reported PositionAll ScientistsExcl. Social Science
I do not believe in God
I do not know if there is a God and there is no way to find out
I have some doubts but I believe in God
I have no doubts about God's existence
Other(Higher Power/believe in God sometimes
Source: Ecklund and Park 2009
rounded to
nearest 1%

When asked for their view on the statement “there is an irreconcilable conflict between religious knowledge and scientific knowledge.” 17% Strongly Agree, 19% Somewhat Agree, 7% have No Opinion, 24% Somewhat Disagree and 33% Strongly Disagree”.

So only 36% of scientists Agree with (B) vs 56% who Disagree. It would of course be very interesting to se how this correlated with atheism. Strongly no doubt, but probably not more than 50%.

Friday, May 20, 2011

Great talk by Onora, good news re Bela, and interesting mind/body links

Excellent talk last night by Onora O'Neill at the RSA sponsored by the Nuffield Council on Bioethics.  She spoke of the need to broaden the focus of bioethics away from a very individualistic view of "the patient" and to address wider issues in say public health.  She was clear that properly speaking public goods have to be non-contestable and non-excludable (so creating an environment where there is safe food is a public good, a plate of free food is not).  We spoke briefly before the meeting and she is very critical of the quality of arguments used on both sides of the science and religion debate.

Delighted to see that Bela Bollobas has been elected an FRS. Of course this should have happened decades ago - I understand (not from Bela) that there were some personal animosities involved.  Haven't seen the full list yet - there may be other friends.

I've been meaning to blog for a while about a fascinating paper in Science about how the nervous systems controls the innate immune system even in C. elegans.  This is a further nail in the coffin of the idiotic idea that bodily ailments are "purely physical" and confirmation that mental and phyisical well-being are intimately interlinked.  Naturally it will turn out that these links are infinitely more complex and deep in humans.

Tuesday, May 17, 2011

Exploring the negative correlation between science and religion

Interesting dialogue continues with Nobel Laureate about the supposed incompatibility of science and religion.  He cites Laureate colleagues hostile to religion, low levels of religious belief amongst top scientists, and positive reactions of young scientists "liberated from superstition." 

The following facts seem indisputable:
  • Currently the great majority of top scientists do not believe in "a personal God"
  • Some top scientists (eg even amongst Nobel Laureates Hewish, Phillips and I think Martin Evans) do. And many of the all time greats (eg Newton, Faraday, Maxwell) certainly did. Indeed from about 1500-1900 almost all the world's top scientists were Judaeo-Christian, at a time when only about 20% of the world's population was.
So clearly theism is at present currently negatively correlated with outstanding scientific achievement although not incompatible with it.  Why might this be? Some possible reasons spring to mind:
  1. Broadly speaking we can distinguish between left-brain and right-brain thinking, with left-brain thinking tending to view the world mechanistically and right-brain tending to view the world relationally. Western science has over the last 100yrs or so become very left-brain whereas religion is a very right-brain activity.
  2. If you believe that Science is The Most Important activity in the world you are much more likely to become a professional scientist.
  3. Worldly success tends to give people a feeling of self-sufficiency. If you are at (or near) the top of your profession, financially secure etc. you may be less likely to believe in, and practice, a religion which emphasises that we are all equal in the sight of God, and have a duty of service to each other. 

This is not, of course, to suggest that very smart people who are atheists are insincere: but to recognise that our beliefs and attitudes are shaped to a significant extent by the situations in which we find ourselves.  We are social animals, not isolated idealised individual minds: on that surely both atheists and theists can agree.

PS amusing thwack of Dawkins from Archbishop Cranmer.

Saturday, May 14, 2011

What a week

What a week.  On Friday watched grandson playing cricket.  Sailed on Sun and then (just) caught the plane to Harvard. Great working session with Nowak and Rand on Monday and other project meetings in Boston and NY. Flew back overnight Thurs and up to Cambridge: celebrate birthday of Elder Grandson, watched Son playing cricket and dined on Trinity high table with some contemporaries, organised by Andrew Blake.  Sat next to the great Béla Bollobás (my most inspiring mathematics teacher) and was also delighted to see Amartya Sen: we keep missing each other in Harvard but hopefully will catch up this side of the atlantic.

Wednesday, May 04, 2011

Four reasons for monarchy

Three of the many reasons why I am a strong supporter of the monarchy are that:
  1. It makes it clear that neither politicians nor plutocrats are the "top" of society.
  2. It encourages long-termism at the pinnacle of government.
  3. It makes real democracy more likely.
  4. It allows national symolism to transcend party lines.
These are of course interconnected.

I admire and respect some of my friends who have gone into politics, and there are certainly politicians who do so out of a genuine sense of public service. Nevertheless no-one in their right mind would claim that politicians as a group represent the flower of the nation and all that is brightest, best and most admirable.  Much of politics is a very grubby business and some at least go in to it with mixed motives to say the least.  Keeping the very pinnacle of society free from politicians is highly desirable for that reason alone.

Politicians inevitably tend to think in terms of the next election (at least in a democracy) and this tends on average to be about 2 years away.  But most serious social and economic problems take a decade or more to deal with.  The Queen has been on the throne since 1952 and can reasonably hope that her grandson will be on the throne in 2052 - and maybe even 2082. She can thus bring a 130-year perspective when every week her Prime Minister meets her to discuss the affairs of state and listen to her advice and warnings.

As for real democracy, look at the 2010 Democracy Index.  26 out of 167 countries are "full democracies" and of those 26, 12 are "constitutional monarchies". There are only 24 constitutional monarchies in the list. By contrast there are 10 republics in the full democracies and 91/92 republics in the other category (the People's Repubilc of China is not listed as a republic, which seems perverse to say the least). Nevertheless we can say that constitutional monarchies are 5 times more likely to be full democracies than republics are.

Fourthly in the nature of things, politicians tend to be somewhat divisive figures, who very rarely have approval ratings much about 60% and often have strong political opponents. Constitutional monarchs tend to be "above" politics and although there are always republican intellectuals they tend to be in a very small minority, and respectful of the person of the monarch even if they (misguidedly) think the instiution should be abolished. It is right that politicians should be criticised and opposed - it's great that this does not get muddled with our Head of State.

Finally, it's noteworthy that 4 of the full democracies have the same monarch. God save the Queen!