21 November 2012

Tax Pwnium

I have a rule, which I use to guide my moaning: only whinge if you have a solution in mind. Generally, I stick to this rule because it's marginally less depressing than the alternative, but recently I've found myself whining about high profile cases of tax avoidance, unable to offer any intelligent suggestions as to how matters might be better arranged. The problem is this: billion-dollar businesses see it as their duty to shareholders to pay the legal minimum amount of tax in each country in which they operate. Consequently, it makes logical sense for them to spend large amounts of money on the very best tax attorneys and accountants in order to maximally exploit opportunities to avoid paying tax, however exotic or unanticipated these methods might be. In fact, the only real constraint on their spending is that they should claw back more in savings than they spend in avoiding tax in the first place. On the other side, governments want to collect as much tax as possible, but it is politically inexpedient to offer equivalent salaries to attract the wiliest of tax experts in order to rewrite laws or at least plug some holes; taxpayers do not like million dollar salaries. To make matters worse, in most cases governments must allow companies to trade freely across borders and in countries where they have no ability to control tax, thus forcing them to take into account not only their own system but those of dozens of other nations.

So what's to be done? I think we can draw a reasonable analogy between tax avoidance and computer hacking and perhaps even exploit a similar solution to that currently being used by companies who make internet browsers. Pwnium, is a competition run by Google, where hackers are invited to find methods of compromising Google's internet browser Chrome. Anyone who can successfully exploit a weakness in Chrome is given a cash prize in return for the details of their technique. Knowing the details of the exploit, Google can then patch Chrome ensuring that their browser is safe for its users whilst incentivising other hackers to spot problems in a constructive way. And there's the point: could governments not use a similar scheme to spot potential loopholes in their tax systems before anyone gets the chance to exploit them? Using this approach they could avoid competing on salaries and instead open a competition to the masses. There are certainly plenty of aggrieved accountants at small firms who would be more than happy to stick it to big business and get a tasty prize into the bargain.

17 March 2011

Less than unplugged: the simulation argument

Inception and The Matrix are films that tell compelling stories about people living within simulated worlds. In the case of Inception, the simulations are created in the dreams of corporate spies known as ‘Extractors’; in The Matrix, the simulated world is an illusion created by machines as a means of enslaving humanity. Both films explore the issue of how someone could possibly know if they were in a simulation, and the feeling we get is that perhaps we wouldn't.

Whilst people might be prepared to acknowledge the power of such an illusion for the characters in a film, presumably rather fewer would accept that there is a genuine chance they are in a simulation right now. One barrier to taking this notion seriously, is the fact that there is currently no technology capable of performing such simulations. But that is not to say that this technology will always be beyond us. It is reasonable to suppose that if humans survive into the far future, our technology would be more than adequate. Whilst we are not at that stage yet, it is an open question as to how many civilisations in the universe are at such an advanced stage of technology. And there’s the rub: the evolution of life to the point where intelligent organisms are capable of creating civilisations is probably exceedingly rare, but amongst the complex civilisations that do exist, the simulation of intelligent agents is potentially much less rare. Furthermore, if we assume that a civilisation capable of simulating one universe is capable of simulating many universes, there would appear to be the very real possibility that there are more simulated conscious agents in existence than there are real ones; it might be more likely that we are simulated than real.

The notion of being a simulated entity is admittedly rather unappealing, but perhaps it’s not the worst case scenario. Might it not also be possible for sufficiently rich simulations to run simulations of their own? In other words, there is presumably a chance that, far from being real, we are merely second order simulations, simulated within a simulated world! Perhaps we are at the mercy of several higher-order coffee cups, any one of which could spill and destroy one of the machines that computes our reality.

When I first drafted this post, it was an amalgamation of ideas from lots of popular sources; however, a glance at the literature makes clear that the simulation argument owes everything to the work of the Philosopher Nick Bostrom, in particular his paper from 2003. For anyone interested in further exploration of the idea, listen to Bostrom explain the idea in this excellent interview. Bostrom also curates a useful set of links on the subject at his simulation argument website.

Bostrom, N. (2003). Are you living in a computer simulation. Philosophical Quarterly, 53(211), 243-255.

9 November 2010

Hardware evolution

I have previously written about the idea of evolving solutions to problems, but never have I seen a more beautiful example of this approach than Adrian Thompson’s (1997) investigation into hardware evolution. His paper details an attempt at using selection to find a circuit capable of discriminating between two tones. He isolated a 10 by 10 corner of a reconfigurable chip, such that the behaviour of just 100 of the chip’s 4096 cells was assessed. A genetic algorithm was then used to create different arrangements of the connections between these 100 cells over successive generations. Specifically, a population of 50 individual arrangements existed in each generation and the relative contribution of any one of these arrangements to the next generation was dependent on the extent to which it succeeded in discriminating the tones. After around four thousand generations, an arrangement was found that could discriminate consistently.

The structure of the successful circuit is quite astonishing. A schematic of its arrangement shows that just 21 cells were required to carry out the discrimination and, of these, 5 were special. Like the other 16 they were necessary to ensure that the circuit performed normally, but, bizarrely, there was “no connected path by which they could influence the output” (p.399). In other words, they were contributing to the performance of the circuit in some way other than the direct connections between cells! The means by which these 5 cells exerted their effect isn’t clear, but Thompson suggests that it might be something to do with their analogue output such as radiative coupling or temperature modulation. This is supported by the fact that the chip’s performance was sensitive to ambient temperature, working best in conditions experienced during its evolution.

What Thompson's study tells us is that not only can evolution help us to solve a problem we don’t know how to solve but it is capable of exploiting properties of systems that we are barely even aware of, let alone in a position to fully understand and exploit. Indeed, the physical properties utilised in this circuit are so peripheral to how we normally understand the function of logic circuits, that its behaviour wouldn’t even be captured in a standard simulation. Curiously the selection process can only do this because it has no insight into how or why things work; it simply relies on whether they worked in the past.

Thompson, A. (1997). An evolved circuit, intrinsic in silicon, entwined with physics. Evolvable Systems: From Biology to Hardware, 1259, 390-405.

6 October 2010

The uniqueness of children

Children are fascinating for all sorts of reasons, from their mind-boggling learning abilities to their unshakable cheeriness and desire to have fun (apparently frontal lobes turn you into an arsehole), but lately the thing that particularly interests me is their uniqueness.

This individuality owes much to the genetic relationship between parent and offspring.  Children contain half of each parent's genome, but in a form that is truly unique, the chromosomes having been created from a process of random selection and recombination as part of the magic of meiosis. The result, as we all know, is that children look and behave differently to both parents but simultaneously exhibit that peculiar trait known as family resemblance: the similarity that occurs when unrelated adults are linked in our minds by the phenotypic bridge provided by their children.  Furthermore, owing to a giant mismatch in parental investment between the sexes, men release hundreds of millions of sperm in a single ejaculation; so many indeed that the moment of conception that decided the existence of a particular child has a temporal sensitivity which is scarcely imaginable.  

Like everyone, I am a product of this very process and, amazing though it is, when I consider my own existence the improbability doesn't much impress; sure, it seems like a long shot but then again I would say that because I happen to be the entity that won out.  See it through the eyes of a parent however and things are totally different.  When I reflect on the existence of my little boy I understand that he couldn't happen again and this doesn't just ensure that his life is precious, it ensures that my history is precious. Though my life has been far from perfect, I know that had I done anything differently prior to the moment of his conception, he wouldn't be here now. In a small way, I am freed from regret by an unanticipated causal chain.

28 July 2010

He wishes for the cloths of heaven

What follows is my favourite poem, and indeed my favourite collection of words of any description. It was written by W. B. Yeats and conveys a sentiment that is ostensibly romantic, but to me speaks more generally of how vulnerable we all are every time we embark on a project that really matters to us. It is the earnestness of the final three lines that I find particularly moving.

Had I the heavens’ embroidered cloths,
Enwrought with golden and silver light,
The blue and the dim and the dark cloths
Of night and light and the half light,
I would spread the cloths under your feet:
But I, being poor, have only my dreams;
I have spread my dreams under your feet;
Tread softly because you tread on my dreams.

The education advisor Sir Ken Robinson uses this poem to powerful effect at the end of his recent TED talk, which I highly recommend.

Thanks to my little boy for the gorgeous picture of his bear. He drew it when he was two years old and it is one of his first pictures to have a recognisable form.

26 July 2010

The unbearable sound of me

Today I listened to a 5-minute recording of myself talking. Whilst the content was never going to be novel, there's no hiding from the fact that it was spectacularly uninspiring and delivered in a voice so utterly lacking in gravitas and emotion as to be barely preferable to tinnitus. I hereby apologise to anyone who has ever had the misfortune of listening to me speak and consider any nods and kind words you have offered to be acts of the utmost tolerance, compassion and charity in the face of the most unpleasant provocation.

13 April 2010

Working for nothing: the power of variable-ratio reinforcement

The ability to manipulate behaviour simply by changing schedules of reinforcement, has always amazed me. This passage from Skinner (1961, pp. 106-7) gives some idea of just how powerful variable-ratio reinforcement in particular can be:
We are all familiar with this schedule because it is the heart of all gambling devices and systems. The confirmed or pathological gambler exemplifies the result: a very high rate of activity is generated by a relatively slight net reinforcement. Where the “cost” of a response can be estimated (in terms, say, of the food required to supply the energy needed, or of the money required to play the gambling device), it may be demonstrated that organisms will operate at a net loss.
When the food magazine is disconnected after intermittent reinforcement, many responses continue to occur in greater number and for a longer time than after continuous reinforcement ... The potential responding built up by reinforcement may last a long time. We have obtained extinction curves six years after prolonged reinforcement on a variable-ratio schedule. Ratio schedules characteristically produce large numbers of responses in extinction. After prolonged exposure to a ratio of 900:1 (Figure 4) the bird was put in the apparatus with the magazine disconnected. During the first 4½ hours it emitted 73,000 responses.
The implications of this are of course huge for our understanding of human behaviour. Suffice to say, a person's reinforcement landscape can be as coercive and disempowering as a drug addiction, just as it can be nurturing and make manifest all of the best and most desirable of human characteristics.

  • Skinner, B. F. (1961). Cumulative Record. (Enlarged ed.) New York: Appleton-Century-Crofts. (Reprinted from Skinner, B. F. (1957). The experimental analysis of behavior. American Scientist, 45, 343-371). 

13 March 2010

Thinking machines

I have always been interested in what people have to say on the subject of thinking machines and thought I would share a couple of my favourite quotations.  The first is from the late Dutch computer scientist, Edsger Dijkstra:
The European mind (...) considers the question whether machines can think as relevant as the question whether submarines can swim. (1986, p.10)

I am not certain what Dijkstra really meant when he wrote this, but, based on the context of the talk from which it is taken, it seems he was trying to get across the idea that Europeans perceive a greater difference between humans and machines than do Americans.  Curiously enough, it is often now used to emphasise the point that questions about thinking, especially where machines are concerned, are semantic inventions to be avoided if at all possible.  Whilst the latter interpretation is certainly not an opinion I share, it is, I believe, a much more interesting use of the analogy.

The second quotation is one of my favourites on any subject and is attributable to the psychologist, Bhurrus Skinner.  It has the rare quality of losing none of its clarity even when taken out of context and beautifully and succinctly captures one of the central motivating factors behind Skinner's philosophy of behavioural research.
The real question is not whether machines think, but whether men do. The mystery which surrounds a thinking machine already surrounds a thinking man." (1969, p.288)

Dijkstra, E. W. (1986). Science fiction and science reality in computing. Unpublished talk.
Skinner, B. F. (1969). Contingencies of Reinforcement. New Jersey: Prentice-Hall.

Thanks to Tom Stafford for originally bringing the Dijkstra quotation to my attention.  It was, however, rather troublesome to track down the source and it is only due to the website of The University of Texas Austin that I could find it at all.

3 January 2010

One million giraffes

Ola Helland, a Norwegian web designer, has a bet with one of his friends that by 2011 he can collect one million giraffes created for him by members of the public.  The challenge has been running since the middle of June 2009 and he currently has close to half a million!  From what I've read, Ola is attempting to get sponsorship for each giraffe added so that the project can provide some money to be used in protecting wild giraffes.  I hope he gets the money but, either way, the idea is so deliciously silly that it would be great if he reaches his target.  If you want to add a giraffe of your own or have a look at some of the creations by other people, you can find the website here (look out for the stats page which, amongst other things, shows that the UK and Germany are battling it out at the top of the nations table for giraffe generosity). You can find my giraffe contribution on the website here.

13 December 2009

Cup to which I have a sentimental attachment

As the handful of people who know me will testify, I have the emotional constitution of an eighty year old woman who has just watched a particularly weepy episode of Heartbeat and received a phone call about the birth of her latest grandchild.  However, in spite of this I have never been one for having favourite objects or keeping things for their sentimental value (my wife's near pathological hoarding ensures that this simply isn't necessary).  Well, that isn't strictly true: I do have one sentimental item.  It is a cup my dad bought for me when he was on a business trip to Holland.  In fact, it doesn't matter where it's from, he could have picked it up at the petrol station on the way home and I wouldn't care, for some reason it is important to me because it reminds me of home and family between the ages of ten and eighteen.  There's no story behind the cup, no economic value, no special properties (well, that's not exactly true, the handle is unusually comfortable and it holds just the right quantity of tea); it's just a cup that elicits feelings of familiarity that I would sooner not lose.