Sunday, 7 March 2010
Info content of the FA cup draw
For the semi-final draw they dramatically select each of the four balls for the four clubs, but in fact there's only log2(3) = 1.58 bits of information, and it could be done with a single draw. Since both matches play at Wembley, there's no 'home' or 'away', so there's only three possibilities:
A - B and C - D
A - C and B - D
A - D and B - C
During the draw:
- first team out of the box: gives no information
- second team out, select one from the three remaining, and gives all of the information
- third and fourth teams out, tell us nothing, because we already knew they were to play each other
Unless I suppose it makes a difference which match is played first, in which case there are six possibilities, adding one bit of information, 2.58 bits. (log2(6) = 2.58)
A - B then C - D
A - C then B - D
A - D then B - C
C - D then A - B
B - D then A - C
B - C then A - D
- first team out. Tells us that team plays in the first match. That is a selection from two equal possibilities (that team could have played in the first or second match), so contributes 1 bit of information
- second team out. This is a selection of one from three (the three teams still in the hat) so is 1.58 bits of information. This is now all the information, because we know the other two teams play each other in the second match. Information adds, so total information is 2.58 bits.
- third and fourth teams out contribute no information.
A - B and C - D
A - C and B - D
A - D and B - C
During the draw:
- first team out of the box: gives no information
- second team out, select one from the three remaining, and gives all of the information
- third and fourth teams out, tell us nothing, because we already knew they were to play each other
Unless I suppose it makes a difference which match is played first, in which case there are six possibilities, adding one bit of information, 2.58 bits. (log2(6) = 2.58)
A - B then C - D
A - C then B - D
A - D then B - C
C - D then A - B
B - D then A - C
B - C then A - D
- first team out. Tells us that team plays in the first match. That is a selection from two equal possibilities (that team could have played in the first or second match), so contributes 1 bit of information
- second team out. This is a selection of one from three (the three teams still in the hat) so is 1.58 bits of information. This is now all the information, because we know the other two teams play each other in the second match. Information adds, so total information is 2.58 bits.
- third and fourth teams out contribute no information.
Monday, 22 February 2010
Themes and alternative readings of "The Virtual Revolution"
The four programmes of The Virtual Revolution tell the story of the world wide web, but of course it can’t really be the story, because there’s no such thing as the story. There’s always many different stories that can be told about anything. It is a story (and it my view a pretty good one), and like all stories it is built on underlying assumptions and held together by explicit or implicit themes. We can take the story at face value and leave it there, but we can always learn more by questioning: What are the themes? What assumptions are they based on? Are there alternatives, and if so, what story would they tell?
Running through the series was a tension between techno-utopianism and techno-dystopianism. Techno-utopianism – the advent of the web heralds a new golden age – was implicit in many of the stories: the web will solve the problems of Africa (both poverty and violence), will transform education (as witnessed by Korea) and will topple totalitarian regimes such as in Iran.
It was most unambiguously championed by Stephen Fry:
(Incidentally, this idea of the internet as a global brain was a theme of a former academic at the Open University, Gary Alexander, in his book on eGaia.)
Warnings of a dystopianism future were less in evidence, but in the stories of Programme 3, ‘The Cost of Free’, there were clear allusions to the classic techno-dystopia of George Orwell’s 1984, though in this case ‘Big Brother’ wasn’t the state, but private businesses like Google.
And then in Programme 4 we heard about some of the fears arising from excessive use of the web by children. Sam Koh Young talked about some of the observed consequences for people in Korea:
This interpretation was evident in Programme 1, where we saw Tim Berners-Lee and Aleks Krotoski visit a community centre in Ghana, and Berners-Lee observes:
Running through the series was often an implicit technological determinism. The technology happens, come what may, and people and society are dragged along with it. For example, in the commentary of Programme 2, it seems as though it is ‘the web’ itself that’s in charge:
Running through the series was a tension between techno-utopianism and techno-dystopianism. Techno-utopianism – the advent of the web heralds a new golden age – was implicit in many of the stories: the web will solve the problems of Africa (both poverty and violence), will transform education (as witnessed by Korea) and will topple totalitarian regimes such as in Iran.
It was most unambiguously championed by Stephen Fry:
We have the knowledge of the ages gathered for us to browse in our pockets. And if we seriously think that is something we should turn a backs on or sniff at then we really deserve a slapping. This is astounding technology and we should take a moment to celebrate the power, the reach it gives us across time and across ideas and across continents both past, future and present to connect with peopleBut it was more or less explicit in the contributions of many of the other contributors. Al Gore, for example:
Human civilisation as a whole is now witnessing the connection of people everywhere on earth through this web in ways that actually do mimic the growth of a human brain. And the analogy is imperfect. But it’s also real. We are seeing the emergence of a global brain
(Incidentally, this idea of the internet as a global brain was a theme of a former academic at the Open University, Gary Alexander, in his book on eGaia.)
Warnings of a dystopianism future were less in evidence, but in the stories of Programme 3, ‘The Cost of Free’, there were clear allusions to the classic techno-dystopia of George Orwell’s 1984, though in this case ‘Big Brother’ wasn’t the state, but private businesses like Google.
And then in Programme 4 we heard about some of the fears arising from excessive use of the web by children. Sam Koh Young talked about some of the observed consequences for people in Korea:
If they don't use the internet they feel anxious and unstable. They don't feel satisfied. Their friends don't talk to them any more, and a lot of friction builds up with a relationship with their parents, and those are the consequences over too much internet use.Other contributors were sceptical of the utopianism, without necessarily predicting dystopia. This was true of Lee Siegel and Andrew Keen. Andrew Keen was the most outspoken, more cynical that sceptical. Countering the utopian talk of the democracy of the web in Programme 1:
In Korea there were cases of people using the internet for eighteen hours a day.
The massive aggregation of new wealth and power are the tiny elite from mainly Silicon Valley..Though less explicit, another theme running through the series – and indeed in any discourse around the web – is that of globalisation and ‘the death of distance’. In the utopian reading of the web, this is inherently a good thing. While few would find fault in improved communication between distant people, there is an argument that the death of distance means that geography is history, which hints at some more ambiguous implications. Implicit in some of the narratives of the web is that human geography – the differences between peoples and societies – can be interpreted not as genuine geographic differences, but as people at different stages on a single historical time-line. Thus Europe is a few years behind the USA, and Africa is further back still – the time-line invariably has the USA at the front with Western Europe close behind.
This interpretation was evident in Programme 1, where we saw Tim Berners-Lee and Aleks Krotoski visit a community centre in Ghana, and Berners-Lee observes:
It was a little bit like going back in time to when people first came across the web.When we start to question the stories along these lines, we can uncover even more troubling interpretations. The Western, wealthy, white, Berners-Lee and Krotoski stride among the poor, black, Africans. Even the Ushahidi story in which the website was created by a black African woman may be read as the Western technology coming to the rescue of a primitive Kenya. Though it seems churlish to question so much goodwill, maybe there’s a colonialist theme in there.
Running through the series was often an implicit technological determinism. The technology happens, come what may, and people and society are dragged along with it. For example, in the commentary of Programme 2, it seems as though it is ‘the web’ itself that’s in charge:
…the Web is shifting power, sometimes menacingly, in ways we could never have imagined. It's accelerating globalisation. It's providing us with new allegiances that cross traditional borders, but it's also reinventing warfare and seems to be creating frightening cultural cul-de-sacs.An alternative view, the social construction of technology, is that technology reflects the people and society, and this was aired by several of the more sceptical contributors, including Lee Siegel in Programme 1:
I think The Web will really take on the contours of what culture has always been. There will be hierarchies, there will be elites. Like all technology the internet is not a cure for human nature, it is an amplification of human nature, both the good and the bad.Over the four programmes the series covers a vast territory, and the BBC has made available several hours more material from the interview rushes on the associated website. Together this is an invaluable resource for understanding the web, and whatever your own position on the nature of the web: enthusiastic; sceptical; or scared, this material should provide food for thought.
Wednesday, 17 February 2010
Optical fibre dispersion compensation with a fibre Bragg grating
Though I've largely left my optical fibre research behind, occasionally I spot things of interest. This, reported in Lightwave, is really nice, partly because it is easy to understand and uses a couple of neat optical fibre devices.
Dispersion is the (optical) frequency-dependent variation of propagation speed which causes pulse-spreading in optical fibre. In single-mode fibre it is often the factor that limits the bit rate that can be transmitted over long distances. A way to overcome it is through 'dispersion compensation': adding a device that does the opposite of the dispersion in the fibre. So if the fibre causes the longer wavelengths to be take longer than the shorter wavelengths, the device needs to delay the shorter wavelengths more than the longer wavelength.
The device reported here does that using a fibre Bragg grating, which is a length of optical fibre with a regular variations in the refractive index, on a scale similar to the wavelength of light. (Incidentally, the wavelength of light used in optical comms, of the order of 1.5 micro-metres, is large compared to the 'feature size' of electronic devices, so doing things on that scale is not unreasonable.) Interference effects mean that the grating reflects light which has a wavelength that matches the grating, and by careful control of the grating spacing - varying the spacing over the length of the grating, a technique known as 'chirp' - the light can be manipulated in various ways dependent upon the wavelength. You can, for example, arrange for light of different wavelengths to be reflected at different locations, thereby making the path-length different for different wavelengths.
The fibre Bragg grating (one of the 'neat' optical devices I referred to above) is combined with an optical circulator (the other 'neat' device). An optical circulator is a three- or four-port device, which I picture as like a roundabout in road, but with the rule that you are only allowed to turn left.
Have a look at picture in the Lightwave article to see how they are combined, but what happens is that light enters the circulator from the incoming fibre, turns left down to the fibre Bragg grating (a cul-de-sac) and gets reflected back to the circulator where it turns left to the output fibre. Having taken the detour down the Bragg grating, the light propagation time between input and output is controlled by the details of the grating dimensions.
Dispersion is the (optical) frequency-dependent variation of propagation speed which causes pulse-spreading in optical fibre. In single-mode fibre it is often the factor that limits the bit rate that can be transmitted over long distances. A way to overcome it is through 'dispersion compensation': adding a device that does the opposite of the dispersion in the fibre. So if the fibre causes the longer wavelengths to be take longer than the shorter wavelengths, the device needs to delay the shorter wavelengths more than the longer wavelength.
The device reported here does that using a fibre Bragg grating, which is a length of optical fibre with a regular variations in the refractive index, on a scale similar to the wavelength of light. (Incidentally, the wavelength of light used in optical comms, of the order of 1.5 micro-metres, is large compared to the 'feature size' of electronic devices, so doing things on that scale is not unreasonable.) Interference effects mean that the grating reflects light which has a wavelength that matches the grating, and by careful control of the grating spacing - varying the spacing over the length of the grating, a technique known as 'chirp' - the light can be manipulated in various ways dependent upon the wavelength. You can, for example, arrange for light of different wavelengths to be reflected at different locations, thereby making the path-length different for different wavelengths.
The fibre Bragg grating (one of the 'neat' optical devices I referred to above) is combined with an optical circulator (the other 'neat' device). An optical circulator is a three- or four-port device, which I picture as like a roundabout in road, but with the rule that you are only allowed to turn left.
Have a look at picture in the Lightwave article to see how they are combined, but what happens is that light enters the circulator from the incoming fibre, turns left down to the fibre Bragg grating (a cul-de-sac) and gets reflected back to the circulator where it turns left to the output fibre. Having taken the detour down the Bragg grating, the light propagation time between input and output is controlled by the details of the grating dimensions.
Wednesday, 10 February 2010
Luciano Floridi on the fourth revolution and the infosphere
In a Philosophy bites interview, Luciano Floridi talks about the fourth revolution - the information revolution.
I've removed the emedded audio because it was taking a long time to load - please go to the site instead if you want to listed to it.
Some notes and comments:
Four revolutions which change our understanding of where we stand in relation to the universe.
1st Copernicus
2nd Darwin
3rd Freud
4th The information revolution. ICT modifies our interaction with reality. "Things exist if we can interact with them."
"The infosphere", goes back to the invention of writing, expanding to include more and more aspects of our reality.
A square with four corners:
1 knowledge
2 ethics
3 our self-understanding
4 how we make sense of reality
ICT has changed all four. 4th: Things exist if we can interact with them - "For example, in the world of physics"... we have become used to treating as existing subatomic particles that we have never perceived but we have been able to interact with"
He talks about the way in which we can play different roles and characters online (as in Second Life) and makes the point that if someone spends a lot of time playing these roles it can feed back in to who that person is.
This reminded me of an episode in "The Joke" by Milan Kundera, where the narrator is in a jail, and the man in charge of the jail is young and cruel. Kundera argues that his cruelty arises from not knowing how he should behave, so he has to create a role for himself:
"We are 80% 90% information"
"There is a sense in which people who are not online do not exist"
Information technology has given us reasons to reconsider the classical problems from a different perspective.
I've removed the emedded audio because it was taking a long time to load - please go to the site instead if you want to listed to it.
Some notes and comments:
Four revolutions which change our understanding of where we stand in relation to the universe.
1st Copernicus
2nd Darwin
3rd Freud
4th The information revolution. ICT modifies our interaction with reality. "Things exist if we can interact with them."
"The infosphere", goes back to the invention of writing, expanding to include more and more aspects of our reality.
A square with four corners:
1 knowledge
2 ethics
3 our self-understanding
4 how we make sense of reality
ICT has changed all four. 4th: Things exist if we can interact with them - "For example, in the world of physics"... we have become used to treating as existing subatomic particles that we have never perceived but we have been able to interact with"
He talks about the way in which we can play different roles and characters online (as in Second Life) and makes the point that if someone spends a lot of time playing these roles it can feed back in to who that person is.
This reminded me of an episode in "The Joke" by Milan Kundera, where the narrator is in a jail, and the man in charge of the jail is young and cruel. Kundera argues that his cruelty arises from not knowing how he should behave, so he has to create a role for himself:
The young can't help playacting; themselves incomplete, they are thrust by life into a completed world where they are compelled to act fully grown. They therefore adopt forms, pattern, models - those that are in fashion, that suit, that please - and enact them.My point is that it is not just online that we act out roles. Maybe, though, the virtual world provides somewhere we can start afresh, and escape from the role we created in the physical world?
"We are 80% 90% information"
"There is a sense in which people who are not online do not exist"
Information technology has given us reasons to reconsider the classical problems from a different perspective.
Tuesday, 26 January 2010
Information & consciousness
One of the reasons I'm so interested in information is the link to consciousness. Consciousness is surely on the front line of our struggle to make sense of the world, it is one of the really big problems. See what Dennett wrote in 1969:
Information surely lies at the boundary of these two spheres.
In the London Review of Books there was recently a review of a work by the philosopher Galen Strawson [1]. There's lots of really intriguing ideas in there, like the suggestion that
But that's not really what I wanted to highlight here. What I want to raise (which I have just discovered was not in that LRB article, but in an earlier one [2]!) is Strawson's panpsychism:
One of the steps in the argument that leads Strawson to panpsychism is that he doesn't believe in emergence. So, since we are conscious, so too must the stuff we are made of also be conscious. And since that stuff is the same stuff that trees, rocks and rivers are made of, so too might they be conscious. Well, I think that is where I can point to a straightforward disagreement: I do believe in emergence. I think information is an emergent property. The information carried by the bits in a digital communication channel is not in the bits, but 'emerges' from the order in which they are put together.
Refs
1 The I in me, Thomes Nagel, review of Selves: An Essay in Revisionary Metaphysics by Galen Strawson, London Review of Books Vol. 31 No. 21 · 5 November 2009 pp33-34
2 Headaches have themselves Jerry Fodor review of Consciousness and Its Place in Nature: Does Physicalism Entail Panpsychism? by Galen Strawson et al, LRB v29 n10 24 may 2007)
THOSE who are convinced of the futility of philosophy are fond of pointing to its history and claiming that there is no progress to be discerned there. In no area of philosophy is this claim easier to support than in philosophy of mind, the history of which, when viewed through a wide-angle lens, appears to be a fruitless pendulum swing from Descartes' dualism to Hobbes’ materialism, to Berkeley’s idealism, and then back to dualism, idealism and materialism, with a few ingenious but implausible adjustments and changes of terminology. The innovations of one generation have been rescinded by the next so that despite a growing intricacy of argument and a burgeoning vocabulary of abstruse jargon, supplemented in each era by the fashionable scientific terms of the day, there have been no real and permanent gains.Of course since that was written 40 years ago it could all of changed - maybe the problem of the mind has been solved, but I don't think so.
The question that defined the pendulum is what the relation is between mind and body, and the problem that set the pendulum in motion was Descartes' dilemma of interaction. If, as seems plausible at first glance, there are minds and mental events on the one hand and bodies and physical events on the other, then these two spheres either interact or not.
"Content and Consciousness", D. C. Dennett, Routledge & Kegan Paul 1969
Information surely lies at the boundary of these two spheres.
In the London Review of Books there was recently a review of a work by the philosopher Galen Strawson [1]. There's lots of really intriguing ideas in there, like the suggestion that
...the subjective experience of the self does not require that it persist beyond the lived present, which lasts for less than a secondso not only am I not that same person when I wake up in the morning as the person who went to sleep the night before, but I am a different person from one second to the next.
Not only does the self not persist across gaps in consciousness; it also doesn’t persist across the shifts in the content of consciousness that occur constantly in the course of waking life.
But that's not really what I wanted to highlight here. What I want to raise (which I have just discovered was not in that LRB article, but in an earlier one [2]!) is Strawson's panpsychism:
Strawson ... stands revealed as a panpsychist: basic things (protons, for example) are loci of conscious experienceHaving been reading about native American religions over the Christmas it is quite nice to come across a (modern, Western) philosopher with an argument that might support the idea that trees, rocks and rivers might be conscious, but it is a lot to swallow and I'm not quite there yet!
One of the steps in the argument that leads Strawson to panpsychism is that he doesn't believe in emergence. So, since we are conscious, so too must the stuff we are made of also be conscious. And since that stuff is the same stuff that trees, rocks and rivers are made of, so too might they be conscious. Well, I think that is where I can point to a straightforward disagreement: I do believe in emergence. I think information is an emergent property. The information carried by the bits in a digital communication channel is not in the bits, but 'emerges' from the order in which they are put together.
Refs
1 The I in me, Thomes Nagel, review of Selves: An Essay in Revisionary Metaphysics by Galen Strawson, London Review of Books Vol. 31 No. 21 · 5 November 2009 pp33-34
2 Headaches have themselves Jerry Fodor review of Consciousness and Its Place in Nature: Does Physicalism Entail Panpsychism? by Galen Strawson et al, LRB v29 n10 24 may 2007)
Monday, 18 January 2010
ICT4D: Information and communication technologies for development
The following is something I drafted for use elsewhere, and didn't use. Someone asked me today whether you can embed audio in blogs, so this is really a test of that.
Back in 1999 the BBC made a programme for the OU on the ways in which cellphone technology was being harnessed to get phones to people in the townships of South Africa. One of the contributors, Peter Dzingwa, ran a ‘phoneshop’ – a shipping container furnished with phones connected to the mobile network and used as payphones – and was full of enthusiasm:
The statistics and the stories coming from countries not just in Africa but across the developing world since then seem to suggest that his enthusiasm was fully justified. Indeed, some of the statistics are quite dramatic. Subscriber growth rates in developing countries have been more than 25% a year, and half the world’s population now use a mobile phone [2].
Mobile phones have taken off in developing countries in a way that other new technologies haven’t. Personal computer ownership doesn’t yet seem to be having much of impact, with even the much-publicised ‘One Laptop Per Child’ programme struggling to make a significant impact beyond one or two countries where the government have backed national programmes.
There are many reasons behind the relative success of mobile phones, including details like the fact that you don’t need to be literate in English or another major language – you can talk in your own language – but more generally this is a technology that people have been able to adapt to their own needs. Phones are ‘general purpose’ tools that their owners use however they want to and for whatever purposes suits them.
Hannah Beardon, an independent consultant on development, discussed this in a recent interview for the Open University:
This isn’t the whole story, though. Technology doesn’t exist in a vacuum, and, as Hannah explains, the introduction of new technologies changes things
A version of this post also appears on the Open University open2.net blog
Further study:
T324, Keeping ahead in ICT,
Environment, Development and International Studies curriculum
ICT and Computing curriculum
Sources
1 From Breaking down barriers, and Affordable technologies, available from iTunesU
2 ID21 Insights 69, September 2007. Institute of Development Studies, University of Sussex
3 Extract from interview about mobile phones for development, recorded for T324, Keeping Ahead in ICT, full interview
4 Extract from interview about ICT for development, recorded for T324, Keeping Ahead in ICT, full interview
Back in 1999 the BBC made a programme for the OU on the ways in which cellphone technology was being harnessed to get phones to people in the townships of South Africa. One of the contributors, Peter Dzingwa, ran a ‘phoneshop’ – a shipping container furnished with phones connected to the mobile network and used as payphones – and was full of enthusiasm:
"I think cellphones are what Africa has been waiting for....(South Africa) came to a standstill for 40 years. There was no development there, a lot of guns going off....now the cellphone has actually made them lift those 40 years and be smack right in the middle of everybody's communication system, which I think is a fantastic thing." [1]
The statistics and the stories coming from countries not just in Africa but across the developing world since then seem to suggest that his enthusiasm was fully justified. Indeed, some of the statistics are quite dramatic. Subscriber growth rates in developing countries have been more than 25% a year, and half the world’s population now use a mobile phone [2].
Mobile phones have taken off in developing countries in a way that other new technologies haven’t. Personal computer ownership doesn’t yet seem to be having much of impact, with even the much-publicised ‘One Laptop Per Child’ programme struggling to make a significant impact beyond one or two countries where the government have backed national programmes.
There are many reasons behind the relative success of mobile phones, including details like the fact that you don’t need to be literate in English or another major language – you can talk in your own language – but more generally this is a technology that people have been able to adapt to their own needs. Phones are ‘general purpose’ tools that their owners use however they want to and for whatever purposes suits them.
Hannah Beardon, an independent consultant on development, discussed this in a recent interview for the Open University:
This isn’t the whole story, though. Technology doesn’t exist in a vacuum, and, as Hannah explains, the introduction of new technologies changes things
A version of this post also appears on the Open University open2.net blog
Further study:
T324, Keeping ahead in ICT,
Environment, Development and International Studies curriculum
ICT and Computing curriculum
Sources
1 From Breaking down barriers, and Affordable technologies, available from iTunesU
2 ID21 Insights 69, September 2007. Institute of Development Studies, University of Sussex
3 Extract from interview about mobile phones for development, recorded for T324, Keeping Ahead in ICT, full interview
4 Extract from interview about ICT for development, recorded for T324, Keeping Ahead in ICT, full interview
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