In terms of mathematical physics, civilisation is a deterministic non-linear dynamical system far-from thermodynamic equilibrium, and human history is the study of one particular trajectory of that dynamical system. This means that there is a set of variables {Xi: i=1,...,n} whose values uniquely characterise the state of a civilisation at a moment in time. All other properties of a civilisation are functions of these state variables.
The evolution in time of a civilisation is then governed by a set of n coupled non-linear differential equations, which the state variables must satisfy:
dXi/dt = Fi(X1,...,Xn;λ1,...,λm), (i=1,...,n).
The m parameters define external constraints upon a civilisation, such as those determined by the geography, geology and meteorology of the planet on which the civilisation exists.
Unfortunately, unlike Hari Seldon in Isaac Asimov's Foundation books, we don't yet know what these equations are. We don't even know what the state variables are. One might, however, hypothesise the following candidates:
(i) Population size, and population rate of change.
(ii) Total amount of available free energy (i.e., energy resources), and rate of energy consumption (i.e., power output).
(iii) Amount of information stored, and amount of information processed.
Additional variables might then be required to characterise the hierarchies and organisations which define the political state of a civilisation. All economic variables, however, can be treated as functions of the variables in categories (i), (ii) and (iii).
Identifying the correct state variables, and the equations which govern the evolution of civilisations, is a task set for the reader. However, some progress towards understanding the dynamical processes in human history is being made by people such as Peter Turchin, who has launched his cliodynamics research programme, which aims to identify the mathematical patterns in human history. Turchin has identified, he claims:
...long-term cycles that, it turns out, characterize the dynamics of agrarian states and empires. When we consider the long course of history of Western Europe from the days of the Roman empire until the Industrial Revolution, we observe waves of internal instability (widespread rebellions, state collapse, and persistent civil war) that recur every two or three centuries. The internal warfare cycles appear to be dynamically linked with cycles of population increase and decline or stagnation: population peaks are followed, after a time lag, with peaks of instability. This empirical pattern suggests some kind of a Malthusian explanation. However, the American sociologist Jack Goldstone showed that population growth beyond the means of subsistence does not directly bring the onset of civil wars. Instead, its effect is indirect, mediated through the social and political structures (elite overproduction and state fiscal insolvency), which is why there is a time lag between population and instability peaks. This pattern of linked population and internal warfare oscillations is not limited to Europe. Recently two Russian historians, Sergey Nefedov and Andrey Korotayev, showed that the same relationship holds for China during its two thousand year imperial history, for Egypt (from the Hellenistic period to the nineteenth century), and for Russia. It is remarkable that such complex, and very different, societies would all show similar dynamical patterns.
Civilisation is a deterministic non-linear dynamical system, and it is also, presumably, one which exhibits sensitive dependence upon initial conditions: two different histories which begin in a very similar state can, one presumes, diverge from each other at an exponential rate. In terms of dynamical systems theory, such systems are said to be chaotic, hence civilisation is a chaotic dynamical system. Human history also appears to be an aperiodic trajectory in civilisation space, at least over the space of 10,000 years or so. A crucial question, however, is whether the laws of civilisation permit the exist of attractors.
An attractor is a subset of the set of all possible states of a dynamical system, which is such that once a trajectory of the system enters, it never leaves. This doesn't entail that the trajectories are doomed to become periodic once they enter the attractor; they can continue indefinitely, without repeating the same exact state. Whilst chaotic systems are defined by the sensitive dependence on initial conditions that they exhibit, they also tend to possess various chaotic attractors. Which begs the questions:
Is civilisation a chaotic system which possesses attractors, and if so, is human history converging to such an attractor?
The obvious candidate for such an attractor is secular, liberal, democratic, capitalist society. This is essentially the possibility Francis Fukuyama was raising in The End of History. Whilst the current state of the world might not currently reside inside this attractor, and perturbations like 9/11 might be capable of temporarily taking it further away from the attractor, perhaps the current state of the world lies inside the basin of attraction for global secular, liberal, democratic, capitalist society.
Cliodynamics Deterministic nonlinear dynamical system Attractors
Tuesday, July 29, 2008
Sunday, July 27, 2008
Smolin on multiculturalism
Physicist Lee Smolin pens an article for New Scientist on the principles which, he believes, should underlie a multicultural society:
The older notions of liberal democracy grew out of societies where everyone had the same background and history. Today, a citizen of the UK, Sweden, Canada, France or the US may have any ethnic origin, any appearance, and practice any religion – or none. Diversity is increasingly becoming the norm, as unprecedented mobility delivers a planetary society.
But as we move around and mix, our differences move with us and, if anything, deepen as the number of philosophies, religions and life styles combine and multiply in unexpected ways. The challenge is how to have a diverse, multicultural society that is based on reason.
The answer is that we cannot expect to agree about everything. Nor should we: history has shown that a society in complete agreement is impossible, and societies led by religious or political fanatics who attempted to impose agreement, failed - without exception. The success of the pluralistic nations tell us that diversity of views, faiths and styles of living and thinking are good for everyone.
Smolin's answer to the problem of conflict between different cultures in a pluralistic society is that "when reason applied to the publicly-available evidence does not suffice...we must agree to disagree. Clearly, disagreements about religious faith are not in the domain that can be answered [with the application of reason to publicly-available evidence], so here we must allow and even encourage a diversity of views."
Let me, however, pose the following question: if one of the cultures in a pluralistic liberal democracy rejects the principles of liberal democracy, and exercises a capability to engage in acts of violence to undermine that society, how should the liberal democracy respond? Should we merely 'agree to disagree' with such people? It would be labouring the obvious to suggest that this is no longer a hypothetical question, and that there exist Wahhabist, Islamo-fascist sub-cultures in European liberal democracies, which reject the principles of liberal democracy, which aspire to create a world-wide Islamic theocracy, and which have both the will and the capability to engage in acts of violence to further those ends.
Tolerating Islamo-fascism, seems unwise. I would suggest that the definition of multiculturalism needs to be qualified: all races, ethnicities, sexualities, religions, and cultures within a liberal democracy should be tolerated, but within the constraint that they agree with the fundamental principles of liberal democracy. Any sub-cultures which aim to undermine or destroy liberal democracy should not be tolerated.
Exactly what form such intolerance should take is one of the great issues of our time. Legislating against the teaching of Wahhabist beliefs in schools and mosques, and disrupting Saudia Arabian sponsorship of Wahhabism, are obvious options here.
The older notions of liberal democracy grew out of societies where everyone had the same background and history. Today, a citizen of the UK, Sweden, Canada, France or the US may have any ethnic origin, any appearance, and practice any religion – or none. Diversity is increasingly becoming the norm, as unprecedented mobility delivers a planetary society.
But as we move around and mix, our differences move with us and, if anything, deepen as the number of philosophies, religions and life styles combine and multiply in unexpected ways. The challenge is how to have a diverse, multicultural society that is based on reason.
The answer is that we cannot expect to agree about everything. Nor should we: history has shown that a society in complete agreement is impossible, and societies led by religious or political fanatics who attempted to impose agreement, failed - without exception. The success of the pluralistic nations tell us that diversity of views, faiths and styles of living and thinking are good for everyone.
Smolin's answer to the problem of conflict between different cultures in a pluralistic society is that "when reason applied to the publicly-available evidence does not suffice...we must agree to disagree. Clearly, disagreements about religious faith are not in the domain that can be answered [with the application of reason to publicly-available evidence], so here we must allow and even encourage a diversity of views."
Let me, however, pose the following question: if one of the cultures in a pluralistic liberal democracy rejects the principles of liberal democracy, and exercises a capability to engage in acts of violence to undermine that society, how should the liberal democracy respond? Should we merely 'agree to disagree' with such people? It would be labouring the obvious to suggest that this is no longer a hypothetical question, and that there exist Wahhabist, Islamo-fascist sub-cultures in European liberal democracies, which reject the principles of liberal democracy, which aspire to create a world-wide Islamic theocracy, and which have both the will and the capability to engage in acts of violence to further those ends.
Tolerating Islamo-fascism, seems unwise. I would suggest that the definition of multiculturalism needs to be qualified: all races, ethnicities, sexualities, religions, and cultures within a liberal democracy should be tolerated, but within the constraint that they agree with the fundamental principles of liberal democracy. Any sub-cultures which aim to undermine or destroy liberal democracy should not be tolerated.
Exactly what form such intolerance should take is one of the great issues of our time. Legislating against the teaching of Wahhabist beliefs in schools and mosques, and disrupting Saudia Arabian sponsorship of Wahhabism, are obvious options here.
Thursday, July 24, 2008
Scientism
Scientism is the purported belief that science provides the only source of knowledge and understanding of the world, and the only source of value and meaning in life. Almost no-one holds this belief, and the vast majority of scientists would agree that in addition to science, there is ethics and morality, logic and mathematics, literature, and art in general. However, the development of science has progressively eroded the historical and cosmological claims which Christianity, Judaism and Islam were dependent upon, and when the combination of scientific belief and humanist morality further threatens religious dogma, the modern theist will often attempt to mis-represent scientific-humanist beliefs as 'scientistic'.
When, in 1616, the heliocentric Copernican worldview was declared to be heretical by the Catholic church, and when, in 1633, Galileo was convicted of heresy for advocating such a worldview, the Catholic church would, no doubt, have referred to the Copernican worldview as 'scientistic', if such a term had been available to them then. Heliocentrism contradicted scripture in numerous places, and such an attempt to remove man from his central position in the universe was clearly part of an attempt to extend science beyond its legitimate scope.
When a modern theist argues that science is not the only source of knowledge, the real intention is not to acknowledge the existence of ethics, philosophy and art, but to open the door to divine revelation, holy scripture, and other so-called 'spiritualities', as alternative sources of knowledge. In particular, the theist takes what is belief without evidence or reason, refers to it as 'faith', and suggests that faith offers an alternative source of knowledge, almost like a type of additional, parallel information channel to that provided by empirical, rational science. In reality, this is nothing more than an attempt to re-brand blind, ignorant belief and wishful thinking.
Another, closely allied, strategy employed by the modern theist is to argue that belief in science is itself a faith. Such claims depend upon an attempt to re-define the meaning of the term 'faith' so that a belief in anything becomes a faith. Correctly defined, as noted above, faith is belief without evidence or reason. In contrast, both scientific beliefs, and belief in the scientific method itself, are beliefs supported by reason and evidence. There is copious evidence for the success of the scientific method, and an understanding of Bayesian probability provides an understanding of why the scientific technique is so successful. Science, then, is clearly no faith.
The modern theist, wary of the success of science and humanism in Western society, is careful not to openly advocate their theism, but to construct first the paper-tiger of scientism, as an imaginary enemy, from which religion is then to provide sanctuary and salvation. On the contrary, a worldview which includes a moral system based upon rationality rather than religious decree, a scientific understanding of the physical world based upon reason and evidence, and a fully-rounded population, appreciative of the arts, philosophy and literature as well as science and technology, is the means by which the human race will be capable of progressing.
Scientism
When, in 1616, the heliocentric Copernican worldview was declared to be heretical by the Catholic church, and when, in 1633, Galileo was convicted of heresy for advocating such a worldview, the Catholic church would, no doubt, have referred to the Copernican worldview as 'scientistic', if such a term had been available to them then. Heliocentrism contradicted scripture in numerous places, and such an attempt to remove man from his central position in the universe was clearly part of an attempt to extend science beyond its legitimate scope.
When a modern theist argues that science is not the only source of knowledge, the real intention is not to acknowledge the existence of ethics, philosophy and art, but to open the door to divine revelation, holy scripture, and other so-called 'spiritualities', as alternative sources of knowledge. In particular, the theist takes what is belief without evidence or reason, refers to it as 'faith', and suggests that faith offers an alternative source of knowledge, almost like a type of additional, parallel information channel to that provided by empirical, rational science. In reality, this is nothing more than an attempt to re-brand blind, ignorant belief and wishful thinking.
Another, closely allied, strategy employed by the modern theist is to argue that belief in science is itself a faith. Such claims depend upon an attempt to re-define the meaning of the term 'faith' so that a belief in anything becomes a faith. Correctly defined, as noted above, faith is belief without evidence or reason. In contrast, both scientific beliefs, and belief in the scientific method itself, are beliefs supported by reason and evidence. There is copious evidence for the success of the scientific method, and an understanding of Bayesian probability provides an understanding of why the scientific technique is so successful. Science, then, is clearly no faith.
The modern theist, wary of the success of science and humanism in Western society, is careful not to openly advocate their theism, but to construct first the paper-tiger of scientism, as an imaginary enemy, from which religion is then to provide sanctuary and salvation. On the contrary, a worldview which includes a moral system based upon rationality rather than religious decree, a scientific understanding of the physical world based upon reason and evidence, and a fully-rounded population, appreciative of the arts, philosophy and literature as well as science and technology, is the means by which the human race will be capable of progressing.
Scientism
Monday, July 21, 2008
Doctor Who's assistants
The wonderful Richard Dawkins is back with a new TV series, Dawkins on Darwin, and, to celebrate this imminent broadcasting milestone, The Times went off for a chat with everyone's favourite atheist.
However, what intrigued me most in this article was Dawkins's wife, Lalla Ward:
Dawkins has a real-life connection with Doctor Who: he is married to Lalla Ward, who was previously the wife of Tom Baker, having played the role of his assistant, Romana, in the series in the Seventies. Dawkins met her at a birthday party in 1992 for the late Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy. Lalla floats in and out of Dawkins’s vast living room and kitchen in Oxford, smiling and bearing espressos in terracotta mugs.
Now, personally, I think it's a bit tasteless to hold a birthday party for someone who's dead, but I guess everything goes in the media world, and if it enables you to meet an ex-Doctor Who assistant who can float whilst carrying terracotta mugs, then that's the world for me. To this end, I attended Richard Whiteley's birthday party last night, and I'm happy to report that, as I write this, Billie Piper is gliding towards me with a cup of tea in a Liverpool FC mug, and a raisin-and-oatmeal cookie on a plate.
However, what intrigued me most in this article was Dawkins's wife, Lalla Ward:
Dawkins has a real-life connection with Doctor Who: he is married to Lalla Ward, who was previously the wife of Tom Baker, having played the role of his assistant, Romana, in the series in the Seventies. Dawkins met her at a birthday party in 1992 for the late Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy. Lalla floats in and out of Dawkins’s vast living room and kitchen in Oxford, smiling and bearing espressos in terracotta mugs.
Now, personally, I think it's a bit tasteless to hold a birthday party for someone who's dead, but I guess everything goes in the media world, and if it enables you to meet an ex-Doctor Who assistant who can float whilst carrying terracotta mugs, then that's the world for me. To this end, I attended Richard Whiteley's birthday party last night, and I'm happy to report that, as I write this, Billie Piper is gliding towards me with a cup of tea in a Liverpool FC mug, and a raisin-and-oatmeal cookie on a plate.
Saturday, July 19, 2008
Music festivals
Holy crap.
It's the Glade Electronic Dance Music Festival this weekend. Sadly, the weather has cleared up, and all I can hear, and feel, is:
thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump
Most of the people at music festivals these days seem to be twenty-somethings and thirty-somethings, trying to pretend they're still students. Listen, you're not a student anymore, you've got a boring job, a car, a mortgage, and a pension; spending two days in a tent listening to shit music doesn't change any of the material facts about your life: you're not cool, you're part of the capitalist system, you're middle-class, you're not subverting anything, and you're not really 'roughing it'.
If I had my way, heat rays would piss the decks, and hundreds of tone-deaf imbeciles would flee in terror before my engines of destruction.
It's the Glade Electronic Dance Music Festival this weekend. Sadly, the weather has cleared up, and all I can hear, and feel, is:
thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump, thump
Most of the people at music festivals these days seem to be twenty-somethings and thirty-somethings, trying to pretend they're still students. Listen, you're not a student anymore, you've got a boring job, a car, a mortgage, and a pension; spending two days in a tent listening to shit music doesn't change any of the material facts about your life: you're not cool, you're part of the capitalist system, you're middle-class, you're not subverting anything, and you're not really 'roughing it'.
If I had my way, heat rays would piss the decks, and hundreds of tone-deaf imbeciles would flee in terror before my engines of destruction.
Religious and moral evil in the central 'scientific romances' of HG Wells
Bravely, Elberry has decided to publish a university essay he wrote on TS Eliot. This sent me down to the basement, past the various women I've kidnapped over the years, and into the labyrinthine recesses of my voluminous personal library. Here, between various dusty parchments and palimpsests, I uncovered my university English literature notes, and in particular the essay on HG Wells, submitted to Professor Parrinder, which forms the title of this blog.
It's rubbish, so I shall spare you all but an extract from the first page:
Whilst the Martians in the 'The War of the Worlds' are certainly portrayed as fearsome enemies, the narrator refrains from describing them as morally evil. In the opening pages, it is explained that the Martians launched their attack as part of the Darwinian struggle for existence. We learn that Mars is decaying, and it is asserted that the colonisation of another planet is their "only escape from the destruction that generation after generation creeps upon them." The Martians' strategy is interpreted as one of survival rather than aggrandisement.
The narrator warns that "before we judge of them [the Martians] too harshly, we must remember what ruthless and utter destruction our own species has wrought, not only upon animals...but upon its own inferior races." This attitude pervades the novel, the narrator repeatedly describing the relationship between Martians and humans as akin to the relationship between humans and animals. On various occasions, humanity is compared to lemurs, sheep, ants, bees, wasps, infusoria, and dodos. The implication is that if the Martians are morally evil, then so is humanity.
The narrator actually condemns humanity more strongly than he condemns the Martians. Mankind is described as "blinded by his vanity," complacently trusting in the security of human civilisation. The Martian invasion rids mankind of this attitude, and in this respect, is considered by the narrator to constitute a learning experience for mankind. An illustration of this is the protagonist's comment at the start of Chapter 7, (Book Two): "Surely, if we have learnt nothing else, this war has taught us to pity - pity for those witless souls that suffer our dominion."
Written at a time of strong, British colonial rule, it is significant that the novel depicts the population of England subjected to Imperialism. The implication is that, if the Martians are immoral, then so too are the British.
It's rubbish, so I shall spare you all but an extract from the first page:
Whilst the Martians in the 'The War of the Worlds' are certainly portrayed as fearsome enemies, the narrator refrains from describing them as morally evil. In the opening pages, it is explained that the Martians launched their attack as part of the Darwinian struggle for existence. We learn that Mars is decaying, and it is asserted that the colonisation of another planet is their "only escape from the destruction that generation after generation creeps upon them." The Martians' strategy is interpreted as one of survival rather than aggrandisement.
The narrator warns that "before we judge of them [the Martians] too harshly, we must remember what ruthless and utter destruction our own species has wrought, not only upon animals...but upon its own inferior races." This attitude pervades the novel, the narrator repeatedly describing the relationship between Martians and humans as akin to the relationship between humans and animals. On various occasions, humanity is compared to lemurs, sheep, ants, bees, wasps, infusoria, and dodos. The implication is that if the Martians are morally evil, then so is humanity.
The narrator actually condemns humanity more strongly than he condemns the Martians. Mankind is described as "blinded by his vanity," complacently trusting in the security of human civilisation. The Martian invasion rids mankind of this attitude, and in this respect, is considered by the narrator to constitute a learning experience for mankind. An illustration of this is the protagonist's comment at the start of Chapter 7, (Book Two): "Surely, if we have learnt nothing else, this war has taught us to pity - pity for those witless souls that suffer our dominion."
Written at a time of strong, British colonial rule, it is significant that the novel depicts the population of England subjected to Imperialism. The implication is that, if the Martians are immoral, then so too are the British.
Friday, July 18, 2008
Stars, radiation, DNA, and cancer
There are in the order of 100 billion (1011) stars in a typical spiral galaxy, such as our own Milky Way. Only about a thousand of these are visible to the naked eye at any one time, in the absence of light pollution. In contrast, there are in the order of 100 trillion cells (1014) cells in the human body. That's a thousand cells for every star in the Milky Way.
Within almost all of those 100 trillion cells is a nucleus which contains DNA. The DNA suffers various types of damage on a routine basis, and in fact, an estimated 2,000,000,000,000,000,000 DNA lesions occur per person, per day! Whilst there are copious DNA repair mechanisms within each cell to deal with this damage, they aren't 100% effective.
The most serious types of lesion are double-strand breaks. DNA is, famously, a double-helix, and when both helical strands are ripped asunder, this is referred to as a double-strand break. Double-strand breaks are capable of causing DNA mutation, and certain types of DNA mutation lead to the formation of cancer.
Whilst some of the DNA damage is caused by chemicals, radiation is also capable of causing DNA damage. Everyone on the Earth is subject to a background level of radiation, which averages about 2.4 milliSievert per annum. About 1 milliSievert of that is external radiation from X-rays and gamma rays. At 1 milliSievert of whole-body exposure, every cell nucleus in the human body is crossed by, on average, one X-ray/gamma-ray per year. This will cause, on average, 4 double-strand breaks per hundred cells, 15 DNA crosslink breaks per hundred cells, 100 single-strand breaks per hundred cells, and 250 damaged DNA base-molecules per hundred cells.
The most damaging type of radiation to biological material is ionising radiation. This is radiation which possesses sufficient energy to liberate the electrons from the host atoms or molecules in biological tissue. X-rays and gamma rays are ionising radiation, which deposit their energy indirectly in biological material. That is, they create secondary charged particles, typically electrons, which deposit their energy by means of the direct ionisation and excitation of the atoms and molecules in the biological medium.
An X-ray or gamma ray photon can liberate an electron by means of either:
(i) the photoelectric effect, in which a tightly bound inner electron is freed from its atom, and the photon is absorbed;
(ii) Compton scattering, in which the photon transfers some of its energy to free a loosely-held outer electron;
(iii) pair production, in which the photon interacts with the electrostatic field of an atomic nucleus, and is converted into an electron and a positron.
Once a secondary particle is created by this means, it can typically undergo millions of Coulomb force interactions with other atoms and molecules before it loses all its kinetic energy, exciting and ionising those atoms and molecules en route. A high-energy electron can sometimes also lose energy by bremsstrahlung X-ray production, if accelerated by a nearby atomic nucleus. This X-ray may, in turn, ionise other atoms, or may simply exit the biological medium. Within the trail of ionised atoms created by an electron, those atoms which have lost an electron from an inner shell may themselves emit fluorescent radiation, or may emit a cascade of low-energy Auger electrons.
There's a lot going on, then.
In addition to the complexity of the particle interactions, it is necessary to consider the complex levels of DNA structure within a cell nucleus. The DNA double helix is wound around spools of protein called histones. The spools are themselves linked together, and the DNA winds one and a half-times around each histone to form what's called a nucleosome. The nucleosomes are then wound into a spiral structure themselves, and this spiral forms loops attached to so-called protein scaffolding.
Whilst there is obviously an enormous amount of complexity here, I don't see much evidence of ambitious theoretical and mathematical programmes within the field of oncology. Too much research time and money is expended on trial-and-error experimentation. What we need is a decent theoretical model of all the structures and processes involved in the formation of cancer, and then we need a supercomputer simulation, or distributed computing simulation of these structures and processes. Without wishing to trivialise the difficulty involved, the field of oncology needs something comparable to the Millennium simulation in cosmology.
Within almost all of those 100 trillion cells is a nucleus which contains DNA. The DNA suffers various types of damage on a routine basis, and in fact, an estimated 2,000,000,000,000,000,000 DNA lesions occur per person, per day! Whilst there are copious DNA repair mechanisms within each cell to deal with this damage, they aren't 100% effective.
The most serious types of lesion are double-strand breaks. DNA is, famously, a double-helix, and when both helical strands are ripped asunder, this is referred to as a double-strand break. Double-strand breaks are capable of causing DNA mutation, and certain types of DNA mutation lead to the formation of cancer.
Whilst some of the DNA damage is caused by chemicals, radiation is also capable of causing DNA damage. Everyone on the Earth is subject to a background level of radiation, which averages about 2.4 milliSievert per annum. About 1 milliSievert of that is external radiation from X-rays and gamma rays. At 1 milliSievert of whole-body exposure, every cell nucleus in the human body is crossed by, on average, one X-ray/gamma-ray per year. This will cause, on average, 4 double-strand breaks per hundred cells, 15 DNA crosslink breaks per hundred cells, 100 single-strand breaks per hundred cells, and 250 damaged DNA base-molecules per hundred cells.
The most damaging type of radiation to biological material is ionising radiation. This is radiation which possesses sufficient energy to liberate the electrons from the host atoms or molecules in biological tissue. X-rays and gamma rays are ionising radiation, which deposit their energy indirectly in biological material. That is, they create secondary charged particles, typically electrons, which deposit their energy by means of the direct ionisation and excitation of the atoms and molecules in the biological medium.
An X-ray or gamma ray photon can liberate an electron by means of either:
(i) the photoelectric effect, in which a tightly bound inner electron is freed from its atom, and the photon is absorbed;
(ii) Compton scattering, in which the photon transfers some of its energy to free a loosely-held outer electron;
(iii) pair production, in which the photon interacts with the electrostatic field of an atomic nucleus, and is converted into an electron and a positron.
Once a secondary particle is created by this means, it can typically undergo millions of Coulomb force interactions with other atoms and molecules before it loses all its kinetic energy, exciting and ionising those atoms and molecules en route. A high-energy electron can sometimes also lose energy by bremsstrahlung X-ray production, if accelerated by a nearby atomic nucleus. This X-ray may, in turn, ionise other atoms, or may simply exit the biological medium. Within the trail of ionised atoms created by an electron, those atoms which have lost an electron from an inner shell may themselves emit fluorescent radiation, or may emit a cascade of low-energy Auger electrons.
There's a lot going on, then.
In addition to the complexity of the particle interactions, it is necessary to consider the complex levels of DNA structure within a cell nucleus. The DNA double helix is wound around spools of protein called histones. The spools are themselves linked together, and the DNA winds one and a half-times around each histone to form what's called a nucleosome. The nucleosomes are then wound into a spiral structure themselves, and this spiral forms loops attached to so-called protein scaffolding.
Whilst there is obviously an enormous amount of complexity here, I don't see much evidence of ambitious theoretical and mathematical programmes within the field of oncology. Too much research time and money is expended on trial-and-error experimentation. What we need is a decent theoretical model of all the structures and processes involved in the formation of cancer, and then we need a supercomputer simulation, or distributed computing simulation of these structures and processes. Without wishing to trivialise the difficulty involved, the field of oncology needs something comparable to the Millennium simulation in cosmology.
Wednesday, July 16, 2008
Lauren
Friday, July 11, 2008
Tea-bagging
The wonderfully urbane and erudite Dr Karl continues to facilitate the uncovering of some delightful scientific miscellany on his Radio 5 phone-in. A listener called last week to ask why it is that, when you pour boiling water onto a tea-bag already placed in the cup, the tea-bag will inflate, and rise buoyantly with the water, to the top of the cup, whilst if you fill the cup with boiling water first, and then place the tea-bag into the cup, the tea-bag will generally sink beneath the surface of the water. (Try it!)
Whilst Dr Karl was bereft of an answer on this occasion, another listener reported this week that if you re-boil a kettle of water, and repeat the experiment with the tea-bag already in the cup, then the tea-bag will not inflate under these conditions. The explanation inferred from this is that the tea-bag is inflated on the first occasion by oxygen dissolved in the water; when the experiment is repeated, there is no longer a sufficient amount of dissolved oxygen in the water.
So, I exhort you all to re-fill your kettles to avoid the disappointment of a non-inflating tea-bag. Also, as ever, please refrain from drinking coffee at all times.
Whilst Dr Karl was bereft of an answer on this occasion, another listener reported this week that if you re-boil a kettle of water, and repeat the experiment with the tea-bag already in the cup, then the tea-bag will not inflate under these conditions. The explanation inferred from this is that the tea-bag is inflated on the first occasion by oxygen dissolved in the water; when the experiment is repeated, there is no longer a sufficient amount of dissolved oxygen in the water.
So, I exhort you all to re-fill your kettles to avoid the disappointment of a non-inflating tea-bag. Also, as ever, please refrain from drinking coffee at all times.
Tuesday, July 08, 2008
The Dark Ages
The Dark Ages is the period of cosmic history in which there was no visible light in the universe. When the universe was about 380,000 years old, the temperature dropped to about 3,000K, electrons combined with protons to form neutral hydrogen atoms, and the radiation which had previously been scattered by the free electrons, was able to travel freely through space. The universe therefore became transparent to the passage of radiation, and this radiation was distributed over visible and infrared wavelengths. However, as the universe expanded, the radiation was rapidly redshifted to longer wavelengths beyond the visible range, (to ultimately become the cosmic microwave background radiation we detect today), and the universe became completely dark for many millions of years. These are the cosmic Dark Ages.
The Dark Ages lasted until the first stars, galaxies and quasars were created. Until recently, it was estimated that this didn't occur until the universe was 1 billion years old. Recent data from the WMAP satellite in 2003, however, suggests that the Dark Ages ended when the universe was somewhere between 100 million and 400 million years old.
The Dark Ages, or Early Middle Ages, is the period of human history between approximately AD 600 and 1000, when the classical pagan culture of Greek, Hellenistic and Roman civilisation was succeeded in Western Europe by a period of economic and intellectual stagnation.
After the Roman Empire was converted to Christianity, it fell into decline, and the Western Roman Empire was overcome by the pagan barbarians.
In 'Ideas: A History from Fire to Freud', Peter Watson writes that "in early antiquity religious toleration had been the rule rather than the exception, but that changed with the animosity with which the pagans and Christians regarded one another. We should not overlook the change that had come about in men's attitudes with the arrival of Christianity as a state religion. There was an overwhelming desire to 'surrender to the new divine powers which bound men inwardly' and 'a need for' suprahuman revelation. As a result, the thinkers of the period were not much interested in (or were discouraged from) unravelling the secrets of the physical world: 'The supreme task of Christian scholarship was to apprehend and deepen the truths of revelation.' Whereas paganism had imposed few restrictions on the intellectuals of Rome, Christianity actively rejected scientific enquiry. The scientific study of the heavens could be neglected, said Ambrose, bishop of Milan...'for wherein does it assist our salvation?'"
Between Boethius (AD c.480-524) and Anselm in the 11th century, there was only one significant thinker, Erigena in Ireland. Books and learning fell into an almost terminal decline in Western Europe, and it was the Islamic world which preserved much of the classical culture. In particular, the works of Aristotle, most of which were totally lost in Europe, were preserved by the Arabs, and only re-introduced to Europe in the 13th century.
The Dark Ages lasted until the first stars, galaxies and quasars were created. Until recently, it was estimated that this didn't occur until the universe was 1 billion years old. Recent data from the WMAP satellite in 2003, however, suggests that the Dark Ages ended when the universe was somewhere between 100 million and 400 million years old.
The Dark Ages, or Early Middle Ages, is the period of human history between approximately AD 600 and 1000, when the classical pagan culture of Greek, Hellenistic and Roman civilisation was succeeded in Western Europe by a period of economic and intellectual stagnation.
After the Roman Empire was converted to Christianity, it fell into decline, and the Western Roman Empire was overcome by the pagan barbarians.
In 'Ideas: A History from Fire to Freud', Peter Watson writes that "in early antiquity religious toleration had been the rule rather than the exception, but that changed with the animosity with which the pagans and Christians regarded one another. We should not overlook the change that had come about in men's attitudes with the arrival of Christianity as a state religion. There was an overwhelming desire to 'surrender to the new divine powers which bound men inwardly' and 'a need for' suprahuman revelation. As a result, the thinkers of the period were not much interested in (or were discouraged from) unravelling the secrets of the physical world: 'The supreme task of Christian scholarship was to apprehend and deepen the truths of revelation.' Whereas paganism had imposed few restrictions on the intellectuals of Rome, Christianity actively rejected scientific enquiry. The scientific study of the heavens could be neglected, said Ambrose, bishop of Milan...'for wherein does it assist our salvation?'"
Between Boethius (AD c.480-524) and Anselm in the 11th century, there was only one significant thinker, Erigena in Ireland. Books and learning fell into an almost terminal decline in Western Europe, and it was the Islamic world which preserved much of the classical culture. In particular, the works of Aristotle, most of which were totally lost in Europe, were preserved by the Arabs, and only re-introduced to Europe in the 13th century.
Sunday, July 06, 2008
A British Grand Prix at Donington?
"I offered the BRDC the opportunity to renew their contract, but they felt they were not in a position to do so," said Bernie Ecclestone. "The British Grand Prix has been saved. If we had not done the deal...these people would not have agreed, and the British Grand Prix would have gone."
This, you might think, was Bernie speaking on Friday, as he announced that a new deal had been signed with Donington to host the British Grand Prix from 2010. If so, then you would be wrong, because this was Bernie speaking in the Spring of 1999, after announcing that a new deal had been signed with Brands Hatch to host the British Grand Prix from 2002.
The owners of Brands Hatch gave assurances that they had the finance and planning permission to complete the extensive construction work necessary to bring Brands Hatch up to Formula 1 standards. "There is no problem there," said Nicola Foulston, then CEO of Brands Hatch Leisure. "We have planning permission as a motor racing circuit and all we would be doing is precisely that. There is no change of use involved."
As it transpired, Brands Hatch didn't obtain the necessary planning permission. In possession of a contract which entitled them to host a Grand Prix, Brands Hatch Leisure were sold to a subsidiary of the US Interpublic Group in January of 2000, and Nicola Foulston departed, having pocketed $40 million. The US Interpublic Group then slowly discovered what is a well-known fact about the modern sport:
Hosting a Grand Prix is not a profit-making activity.
Bernie takes the revenue from the television rights and corporate hospitality, and charges each circuit a so-called 'sanctioning fee' for the right to host a Grand Prix. Back in 1999, the cost of hosting the British Grand Prix from 2002 onwards was £8 million a year initially, with 10% compound interest. One trusts it is no cheaper today. Making a profit from gate receipts alone is therefore a task which challenges most Grand Prix promoters. In fact, most Grands Prix around the world make a loss, and the races are generally subsidised by local and national governments. A Grand Prix is, in effect, an extremely effective advert for countries such as Malaysia, Bahrain, China and Abu Dhabi; a place in the Formula 1 World Championship calendar says 'We're a modern, commercial economy: invest and trade with us.'
Back in 2001, the Interpublic Group found that, not only did they have to pay Bernie's sanctioning fee, but because Brands Hatch was incapable of hosting the race, they also had to pay Silverstone $12 million a year to actually host the race on their behalf.
Donington, however, claim that they will invest £100 million over five years. They would certainly need to, because the Donington track does not meet current Formula 1 safety criteria, and the pits, paddock, media and corporate facilities also do not meet current Formula 1 standards. Given the difficulty of making a profit from hosting a Grand Prix, it is difficult to see where the money for this would come from. According to the statement issued by Donington on Friday, "funding for the massive redevelopment would be led by a private investor who is also a large shareholder in the company." According to a televised interview with joint Donington CEO Simon Gillett today, the money will be 'venture capital'.
If they can raise this money from gullible investors who fail to do due diligence, then good luck to them. But at the moment, all Donington have demonstrated is that they possess a contract to hold the British Grand Prix. That contract has a value, and it may be necessary for some other party to buy the contract from Donington (and Bernie), at a future date. The only thing which is guaranteed, is that Bernie will come out of it a winner.
This, you might think, was Bernie speaking on Friday, as he announced that a new deal had been signed with Donington to host the British Grand Prix from 2010. If so, then you would be wrong, because this was Bernie speaking in the Spring of 1999, after announcing that a new deal had been signed with Brands Hatch to host the British Grand Prix from 2002.
The owners of Brands Hatch gave assurances that they had the finance and planning permission to complete the extensive construction work necessary to bring Brands Hatch up to Formula 1 standards. "There is no problem there," said Nicola Foulston, then CEO of Brands Hatch Leisure. "We have planning permission as a motor racing circuit and all we would be doing is precisely that. There is no change of use involved."
As it transpired, Brands Hatch didn't obtain the necessary planning permission. In possession of a contract which entitled them to host a Grand Prix, Brands Hatch Leisure were sold to a subsidiary of the US Interpublic Group in January of 2000, and Nicola Foulston departed, having pocketed $40 million. The US Interpublic Group then slowly discovered what is a well-known fact about the modern sport:
Hosting a Grand Prix is not a profit-making activity.
Bernie takes the revenue from the television rights and corporate hospitality, and charges each circuit a so-called 'sanctioning fee' for the right to host a Grand Prix. Back in 1999, the cost of hosting the British Grand Prix from 2002 onwards was £8 million a year initially, with 10% compound interest. One trusts it is no cheaper today. Making a profit from gate receipts alone is therefore a task which challenges most Grand Prix promoters. In fact, most Grands Prix around the world make a loss, and the races are generally subsidised by local and national governments. A Grand Prix is, in effect, an extremely effective advert for countries such as Malaysia, Bahrain, China and Abu Dhabi; a place in the Formula 1 World Championship calendar says 'We're a modern, commercial economy: invest and trade with us.'
Back in 2001, the Interpublic Group found that, not only did they have to pay Bernie's sanctioning fee, but because Brands Hatch was incapable of hosting the race, they also had to pay Silverstone $12 million a year to actually host the race on their behalf.
Donington, however, claim that they will invest £100 million over five years. They would certainly need to, because the Donington track does not meet current Formula 1 safety criteria, and the pits, paddock, media and corporate facilities also do not meet current Formula 1 standards. Given the difficulty of making a profit from hosting a Grand Prix, it is difficult to see where the money for this would come from. According to the statement issued by Donington on Friday, "funding for the massive redevelopment would be led by a private investor who is also a large shareholder in the company." According to a televised interview with joint Donington CEO Simon Gillett today, the money will be 'venture capital'.
If they can raise this money from gullible investors who fail to do due diligence, then good luck to them. But at the moment, all Donington have demonstrated is that they possess a contract to hold the British Grand Prix. That contract has a value, and it may be necessary for some other party to buy the contract from Donington (and Bernie), at a future date. The only thing which is guaranteed, is that Bernie will come out of it a winner.
Tuesday, July 01, 2008
A solution to the world's energy problems
A couple of weeks ago, 'British engineers' proposed that underfloor generators, installed in shopping centres and transport hubs, could provide a significant source of power. The idea is that the footfall of pedestrians can be used to compress pads, which force fluid through mini-turbines, thereby generating electricity.
A fantastic idea. But that's still thinking on a small scale. I propose that we carpet millions of square miles of workplaces, shopping centres, airports, railway stations, and pavements across the world. Specifically, we need nylon carpets. As people walk on these carpets, they will build up a huge static electric charge. They can then discharge this energy into supercapacitors installed in their personal automobiles, and use that electrical power to drive home in the evening.
Problem solved.
A fantastic idea. But that's still thinking on a small scale. I propose that we carpet millions of square miles of workplaces, shopping centres, airports, railway stations, and pavements across the world. Specifically, we need nylon carpets. As people walk on these carpets, they will build up a huge static electric charge. They can then discharge this energy into supercapacitors installed in their personal automobiles, and use that electrical power to drive home in the evening.
Problem solved.