Monthly Archives: February 2010

And out of iniquity came forth goodness

Politics & Society

Founders of British obstetrics ‘were callous murderers’ and The incredible story of the most important woman in the history of modern medicine. The research on which the first article is based presents circumstantial evidence that the pioneers of obstetrics, Hunter and Smellie between 1749 and 1774 procured the death of women (probably rural girls who had come to the city and could disappear without questions) in various stages pregnancy in order to study the details of the anatomy of the process. The second article is about cervical cancer cells taken from a slave descended woman in 1951 at the Johns Hopkins Hospital in Baltimore. The woman died but these cells have been propagated for research ever since as they propagated aggressively in culture, with an estimated mass of cells to date of millions of tonnes. Neither she nor her children have had any benefit from this use, but commercial companies have enjoyed large incomes and the cells have been invaluable in helping develop treatments.

These histories bring to mind the Christian hymn, God moves in a mysterious way, written by William Cowper who wrote an anti slavery poem, The Negro’s complaint, and was a friend of John Newton at one time a slave ship commander (after spending time as a slave himself) who wrote Amazing Grace and who presided at the funeral of William Cowper. The tortuous sentence is meant to match the tortuous history.

Scientists as mere humans

Climate Change, Politics & Society, Science & Mathematics

Having read many biographies of scientists and mathematicians, after my school and university days uncritical admiration of scientists, I know they are a mixed lot of personality types like any other grouping of people. From Galileo to Newton to Einstein one finds behaviour that is not always admirable. Newton was especially ruthless in trying to eliminate rivals; the comment about standing on the shoulders of giants (in a letter to Robert Hooke) that is often used to show his humility was also a put-down for Robert Hooke who was a person of small stature. Newton is thought to have destroyed the painting of Hooke at the Royal Society. Etc.

The revelations about scientists studying climate change is therefore no surprise to me: Climate scientists shut out sceptics by turning down data requests. See Simon Jenkins in full swing too: Scientists, you are fallible.

But Newton and others did have deep insights that have proved true (rather partially true in the way that all science is) inspite of their personality failings. So just as some sports people have unorthodox personal lives but play amazing games, let us not throw out the science when focussing on the personality frailities of scientists.

I agree with Simon Jenkins that the humanities are being seen as mere entertainment value yet they are also vital to our survival.  The human natures that we can explore though literature and history are neglected to our detriment: the wars in Afghanistan and Iraq showed a profound lack of historical perspective. Here is sad news that another world-view has been lost; that which comes with each of the world’s different languages: Ancient tribal language becomes extinct as last speaker dies.

Fear not radiation

Books, Science & Mathematics

Radiation and Reason, Wade Allison, 2009

In summary this book presents evidence to show that there is no known harm to us for radiation levels that do not exceed 100 millisieverts per month, with a cautious life-time limit (for now, maybe it could be higher) of 5,000 millisieverts. The International Commission for Radiological Protection limit is 1 millisievert per year so the argument is that this is about 1000 times too restrictive.

The Sievert is an attempt to give a unit to effects of radiation in living tissue. Although other units have to be used in particular situations for precision, the book is not concerned with fine detail and everything is assessed via the millisievert.

Cornwall in the UK has background radiation at 8 millisieverts per year, and that is as high as anywhere in the country. Cancer radiation treatment is 1000 to 10,000 millisieverts in a session, though this is meant to be targeted on the tumour with geometry to minimize radiation in healthy tissue. Numbers such as these present the arena for the discussions in the book.

The aim of the presentation is to suggest that safety limits could be relaxed a thousand fold, thereby making fission nuclear power stations cheaper; they must be structurally robust with multiple fail-safe mechanisms, but they do not need to be so radiologically protective. Especially decommissioning should be much easier and cheaper and not the huge bogeyman that it is currently made to be.

Prof Allison is not doing this to win favour with the nuclear industry but because, like me and others, he is concerned for the human future because of global warming. We have to take a balanced view of risks.

There are good simple discussions of radioactive decay, atomic weapons and nuclear power reactors, and the biological effects of radiation. Even so the book is not for the innumerate or those lacking any scientific background. I would hope that it might be read by policy makers and their advisors. I notice that he is the publisher of the book so I hope he has persuaded the publisher to send a few copies to UK MPs and European MEPs.

The most pertinent discussion is on biological effects of radiation. He points out that the no-safe-dose idea is totally wrong – there is a threshold at which irreversible damage occurs and below that cell repair mechanisms deal with any damage. In fact in morbidity studies people with exposure to radiation lower than the limit he suggests seem to live longer: a little radiation may be a good thing. He makes a good analogy with sunbathing (page 34): too much sun bathing causes damage to skin and sometimes skin cancer, but too little exposure leads to lack of Vitamin D. The demolition of the Linear No-Threshold and Collective Dose models is excellent. There is analysis of Japanese survivors of the atomic bombs of 1945 with the amazing statistic that those who survived to 1950 had only a 4 in 1000 chance of dying of radiation induced cancer.

There is an excellent contrast made between current fossil fuels and nuclear fuel. Fossil fuels put CO2 into the air where it dilutes and distributes globally as well as toxic substances that are then buried but never lose their toxicity. The nuclear waste from a power station after reprocessing is much smaller in volume by a factor of about a million, and any radiation dangers decrease with time; these are volumes we can cope with.

Although he does not point it out explicitly, when people mention long half-life they often miss that this means low activity, the high activity nuclear products have short half-life (maybe years) so if we wait a reasonable time they make themselves safe. 

Page 108 has a table of deaths from various disasters in which the Chernobyl and Three Mile Island reactor accidents are at the low end counting for about 50 and zero deaths. My own favourite comparison (not in this table) is with traffic accident deaths that are in the range 40,000 to 50,000 per year in the EU: a Hiroshima and Nagasaki every two years.

There is a good discussion of the differences between nuclear refinement for power stations versus weapons, though this may not be as easy a political issue as the discussion suggests. Compare Nuclear arms will soon proliferate. So here’s a plan to scrap them all.

I found the suggestion on page 159 that people should be given devices to enable them to ‘see’ radiation levels a bit naive as I suspect that interpretation of what we have not evolved to see takes expertise. Just consider how people are assessing their sense of global warming from experience. I think that better general science education is the key.

I have never myself had a problem with the technology of nuclear power, but I thought that the costs probably made it non-viable. This book attempts to address the cost issue but we need some new careful estimates of costs given the proposed relaxation of safety limits that the book does not provide. David Mackay, Sustainable Energy – without the hot air, provides some rough guides for this.

I await a review of the book by someone with expertise in radiobiology to see what weakness there is in the argument.

Finally I agree totally with the comments on page 194 about specialization. Although each of us may have some specialty we need to have the big picture of how the specialties connect up and be able to see where we are being led.

My minor quibbles:
That the bombs dropped on Hiroshima and Nagasaki were a military and political success (page 5) I think is still debateable. I think the statement was meant to contrast with the lasting suspicion of nuclear power he mentions ever after those events but feels a bit gung-ho.

For anyone who cannot work it out for themselves the graph on page 121 comparing chronic and repeated doses of radiation would not help. I found it confusing at first.

Another odd slip for an otherwise good simple description of the physics of fusion and fission is on page 134 where it says that the neutron being uncharged can enter straight through the coulomb barrier: rather, for the uncharged neutron, there is no coulomb barrier.

On page 133 there is a dismissive footnote on cold fusion that says “predictably, its hopes have not been realised.” I admit that when I first heard about it 1989 I felt it impossible that it could work; now I am not so sure and I certainly don’t think it is predictable that it does not. The footnote just above this one mentions quantum tunnelling so there is clearly a non-zero probability that cold fusion will happen, a minute probability in free space but maybe much greater in some material lattice. I still think it unlikely, but I would not want to be totally dismissive.

Trust evolution

Science & Mathematics

It seems that not wearing running shoes is best for the foot when running: The Barefoot Professor. Bare-foot runners do not land on the heel but on the more flexible (and therefore shock-absorbing) forefoot: the pad under the distal metatarsal joints. I found this presentation fascinating for two reasons. First I had an interest in foot biomechanics some years ago that started with a marathon runner. The ‘heel strike’ mentioned in the video has a resonance for runners because the impact pulse really does travel up the spine. The problem not mentioned is sharp debris that might be in one’s path. The bigger message for me was that this ‘back to basics’ must be a useful starting point in checking any solutions we develop to improve on what evolution has already provided for us. Having developed a shoe, it seemed that the obvious route was to improve it for running rather than to improve on no-shoe for running.

On the matter of foot cuts and infections from running barefoot a distant memory surfaced. My English teacher at school, Mr Oswald Alan Thorpe, had been with the British Army in Europe in WWII. Among his many stories (this was less than 10 years after the end of the war) he mentioned how he used to walk barefoot as much as possible so that the soles of his feet became ‘as tough as old leather’. So after a few weeks of running barefoot you won’t have a problem if you watch out for larger debris as you go.