Due gravity
According to Michael Brooks, we don’t know what gravity is (13 June, p 28). However, in 1992 I proposed a theory to explain its origin (). Gravity is the result of the quantum interaction of matter with the surrounding vacuum, which in turn interacts with the vacuum at different locations.
A refinement of this theory was published in 2007 (). In this theory, no virtual particles are needed, unlike the “gravitons” postulated in other theories. It explains the Pioneer anomaly, flat galaxy rotation curves and why gravity only pulls.
On the question of whether we will ever have a quantum theory of gravity, I can only answer that we have it already. All we need to do is master the calculation of myriads of vacuum-vacuum interactions occurring in parallel. We do not have the mathematical tools or computing power at present to perform this task, but at least we have the general framework.
Brooks asks whether life needs gravity, then goes on to argue that much of the life on Earth does appear to. That is hardly surprising, given that life on Earth has evolved in an environment with gravity. It would be interesting to discuss whether life in general needs gravity to get going and evolve.
Carnforth, Lancashire, UK
Remote viewing
I found Richard Wiseman’s Twitter experiment to determine whether remote viewing 鈥� the psychic ability to “see” distant locations 鈥� was real (13 June, p 23) and its attendant findings (13 June, p 6) very interesting.
“Blind guesswork” screamed the header showing pie charts of the findings. Yet the roughly chance findings are pretty much what one might expect, especially given Wiseman’s self-confessed bias against the ability.
My questions are: how many people guessed Wiseman’s location correctly, and is this number expected by chance alone? It would be interesting, and necessary before dismissing the whole concept of remote viewing, to select out such people and test them more thoroughly than Wiseman did. If this was done, we need to see the results.
Furthermore, the studies into remote viewing by the US government involved intense training of carefully selected participants. These people did indeed appear to have some remote viewing abilities.
Richard Wiseman writes:
鈥� It was impossible to analyse the statistics for each individual because of the way the experiment was run. Valid statistics could only be derived for the group as a whole. However, re-testing of individuals that scored highly would be interesting.
Scientific economics
It amuses me that in Mark Buchanan’s article “Can science fix economics?” it is suggested that “it should be possible within a decade to have functioning models of the global economy to which policy-makers could look for sound insights” (6 June, p 35). For those of us with long memories, this is just what was said when models of the economy first began to appear in the 1960s and 1970s.
Such assertions help to generate funding, but they also make the cardinal error of conflating understanding, prediction and management.
The only sense in which the statement is true is that it might reduce policy-makers to impotence, but they are not likely to draw that conclusion themselves. Paul Ormerod and Craig Mounfield have used the physics tool of random matrix theory to show that much of the economic variability we observe contains noise and not true information ().
The analysis of such data is not capable of generating robust forecasts, let alone the kinds of policy levers which enable us to predict their effects. More complex or complicated models will not remove this fact.
One reason why modern economics is such a “dismal science” is that it has failed to question its underlying assumptions (6 June, p 35).
Can physicists, engineers and biologists work out why financial dealings in money and property are more profitable than the capital and labour that supply goods and services? Why do we allow speculative buying and selling to make the share market as changeable as the weather, rather than sticking to its original purpose of facilitating investment? Psychologists such as Stephen Lea and Peter Cooper are challenging assumptions about human behaviour by describing how our “disastrous heuristics” have contributed to the present financial crisis.
George Akerlof and Robert Shiller’s recent book Animal Spirits: How human psychology drives the economy, and why it matters for global capitalism may help scientists to model a more stable economy, rather than accept what markets have become and try to tinker with them.
Mount Waverley, Victoria, Australia
In his review of the book Newton and the Counterfeiter, Richard Webb talks of England’s currency in 1696 being “debased by counterfeiters and the ‘clippers’ who shave silver from its poorly minted coins” (23 May, p 42). That sounds familiar.
Modern currencies are seriously debased, worth roughly 10 per cent of their value 40 years ago. The difference is that the “clippers” are now governments who tax the inflation component of interest on savings as if it were real income.
It’s about time that mathematically skilled scientists followed Newton’s example and contributed to the present economic debate. The views of eminent scientists on how they would restore trust in today’s currencies, as Newton did over 300 years ago, would be illuminating.
One might begin by asking them if they, like US Federal Reserve’s Donald Kohn and Ben Bernanke, support 2 per cent inflation over the long term, which effectively halves the value of the currency every 35 years.
Carine, Western Australia
Train gain
Your article “Trains recast as climate baddies” discusses the relative emissions of different modes of transport (13 June, p 7). I note with interest that, per kilometre, train travel has a similar carbon dioxide output per passenger to air travel, when manufacture, infrastructure and maintenance are considered.
However, while the study is presented as a holistic assessment of transport methods, it only considers passenger travel. If cargo transport is included, then rail will probably regain its advantage.
Trials of woman
You state in your article “Trial inequality” that women are under-represented in clinical trials of cancer drugs, yet do not give any explanation as to why (13 June, p 7). Rather than being due to sexism, this under-representation arises because it is imperative that women don’t become pregnant when testing new drugs and risk harming the developing fetus.
For this reason, most clinical trials exclude pregnant and breastfeeding women, and all participants must agree to use adequate forms of contraception during the trial and for a period after it ends. In addition, women of child-bearing age are usually excluded completely from trials involving drugs that have been found to affect embryo development. As cancer drugs often fall into this category, these necessary restrictions mean that far fewer women than men are eligible to take part in clinical trials. Thalidomide, which is now being used as a treatment for some cancers, is the obvious example of why such stringent criteria are required.
Antimatters
Perry Bebbington’s idea of an antimatter universe, receding in time from the big bang (6 June, p 27) goes back at least to J. Richard Gott’s 1974 paper in The Astrophysical Journal ().
More recently, John Gribbin ascribed the idea to Victor Stenger while reviewing his book The Comprehensible Cosmos ().
Praise bee
In his report on animal species that appear to have numeracy skills (20 June, p 37), Ewen Calloway says: “The ability to count may date back to even more primitive organisms than fish,” citing bees as an example.
Bees more primitive than fish? Not at all. Bees evolved more recently than fish by about 400 million years. Their social and working lives are more complex than those of fish, and they are known to communicate information about direction and distance by sign language. What fish can do that?
Useless ID
Not only patients whose fingerprints have been degraded by the cancer drug capecitabine are embarrassed by US immigration procedures (30 May, p 5). Playing jazz bass degrades one’s fingerprints to the point of unreadability, in my experience.
Despite Anil Jain’s assertion in the same article, the nuisance of border delays is not “the price you’re paying for security”. These measures would have been useless against high-profile terrorist attacks, such as those in Omagh, New York and Madrid 鈥� they were perpetrated by natives or legitimate residents of the countries concerned.
For the record
鈥� Our article on the role of science in the verification of nuclear weapons failed to make it clear that North Korea left the 1968 Nuclear Non-Proliferation Treaty in 2006 and tested a bomb at that time, as well as in May this year (27 June, p 8).
鈥� Far from suggesting that mathematics proves that black holes do not exist, Max Wallis conceives that Einstein’s 1939 solution to the radially symmetric field equations indicates an alternative description of the collapsed object at the centre of our galaxy (20 June, p 24). Our apologies for the editing error that led to his views being misrepresented.