Malevolent Medea
The research cited in Peter Ward’s article (20 June, p 28) may challenge James Lovelock’s Gaia hypothesis, that the Earth is a self-regulating superorganism, but it falls a long way short of a refutation.
When Lovelock posits feedback mechanisms that keep Earth fit for life, he does not mean fit for any particular form of life or level of biodiversity. Gaia’s job is to keep some kind of biosphere going, ruthlessly sacrificing any number of species and ecosystems to serve that aim.
From a Gaian point of view, the most significant thing about Ward’s catalogue of planetary crises is that at no point did Earth become uninhabitable. The fluctuations in the climate and chemistry always remained within the bounds that allow life to continue. This is surely what Gaian theory sets out to explain.
Peter Ward’s idea that life is self-destructive rather than nurturing 鈥� which he anthropomorphises as the mythical character Medea who killed her own children 鈥� echoes the dualistic beliefs of the Cathars of medieval France.
The Cathars held that the material world was the creation of an evil god, Rex Mundi, who acted through matter and was the embodiment of power and chaos. The twin of Rex Mundi was a spiritual god who embodied order, peace and beauty. The role of humanity in this system was to redeem the material world.
The second law of thermodynamics tells us that the universe is descending to a state of maximum disorder. The objective of science is to understand the material world by the application of the scientific method: bringing order out of chaos. As science is a collection of ideas, and therefore not material, scientists could be seen as fulfilling the role of humanity as envisaged by the Cathars.
Were the Cathars on the right track with their ideas about the nature of the material world? I have always regarded life as a parasite on the second law that accelerates the descent into chaos.
Politicians seem to regard Gaia as a friend who would see to it that humanity will not be destroyed by its own depredations. Has it not occurred to them that saving the Earth may be best achieved by the disappearance of humanity? They might benefit from an acquaintance with Medea.
Rocket science
The anniversary of the moon landing is an appropriate time to note the changing technologies involved. In particular, the moon landing would not have been possible had it not been for the analogue computer.
I worked for Electronic Associates, which made these computers for NASA. They performed calculations using physical variables such as voltage; even the best digital computers of the day were too slow to calculate the parameters needed to ensure that the craft would complete its mission safely.
Analogue computers perform arithmetic operations using large numbers of operational amplifiers, which modify the voltage of the electronic signal inputs. Operating in parallel, they can solve differential equations at very high speed. Coupled to the fastest digital computers of their day, they performed these calculations over and over again until they found the best solutions.
The equations were in this case mainly simultaneous partial differential equations in four variables 鈥� three space dimensions and time 鈥� no mean feat for an early computer.
Home grid
Larry Curley complains that UK law requires small domestic wind turbines to shut down in the event of a mains electricity failure (6 June, p 27).
There is actually a good reason for this. If a turbine remains connected to the mains supply during a power cut, it tries to send power into the system. This, of course, is far too much of a load for it to supply so it short circuits. Even if there is an automatic switch to disconnect your household system from the mains supply, your own loads will probably still be more than the turbine can supply.
It is possible to arrange a more sophisticated system, getting the turbine to charge a battery and then converting the battery output to alternating current. This output can either be permanently separate from the mains, or have an isolator switch that disconnects it from the mains in the event of mains failure.
The whole system will continue to run even in the absence of mains power, as long as your loads are not too great for the system.
Such a system is perfectly legal, but of course considerably more expensive than the simplesystem that shuts down when the mains goes down.
Timely action
Having been diagnosed with attention-deficit hyperactivity disorder (ADHD) in middle age, I was fascinated by the article on altered time perception in children with the condition (6 June, p 12).
My time perception is faulty to the extent that it is almost non-existent. Though it is difficult to assess, I don’t think I perceive time in the way that the general population does.
Seconds, weeks and years are not so much the same, they just have little meaning. If something does not happen now, I cannot easily conceptualise when it might happen, or did happen; sequencing events or waiting for something is a challenge.
There is a slight irony in all this. All time is relative and, judging by the debates in New 杏吧原创, it is still something that we have only a partial insight into. Thus, while those with ADHD have only a rudimentary grasp of a what is seen as a fundamental reality by the majority, it may eventually be shown not to have any real meaning.
Believe in evidence
Stephen Roots suggests that most atheists would admit the possibility of hitherto unknown, vastly intelligent life forms (20 June, p 25).
Indeed, such life forms may exist and they may land in London’s Hyde Park in pink-striped flying saucers tomorrow, demanding an audience with David Attenborough.
So far, no such intelligent aliens have revealed themselves, and we have no reason to think they will. We must continue without any expectation of the good advice they might be able to offer us 鈥� assuming that they have overcome problems similar to those that beset us.
Similarly, gods and goddesses may exist but they neither cause disasters nor answer prayers. We must use what we learn from science to address our problems.
Science’s most useful lesson is that we can only feel secure in our knowledge by constantly doubting and testing it. That’s why belief without evidence, whether in intelligent aliens or gods, undermines our ability to solve our problems.
Sea shares
Your article on the Arctic describes how application of international law might effect peaceful distribution of its untapped resources (6 June, p 6).
Geographical location has never seemed to me to be a legitimate basis for the appropriation of resources and is a barrier to peaceful cohabitation. Instead, the Earth’s resources could be viewed as a single global pool belonging to everyone.
We could calculate how much of each resource should be sustainably extracted each year, based on the Earth’s capacity to regenerate said resource.
An appropriate percentage of the total annual harvest could then be allocated to each nation based on their respective percentage of the global population.
Antibiotic advice
Karl Hoenke questions whether we should adhere to the medical orthodoxy of completing a course of antibiotics, suggesting that this might encourage the emergence of resistant bacteria rather than discourage it (13 June, p 25). His quandary is easily answered.
While antibiotics inhibit or kill susceptible bugs, they are not the only defence mechanism at work. The body’s own cellular and humoral mechanisms are usually still operating at some level. The crucial points is whether the bacterial load is too great for them to cope with.
Killing or inhibiting as many bugs as possible makes it more certain that the body’s systems can take care of the rest, including any fully drug-resistant organisms. Stopping early, before the body itself can mount an effective defence, allows those bugs that are only inhibited to multiply, reduces the likelihood of full recovery and promotes the spread of drug-resistant versions.
Trekkie politics
Lawrence Krauss is his usual entertaining self when he discusses Star Trek (13 June, p 22), but seems to have missed what for me was its most obvious sub-message.
The society Gene Roddenberry created was based upon communal cooperation and a one-world government, in which money played absolutely no part.
The needs of each individual were met as required, and everyone gave to the maximum of their abilities, without the slightest whiff of incentive bonuses. Indeed, money was only occasionally replicated to allow interaction with primitive communities. The only characters who still used cash and credit trading were decidedly unsavoury individuals, like the Ferengi.
That this stable and purely socialist utopia, envisaged only 300 years hence, should be predicted by a Hollywood-based institution and accepted unquestioningly by millions of fans worldwide is remarkable.
For the record
鈥� Christine Maggiore’s daughter Eliza Jane died in 2005, not in 2003 as we suggested (20 June, p 32).
鈥� The scale on our diagram showing the fraction of exposure to gamma radiation inside a building compared with that outside should have been labelled in the following order with the fractions 1/10, 1/20, 1/30, 1/40, 1/50, 1/80, 1/100 and 1/200 (11 July, p 8).