It's a miracle
Hugh McLachlan rightly points out some logical flaws in philosopher David Hume’s arguments regarding miracles, but introduces some others in turn (8 August, p 26).
McLachlan writes: “‘Laws’ that appear firmly established are often overturned, yet we do not need to argue that a miracle must have occurred… the rational thing is to abandon the natural law or modify what we considered to be a true statement of it.” In fact, scientists would first try to reproduce the phenomenon; if it can be reliably reproduced then fair enough.
A miracle should be a one-off, or only happen in circumstances that make no conceivable causal contribution. In the former case, Hume would surely be right to argue that the simpler explanation is a misreport. In the latter, the scientific community would have a real challenge.
In response to the arguments of Richard Dawkins, McLachlan asserts that Jesus could have been a clone of his mother “without violating a universal law”. Perhaps this is the case, but it would have been a miracle if no one at the time noticed the uncanny resemblance of son to mother, down to the last details.
The discussion of whether a normal, natural event may be a miracle by virtue of its happenstance is interesting, but science has an answer here too. An isolated incident cannot by its nature be statistically significant, so poses no threat to rational explanation. Anyone choosing to consider it a miracle would be violating scientific principles. Only at the point that an assemblage of instances proves statistically significant does it become inconsistent with the known natural laws.
From Tim Wilkinson
The universal laws of nature defined by Hugh McLachlan 鈥� such as “all As are Bs”, which “cannot be violated or transgressed, not even by God” 鈥� are not laws of nature at all, but rather of reasoning. In contrast, science is not absolute 鈥� except perhaps in the minds of its detractors 鈥� and is conducted only in part by deduction.
As Hume noted, science rests on inductive reasoning from observation. No “law of nature” is beyond question if the observations demand otherwise. However, science would become impossibly unwieldy if every single uncertainty had to be spelled out all the time. Laws can be repealed, but lawfulness itself cannot be abandoned because when we inspect the universe we find regularity as opposed to anarchy.
It is linguistic hocus-pocus to define miracles into existence by invoking alternative modes of reasoning, juxtapositions of events or even astonishing phenomena awaiting a natural explanation. Theologians accept that God must be constrained by logic, but even an atheist like me can see that if He is also bound by the regularities of nature then He is not God.
Houghton-le-Spring, Tyne and Wear, UK
Panel envy
E. O. Wilson calls for “an effort along the lines of the Intergovernmental Panel on Climate Change to protect species” (22 August, p 23).
The UN Environment Programme has already proposed an Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) to discuss improving biodiversity protection. If there were two processes in development, the effort to reduce the rate of biodiversity loss would be confounded by further layers of bureaucracy.
Is another panel the right approach anyway? We need a melange of approaches to slow the rate of loss of biodiversity, but because the Intergovernmental Panel on Climate Change works well for climate, some scientists think that an IPCC-like process is the only way. Unlike climate change, the needs of biodiversity governance and management lie largely at national level.
The issue, I think, is a severe case of panel envy: climate change has one, biodiversity needs one too. Rather than a new panel with all the trappings, we need an overall reduction in bureaucratic mechanisms at international level, better management and sharing of data, and more effective ways of communicating the results of scientific research to the policy community.
More on methane
Kirk Smith’s reply to Graham Faichney’s well-reasoned letter about the place of biogenic methane in the carbon cycle, and hence its diminished impact on climate change misses some important points (8 August, p 24).
Wetlands are being drained for farming, thereby permanently removing large sources of methane. Loss of carbon to the atmosphere from forest clearance is always included in the budget for the greenhouse cost of farming. Logically, methane reduction from wetland drainage should appear as a credit in this budget, reducing the carbon footprint of agriculture.
The methane myth is a clever ploy by the fossil fuel lobbyists, who know the green movement contains many vegetarians who will fall for it. Cattle and sheep grazing may be an inefficient way to feed people 鈥� though much of it happens on land that is of no use for anything else 鈥� but it is not a substantial contributor to global warming.
Inventive process
W. Brian Arthur’s article on the evolution of technology fails to pay attention to what goes on inside inventors’ heads (22 August, p 26).
A frantic evolution of ideas occurs that no one sees and that even the inventor may be unaware of. To onlookers it may seem that a technology appears fully formed, but there is probably nothing more to it than a good old evolution of ideas through trial and error, and incremental improvement.
Planet Pluto
As Stephen Battersby’s article shows, debate continues within the astronomical community over the status of Pluto and many other significant celestial bodies in the solar system (25 July, p 44). This is not surprising when the term “planet” is so ill-defined. Clear definitions enable us to talk the same scientific language. As more extrasolar planets are discovered these definitions will become increasingly important 鈥� imagine the discord in biological science if the definition of a mammal was still in dispute.
The nonsensical distinction between planets and dwarf planets has arisen partly because of the huge variation in size of celestial bodies, and partly because of the supposed differences in origin. If the definition is to be strictly adhered to, however, then Neptune is not a planet because it has not cleared the neighbourhood of all debris 鈥� Pluto still crosses its orbit. Nor is Jupiter a planet, because the Trojan asteroids are in its orbital path.
The editor writes:
鈥� The debate becomes increasingly esoteric when picking apart the definitions. The debris that a planet must sweep from its orbit is also subject to definition, which excludes objects like Jupiter’s asteroids.
Cerebral computers
I am disappointed by Noel Sharkey’s dismissal of Hans Moravec’s and Ray Kurzweil’s assertions that computers will eventually overtake the human brain in intelligence as “just fairy tales” (29 August, p 28).
There is plenty of evidence that new properties emerge when systems reach a certain complexity, and it can be difficult to predict the properties of any given level from those of levels above or below. Could we deduce the properties of atoms or molecules from those of subatomic particles, or those of cells from the chemistry of molecules?
New computer applications have suddenly emerged now that hardware and software have reached capabilities below which they would have been impossible. With no disrespect intended to Sharkey, it is worth recalling Arthur C. Clarke’s dictum: “When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.”
Black box satellite
Questions on the safety of modern aircraft raised in your report on the loss of an airliner in the mid-Atlantic on 1 June may never be answered if the plane’s “black box” flight recorders cannot be found (13 June, p 19). The drawback of the current system of on-board black boxes is that they may often not be found, so valuable information as to the causes of accidents is lost.
Other reports of the incident mentioned that before the crash some of the plane’s flight data was sent by satellite. This made me wonder why all flight data can’t be sent by satellite for every flight. This data could then be recovered from a “virtual” black box, regardless of the physical inaccessibility of the crash site.
The Aircraft Communications Addressing and Reporting System (ACARS) that was used to send data from the doomed aircraft allows only limited data to be transmitted. But why not combine satellite communication with the internet to record a much greater range of data? Once the transmission has been received at an internet node, of which there are thousands, it immediately becomes available worldwide.
The technology for this already exists. There are well-established standards for digitised transmission, and encrypted transmission is used for many internet communications. If the data were continuously transmitted and recorded on the ground, the crash investigators would have instant access to it, and would no longer have to wait for the physical black box to be found 鈥� if indeed it ever is.
Automatic warnings and alarms could also be added at both ends. What’s more, the exact location of the aircraft would be known, allowing rescue missions to get under way without delay. For the overwhelming majority of flights that are completed safely, the recording could be automatically wiped when the plane lands.
For the record
鈥� We should have made it clear that when discussing carcinogen content, the smokeless tobacco product to which we were referring was moist snuff (22 August, p 5).
鈥� Changfeng Chen is at the University of Nevada, Las Vegas, not Jiao Tong University in Shanghai as we stated (5 September, p 39).