God of the filled-in bits
Bryan Appleyard quotes Richard Swinburne’s bizarre claim that the explicability of the universe “points to the existence of a deity” (3 March, p 47). The irony, of course, is that inexplicability of phenomena used to be the chief evidence presented for the same conclusion 鈥� the “god of the gaps”.
I suggest the claim makes sense only if the deity in question is not too much smarter than ourselves.
And are there really no good reasons for explicability? The mathematician Emmy Noether proved that the various laws of conservation 鈥� of energy and so on 鈥� can be derived merely from the assumption that the universe possesses certain symmetries. Not only does that make such simple laws almost inevitable in a habitable universe, it raises the possibility that they are not absolutely true, just extremely good approximations.
Further, there may an anthropic principle at work here: only in a universe at least partly explicable does intelligence confer an evolutionary advantage. And explicability is a bit tautological: our universe has been found to be explicable only to the extent that we have explained it. Until we have a theory of everything, total explicability is merely a hope.
From Ralph Estling
Brian Appleyard seems to think that answers that answer nothing are preferable to being unsure. “Everywhere we look,” he writes, “there is evidence of something, but it is by no means clear that that something is, in fact, nothing.” It is not easy to determine what he thinks or means here. Is he muttering “intelligent design” under his breath? My suspicions are aroused.
Everywhere we look in his review there is evidence of something, but it is by no means clear that that something is, in fact, anything.
Ilminster, Somerset
Weather reliability
I believe some clarification is in order following Michael Brooks’s discussion of the credibility of weather forecasts (27 January, p 32) and the ensuing correction (10 February, p 19).
My comments on reliability referred solely to the Met Office’s statistical prediction of the winter North Atlantic Oscillation. I showed that, when gauged by means of common performance indicators, their forecasts do not demonstrate more accuracy or skill in the long run than a simple moving average of the NAO indices of the last two winters.
These remarks do not negate the usefulness of the Met Office’s winter NAO forecasts in a wider context.
I have also pointed out that their statistical prediction model has the merit of highlighting key mechanisms, whereas the two-winter moving average merely takes advantage of the properties of the time series of past NAO records without providing any insight into physical causalities.
Earlier refraction
Your article on invisibility and negative refraction says that the 1968 work by Victor Veselago was “the first time that anyone had thought of a way that light could be steered in ways beyond the power of conventional lenses and mirrors. However, nobody took much notice…” (17 February, p 38).
In fact, the well-known Soviet physicist Leonid Mandelshtam suggested similar ideas as early as 1940: see, for example, the 2006 review paper “Spatial dispersion and negative refraction of light” by Vladimir M. Agranovich and Yuri N. Gartstein (Physics-Uspekhi, vol 49, p 1029).
Roman mad cows
Debora MacKenzie reports the discovery of a spontaneous “mad cow disease” in cattle that might have given rise to BSE (17 March, p 11).
A few years ago, while reading my 1936 Gaffiot Latin-French dictionary, I was surprised to find the word mania translated as (1) madness and (2) a bovine disease (maladie du boeuf) 鈥� with a citation from Publius Flavius Vegetius Renatus, author of Digesta Artis Mulomedicinae, a guide to veterinary medicine, in the 4th or 5th century AD. So mad cow disease 鈥� of some kind 鈥� was already known back then.
For the record
鈥� The fractional quantum Hall (not hall) effect experiment was first carried out in 1982, not 1983 as we stated (17 March, p 8). And the experimental group that created the pure sample of the herbertsmithite crystal is led by Young Lee at MIT, not by Joel Helton, who is in fact Lee’s student.
Green gaps
Fred Pearce names a number of complications concerning the market in voluntary carbon offsets (10 March, p 38), but he omits the biggest: it is not scalable to a level required to solve the global problem.
I live in an average-sized town with 50,000 inhabitants. If they all wanted to offset by planting trees, that would mean 25 million trees.
Giving each tree 25 square metres would require 625 square kilometres of fertile land to be dedicated to forest, many times the area of our town. Looking at the map of our region, a convenient land-use gap of this size is prominently absent.
The carbon offset “solution” can only ever be a partial personal conscience-easer for a privileged and guilt-ridden few. It may even have the negative effect of inducing complacency in those who then feel free to continue a lifestyle that is also non-sustainable in many other ways.
From Richard Carter
Last night I took Fred Pearce’s advice and installed 111 energy-efficient light bulbs to offset the 11.1 tonnes of carbon emissions that I will be responsible for this year. All went well, until a passenger airliner en route to Manchester tried to land in my drive.
There must be easier ways to be green.
Hebden Bridge, West Yorkshire, UK
From Ian Chapple
If left on continuously, 111 energy-efficient light bulbs would actually save the target of 11.1 tonnes of carbon dioxide in 333 days (8000 hours). If, however, they were on for an average of 10 hours per day, you would need to install 244 energy-efficient light bulbs.
The Hague, The Netherlands
Fred Pearce writes
鈥� Yes, as soon as you try estimate an annual saving by guessing how long each bulb is left on, it quickly gets messy and ambiguous. That calculation was for illustrative purposes only.
Oil futures
David Humphrey believes that trying to reduce the harmful effects of aviation on the atmosphere is futile, because we will run out of oil in the next 30 years or so (17 March, p 26). Apparently, widespread, cheap intercontinental travel is just a passing phase.
Consider that the synthesis of oil from coal becomes economically attractive when the price of crude oil is $60 per barrel 鈥� roughly the price as I write. All that is required for oil companies to start switching their focus from exploration to synthetic oil production is for synthesising oil to become more profitable and less risky than drilling.
This would require a sustained period of high oil prices; coincidentally, this is exactly what the OPEC countries would also like. But oil producers want us to keep buying their oil, not finding substitutes for it 鈥� because once the substitutes gain economies of scale, oil reserves become economically unrecoverable and worthless.
So one might predict that the cost of oil will remain roughly the same as synthesising it from coal, until such time as depletion of reserves causes scarcity and a sustained higher price. Until then the decision to invest in synthetic petroleum plants would be harder to make if the price of oil fluctuated wildly, so that the mean price over an extended period was much lower than the occasional peaks. This would also help oil producers to maximise income from their reserves. It seems very much like the situation at the moment.
Biomass barrier
There is nothing inherently wrong with Henry Lowe’s plan to burn biomass in power stations and sequester the carbon dioxide (17 March, p 26). The drawback is the issue of scale. Drax power station in North Yorkshire produces around 7 per cent of the UK’s electricity. It has been burning some biomass for a while. Plans are in place to replace 10 per cent of its voracious appetite for coal with such fuel, which will require some 1.5 million tonnes annually.
Much of this is likely to consist of Miscanthus, a tall grass that grows well on sandy soil in the southern UK. Miscanthus is an excellent perennial energy crop, since it returns its nutrients to the rhizomes when the top growth dies off, so it requires no fertiliser once established. Typical annual yields of dry matter for an established crop are 12 to 15 tonnes per hectare.
Some quick calculations show that replacing Drax’s entire input with Miscanthus would mean cultivating a million hectares; and it would take 14 million hectares, an area slightly bigger than England, to meet the UK’s present electricity demand. This does not take into account the energy used in sequestration.
Biomass has its place, but I’m convinced the answer to biological sequestration lies in the oceans, and have this week bought myself a chemistry set and a tropical fish tank (minus the fish) in an attempt to save the planet and win Richard Branson’s big prize.
How many quanta?
Is Marcus Chown right to say a single particle or object can be in two places at once (17 March, p 36)? In the twin-slit experiment, we cannot determine which slit the particle goes through and also maintain the interference pattern. But that does not mean it “goes through” both slits when we don’t look, or that we can see it in both places when we do look. We only ever measure a particle in one place, never two.
So isn’t its being “in two places at once” an unobservable, metaphysical notion resulting from incorrectly applying the macroscopic concepts of wave and particle 鈥� arising from human experience 鈥� to microscopic physics? If a particle were “really” in two places at once, then its mass, charge and spin would be doubled. That would violate the macroscopic laws of conservation of energy and charge 鈥� unless the particle’s appearances were confined within Heisenberg uncertainty limits, which would make it a pair of virtual particles. And if a particle could be “really” in two places at once, why not more, or an infinite number?
This view may be incorrect, but perhaps another email is on its way from me with a different view, right now…
From Peter Fyfe
Marcus Chown’s opening line, “How would you like to be quantum?” demonstrates a common fallacy that arises from interpreting quantum physics without the benefits of contemporary and ancient metaphysics. A quantum superposition does not concern the existence of a thing, but knowledge of it: that is, it is not an ontological concept, but an epistemological one. It arises from a theory that is predicated on the idea that the observer is existentially separate from the observed. Put another way, the superposition stems from the imposition of the model used to understand the world rather than the present experience of the world itself.
As a consequence, one cannot “be” quantum any more than one can “be” in a superposition, because “to be” requires presence in an ontological reality, not an epistemological one that exists only in thought.
As whimsical students and frustrated philosophers often remark, Schr枚dinger’s cat knows if it’s still alive. I suspect its size is unlikely to change its view.
Sydney, Australia
Alive and Bell
Jeff Hecht points out that a large part of the “key to success” of Bell Labs was “the way it encouraged its employees to strive for great ideas and tackle the toughest problems” (3 February, p 18). He suggests that “the unique ability to marshal teams of top technologists to transform bright ideas into effective technology” is now gone. Quite the opposite 鈥� this culture and structure are still the fundamental pillars of the labs today.
While it is true that Bell Labs is a smaller organisation than when it was funded by a different type of company that operated in a very different market, it is still an innovative, vibrant place for researchers to work in many fundamental and applied areas and produce game-changing ideas and technologies.
As we would have been happy to clarify if Hecht had contacted us, Bell Labs Research organisation employed no more than 1400 people at its peak.
I understand that over the years some have considered our colleagues in other technical parts of the business to be part of the Bell Labs “extended community”, but the number Hecht used for today only included core Bell Labs researchers and not our extended technical community of over 20,000.
Speaking as someone who has been in Bell Labs his entire professional career 鈥� over 30 years 鈥� Bell Labs is a unique institution and, though smaller, the special spark that gave rise to the game-changing technologies in the past is still with us today.
Pride and prejudice
Lawrence Hirschfeld’s work, showing that children are naturally inclined to attach more importance to race than to other factors, seems farcical (17 March, p 40). The only black child I know to have grown into a white adult is Michael Jackson.
The most important point that was left out of this article, though, was the distinction between differentiation and discrimination. The most obvious physical characteristic of a person is their skin colour, and this is therefore a characteristic that every person will notice. Those who claim it is wrong to register a difference between a black and a white person are deluded. Acknowledging a difference is not racism. Racism arises when observing a difference leads to different treatment of the person 鈥� to discrimination.