- Email: [email protected]
Before everything
Letters– Before everything From Gareth Roberts In his feature, “The universe before ours”, David Shiga suggests that one day we may be able to answer the question “why is there anything at all instead of nothing?” (28 April, p 28). This is more than optimistic: the question is a priori unanswerable. By definition, there cannot have been anything before everything that is, and there cannot be anything outside it or after it. Calculating the probability of there being something rather than nothing at all is pointless, because this is beyond probability. There just is something rather than nothing, and there can be no deeper answer than that. Edinburgh, UK From Peter White You mention the issue of whether time is infinite or whether it has a beginning and an end. These possibilities both assume that the structure of time is analogous to a straight line. There is another possibility, that time might have a structure analogous to a loop: everything happens only once, but time is not infinite and has no beginning or end. One model of the universe with which this would be compatible is one in which the expansion phase after the big bang is followed by a contraction phase leading to a big crunch. The singularity at the big crunch would not be similar to the singularity at the big bang; it would be the same one. Time has a loop structure, and the singularity is just another point on the loop. I don’t know whether this is compatible with any of the models discussed, but it is at least a logical possibility and a way out of the dilemma. Cardiff, UK From Andy Howe The feature reminded me of an essay by Roger Penrose over 20 years ago. According to the “strong” anthropic principle, the 26 | NewScientist | 19 May 2007
universe is the way it is because it needs to be observed by some selfaware life form. Penrose applied this argument to humans, explaining that the universe did not have to develop this way just to create the likes of us. Noting that an uninhabitable universe of black holes is far more likely than one suitable for us, Penrose said: “The cheapest way of making a roomful of people, or even a world full of people, is by random selection…a statistical fluctuation, if you like, in an otherwise high-entropy universe.” Expand Penrose’s “world full of people” right up to the observable universe, and what you get is perhaps what the “black hole sea” model discussed in the feature is actually describing. Sheffield, UK From Paul Robinson Am I missing something here? Isn’t asking what happened before the big bang rather like asking what conditions are like 25,000 kilometres below the Earth’s surface? London, UK
Warming swindle
From Martin Durkin Alan Thorpe, attacking my film The Great Global Warming Swindle, tells us not to “play games with the evidence” (17 March, p 24). Right ho. Let’s not. He says: “There is no question that the more CO2 there is in the atmosphere, the warmer the planet becomes.” Perhaps Thorpe is too young to remember the
post-war economic boom. To remind him, it was the biggest explosion of economic activity in the history of human civilisation up to that point; an unprecedented volume of CO2 was pumped into the atmosphere from lots of factories. What happened to the temperature? It went down. According to most temperature records, it went down from 1940 to about 1975. Coincidental with the post-war cooling was a marked downturn in solar activity. Yet Thorpe boldly asserts, without any supporting evidence, that solar variations have an insignificant effect on the Earth’s climate. I refer interested readers to the work, published in 2005, by Jan Veizer (Geoscience Canada, vol 32, p 13) and Willie Soon (Geophysical Research Letters, vol 32, L16712). Then Thorpe admits, reluctantly, that in the ice core data, the temperature variation is followed, rather than preceded by changes in the level of CO2 in the atmosphere. So carbon dioxide is clearly not driving climate. Awkward. So what is driving it? Thorpe says it’s the sun (mighty powerful thing, the sun), but then he tries, feebly, to salvage his CO2 argument by suggesting that maybe the resulting changes in CO2 amplify the temperature changes still further. Oh really? As it happens, there is no evidence at all that this is true. Very often in the ice cores CO2 rises like a rocket, while the temperature plummets. So who is playing games? Thorpe implies that I think there is a global warming conspiracy. I don’t. But I know that lots of scientists (like Thorpe), and journalists too, have staked their reputations on this theory being true. Many have built their careers on it. I sympathise with them. London, UK The editor writes: ● For full discussion of climate myths, turn to p 34 and www. newscientist.com/climatemyths – and comment on Veizer’s paper is at http://celestial.notlong.com
Accident on porpoise From Colin MacLeod Discussing how to protect underwater structures from terrorists, Chris Cantell claims Westminster International’s diver detection system is unlikely to harm marine mammals because it can correctly identify a target on 98 out of 100 occasions (28 April, p 34). This sounds great, but to a marine biologist with a knowledge of marine mammal distribution, this level of error is deeply disturbing. While it may be rare for such a system to encounter a diver, it is likely to encounter marine mammals with a frequency many orders of magnitude higher. Marine mammals may pass through the same area many times a day, and many thousands of individuals may pass within range of one of these systems every year. A 98 per cent success rate implies that 2 per cent of identifications are wrong. This could mean hundreds of marine mammals being accidentally classified as divers and thus exposed to high-intensity sounds that could injure or kill them. This level of error is in no way safe for marine mammals. Such automated systems should not be implemented until the classification rate is several orders of magnitude better. Aberdeen, UK From Mark Simmonds, Whale and Dolphin Conservation Society Thank you for drawing attention to the conflict between marine wildlife and new undersea defences. I want, however, to clarify the effects of underwater noise on wildlife. Interruption of normal behaviour, displacement from key habitat areas and impacts on hearing are likely outcomes of exposure to loud noise. For example, there is an association between strandings of beaked whales – a family of deep-diving species – and the deployment of certain military sonars. www.newscientist.com
universe is the way it is because it needs to be observed by some selfaware life form. Penrose applied this argument to humans, explaining that the universe did not have to develop this way just to create the likes of us. Noting that an uninhabitable universe of black holes is far more likely than one suitable for us, Penrose said: “The cheapest way of making a roomful of people, or even a world full of people, is by random selection…a statistical fluctuation, if you like, in an otherwise high-entropy universe.” Expand Penrose’s “world full of people” right up to the observable universe, and what you get is perhaps what the “black hole sea” model discussed in the feature is actually describing. Sheffield, UK From Paul Robinson Am I missing something here? Isn’t asking what happened before the big bang rather like asking what conditions are like 25,000 kilometres below the Earth’s surface? London, UK
Warming swindle
From Martin Durkin Alan Thorpe, attacking my film The Great Global Warming Swindle, tells us not to “play games with the evidence” (17 March, p 24). Right ho. Let’s not. He says: “There is no question that the more CO2 there is in the atmosphere, the warmer the planet becomes.” Perhaps Thorpe is too young to remember the
post-war economic boom. To remind him, it was the biggest explosion of economic activity in the history of human civilisation up to that point; an unprecedented volume of CO2 was pumped into the atmosphere from lots of factories. What happened to the temperature? It went down. According to most temperature records, it went down from 1940 to about 1975. Coincidental with the post-war cooling was a marked downturn in solar activity. Yet Thorpe boldly asserts, without any supporting evidence, that solar variations have an insignificant effect on the Earth’s climate. I refer interested readers to the work, published in 2005, by Jan Veizer (Geoscience Canada, vol 32, p 13) and Willie Soon (Geophysical Research Letters, vol 32, L16712). Then Thorpe admits, reluctantly, that in the ice core data, the temperature variation is followed, rather than preceded by changes in the level of CO2 in the atmosphere. So carbon dioxide is clearly not driving climate. Awkward. So what is driving it? Thorpe says it’s the sun (mighty powerful thing, the sun), but then he tries, feebly, to salvage his CO2 argument by suggesting that maybe the resulting changes in CO2 amplify the temperature changes still further. Oh really? As it happens, there is no evidence at all that this is true. Very often in the ice cores CO2 rises like a rocket, while the temperature plummets. So who is playing games? Thorpe implies that I think there is a global warming conspiracy. I don’t. But I know that lots of scientists (like Thorpe), and journalists too, have staked their reputations on this theory being true. Many have built their careers on it. I sympathise with them. London, UK The editor writes: ● For full discussion of climate myths, turn to p 34 and www. newscientist.com/climatemyths – and comment on Veizer’s paper is at http://celestial.notlong.com
Accident on porpoise From Colin MacLeod Discussing how to protect underwater structures from terrorists, Chris Cantell claims Westminster International’s diver detection system is unlikely to harm marine mammals because it can correctly identify a target on 98 out of 100 occasions (28 April, p 34). This sounds great, but to a marine biologist with a knowledge of marine mammal distribution, this level of error is deeply disturbing. While it may be rare for such a system to encounter a diver, it is likely to encounter marine mammals with a frequency many orders of magnitude higher. Marine mammals may pass through the same area many times a day, and many thousands of individuals may pass within range of one of these systems every year. A 98 per cent success rate implies that 2 per cent of identifications are wrong. This could mean hundreds of marine mammals being accidentally classified as divers and thus exposed to high-intensity sounds that could injure or kill them. This level of error is in no way safe for marine mammals. Such automated systems should not be implemented until the classification rate is several orders of magnitude better. Aberdeen, UK From Mark Simmonds, Whale and Dolphin Conservation Society Thank you for drawing attention to the conflict between marine wildlife and new undersea defences. I want, however, to clarify the effects of underwater noise on wildlife. Interruption of normal behaviour, displacement from key habitat areas and impacts on hearing are likely outcomes of exposure to loud noise. For example, there is an association between strandings of beaked whales – a family of deep-diving species – and the deployment of certain military sonars. www.newscientist.com